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2 | @c %start of fragment | |
3 | ||
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4 | The functions from this section may be had by loading the module: |
5 | ||
6 | @example | |
7ec693ed | 7 | (use-modules (figl glu low-level) |
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8 | @end example |
9 | ||
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10 | @copying |
11 | This section of the manual was derived from the upstream OpenGL | |
12 | documentation. Each function's documentation has its own copyright | |
13 | statement; for full details, see the upstream documentation. The | |
14 | copyright notices and licenses present in this section are as follows. | |
15 | ||
16 | Copyright @copyright{} 1991-2006 Silicon Graphics, Inc. This document is | |
17 | licensed under the SGI Free Software B License. For details, see | |
18 | @uref{http://oss.sgi.com/projects/FreeB/,http://oss.sgi.com/projects/FreeB/}. | |
19 | ||
20 | @end copying | |
21 | ||
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22 | @deftypefun void gluBeginCurve nurb |
23 | @deftypefunx void gluEndCurve nurb | |
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24 | Delimit a NURBS curve definition. |
25 | ||
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26 | @table @asis |
27 | @item @var{nurb} | |
28 | Specifies the NURBS object (created with @code{gluNewNurbsRenderer}). | |
29 | ||
30 | @end table | |
31 | ||
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32 | Use @code{gluBeginCurve} to mark the beginning of a NURBS curve |
33 | definition. After calling @code{gluBeginCurve}, make one or more calls | |
34 | to @code{gluNurbsCurve} to define the attributes of the curve. Exactly | |
35 | one of the calls to @code{gluNurbsCurve} must have a curve type of | |
36 | @code{GLU_MAP1_VERTEX_3} or @code{GLU_MAP1_VERTEX_4}. To mark the end of | |
37 | the NURBS curve definition, call @code{gluEndCurve}. | |
38 | ||
39 | GL evaluators are used to render the NURBS curve as a series of line | |
40 | segments. Evaluator state is preserved during rendering with | |
41 | @code{glPushAttrib}(@code{GLU_EVAL_BIT}) and @code{glPopAttrib}(). See | |
42 | the @code{glPushAttrib} reference page for details on exactly what state | |
43 | these calls preserve. | |
44 | ||
bb894c9d | 45 | @end deftypefun |
8925f36f | 46 | |
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47 | @deftypefun void gluBeginPolygon tess |
48 | @deftypefunx void gluEndPolygon tess | |
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49 | Delimit a polygon description. |
50 | ||
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51 | @table @asis |
52 | @item @var{tess} | |
53 | Specifies the tessellation object (created with @code{gluNewTess}). | |
54 | ||
55 | @end table | |
56 | ||
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57 | @code{gluBeginPolygon} and @code{gluEndPolygon} delimit the definition |
58 | of a nonconvex polygon. To define such a polygon, first call | |
59 | @code{gluBeginPolygon}. Then define the contours of the polygon by | |
60 | calling @code{gluTessVertex} for each vertex and @code{gluNextContour} | |
61 | to start each new contour. Finally, call @code{gluEndPolygon} to signal | |
62 | the end of the definition. See the @code{gluTessVertex} and | |
63 | @code{gluNextContour} reference pages for more details. | |
64 | ||
65 | Once @code{gluEndPolygon} is called, the polygon is tessellated, and the | |
66 | resulting triangles are described through callbacks. See | |
67 | @code{gluTessCallback} for descriptions of the callback functions. | |
68 | ||
bb894c9d | 69 | @end deftypefun |
8925f36f | 70 | |
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71 | @deftypefun void gluBeginSurface nurb |
72 | @deftypefunx void gluEndSurface nurb | |
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73 | Delimit a NURBS surface definition. |
74 | ||
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75 | @table @asis |
76 | @item @var{nurb} | |
77 | Specifies the NURBS object (created with @code{gluNewNurbsRenderer}). | |
78 | ||
79 | @end table | |
80 | ||
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81 | Use @code{gluBeginSurface} to mark the beginning of a NURBS surface |
82 | definition. After calling @code{gluBeginSurface}, make one or more calls | |
83 | to @code{gluNurbsSurface} to define the attributes of the surface. | |
84 | Exactly one of these calls to @code{gluNurbsSurface} must have a surface | |
85 | type of @code{GLU_MAP2_VERTEX_3} or @code{GLU_MAP2_VERTEX_4}. To mark | |
86 | the end of the NURBS surface definition, call @code{gluEndSurface}. | |
87 | ||
88 | Trimming of NURBS surfaces is supported with @code{gluBeginTrim}, | |
89 | @code{gluPwlCurve}, @code{gluNurbsCurve}, and @code{gluEndTrim}. See the | |
90 | @code{gluBeginTrim} reference page for details. | |
91 | ||
92 | GL evaluators are used to render the NURBS surface as a set of polygons. | |
93 | Evaluator state is preserved during rendering with | |
94 | @code{glPushAttrib}(@code{GLU_EVAL_BIT}) and @code{glPopAttrib}. See the | |
95 | @code{glPushAttrib} reference page for details on exactly what state | |
96 | these calls preserve. | |
97 | ||
bb894c9d | 98 | @end deftypefun |
8925f36f | 99 | |
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100 | @deftypefun void gluBeginTrim nurb |
101 | @deftypefunx void gluEndTrim nurb | |
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102 | Delimit a NURBS trimming loop definition. |
103 | ||
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104 | @table @asis |
105 | @item @var{nurb} | |
106 | Specifies the NURBS object (created with @code{gluNewNurbsRenderer}). | |
107 | ||
108 | @end table | |
109 | ||
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110 | Use @code{gluBeginTrim} to mark the beginning of a trimming loop and |
111 | @code{gluEndTrim} to mark the end of a trimming loop. A trimming loop is | |
112 | a set of oriented curve segments (forming a closed curve) that define | |
113 | boundaries of a NURBS surface. You include these trimming loops in the | |
114 | definition of a NURBS surface, between calls to @code{gluBeginSurface} | |
115 | and @code{gluEndSurface}. | |
116 | ||
117 | The definition for a NURBS surface can contain many trimming loops. For | |
118 | example, if you wrote a definition for a NURBS surface that resembled a | |
119 | rectangle with a hole punched out, the definition would contain two | |
120 | trimming loops. One loop would define the outer edge of the rectangle; | |
121 | the other would define the hole punched out of the rectangle. The | |
122 | definitions of each of these trimming loops would be bracketed by a | |
123 | @code{gluBeginTrim}/@code{gluEndTrim} pair. | |
124 | ||
125 | The definition of a single closed trimming loop can consist of multiple | |
126 | curve segments, each described as a piecewise linear curve (see | |
127 | @code{gluPwlCurve}) or as a single NURBS curve (see | |
128 | @code{gluNurbsCurve}), or as a combination of both in any order. The | |
129 | only library calls that can appear in a trimming loop definition | |
130 | (between the calls to @code{gluBeginTrim} and @code{gluEndTrim}) are | |
131 | @code{gluPwlCurve} and @code{gluNurbsCurve}. | |
132 | ||
133 | The area of the NURBS surface that is displayed is the region in the | |
134 | domain to the left of the trimming curve as the curve parameter | |
135 | increases. Thus, the retained region of the NURBS surface is inside a | |
136 | counterclockwise trimming loop and outside a clockwise trimming loop. | |
137 | For the rectangle mentioned earlier, the trimming loop for the outer | |
138 | edge of the rectangle runs counterclockwise, while the trimming loop for | |
139 | the punched-out hole runs clockwise. | |
140 | ||
141 | If you use more than one curve to define a single trimming loop, the | |
142 | curve segments must form a closed loop (that is, the endpoint of each | |
143 | curve must be the starting point of the next curve, and the endpoint of | |
144 | the final curve must be the starting point of the first curve). If the | |
145 | endpoints of the curve are sufficiently close together but not exactly | |
146 | coincident, they will be coerced to match. If the endpoints are not | |
147 | sufficiently close, an error results (see @code{gluNurbsCallback}). | |
148 | ||
149 | If a trimming loop definition contains multiple curves, the direction of | |
150 | the curves must be consistent (that is, the inside must be to the left | |
151 | of all of the curves). Nested trimming loops are legal as long as the | |
152 | curve orientations alternate correctly. If trimming curves are | |
153 | self-intersecting, or intersect one another, an error results. | |
154 | ||
155 | If no trimming information is given for a NURBS surface, the entire | |
156 | surface is drawn. | |
157 | ||
bb894c9d | 158 | @end deftypefun |
8925f36f | 159 | |
bb894c9d | 160 | @deftypefun GLint gluBuild1DMipmapLevels target internalFormat width format type level base max data |
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161 | Builds a subset of one-dimensional mipmap levels. |
162 | ||
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163 | @table @asis |
164 | @item @var{target} | |
165 | Specifies the target texture. Must be @code{GLU_TEXTURE_1D}. | |
166 | ||
167 | @item @var{internalFormat} | |
168 | Requests the internal storage format of the texture image. The most | |
169 | current version of the SGI implementation of GLU does not check this | |
170 | value for validity before passing it on to the underlying OpenGL | |
171 | implementation. A value that is not accepted by the OpenGL | |
172 | implementation will lead to an OpenGL error. The benefit of not checking | |
173 | this value at the GLU level is that OpenGL extensions can add new | |
174 | internal texture formats without requiring a revision of the GLU | |
175 | implementation. Older implementations of GLU check this value and raise | |
176 | a GLU error if it is not 1, 2, 3, or 4 or one of the following symbolic | |
177 | constants: @code{GLU_ALPHA}, @code{GLU_ALPHA4}, @code{GLU_ALPHA8}, | |
178 | @code{GLU_ALPHA12}, @code{GLU_ALPHA16}, @code{GLU_LUMINANCE}, | |
179 | @code{GLU_LUMINANCE4}, @code{GLU_LUMINANCE8}, @code{GLU_LUMINANCE12}, | |
180 | @code{GLU_LUMINANCE16}, @code{GLU_LUMINANCE_ALPHA}, | |
181 | @code{GLU_LUMINANCE4_ALPHA4}, @code{GLU_LUMINANCE6_ALPHA2}, | |
182 | @code{GLU_LUMINANCE8_ALPHA8}, @code{GLU_LUMINANCE12_ALPHA4}, | |
183 | @code{GLU_LUMINANCE12_ALPHA12}, @code{GLU_LUMINANCE16_ALPHA16}, | |
184 | @code{GLU_INTENSITY}, @code{GLU_INTENSITY4}, @code{GLU_INTENSITY8}, | |
185 | @code{GLU_INTENSITY12}, @code{GLU_INTENSITY16}, @code{GLU_RGB}, | |
186 | @code{GLU_R3_G3_B2}, @code{GLU_RGB4}, @code{GLU_RGB5}, @code{GLU_RGB8}, | |
187 | @code{GLU_RGB10}, @code{GLU_RGB12}, @code{GLU_RGB16}, @code{GLU_RGBA}, | |
188 | @code{GLU_RGBA2}, @code{GLU_RGBA4}, @code{GLU_RGB5_A1}, | |
189 | @code{GLU_RGBA8}, @code{GLU_RGB10_A2}, @code{GLU_RGBA12}, or | |
190 | @code{GLU_RGBA16}. | |
191 | ||
192 | @item @var{width} | |
193 | Specifies the width in pixels of the texture image. This should be a | |
194 | power of 2. | |
195 | ||
196 | @item @var{format} | |
197 | Specifies the format of the pixel data. Must be one of: | |
198 | @code{GLU_COLOR_INDEX}, @code{GLU_DEPTH_COMPONENT}, @code{GLU_RED}, | |
199 | @code{GLU_GREEN}, @code{GLU_BLUE}, @code{GLU_ALPHA}, @code{GLU_RGB}, | |
200 | @code{GLU_RGBA}, @code{GLU_BGR}, @code{GLU_BGRA}, @code{GLU_LUMINANCE}, | |
201 | or @code{GLU_LUMINANCE_ALPHA}. | |
202 | ||
203 | @item @var{type} | |
204 | Specifies the data type for @var{data}. Must be one of: | |
205 | @code{GLU_UNSIGNED_BYTE}, @code{GLU_BYTE}, @code{GLU_BITMAP}, | |
206 | @code{GLU_UNSIGNED_SHORT}, @code{GLU_SHORT}, @code{GLU_UNSIGNED_INT}, | |
207 | @code{GLU_INT}, @code{GLU_FLOAT}, @code{GLU_UNSIGNED_BYTE_3_3_2}, | |
208 | @code{GLU_UNSIGNED_BYTE_2_3_3_REV}, @code{GLU_UNSIGNED_SHORT_5_6_5}, | |
209 | @code{GLU_UNSIGNED_SHORT_5_6_5_REV}, @code{GLU_UNSIGNED_SHORT_4_4_4_4}, | |
210 | @code{GLU_UNSIGNED_SHORT_4_4_4_4_REV}, | |
211 | @code{GLU_UNSIGNED_SHORT_5_5_5_1}, | |
212 | @code{GLU_UNSIGNED_SHORT_1_5_5_5_REV}, @code{GLU_UNSIGNED_INT_8_8_8_8}, | |
213 | @code{GLU_UNSIGNED_INT_8_8_8_8_REV}, @code{GLU_UNSIGNED_INT_10_10_10_2}, | |
214 | or @code{GLU_UNSIGNED_INT_2_10_10_10_REV}. | |
215 | ||
216 | @item @var{level} | |
217 | Specifies the mipmap level of the image data. | |
218 | ||
219 | @item @var{base} | |
220 | Specifies the minimum mipmap level to pass to @code{glTexImage1D}. | |
221 | ||
222 | @item @var{max} | |
223 | Specifies the maximum mipmap level to pass to @code{glTexImage1D}. | |
224 | ||
225 | @item @var{data} | |
226 | Specifies a pointer to the image data in memory. | |
227 | ||
228 | @end table | |
229 | ||
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230 | @code{gluBuild1DMipmapLevels} builds a subset of prefiltered |
231 | one-dimensional texture maps of decreasing resolutions called a mipmap. | |
232 | This is used for the antialiasing of texture mapped primitives. | |
233 | ||
234 | A return value of zero indicates success, otherwise a GLU error code is | |
235 | returned (see @code{gluErrorString}). | |
236 | ||
237 | A series of mipmap levels from @var{base} to @var{max} is built by | |
3c9b6116 | 238 | decimating @var{data} in half until size @r{1×1} is reached. At each |
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239 | level, each texel in the halved mipmap level is an average of the |
240 | corresponding two texels in the larger mipmap level. @code{glTexImage1D} | |
241 | is called to load these mipmap levels from @var{base} to @var{max}. If | |
242 | @var{max} is larger than the highest mipmap level for the texture of the | |
243 | specified size, then a GLU error code is returned (see | |
244 | @code{gluErrorString}) and nothing is loaded. | |
245 | ||
246 | For example, if @var{level} is 2 and @var{width} is 16, the following | |
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247 | levels are possible: @r{16×1}, @r{8×1}, @r{4×1}, @r{2×1}, @r{1×1}. These |
248 | correspond to levels 2 through 6 respectively. If @var{base} is 3 and | |
249 | @var{max} is 5, then only mipmap levels @r{8×1}, @r{4×1} and @r{2×1} are | |
250 | loaded. However, if @var{max} is 7, then an error is returned and | |
251 | nothing is loaded since @var{max} is larger than the highest mipmap | |
252 | level which is, in this case, 6. | |
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253 | |
254 | The highest mipmap level can be derived from the formula | |
3c9b6116 | 255 | @r{@var{log}_2(@var{width}×2^@var{level},)}. |
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256 | |
257 | See the @code{glTexImage1D} reference page for a description of the | |
258 | acceptable values for @var{type} parameter. See the @code{glDrawPixels} | |
259 | reference page for a description of the acceptable values for | |
260 | @var{level} parameter. | |
261 | ||
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262 | @code{GLU_INVALID_VALUE} is returned if @var{level} > @var{base}, |
263 | @var{base} < 0, @var{max} < @var{base} or @var{max} is > the highest | |
264 | mipmap level for @var{data}. | |
265 | ||
266 | @code{GLU_INVALID_VALUE} is returned if @var{width} is < 1. | |
267 | ||
268 | @code{GLU_INVALID_ENUM} is returned if @var{internalFormat}, | |
269 | @var{format}, or @var{type} are not legal. | |
270 | ||
271 | @code{GLU_INVALID_OPERATION} is returned if @var{type} is | |
272 | @code{GLU_UNSIGNED_BYTE_3_3_2} or @code{GLU_UNSIGNED_BYTE_2_3_3_REV} and | |
273 | @var{format} is not @code{GLU_RGB}. | |
274 | ||
275 | @code{GLU_INVALID_OPERATION} is returned if @var{type} is | |
276 | @code{GLU_UNSIGNED_SHORT_5_6_5} or @code{GLU_UNSIGNED_SHORT_5_6_5_REV} | |
277 | and @var{format} is not @code{GLU_RGB}. | |
278 | ||
279 | @code{GLU_INVALID_OPERATION} is returned if @var{type} is | |
280 | @code{GLU_UNSIGNED_SHORT_4_4_4_4} or | |
281 | @code{GLU_UNSIGNED_SHORT_4_4_4_4_REV} and @var{format} is neither | |
282 | @code{GLU_RGBA} nor @code{GLU_BGRA}. | |
283 | ||
284 | @code{GLU_INVALID_OPERATION} is returned if @var{type} is | |
285 | @code{GLU_UNSIGNED_SHORT_5_5_5_1} or | |
286 | @code{GLU_UNSIGNED_SHORT_1_5_5_5_REV} and @var{format} is neither | |
287 | @code{GLU_RGBA} nor @code{GLU_BGRA}. | |
288 | ||
289 | @code{GLU_INVALID_OPERATION} is returned if @var{type} is | |
290 | @code{GLU_UNSIGNED_INT_8_8_8_8} or @code{GLU_UNSIGNED_INT_8_8_8_8_REV} | |
291 | and @var{format} is neither @code{GLU_RGBA} nor @code{GLU_BGRA}. | |
292 | ||
293 | @code{GLU_INVALID_OPERATION} is returned if @var{type} is | |
294 | @code{GLU_UNSIGNED_INT_10_10_10_2} or | |
295 | @code{GLU_UNSIGNED_INT_2_10_10_10_REV} and @var{format} is neither | |
296 | @code{GLU_RGBA} nor @code{GLU_BGRA}. | |
297 | ||
bb894c9d | 298 | @end deftypefun |
8925f36f | 299 | |
bb894c9d | 300 | @deftypefun GLint gluBuild1DMipmaps target internalFormat width format type data |
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301 | Builds a one-dimensional mipmap. |
302 | ||
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303 | @table @asis |
304 | @item @var{target} | |
305 | Specifies the target texture. Must be @code{GLU_TEXTURE_1D}. | |
306 | ||
307 | @item @var{internalFormat} | |
308 | Requests the internal storage format of the texture image. The most | |
309 | current version of the SGI implementation of GLU does not check this | |
310 | value for validity before passing it on to the underlying OpenGL | |
311 | implementation. A value that is not accepted by the OpenGL | |
312 | implementation will lead to an OpenGL error. The benefit of not checking | |
313 | this value at the GLU level is that OpenGL extensions can add new | |
314 | internal texture formats without requiring a revision of the GLU | |
315 | implementation. Older implementations of GLU check this value and raise | |
316 | a GLU error if it is not 1, 2, 3, or 4 or one of the following symbolic | |
317 | constants: @code{GLU_ALPHA}, @code{GLU_ALPHA4}, @code{GLU_ALPHA8}, | |
318 | @code{GLU_ALPHA12}, @code{GLU_ALPHA16}, @code{GLU_LUMINANCE}, | |
319 | @code{GLU_LUMINANCE4}, @code{GLU_LUMINANCE8}, @code{GLU_LUMINANCE12}, | |
320 | @code{GLU_LUMINANCE16}, @code{GLU_LUMINANCE_ALPHA}, | |
321 | @code{GLU_LUMINANCE4_ALPHA4}, @code{GLU_LUMINANCE6_ALPHA2}, | |
322 | @code{GLU_LUMINANCE8_ALPHA8}, @code{GLU_LUMINANCE12_ALPHA4}, | |
323 | @code{GLU_LUMINANCE12_ALPHA12}, @code{GLU_LUMINANCE16_ALPHA16}, | |
324 | @code{GLU_INTENSITY}, @code{GLU_INTENSITY4}, @code{GLU_INTENSITY8}, | |
325 | @code{GLU_INTENSITY12}, @code{GLU_INTENSITY16}, @code{GLU_RGB}, | |
326 | @code{GLU_R3_G3_B2}, @code{GLU_RGB4}, @code{GLU_RGB5}, @code{GLU_RGB8}, | |
327 | @code{GLU_RGB10}, @code{GLU_RGB12}, @code{GLU_RGB16}, @code{GLU_RGBA}, | |
328 | @code{GLU_RGBA2}, @code{GLU_RGBA4}, @code{GLU_RGB5_A1}, | |
329 | @code{GLU_RGBA8}, @code{GLU_RGB10_A2}, @code{GLU_RGBA12}, or | |
330 | @code{GLU_RGBA16}. | |
331 | ||
332 | @item @var{width} | |
333 | Specifies the width, in pixels, of the texture image. | |
334 | ||
335 | @item @var{format} | |
336 | Specifies the format of the pixel data. Must be one of | |
337 | @code{GLU_COLOR_INDEX}, @code{GLU_DEPTH_COMPONENT}, @code{GLU_RED}, | |
338 | @code{GLU_GREEN}, @code{GLU_BLUE}, @code{GLU_ALPHA}, @code{GLU_RGB}, | |
339 | @code{GLU_RGBA}, @code{GLU_BGR}, @code{GLU_BGRA}, @code{GLU_LUMINANCE}, | |
340 | or @code{GLU_LUMINANCE_ALPHA}. | |
341 | ||
342 | @item @var{type} | |
343 | Specifies the data type for @var{data}. Must be one of | |
344 | @code{GLU_UNSIGNED_BYTE}, @code{GLU_BYTE}, @code{GLU_BITMAP}, | |
345 | @code{GLU_UNSIGNED_SHORT}, @code{GLU_SHORT}, @code{GLU_UNSIGNED_INT}, | |
346 | @code{GLU_INT}, @code{GLU_FLOAT}, @code{GLU_UNSIGNED_BYTE_3_3_2}, | |
347 | @code{GLU_UNSIGNED_BYTE_2_3_3_REV}, @code{GLU_UNSIGNED_SHORT_5_6_5}, | |
348 | @code{GLU_UNSIGNED_SHORT_5_6_5_REV}, @code{GLU_UNSIGNED_SHORT_4_4_4_4}, | |
349 | @code{GLU_UNSIGNED_SHORT_4_4_4_4_REV}, | |
350 | @code{GLU_UNSIGNED_SHORT_5_5_5_1}, | |
351 | @code{GLU_UNSIGNED_SHORT_1_5_5_5_REV}, @code{GLU_UNSIGNED_INT_8_8_8_8}, | |
352 | @code{GLU_UNSIGNED_INT_8_8_8_8_REV}, @code{GLU_UNSIGNED_INT_10_10_10_2}, | |
353 | or @code{GLU_UNSIGNED_INT_2_10_10_10_REV}. | |
354 | ||
355 | @item @var{data} | |
356 | Specifies a pointer to the image data in memory. | |
357 | ||
358 | @end table | |
359 | ||
8925f36f AW |
360 | @code{gluBuild1DMipmaps} builds a series of prefiltered one-dimensional |
361 | texture maps of decreasing resolutions called a mipmap. This is used for | |
362 | the antialiasing of texture mapped primitives. | |
363 | ||
364 | A return value of zero indicates success, otherwise a GLU error code is | |
365 | returned (see @code{gluErrorString}). | |
366 | ||
367 | Initially, the @var{width} of @var{data} is checked to see if it is a | |
368 | power of 2. If not, a copy of @var{data} is scaled up or down to the | |
369 | nearest power of 2. (If @var{width} is exactly between powers of 2, then | |
370 | the copy of @var{data} will scale upwards.) This copy will be used for | |
371 | subsequent mipmapping operations described below. For example, if | |
372 | @var{width} is 57, then a copy of @var{data} will scale up to 64 before | |
373 | mipmapping takes place. | |
374 | ||
375 | Then, proxy textures (see @code{glTexImage1D}) are used to determine if | |
376 | the implementation can fit the requested texture. If not, @var{width} is | |
377 | continually halved until it fits. | |
378 | ||
379 | Next, a series of mipmap levels is built by decimating a copy of | |
3c9b6116 | 380 | @var{data} in half until size @r{1×1} is reached. At each level, each |
8925f36f AW |
381 | texel in the halved mipmap level is an average of the corresponding two |
382 | texels in the larger mipmap level. | |
383 | ||
384 | @code{glTexImage1D} is called to load each of these mipmap levels. Level | |
385 | 0 is a copy of @var{data}. The highest level is | |
3c9b6116 AW |
386 | @r{@var{log}_2,(@var{width},)}. For example, if @var{width} is 64 and |
387 | the implementation can store a texture of this size, the following | |
388 | mipmap levels are built: @r{64×1}, @r{32×1}, @r{16×1}, @r{8×1}, @r{4×1}, | |
389 | @r{2×1}, and @r{1×1}. These correspond to levels 0 through 6, | |
390 | respectively. | |
8925f36f AW |
391 | |
392 | See the @code{glTexImage1D} reference page for a description of the | |
393 | acceptable values for the @var{type} parameter. See the | |
394 | @code{glDrawPixels} reference page for a description of the acceptable | |
395 | values for the @var{data} parameter. | |
396 | ||
8925f36f AW |
397 | @code{GLU_INVALID_VALUE} is returned if @var{width} is < 1. |
398 | ||
399 | @code{GLU_INVALID_ENUM} is returned if @var{format} or @var{type} are | |
400 | not legal. | |
401 | ||
402 | @code{GLU_INVALID_OPERATION} is returned if @var{type} is | |
403 | @code{GLU_UNSIGNED_BYTE_3_3_2} or @code{GLU_UNSIGNED_BYTE_2_3_3_REV} and | |
404 | @var{format} is not @code{GLU_RGB}. | |
405 | ||
406 | @code{GLU_INVALID_OPERATION} is returned if @var{type} is | |
407 | @code{GLU_UNSIGNED_SHORT_5_6_5} or @code{GLU_UNSIGNED_SHORT_5_6_5_REV} | |
408 | and @var{format} is not @code{GLU_RGB}. | |
409 | ||
410 | @code{GLU_INVALID_OPERATION} is returned if @var{type} is | |
411 | @code{GLU_UNSIGNED_SHORT_4_4_4_4} or | |
412 | @code{GLU_UNSIGNED_SHORT_4_4_4_4_REV} and @var{format} is neither | |
413 | @code{GLU_RGBA} nor @code{GLU_BGRA}. | |
414 | ||
415 | @code{GLU_INVALID_OPERATION} is returned if @var{type} is | |
416 | @code{GLU_UNSIGNED_SHORT_5_5_5_1} or | |
417 | @code{GLU_UNSIGNED_SHORT_1_5_5_5_REV} and @var{format} is neither | |
418 | @code{GLU_RGBA} nor @code{GLU_BGRA}. | |
419 | ||
420 | @code{GLU_INVALID_OPERATION} is returned if @var{type} is | |
421 | @code{GLU_UNSIGNED_INT_8_8_8_8} or @code{GLU_UNSIGNED_INT_8_8_8_8_REV} | |
422 | and @var{format} is neither @code{GLU_RGBA} nor @code{GLU_BGRA}. | |
423 | ||
424 | @code{GLU_INVALID_OPERATION} is returned if @var{type} is | |
425 | @code{GLU_UNSIGNED_INT_10_10_10_2} or | |
426 | @code{GLU_UNSIGNED_INT_2_10_10_10_REV} and @var{format} is neither | |
427 | @code{GLU_RGBA} nor @code{GLU_BGRA}. | |
428 | ||
bb894c9d | 429 | @end deftypefun |
8925f36f | 430 | |
bb894c9d | 431 | @deftypefun GLint gluBuild2DMipmapLevels target internalFormat width height format type level base max data |
3c9b6116 AW |
432 | Builds a subset of two-dimensional mipmap levels. |
433 | ||
8925f36f AW |
434 | @table @asis |
435 | @item @var{target} | |
436 | Specifies the target texture. Must be @code{GLU_TEXTURE_2D}. | |
437 | ||
438 | @item @var{internalFormat} | |
439 | Requests the internal storage format of the texture image. The most | |
440 | current version of the SGI implementation of GLU does not check this | |
441 | value for validity before passing it on to the underlying OpenGL | |
442 | implementation. A value that is not accepted by the OpenGL | |
443 | implementation will lead to an OpenGL error. The benefit of not checking | |
444 | this value at the GLU level is that OpenGL extensions can add new | |
445 | internal texture formats without requiring a revision of the GLU | |
446 | implementation. Older implementations of GLU check this value and raise | |
447 | a GLU error if it is not 1, 2, 3, or 4 or one of the following symbolic | |
448 | constants: @code{GLU_ALPHA}, @code{GLU_ALPHA4}, @code{GLU_ALPHA8}, | |
449 | @code{GLU_ALPHA12}, @code{GLU_ALPHA16}, @code{GLU_LUMINANCE}, | |
450 | @code{GLU_LUMINANCE4}, @code{GLU_LUMINANCE8}, @code{GLU_LUMINANCE12}, | |
451 | @code{GLU_LUMINANCE16}, @code{GLU_LUMINANCE_ALPHA}, | |
452 | @code{GLU_LUMINANCE4_ALPHA4}, @code{GLU_LUMINANCE6_ALPHA2}, | |
453 | @code{GLU_LUMINANCE8_ALPHA8}, @code{GLU_LUMINANCE12_ALPHA4}, | |
454 | @code{GLU_LUMINANCE12_ALPHA12}, @code{GLU_LUMINANCE16_ALPHA16}, | |
455 | @code{GLU_INTENSITY}, @code{GLU_INTENSITY4}, @code{GLU_INTENSITY8}, | |
456 | @code{GLU_INTENSITY12}, @code{GLU_INTENSITY16}, @code{GLU_RGB}, | |
457 | @code{GLU_R3_G3_B2}, @code{GLU_RGB4}, @code{GLU_RGB5}, @code{GLU_RGB8}, | |
458 | @code{GLU_RGB10}, @code{GLU_RGB12}, @code{GLU_RGB16}, @code{GLU_RGBA}, | |
459 | @code{GLU_RGBA2}, @code{GLU_RGBA4}, @code{GLU_RGB5_A1}, | |
460 | @code{GLU_RGBA8}, @code{GLU_RGB10_A2}, @code{GLU_RGBA12}, or | |
461 | @code{GLU_RGBA16}. | |
462 | ||
463 | @item @var{width} | |
464 | @itemx @var{height} | |
465 | Specifies the width and height, respectively, in pixels of the texture | |
466 | image. These should be a power of 2. | |
467 | ||
468 | @item @var{format} | |
469 | Specifies the format of the pixel data. Must be one of | |
470 | @code{GLU_COLOR_INDEX}, @code{GLU_DEPTH_COMPONENT}, @code{GLU_RED}, | |
471 | @code{GLU_GREEN}, @code{GLU_BLUE}, @code{GLU_ALPHA}, @code{GLU_RGB}, | |
472 | @code{GLU_RGBA}, @code{GLU_BGR}, @code{GLU_BGRA}, @code{GLU_LUMINANCE}, | |
473 | or @code{GLU_LUMINANCE_ALPHA}. | |
474 | ||
475 | @item @var{type} | |
476 | Specifies the data type for @var{data}. Must be one of | |
477 | @code{GLU_UNSIGNED_BYTE}, @code{GLU_BYTE}, @code{GLU_BITMAP}, | |
478 | @code{GLU_UNSIGNED_SHORT}, @code{GLU_SHORT}, @code{GLU_UNSIGNED_INT}, | |
479 | @code{GLU_INT}, @code{GLU_FLOAT}, @code{GLU_UNSIGNED_BYTE_3_3_2}, | |
480 | @code{GLU_UNSIGNED_BYTE_2_3_3_REV}, @code{GLU_UNSIGNED_SHORT_5_6_5}, | |
481 | @code{GLU_UNSIGNED_SHORT_5_6_5_REV}, @code{GLU_UNSIGNED_SHORT_4_4_4_4}, | |
482 | @code{GLU_UNSIGNED_SHORT_4_4_4_4_REV}, | |
483 | @code{GLU_UNSIGNED_SHORT_5_5_5_1}, | |
484 | @code{GLU_UNSIGNED_SHORT_1_5_5_5_REV}, @code{GLU_UNSIGNED_INT_8_8_8_8}, | |
485 | @code{GLU_UNSIGNED_INT_8_8_8_8_REV}, @code{GLU_UNSIGNED_INT_10_10_10_2}, | |
486 | or @code{GLU_UNSIGNED_INT_2_10_10_10_REV}. | |
487 | ||
488 | @item @var{level} | |
489 | Specifies the mipmap level of the image data. | |
490 | ||
491 | @item @var{base} | |
492 | Specifies the minimum mipmap level to pass to @code{glTexImage2D}. | |
493 | ||
494 | @item @var{max} | |
495 | Specifies the maximum mipmap level to pass to @code{glTexImage2D}. | |
496 | ||
497 | @item @var{data} | |
498 | Specifies a pointer to the image data in memory. | |
499 | ||
500 | @end table | |
501 | ||
8925f36f AW |
502 | @code{gluBuild2DMipmapLevels} builds a subset of prefiltered |
503 | two-dimensional texture maps of decreasing resolutions called a mipmap. | |
504 | This is used for the antialiasing of texture mapped primitives. | |
505 | ||
506 | A return value of zero indicates success, otherwise a GLU error code is | |
507 | returned (see @code{gluErrorString}). | |
508 | ||
509 | A series of mipmap levels from @var{base} to @var{max} is built by | |
3c9b6116 AW |
510 | decimating @var{data} in half along both dimensions until size @r{1×1} |
511 | is reached. At each level, each texel in the halved mipmap level is an | |
512 | average of the corresponding four texels in the larger mipmap level. (In | |
513 | the case of rectangular images, the decimation will ultimately reach an | |
514 | @r{@var{N}×1} or @r{1×@var{N}} configuration. Here, two texels are | |
515 | averaged instead.) @code{glTexImage2D} is called to load these mipmap | |
516 | levels from @var{base} to @var{max}. If @var{max} is larger than the | |
517 | highest mipmap level for the texture of the specified size, then a GLU | |
518 | error code is returned (see @code{gluErrorString}) and nothing is | |
519 | loaded. | |
8925f36f AW |
520 | |
521 | For example, if @var{level} is 2 and @var{width} is 16 and @var{height} | |
3c9b6116 AW |
522 | is 8, the following levels are possible: @r{16×8}, @r{8×4}, @r{4×2}, |
523 | @r{2×1}, @r{1×1}. These correspond to levels 2 through 6 respectively. | |
524 | If @var{base} is 3 and @var{max} is 5, then only mipmap levels @r{8×4}, | |
525 | @r{4×2}, and @r{2×1} are loaded. However, if @var{max} is 7, then an | |
526 | error is returned and nothing is loaded since @var{max} is larger than | |
527 | the highest mipmap level which is, in this case, 6. | |
8925f36f AW |
528 | |
529 | The highest mipmap level can be derived from the formula | |
3c9b6116 | 530 | @r{@var{log}_2(@var{max}(@var{width},@var{height})×2^@var{level},)}. |
8925f36f AW |
531 | |
532 | See the @code{glTexImage1D} reference page for a description of the | |
533 | acceptable values for @var{format} parameter. See the | |
534 | @code{glDrawPixels} reference page for a description of the acceptable | |
535 | values for @var{type} parameter. | |
536 | ||
8925f36f AW |
537 | @code{GLU_INVALID_VALUE} is returned if @var{level} > @var{base}, |
538 | @var{base} < 0, @var{max} < @var{base}, or @var{max} is > the highest | |
539 | mipmap level for @var{data}. | |
540 | ||
541 | @code{GLU_INVALID_VALUE} is returned if @var{width} or @var{height} is < | |
542 | 1. | |
543 | ||
544 | @code{GLU_INVALID_ENUM} is returned if @var{internalFormat}, | |
545 | @var{format}, or @var{type} is not legal. | |
546 | ||
547 | @code{GLU_INVALID_OPERATION} is returned if @var{type} is | |
548 | @code{GLU_UNSIGNED_BYTE_3_3_2} or @code{GLU_UNSIGNED_BYTE_2_3_3_REV} and | |
549 | @var{format} is not @code{GLU_RGB}. | |
550 | ||
551 | @code{GLU_INVALID_OPERATION} is returned if @var{type} is | |
552 | @code{GLU_UNSIGNED_SHORT_5_6_5} or @code{GLU_UNSIGNED_SHORT_5_6_5_REV} | |
553 | and @var{format} is not @code{GLU_RGB}. | |
554 | ||
555 | @code{GLU_INVALID_OPERATION} is returned if @var{type} is | |
556 | @code{GLU_UNSIGNED_SHORT_4_4_4_4} or | |
557 | @code{GLU_UNSIGNED_SHORT_4_4_4_4_REV} and @var{format} is neither | |
558 | @code{GLU_RGBA} nor @code{GLU_BGRA}. | |
559 | ||
560 | @code{GLU_INVALID_OPERATION} is returned if @var{type} is | |
561 | @code{GLU_UNSIGNED_SHORT_5_5_5_1} or | |
562 | @code{GLU_UNSIGNED_SHORT_1_5_5_5_REV} and @var{format} is neither | |
563 | @code{GLU_RGBA} nor @code{GLU_BGRA}. | |
564 | ||
565 | @code{GLU_INVALID_OPERATION} is returned if @var{type} is | |
566 | @code{GLU_UNSIGNED_INT_8_8_8_8} or @code{GLU_UNSIGNED_INT_8_8_8_8_REV} | |
567 | and @var{format} is neither @code{GLU_RGBA} nor @code{GLU_BGRA}. | |
568 | ||
569 | @code{GLU_INVALID_OPERATION} is returned if @var{type} is | |
570 | @code{GLU_UNSIGNED_INT_10_10_10_2} or | |
571 | @code{GLU_UNSIGNED_INT_2_10_10_10_REV} and @var{format} is neither | |
572 | @code{GLU_RGBA} nor @code{GLU_BGRA}. | |
573 | ||
bb894c9d | 574 | @end deftypefun |
8925f36f | 575 | |
bb894c9d | 576 | @deftypefun GLint gluBuild2DMipmaps target internalFormat width height format type data |
3c9b6116 AW |
577 | Builds a two-dimensional mipmap. |
578 | ||
8925f36f AW |
579 | @table @asis |
580 | @item @var{target} | |
581 | Specifies the target texture. Must be @code{GLU_TEXTURE_2D}. | |
582 | ||
583 | @item @var{internalFormat} | |
584 | Requests the internal storage format of the texture image. The most | |
585 | current version of the SGI implementation of GLU does not check this | |
586 | value for validity before passing it on to the underlying OpenGL | |
587 | implementation. A value that is not accepted by the OpenGL | |
588 | implementation will lead to an OpenGL error. The benefit of not checking | |
589 | this value at the GLU level is that OpenGL extensions can add new | |
590 | internal texture formats without requiring a revision of the GLU | |
591 | implementation. Older implementations of GLU check this value and raise | |
592 | a GLU error if it is not 1, 2, 3, or 4 or one of the following symbolic | |
593 | constants: @code{GLU_ALPHA}, @code{GLU_ALPHA4}, @code{GLU_ALPHA8}, | |
594 | @code{GLU_ALPHA12}, @code{GLU_ALPHA16}, @code{GLU_LUMINANCE}, | |
595 | @code{GLU_LUMINANCE4}, @code{GLU_LUMINANCE8}, @code{GLU_LUMINANCE12}, | |
596 | @code{GLU_LUMINANCE16}, @code{GLU_LUMINANCE_ALPHA}, | |
597 | @code{GLU_LUMINANCE4_ALPHA4}, @code{GLU_LUMINANCE6_ALPHA2}, | |
598 | @code{GLU_LUMINANCE8_ALPHA8}, @code{GLU_LUMINANCE12_ALPHA4}, | |
599 | @code{GLU_LUMINANCE12_ALPHA12}, @code{GLU_LUMINANCE16_ALPHA16}, | |
600 | @code{GLU_INTENSITY}, @code{GLU_INTENSITY4}, @code{GLU_INTENSITY8}, | |
601 | @code{GLU_INTENSITY12}, @code{GLU_INTENSITY16}, @code{GLU_RGB}, | |
602 | @code{GLU_R3_G3_B2}, @code{GLU_RGB4}, @code{GLU_RGB5}, @code{GLU_RGB8}, | |
603 | @code{GLU_RGB10}, @code{GLU_RGB12}, @code{GLU_RGB16}, @code{GLU_RGBA}, | |
604 | @code{GLU_RGBA2}, @code{GLU_RGBA4}, @code{GLU_RGB5_A1}, | |
605 | @code{GLU_RGBA8}, @code{GLU_RGB10_A2}, @code{GLU_RGBA12}, or | |
606 | @code{GLU_RGBA16}. | |
607 | ||
608 | @item @var{width} | |
609 | @itemx @var{height} | |
610 | Specifies in pixels the width and height, respectively, of the texture | |
611 | image. | |
612 | ||
613 | @item @var{format} | |
614 | Specifies the format of the pixel data. Must be one of | |
615 | @code{GLU_COLOR_INDEX}, @code{GLU_DEPTH_COMPONENT}, @code{GLU_RED}, | |
616 | @code{GLU_GREEN}, @code{GLU_BLUE}, @code{GLU_ALPHA}, @code{GLU_RGB}, | |
617 | @code{GLU_RGBA}, @code{GLU_BGR}, @code{GLU_BGRA}, @code{GLU_LUMINANCE}, | |
618 | or @code{GLU_LUMINANCE_ALPHA}. | |
619 | ||
620 | @item @var{type} | |
621 | Specifies the data type for @var{data}. Must be one of | |
622 | @code{GLU_UNSIGNED_BYTE}, @code{GLU_BYTE}, @code{GLU_BITMAP}, | |
623 | @code{GLU_UNSIGNED_SHORT}, @code{GLU_SHORT}, @code{GLU_UNSIGNED_INT}, | |
624 | @code{GLU_INT}, @code{GLU_FLOAT}, @code{GLU_UNSIGNED_BYTE_3_3_2}, | |
625 | @code{GLU_UNSIGNED_BYTE_2_3_3_REV}, @code{GLU_UNSIGNED_SHORT_5_6_5}, | |
626 | @code{GLU_UNSIGNED_SHORT_5_6_5_REV}, @code{GLU_UNSIGNED_SHORT_4_4_4_4}, | |
627 | @code{GLU_UNSIGNED_SHORT_4_4_4_4_REV}, | |
628 | @code{GLU_UNSIGNED_SHORT_5_5_5_1}, | |
629 | @code{GLU_UNSIGNED_SHORT_1_5_5_5_REV}, @code{GLU_UNSIGNED_INT_8_8_8_8}, | |
630 | @code{GLU_UNSIGNED_INT_8_8_8_8_REV}, @code{GLU_UNSIGNED_INT_10_10_10_2}, | |
631 | or @code{GLU_UNSIGNED_INT_2_10_10_10_REV}. | |
632 | ||
633 | @item @var{data} | |
634 | Specifies a pointer to the image data in memory. | |
635 | ||
636 | @end table | |
637 | ||
8925f36f AW |
638 | @code{gluBuild2DMipmaps} builds a series of prefiltered two-dimensional |
639 | texture maps of decreasing resolutions called a mipmap. This is used for | |
640 | the antialiasing of texture-mapped primitives. | |
641 | ||
642 | A return value of zero indicates success, otherwise a GLU error code is | |
643 | returned (see @code{gluErrorString}). | |
644 | ||
645 | Initially, the @var{width} and @var{height} of @var{data} are checked to | |
646 | see if they are a power of 2. If not, a copy of @var{data} (not | |
647 | @var{data}), is scaled up or down to the nearest power of 2. This copy | |
648 | will be used for subsequent mipmapping operations described below. (If | |
649 | @var{width} or @var{height} is exactly between powers of 2, then the | |
650 | copy of @var{data} will scale upwards.) For example, if @var{width} is | |
651 | 57 and @var{height} is 23, then a copy of @var{data} will scale up to 64 | |
652 | in @var{width} and down to 16 in depth, before mipmapping takes place. | |
653 | ||
654 | Then, proxy textures (see @code{glTexImage2D}) are used to determine if | |
655 | the implementation can fit the requested texture. If not, both | |
656 | dimensions are continually halved until it fits. (If the OpenGL version | |
657 | is \(<= 1.0, both maximum texture dimensions are clamped to the value | |
658 | returned by @code{glGetIntegerv} with the argument | |
659 | @code{GLU_MAX_TEXTURE_SIZE}.) | |
660 | ||
661 | Next, a series of mipmap levels is built by decimating a copy of | |
3c9b6116 AW |
662 | @var{data} in half along both dimensions until size @r{1×1} is reached. |
663 | At each level, each texel in the halved mipmap level is an average of | |
664 | the corresponding four texels in the larger mipmap level. (In the case | |
665 | of rectangular images, the decimation will ultimately reach an | |
666 | @r{@var{N}×1} or @r{1×@var{N}} configuration. Here, two texels are | |
8925f36f AW |
667 | averaged instead.) |
668 | ||
669 | @code{glTexImage2D} is called to load each of these mipmap levels. Level | |
670 | 0 is a copy of @var{data}. The highest level is | |
3c9b6116 AW |
671 | @r{@var{log}_2,(@var{max}(@var{width},@var{height}),)}. For example, |
672 | if @var{width} is 64 and @var{height} is 16 and the implementation can | |
673 | store a texture of this size, the following mipmap levels are built: | |
674 | @r{64×16}, @r{32×8}, @r{16×4}, @r{8×2}, @r{4×1}, @r{2×1}, and @r{1×1} | |
675 | These correspond to levels 0 through 6, respectively. | |
8925f36f AW |
676 | |
677 | See the @code{glTexImage1D} reference page for a description of the | |
678 | acceptable values for @var{format} parameter. See the | |
679 | @code{glDrawPixels} reference page for a description of the acceptable | |
680 | values for @var{type} parameter. | |
681 | ||
8925f36f AW |
682 | @code{GLU_INVALID_VALUE} is returned if @var{width} or @var{height} is < |
683 | 1. | |
684 | ||
685 | @code{GLU_INVALID_ENUM} is returned if @var{internalFormat}, | |
686 | @var{format}, or @var{type} is not legal. | |
687 | ||
688 | @code{GLU_INVALID_OPERATION} is returned if @var{type} is | |
689 | @code{GLU_UNSIGNED_BYTE_3_3_2} or @code{GLU_UNSIGNED_BYTE_2_3_3_REV} and | |
690 | @var{format} is not @code{GLU_RGB}. | |
691 | ||
692 | @code{GLU_INVALID_OPERATION} is returned if @var{type} is | |
693 | @code{GLU_UNSIGNED_SHORT_5_6_5} or @code{GLU_UNSIGNED_SHORT_5_6_5_REV} | |
694 | and @var{format} is not @code{GLU_RGB}. | |
695 | ||
696 | @code{GLU_INVALID_OPERATION} is returned if @var{type} is | |
697 | @code{GLU_UNSIGNED_SHORT_4_4_4_4} or | |
698 | @code{GLU_UNSIGNED_SHORT_4_4_4_4_REV} and @var{format} is neither | |
699 | @code{GLU_RGBA} nor @code{GLU_BGRA}. | |
700 | ||
701 | @code{GLU_INVALID_OPERATION} is returned if @var{type} is | |
702 | @code{GLU_UNSIGNED_SHORT_5_5_5_1} or | |
703 | @code{GLU_UNSIGNED_SHORT_1_5_5_5_REV} and @var{format} is neither | |
704 | @code{GLU_RGBA} nor @code{GLU_BGRA}. | |
705 | ||
706 | @code{GLU_INVALID_OPERATION} is returned if @var{type} is | |
707 | @code{GLU_UNSIGNED_INT_8_8_8_8} or @code{GLU_UNSIGNED_INT_8_8_8_8_REV} | |
708 | and @var{format} is neither @code{GLU_RGBA} nor @code{GLU_BGRA}. | |
709 | ||
710 | @code{GLU_INVALID_OPERATION} is returned if @var{type} is | |
711 | @code{GLU_UNSIGNED_INT_10_10_10_2} or | |
712 | @code{GLU_UNSIGNED_INT_2_10_10_10_REV} and @var{format} is neither | |
713 | @code{GLU_RGBA} nor @code{GLU_BGRA}. | |
714 | ||
bb894c9d | 715 | @end deftypefun |
8925f36f | 716 | |
bb894c9d | 717 | @deftypefun GLint gluBuild3DMipmapLevels target internalFormat width height depth format type level base max data |
3c9b6116 AW |
718 | Builds a subset of three-dimensional mipmap levels. |
719 | ||
8925f36f AW |
720 | @table @asis |
721 | @item @var{target} | |
722 | Specifies the target texture. Must be @code{GLU_TEXTURE_3D}. | |
723 | ||
724 | @item @var{internalFormat} | |
725 | Requests the internal storage format of the texture image. The most | |
726 | current version of the SGI implementation of GLU does not check this | |
727 | value for validity before passing it on to the underlying OpenGL | |
728 | implementation. A value that is not accepted by the OpenGL | |
729 | implementation will lead to an OpenGL error. The benefit of not checking | |
730 | this value at the GLU level is that OpenGL extensions can add new | |
731 | internal texture formats without requiring a revision of the GLU | |
732 | implementation. Older implementations of GLU check this value and raise | |
733 | a GLU error if it is not 1, 2, 3, or 4 or one of the following symbolic | |
734 | constants: @code{GLU_ALPHA}, @code{GLU_ALPHA4}, @code{GLU_ALPHA8}, | |
735 | @code{GLU_ALPHA12}, @code{GLU_ALPHA16}, @code{GLU_LUMINANCE}, | |
736 | @code{GLU_LUMINANCE4}, @code{GLU_LUMINANCE8}, @code{GLU_LUMINANCE12}, | |
737 | @code{GLU_LUMINANCE16}, @code{GLU_LUMINANCE_ALPHA}, | |
738 | @code{GLU_LUMINANCE4_ALPHA4}, @code{GLU_LUMINANCE6_ALPHA2}, | |
739 | @code{GLU_LUMINANCE8_ALPHA8}, @code{GLU_LUMINANCE12_ALPHA4}, | |
740 | @code{GLU_LUMINANCE12_ALPHA12}, @code{GLU_LUMINANCE16_ALPHA16}, | |
741 | @code{GLU_INTENSITY}, @code{GLU_INTENSITY4}, @code{GLU_INTENSITY8}, | |
742 | @code{GLU_INTENSITY12}, @code{GLU_INTENSITY16}, @code{GLU_RGB}, | |
743 | @code{GLU_R3_G3_B2}, @code{GLU_RGB4}, @code{GLU_RGB5}, @code{GLU_RGB8}, | |
744 | @code{GLU_RGB10}, @code{GLU_RGB12}, @code{GLU_RGB16}, @code{GLU_RGBA}, | |
745 | @code{GLU_RGBA2}, @code{GLU_RGBA4}, @code{GLU_RGB5_A1}, | |
746 | @code{GLU_RGBA8}, @code{GLU_RGB10_A2}, @code{GLU_RGBA12}, or | |
747 | @code{GLU_RGBA16}. | |
748 | ||
749 | @item @var{width} | |
750 | @itemx @var{height} | |
751 | @itemx @var{depth} | |
752 | Specifies in pixels the width, height and depth respectively, of the | |
753 | texture image. These should be a power of 2. | |
754 | ||
755 | @item @var{format} | |
756 | Specifies the format of the pixel data. Must be one of | |
757 | @code{GLU_COLOR_INDEX}, @code{GLU_DEPTH_COMPONENT}, @code{GLU_RED}, | |
758 | @code{GLU_GREEN}, @code{GLU_BLUE}, @code{GLU_ALPHA}, @code{GLU_RGB}, | |
759 | @code{GLU_RGBA}, @code{GLU_BGR}, @code{GLU_BGRA}, @code{GLU_LUMINANCE}, | |
760 | or @code{GLU_LUMINANCE_ALPHA}. | |
761 | ||
762 | @item @var{type} | |
763 | Specifies the data type for @var{data}. Must be one of | |
764 | @code{GLU_UNSIGNED_BYTE}, @code{GLU_BYTE}, @code{GLU_BITMAP}, | |
765 | @code{GLU_UNSIGNED_SHORT}, @code{GLU_SHORT}, @code{GLU_UNSIGNED_INT}, | |
766 | @code{GLU_INT}, @code{GLU_FLOAT}, @code{GLU_UNSIGNED_BYTE_3_3_2}, | |
767 | @code{GLU_UNSIGNED_BYTE_2_3_3_REV}, @code{GLU_UNSIGNED_SHORT_5_6_5}, | |
768 | @code{GLU_UNSIGNED_SHORT_5_6_5_REV}, @code{GLU_UNSIGNED_SHORT_4_4_4_4}, | |
769 | @code{GLU_UNSIGNED_SHORT_4_4_4_4_REV}, | |
770 | @code{GLU_UNSIGNED_SHORT_5_5_5_1}, | |
771 | @code{GLU_UNSIGNED_SHORT_1_5_5_5_REV}, @code{GLU_UNSIGNED_INT_8_8_8_8}, | |
772 | @code{GLU_UNSIGNED_INT_8_8_8_8_REV}, @code{GLU_UNSIGNED_INT_10_10_10_2}, | |
773 | or @code{GLU_UNSIGNED_INT_2_10_10_10_REV}. | |
774 | ||
775 | @item @var{level} | |
776 | Specifies the mipmap level of the image data. | |
777 | ||
778 | @item @var{base} | |
779 | Specifies the minimum mipmap level to pass to @code{glTexImage3D}. | |
780 | ||
781 | @item @var{max} | |
782 | Specifies the maximum mipmap level to pass to @code{glTexImage3D}. | |
783 | ||
784 | @item @var{data} | |
785 | Specifies a pointer to the image data in memory. | |
786 | ||
787 | @end table | |
788 | ||
8925f36f AW |
789 | @code{gluBuild3DMipmapLevels} builds a subset of prefiltered |
790 | three-dimensional texture maps of decreasing resolutions called a | |
791 | mipmap. This is used for the antialiasing of texture mapped primitives. | |
792 | ||
793 | A return value of zero indicates success, otherwise a GLU error code is | |
794 | returned (see @code{gluErrorString}). | |
795 | ||
796 | A series of mipmap levels from @var{base} to @var{max} is built by | |
3c9b6116 AW |
797 | decimating @var{data} in half along both dimensions until size @r{1×1×1} |
798 | is reached. At each level, each texel in the halved mipmap level is an | |
799 | average of the corresponding eight texels in the larger mipmap level. | |
800 | (If exactly one of the dimensions is 1, four texels are averaged. If | |
801 | exactly two of the dimensions are 1, two texels are averaged.) | |
802 | @code{glTexImage3D} is called to load these mipmap levels from | |
803 | @var{base} to @var{max}. If @var{max} is larger than the highest mipmap | |
804 | level for the texture of the specified size, then a GLU error code is | |
805 | returned (see @code{gluErrorString}) and nothing is loaded. | |
8925f36f AW |
806 | |
807 | For example, if @var{level} is 2 and @var{width} is 16, @var{height} is | |
3c9b6116 AW |
808 | 8 and @var{depth} is 4, the following levels are possible: @r{16×8×4}, |
809 | @r{8×4×2}, @r{4×2×1}, @r{2×1×1}, @r{1×1×1}. These correspond to levels 2 | |
810 | through 6 respectively. If @var{base} is 3 and @var{max} is 5, then only | |
811 | mipmap levels @r{8×4×2}, @r{4×2×1}, and @r{2×1×1} are loaded. However, | |
812 | if @var{max} is 7, then an error is returned and nothing is loaded, | |
813 | since @var{max} is larger than the highest mipmap level which is, in | |
814 | this case, 6. | |
8925f36f AW |
815 | |
816 | The highest mipmap level can be derived from the formula | |
3c9b6116 | 817 | @r{@var{log}_2(@var{max}(@var{width},@var{height}@var{depth})×2^@var{level},)}. |
8925f36f AW |
818 | |
819 | See the @code{glTexImage1D} reference page for a description of the | |
820 | acceptable values for @var{format} parameter. See the | |
821 | @code{glDrawPixels} reference page for a description of the acceptable | |
822 | values for @var{type} parameter. | |
823 | ||
8925f36f AW |
824 | @code{GLU_INVALID_VALUE} is returned if @var{level} > @var{base}, |
825 | @var{base} < 0, @var{max} < @var{base}, or @var{max} is > the highest | |
826 | mipmap level for @var{data}. | |
827 | ||
828 | @code{GLU_INVALID_VALUE} is returned if @var{width}, @var{height}, or | |
829 | @var{depth} is < 1. | |
830 | ||
831 | @code{GLU_INVALID_ENUM} is returned if @var{internalFormat}, | |
832 | @var{format}, or @var{type} is not legal. | |
833 | ||
834 | @code{GLU_INVALID_OPERATION} is returned if @var{type} is | |
835 | @code{GLU_UNSIGNED_BYTE_3_3_2} or @code{GLU_UNSIGNED_BYTE_2_3_3_REV} and | |
836 | @var{format} is not @code{GLU_RGB}. | |
837 | ||
838 | @code{GLU_INVALID_OPERATION} is returned if @var{type} is | |
839 | @code{GLU_UNSIGNED_SHORT_5_6_5} or @code{GLU_UNSIGNED_SHORT_5_6_5_REV} | |
840 | and @var{format} is not @code{GLU_RGB}. | |
841 | ||
842 | @code{GLU_INVALID_OPERATION} is returned if @var{type} is | |
843 | @code{GLU_UNSIGNED_SHORT_4_4_4_4} or | |
844 | @code{GLU_UNSIGNED_SHORT_4_4_4_4_REV} and @var{format} is neither | |
845 | @code{GLU_RGBA} nor @code{GLU_BGRA}. | |
846 | ||
847 | @code{GLU_INVALID_OPERATION} is returned if @var{type} is | |
848 | @code{GLU_UNSIGNED_SHORT_5_5_5_1} or | |
849 | @code{GLU_UNSIGNED_SHORT_1_5_5_5_REV} and @var{format} is neither | |
850 | @code{GLU_RGBA} nor @code{GLU_BGRA}. | |
851 | ||
852 | @code{GLU_INVALID_OPERATION} is returned if @var{type} is | |
853 | @code{GLU_UNSIGNED_INT_8_8_8_8} or @code{GLU_UNSIGNED_INT_8_8_8_8_REV} | |
854 | and @var{format} is neither @code{GLU_RGBA} nor @code{GLU_BGRA}. | |
855 | ||
856 | @code{GLU_INVALID_OPERATION} is returned if @var{type} is | |
857 | @code{GLU_UNSIGNED_INT_10_10_10_2} or | |
858 | @code{GLU_UNSIGNED_INT_2_10_10_10_REV} and @var{format} is neither | |
859 | @code{GLU_RGBA} nor @code{GLU_BGRA}. | |
860 | ||
bb894c9d | 861 | @end deftypefun |
8925f36f | 862 | |
bb894c9d | 863 | @deftypefun GLint gluBuild3DMipmaps target internalFormat width height depth format type data |
3c9b6116 AW |
864 | Builds a three-dimensional mipmap. |
865 | ||
8925f36f AW |
866 | @table @asis |
867 | @item @var{target} | |
868 | Specifies the target texture. Must be @code{GLU_TEXTURE_3D}. | |
869 | ||
870 | @item @var{internalFormat} | |
871 | Requests the internal storage format of the texture image. The most | |
872 | current version of the SGI implementation of GLU does not check this | |
873 | value for validity before passing it on to the underlying OpenGL | |
874 | implementation. A value that is not accepted by the OpenGL | |
875 | implementation will lead to an OpenGL error. The benefit of not checking | |
876 | this value at the GLU level is that OpenGL extensions can add new | |
877 | internal texture formats without requiring a revision of the GLU | |
878 | implementation. Older implementations of GLU check this value and raise | |
879 | a GLU error if it is not 1, 2, 3, or 4 or one of the following symbolic | |
880 | constants: @code{GLU_ALPHA}, @code{GLU_ALPHA4}, @code{GLU_ALPHA8}, | |
881 | @code{GLU_ALPHA12}, @code{GLU_ALPHA16}, @code{GLU_LUMINANCE}, | |
882 | @code{GLU_LUMINANCE4}, @code{GLU_LUMINANCE8}, @code{GLU_LUMINANCE12}, | |
883 | @code{GLU_LUMINANCE16}, @code{GLU_LUMINANCE_ALPHA}, | |
884 | @code{GLU_LUMINANCE4_ALPHA4}, @code{GLU_LUMINANCE6_ALPHA2}, | |
885 | @code{GLU_LUMINANCE8_ALPHA8}, @code{GLU_LUMINANCE12_ALPHA4}, | |
886 | @code{GLU_LUMINANCE12_ALPHA12}, @code{GLU_LUMINANCE16_ALPHA16}, | |
887 | @code{GLU_INTENSITY}, @code{GLU_INTENSITY4}, @code{GLU_INTENSITY8}, | |
888 | @code{GLU_INTENSITY12}, @code{GLU_INTENSITY16}, @code{GLU_RGB}, | |
889 | @code{GLU_R3_G3_B2}, @code{GLU_RGB4}, @code{GLU_RGB5}, @code{GLU_RGB8}, | |
890 | @code{GLU_RGB10}, @code{GLU_RGB12}, @code{GLU_RGB16}, @code{GLU_RGBA}, | |
891 | @code{GLU_RGBA2}, @code{GLU_RGBA4}, @code{GLU_RGB5_A1}, | |
892 | @code{GLU_RGBA8}, @code{GLU_RGB10_A2}, @code{GLU_RGBA12}, or | |
893 | @code{GLU_RGBA16}. | |
894 | ||
895 | @item @var{width} | |
896 | @itemx @var{height} | |
897 | @itemx @var{depth} | |
898 | Specifies in pixels the width, height and depth respectively, in pixels | |
899 | of the texture image. | |
900 | ||
901 | @item @var{format} | |
902 | Specifies the format of the pixel data. Must be one of | |
903 | @code{GLU_COLOR_INDEX}, @code{GLU_DEPTH_COMPONENT}, @code{GLU_RED}, | |
904 | @code{GLU_GREEN}, @code{GLU_BLUE}, @code{GLU_ALPHA}, @code{GLU_RGB}, | |
905 | @code{GLU_RGBA}, @code{GLU_BGR}, @code{GLU_BGRA}, @code{GLU_LUMINANCE}, | |
906 | or @code{GLU_LUMINANCE_ALPHA}. | |
907 | ||
908 | @item @var{type} | |
909 | Specifies the data type for @var{data}. Must be one of: | |
910 | @code{GLU_UNSIGNED_BYTE}, @code{GLU_BYTE}, @code{GLU_BITMAP}, | |
911 | @code{GLU_UNSIGNED_SHORT}, @code{GLU_SHORT}, @code{GLU_UNSIGNED_INT}, | |
912 | @code{GLU_INT}, @code{GLU_FLOAT}, @code{GLU_UNSIGNED_BYTE_3_3_2}, | |
913 | @code{GLU_UNSIGNED_BYTE_2_3_3_REV}, @code{GLU_UNSIGNED_SHORT_5_6_5}, | |
914 | @code{GLU_UNSIGNED_SHORT_5_6_5_REV}, @code{GLU_UNSIGNED_SHORT_4_4_4_4}, | |
915 | @code{GLU_UNSIGNED_SHORT_4_4_4_4_REV}, | |
916 | @code{GLU_UNSIGNED_SHORT_5_5_5_1}, | |
917 | @code{GLU_UNSIGNED_SHORT_1_5_5_5_REV}, @code{GLU_UNSIGNED_INT_8_8_8_8}, | |
918 | @code{GLU_UNSIGNED_INT_8_8_8_8_REV}, @code{GLU_UNSIGNED_INT_10_10_10_2}, | |
919 | or @code{GLU_UNSIGNED_INT_2_10_10_10_REV}. | |
920 | ||
921 | @item @var{data} | |
922 | Specifies a pointer to the image data in memory. | |
923 | ||
924 | @end table | |
925 | ||
8925f36f AW |
926 | @code{gluBuild3DMipmaps} builds a series of prefiltered |
927 | three-dimensional texture maps of decreasing resolutions called a | |
928 | mipmap. This is used for the antialiasing of texture-mapped primitives. | |
929 | ||
930 | A return value of zero indicates success, otherwise a GLU error code is | |
931 | returned (see @code{gluErrorString}). | |
932 | ||
933 | Initially, the @var{width}, @var{height} and @var{depth} of @var{data} | |
934 | are checked to see if they are a power of 2. If not, a copy of | |
935 | @var{data} is made and scaled up or down to the nearest power of 2. (If | |
936 | @var{width}, @var{height}, or @var{depth} is exactly between powers of | |
937 | 2, then the copy of @var{data} will scale upwards.) This copy will be | |
938 | used for subsequent mipmapping operations described below. For example, | |
939 | if @var{width} is 57, @var{height} is 23, and @var{depth} is 24, then a | |
940 | copy of @var{data} will scale up to 64 in width, down to 16 in height, | |
941 | and up to 32 in depth before mipmapping takes place. | |
942 | ||
943 | Then, proxy textures (see @code{glTexImage3D}) are used to determine if | |
944 | the implementation can fit the requested texture. If not, all three | |
945 | dimensions are continually halved until it fits. | |
946 | ||
947 | Next, a series of mipmap levels is built by decimating a copy of | |
3c9b6116 | 948 | @var{data} in half along all three dimensions until size @r{1×1×1} is |
8925f36f AW |
949 | reached. At each level, each texel in the halved mipmap level is an |
950 | average of the corresponding eight texels in the larger mipmap level. | |
951 | (If exactly one of the dimensions is 1, four texels are averaged. If | |
952 | exactly two of the dimensions are 1, two texels are averaged.) | |
953 | ||
954 | @code{glTexImage3D} is called to load each of these mipmap levels. Level | |
955 | 0 is a copy of @var{data}. The highest level is | |
3c9b6116 AW |
956 | @r{@var{log}_2,(@var{max}(@var{width},@var{height}@var{depth}),)}. For |
957 | example, if @var{width} is 64, @var{height} is 16, and @var{depth} is | |
958 | 32, and the implementation can store a texture of this size, the | |
959 | following mipmap levels are built: @r{64×16×32}, @r{32×8×16}, | |
960 | @r{16×4×8}, @r{8×2×4}, @r{4×1×2}, @r{2×1×1}, and @r{1×1×1}. These | |
961 | correspond to levels 0 through 6, respectively. | |
8925f36f AW |
962 | |
963 | See the @code{glTexImage1D} reference page for a description of the | |
964 | acceptable values for @var{format} parameter. See the | |
965 | @code{glDrawPixels} reference page for a description of the acceptable | |
966 | values for @var{type} parameter. | |
967 | ||
8925f36f AW |
968 | @code{GLU_INVALID_VALUE} is returned if @var{width}, @var{height}, or |
969 | @var{depth} is < 1. | |
970 | ||
971 | @code{GLU_INVALID_ENUM} is returned if @var{internalFormat}, | |
972 | @var{format}, or @var{type} is not legal. | |
973 | ||
974 | @code{GLU_INVALID_OPERATION} is returned if @var{type} is | |
975 | @code{GLU_UNSIGNED_BYTE_3_3_2} or @code{GLU_UNSIGNED_BYTE_2_3_3_REV} and | |
976 | @var{format} is not @code{GLU_RGB}. | |
977 | ||
978 | @code{GLU_INVALID_OPERATION} is returned if @var{type} is | |
979 | @code{GLU_UNSIGNED_SHORT_5_6_5} or @code{GLU_UNSIGNED_SHORT_5_6_5_REV} | |
980 | and @var{format} is not @code{GLU_RGB}. | |
981 | ||
982 | @code{GLU_INVALID_OPERATION} is returned if @var{type} is | |
983 | @code{GLU_UNSIGNED_SHORT_4_4_4_4} or | |
984 | @code{GLU_UNSIGNED_SHORT_4_4_4_4_REV} and @var{format} is neither | |
985 | @code{GLU_RGBA} nor @code{GLU_BGRA}. | |
986 | ||
987 | @code{GLU_INVALID_OPERATION} is returned if @var{type} is | |
988 | @code{GLU_UNSIGNED_SHORT_5_5_5_1} or | |
989 | @code{GLU_UNSIGNED_SHORT_1_5_5_5_REV} and @var{format} is neither | |
990 | @code{GLU_RGBA} nor @code{GLU_BGRA}. | |
991 | ||
992 | @code{GLU_INVALID_OPERATION} is returned if @var{type} is | |
993 | @code{GLU_UNSIGNED_INT_8_8_8_8} or @code{GLU_UNSIGNED_INT_8_8_8_8_REV} | |
994 | and @var{format} is neither @code{GLU_RGBA} nor @code{GLU_BGRA}. | |
995 | ||
996 | @code{GLU_INVALID_OPERATION} is returned if @var{type} is | |
997 | @code{GLU_UNSIGNED_INT_10_10_10_2} or | |
998 | @code{GLU_UNSIGNED_INT_2_10_10_10_REV} and @var{format} is neither | |
999 | @code{GLU_RGBA} nor @code{GLU_BGRA}. | |
1000 | ||
bb894c9d | 1001 | @end deftypefun |
8925f36f | 1002 | |
bb894c9d | 1003 | @deftypefun GLboolean gluCheckExtension extName extString |
3c9b6116 AW |
1004 | Determines if an extension name is supported. |
1005 | ||
8925f36f AW |
1006 | @table @asis |
1007 | @item @var{extName} | |
1008 | Specifies an extension name. | |
1009 | ||
1010 | @item @var{extString} | |
1011 | Specifies a space-separated list of extension names supported. | |
1012 | ||
1013 | @end table | |
1014 | ||
8925f36f AW |
1015 | @code{gluCheckExtension} returns @code{GLU_TRUE} if @var{extName} is |
1016 | supported otherwise @code{GLU_FALSE} is returned. | |
1017 | ||
1018 | This is used to check for the presence for OpenGL, GLU, or GLX extension | |
1019 | names by passing the extension strings returned by @code{glGetString}, | |
1020 | @code{gluGetString}, @code{glXGetClientString}, | |
1021 | @code{glXQueryExtensionsString}, or @code{glXQueryServerString}, | |
1022 | respectively, as @var{extString}. | |
1023 | ||
bb894c9d | 1024 | @end deftypefun |
8925f36f | 1025 | |
bb894c9d | 1026 | @deftypefun void gluCylinder quad base top height slices stacks |
3c9b6116 AW |
1027 | Draw a cylinder. |
1028 | ||
8925f36f AW |
1029 | @table @asis |
1030 | @item @var{quad} | |
1031 | Specifies the quadrics object (created with @code{gluNewQuadric}). | |
1032 | ||
1033 | @item @var{base} | |
1034 | Specifies the radius of the cylinder at @var{z} = 0. | |
1035 | ||
1036 | @item @var{top} | |
1037 | Specifies the radius of the cylinder at @var{z} = @var{height}. | |
1038 | ||
1039 | @item @var{height} | |
1040 | Specifies the height of the cylinder. | |
1041 | ||
1042 | @item @var{slices} | |
1043 | Specifies the number of subdivisions around the @var{z} axis. | |
1044 | ||
1045 | @item @var{stacks} | |
1046 | Specifies the number of subdivisions along the @var{z} axis. | |
1047 | ||
1048 | @end table | |
1049 | ||
8925f36f AW |
1050 | @code{gluCylinder} draws a cylinder oriented along the @var{z} axis. The |
1051 | base of the cylinder is placed at @var{z} = 0 and the top at | |
3c9b6116 AW |
1052 | @r{@var{z}=@var{height}}. Like a sphere, a cylinder is subdivided around |
1053 | the @var{z} axis into slices and along the @var{z} axis into stacks. | |
8925f36f AW |
1054 | |
1055 | Note that if @var{top} is set to 0.0, this routine generates a cone. | |
1056 | ||
1057 | If the orientation is set to @code{GLU_OUTSIDE} (with | |
1058 | @code{gluQuadricOrientation}), then any generated normals point away | |
1059 | from the @var{z} axis. Otherwise, they point toward the @var{z} axis. | |
1060 | ||
1061 | If texturing is turned on (with @code{gluQuadricTexture}), then texture | |
1062 | coordinates are generated so that @var{t} ranges linearly from 0.0 at | |
1063 | @var{z} = 0 to 1.0 at @var{z} = @var{height}, and @var{s} ranges from | |
1064 | 0.0 at the +@var{y} axis, to 0.25 at the +@var{x} axis, to 0.5 at the | |
1065 | -@var{y} axis, to 0.75 at the \-@var{x} axis, and back to 1.0 at the | |
1066 | +@var{y} axis. | |
1067 | ||
bb894c9d | 1068 | @end deftypefun |
8925f36f | 1069 | |
bb894c9d | 1070 | @deftypefun void gluDeleteNurbsRenderer nurb |
3c9b6116 AW |
1071 | Destroy a NURBS object. |
1072 | ||
8925f36f AW |
1073 | @table @asis |
1074 | @item @var{nurb} | |
1075 | Specifies the NURBS object to be destroyed. | |
1076 | ||
1077 | @end table | |
1078 | ||
8925f36f AW |
1079 | @code{gluDeleteNurbsRenderer} destroys the NURBS object (which was |
1080 | created with @code{gluNewNurbsRenderer}) and frees any memory it uses. | |
1081 | Once @code{gluDeleteNurbsRenderer} has been called, @var{nurb} cannot be | |
1082 | used again. | |
1083 | ||
bb894c9d | 1084 | @end deftypefun |
8925f36f | 1085 | |
bb894c9d | 1086 | @deftypefun void gluDeleteQuadric quad |
3c9b6116 AW |
1087 | Destroy a quadrics object. |
1088 | ||
8925f36f AW |
1089 | @table @asis |
1090 | @item @var{quad} | |
1091 | Specifies the quadrics object to be destroyed. | |
1092 | ||
1093 | @end table | |
1094 | ||
8925f36f AW |
1095 | @code{gluDeleteQuadric} destroys the quadrics object (created with |
1096 | @code{gluNewQuadric}) and frees any memory it uses. Once | |
1097 | @code{gluDeleteQuadric} has been called, @var{quad} cannot be used | |
1098 | again. | |
1099 | ||
bb894c9d | 1100 | @end deftypefun |
8925f36f | 1101 | |
bb894c9d | 1102 | @deftypefun void gluDeleteTess tess |
3c9b6116 AW |
1103 | Destroy a tessellation object. |
1104 | ||
8925f36f AW |
1105 | @table @asis |
1106 | @item @var{tess} | |
1107 | Specifies the tessellation object to destroy. | |
1108 | ||
1109 | @end table | |
1110 | ||
8925f36f AW |
1111 | @code{gluDeleteTess} destroys the indicated tessellation object (which |
1112 | was created with @code{gluNewTess}) and frees any memory that it used. | |
1113 | ||
bb894c9d | 1114 | @end deftypefun |
8925f36f | 1115 | |
bb894c9d | 1116 | @deftypefun void gluDisk quad inner outer slices loops |
3c9b6116 AW |
1117 | Draw a disk. |
1118 | ||
8925f36f AW |
1119 | @table @asis |
1120 | @item @var{quad} | |
1121 | Specifies the quadrics object (created with @code{gluNewQuadric}). | |
1122 | ||
1123 | @item @var{inner} | |
1124 | Specifies the inner radius of the disk (may be 0). | |
1125 | ||
1126 | @item @var{outer} | |
1127 | Specifies the outer radius of the disk. | |
1128 | ||
1129 | @item @var{slices} | |
1130 | Specifies the number of subdivisions around the @var{z} axis. | |
1131 | ||
1132 | @item @var{loops} | |
1133 | Specifies the number of concentric rings about the origin into which the | |
1134 | disk is subdivided. | |
1135 | ||
1136 | @end table | |
1137 | ||
8925f36f AW |
1138 | @code{gluDisk} renders a disk on the @var{z} = 0 plane. The disk has a |
1139 | radius of @var{outer} and contains a concentric circular hole with a | |
1140 | radius of @var{inner}. If @var{inner} is 0, then no hole is generated. | |
1141 | The disk is subdivided around the @var{z} axis into slices (like pizza | |
1142 | slices) and also about the @var{z} axis into rings (as specified by | |
1143 | @var{slices} and @var{loops}, respectively). | |
1144 | ||
1145 | With respect to orientation, the +@var{z} side of the disk is considered | |
1146 | to be ``outside'' (see @code{gluQuadricOrientation}). This means that if | |
1147 | the orientation is set to @code{GLU_OUTSIDE}, then any normals generated | |
1148 | point along the +@var{z} axis. Otherwise, they point along the \-@var{z} | |
1149 | axis. | |
1150 | ||
1151 | If texturing has been turned on (with @code{gluQuadricTexture}), texture | |
1152 | coordinates are generated linearly such that where | |
3c9b6116 | 1153 | @r{@var{r}=@var{outer}}, the value at (@var{r}, 0, 0) is (1, 0.5), at |
8925f36f AW |
1154 | (0, @var{r}, 0) it is (0.5, 1), at (\-@var{r}, 0, 0) it is (0, 0.5), and |
1155 | at (0, \-@var{r}, 0) it is (0.5, 0). | |
1156 | ||
bb894c9d | 1157 | @end deftypefun |
8925f36f | 1158 | |
00239761 | 1159 | @deftypefun const-GLubyte-* gluErrorString error |
3c9b6116 AW |
1160 | Produce an error string from a GL or GLU error code. |
1161 | ||
8925f36f AW |
1162 | @table @asis |
1163 | @item @var{error} | |
1164 | Specifies a GL or GLU error code. | |
1165 | ||
1166 | @end table | |
1167 | ||
8925f36f AW |
1168 | @code{gluErrorString} produces an error string from a GL or GLU error |
1169 | code. The string is in ISO Latin 1 format. For example, | |
1170 | @code{gluErrorString}(@code{GLU_OUT_OF_MEMORY}) returns the string | |
1171 | @var{out of memory}. | |
1172 | ||
1173 | The standard GLU error codes are @code{GLU_INVALID_ENUM}, | |
1174 | @code{GLU_INVALID_VALUE}, and @code{GLU_OUT_OF_MEMORY}. Certain other | |
1175 | GLU functions can return specialized error codes through callbacks. See | |
1176 | the @code{glGetError} reference page for the list of GL error codes. | |
1177 | ||
8925f36f AW |
1178 | @code{NULL} is returned if @var{error} is not a valid GL or GLU error |
1179 | code. | |
1180 | ||
bb894c9d | 1181 | @end deftypefun |
8925f36f | 1182 | |
bb894c9d | 1183 | @deftypefun void gluGetNurbsProperty nurb property data |
3c9b6116 AW |
1184 | Get a NURBS property. |
1185 | ||
8925f36f AW |
1186 | @table @asis |
1187 | @item @var{nurb} | |
1188 | Specifies the NURBS object (created with @code{gluNewNurbsRenderer}). | |
1189 | ||
1190 | @item @var{property} | |
1191 | Specifies the property whose value is to be fetched. Valid values are | |
1192 | @code{GLU_CULLING}, @code{GLU_SAMPLING_TOLERANCE}, | |
1193 | @code{GLU_DISPLAY_MODE}, @code{GLU_AUTO_LOAD_MATRIX}, | |
1194 | @code{GLU_PARAMETRIC_TOLERANCE}, @code{GLU_SAMPLING_METHOD}, | |
1195 | @code{GLU_U_STEP}, @code{GLU_V_STEP}, and @code{GLU_NURBS_MODE}. | |
1196 | ||
1197 | @item @var{data} | |
1198 | Specifies a pointer to the location into which the value of the named | |
1199 | property is written. | |
1200 | ||
1201 | @end table | |
1202 | ||
8925f36f AW |
1203 | @code{gluGetNurbsProperty} retrieves properties stored in a NURBS |
1204 | object. These properties affect the way that NURBS curves and surfaces | |
1205 | are rendered. See the @code{gluNurbsProperty} reference page for | |
1206 | information about what the properties are and what they do. | |
1207 | ||
bb894c9d | 1208 | @end deftypefun |
8925f36f | 1209 | |
00239761 | 1210 | @deftypefun const-GLubyte-* gluGetString name |
3c9b6116 AW |
1211 | Return a string describing the GLU version or GLU extensions . |
1212 | ||
8925f36f AW |
1213 | @table @asis |
1214 | @item @var{name} | |
1215 | Specifies a symbolic constant, one of @code{GLU_VERSION}, or | |
1216 | @code{GLU_EXTENSIONS}. | |
1217 | ||
1218 | @end table | |
1219 | ||
8925f36f AW |
1220 | @code{gluGetString} returns a pointer to a static string describing the |
1221 | GLU version or the GLU extensions that are supported. | |
1222 | ||
1223 | The version number is one of the following forms: | |
1224 | ||
1225 | @var{major_number.minor_number}@var{major_number.minor_number.release_number}. | |
1226 | ||
1227 | The version string is of the following form: | |
1228 | ||
1229 | @var{version number<space>vendor-specific information} | |
1230 | ||
1231 | Vendor-specific information is optional. Its format and contents depend | |
1232 | on the implementation. | |
1233 | ||
1234 | The standard GLU contains a basic set of features and capabilities. If a | |
1235 | company or group of companies wish to support other features, these may | |
1236 | be included as extensions to the GLU. If @var{name} is | |
1237 | @code{GLU_EXTENSIONS}, then @code{gluGetString} returns a | |
1238 | space-separated list of names of supported GLU extensions. (Extension | |
1239 | names never contain spaces.) | |
1240 | ||
1241 | All strings are null-terminated. | |
1242 | ||
8925f36f AW |
1243 | NULL is returned if @var{name} is not @code{GLU_VERSION} or |
1244 | @code{GLU_EXTENSIONS}. | |
1245 | ||
1246 | ||
1247 | ||
bb894c9d | 1248 | @end deftypefun |
8925f36f | 1249 | |
bb894c9d | 1250 | @deftypefun void gluGetTessProperty tess which data |
3c9b6116 AW |
1251 | Get a tessellation object property. |
1252 | ||
8925f36f AW |
1253 | @table @asis |
1254 | @item @var{tess} | |
1255 | Specifies the tessellation object (created with @code{gluNewTess}). | |
1256 | ||
1257 | @item @var{which} | |
1258 | Specifies the property whose value is to be fetched. Valid values are | |
1259 | @code{GLU_TESS_WINDING_RULE}, @code{GLU_TESS_BOUNDARY_ONLY}, and | |
1260 | @code{GLU_TESS_TOLERANCE}. | |
1261 | ||
1262 | @item @var{data} | |
1263 | Specifies a pointer to the location into which the value of the named | |
1264 | property is written. | |
1265 | ||
1266 | @end table | |
1267 | ||
8925f36f AW |
1268 | @code{gluGetTessProperty} retrieves properties stored in a tessellation |
1269 | object. These properties affect the way that tessellation objects are | |
1270 | interpreted and rendered. See the @code{gluTessProperty} reference page | |
1271 | for information about the properties and what they do. | |
1272 | ||
bb894c9d | 1273 | @end deftypefun |
8925f36f | 1274 | |
bb894c9d | 1275 | @deftypefun void gluLoadSamplingMatrices nurb model perspective view |
3c9b6116 AW |
1276 | Load NURBS sampling and culling matrices. |
1277 | ||
8925f36f AW |
1278 | @table @asis |
1279 | @item @var{nurb} | |
1280 | Specifies the NURBS object (created with @code{gluNewNurbsRenderer}). | |
1281 | ||
1282 | @item @var{model} | |
1283 | Specifies a modelview matrix (as from a @code{glGetFloatv} call). | |
1284 | ||
1285 | @item @var{perspective} | |
1286 | Specifies a projection matrix (as from a @code{glGetFloatv} call). | |
1287 | ||
1288 | @item @var{view} | |
1289 | Specifies a viewport (as from a @code{glGetIntegerv} call). | |
1290 | ||
1291 | @end table | |
1292 | ||
8925f36f AW |
1293 | @code{gluLoadSamplingMatrices} uses @var{model}, @var{perspective}, and |
1294 | @var{view} to recompute the sampling and culling matrices stored in | |
1295 | @var{nurb}. The sampling matrix determines how finely a NURBS curve or | |
1296 | surface must be tessellated to satisfy the sampling tolerance (as | |
1297 | determined by the @code{GLU_SAMPLING_TOLERANCE} property). The culling | |
1298 | matrix is used in deciding if a NURBS curve or surface should be culled | |
1299 | before rendering (when the @code{GLU_CULLING} property is turned on). | |
1300 | ||
1301 | @code{gluLoadSamplingMatrices} is necessary only if the | |
1302 | @code{GLU_AUTO_LOAD_MATRIX} property is turned off (see | |
1303 | @code{gluNurbsProperty}). Although it can be convenient to leave the | |
1304 | @code{GLU_AUTO_LOAD_MATRIX} property turned on, there can be a | |
1305 | performance penalty for doing so. (A round trip to the GL server is | |
1306 | needed to fetch the current values of the modelview matrix, projection | |
1307 | matrix, and viewport.) | |
1308 | ||
bb894c9d | 1309 | @end deftypefun |
8925f36f | 1310 | |
bb894c9d | 1311 | @deftypefun void gluLookAt eyeX eyeY eyeZ centerX centerY centerZ upX upY upZ |
3c9b6116 AW |
1312 | Define a viewing transformation. |
1313 | ||
8925f36f AW |
1314 | @table @asis |
1315 | @item @var{eyeX} | |
1316 | @itemx @var{eyeY} | |
1317 | @itemx @var{eyeZ} | |
1318 | Specifies the position of the eye point. | |
1319 | ||
1320 | @item @var{centerX} | |
1321 | @itemx @var{centerY} | |
1322 | @itemx @var{centerZ} | |
1323 | Specifies the position of the reference point. | |
1324 | ||
1325 | @item @var{upX} | |
1326 | @itemx @var{upY} | |
1327 | @itemx @var{upZ} | |
1328 | Specifies the direction of the @var{up} vector. | |
1329 | ||
1330 | @end table | |
1331 | ||
8925f36f AW |
1332 | @code{gluLookAt} creates a viewing matrix derived from an eye point, a |
1333 | reference point indicating the center of the scene, and an @var{UP} | |
1334 | vector. | |
1335 | ||
1336 | The matrix maps the reference point to the negative @var{z} axis and the | |
1337 | eye point to the origin. When a typical projection matrix is used, the | |
1338 | center of the scene therefore maps to the center of the viewport. | |
1339 | Similarly, the direction described by the @var{UP} vector projected onto | |
1340 | the viewing plane is mapped to the positive @var{y} axis so that it | |
1341 | points upward in the viewport. The @var{UP} vector must not be parallel | |
1342 | to the line of sight from the eye point to the reference point. | |
1343 | ||
1344 | Let | |
1345 | ||
3c9b6116 | 1346 | @r{@var{F}=((@var{centerX}-@var{eyeX}), (@var{centerY}-@var{eyeY}), |
8925f36f AW |
1347 | (@var{centerZ}-@var{eyeZ}),)} |
1348 | ||
1349 | ||
1350 | ||
3c9b6116 | 1351 | Let @var{UP} be the vector @r{(@var{upX},@var{upY}@var{upZ})}. |
8925f36f | 1352 | |
3c9b6116 | 1353 | Then normalize as follows: @r{@var{f}=@var{F}/∥@var{F},∥,} |
8925f36f | 1354 | |
3c9b6116 | 1355 | @r{@var{UP}^″=@var{UP}/∥@var{UP},∥,} |
8925f36f AW |
1356 | |
1357 | ||
1358 | ||
3c9b6116 AW |
1359 | Finally, let @r{@var{s}=@var{f}×@var{UP}^″}, and |
1360 | @r{@var{u}=@var{s}×@var{f}}. | |
8925f36f AW |
1361 | |
1362 | ||
1363 | ||
3c9b6116 AW |
1364 | M is then constructed as follows: @r{@var{M}=((@var{s}[0,] @var{s}[1,] |
1365 | @var{s}[2,] 0), (@var{u}[0,] @var{u}[1,] @var{u}[2,] 0), | |
1366 | (-@var{f}[0,] -@var{f}[1,] -@var{f}[2,] 0), (0 0 0 1),)} | |
8925f36f AW |
1367 | |
1368 | and @code{gluLookAt} is equivalent to | |
1369 | ||
1370 | @example | |
1371 | ||
1372 | glMultMatrixf(M); | |
1373 | glTranslated(-eyex, -eyey, -eyez); | |
1374 | @end example | |
1375 | ||
bb894c9d | 1376 | @end deftypefun |
8925f36f | 1377 | |
00239761 | 1378 | @deftypefun GLUnurbs* gluNewNurbsRenderer |
3c9b6116 AW |
1379 | Create a NURBS object. |
1380 | ||
8925f36f AW |
1381 | @code{gluNewNurbsRenderer} creates and returns a pointer to a new NURBS |
1382 | object. This object must be referred to when calling NURBS rendering and | |
1383 | control functions. A return value of 0 means that there is not enough | |
1384 | memory to allocate the object. | |
1385 | ||
bb894c9d | 1386 | @end deftypefun |
8925f36f | 1387 | |
00239761 | 1388 | @deftypefun GLUquadric* gluNewQuadric |
3c9b6116 AW |
1389 | Create a quadrics object. |
1390 | ||
8925f36f AW |
1391 | @code{gluNewQuadric} creates and returns a pointer to a new quadrics |
1392 | object. This object must be referred to when calling quadrics rendering | |
1393 | and control functions. A return value of 0 means that there is not | |
1394 | enough memory to allocate the object. | |
1395 | ||
bb894c9d | 1396 | @end deftypefun |
8925f36f | 1397 | |
00239761 | 1398 | @deftypefun GLUtesselator* gluNewTess |
3c9b6116 AW |
1399 | Create a tessellation object. |
1400 | ||
8925f36f AW |
1401 | @code{gluNewTess} creates and returns a pointer to a new tessellation |
1402 | object. This object must be referred to when calling tessellation | |
1403 | functions. A return value of 0 means that there is not enough memory to | |
1404 | allocate the object. | |
1405 | ||
bb894c9d | 1406 | @end deftypefun |
8925f36f | 1407 | |
bb894c9d | 1408 | @deftypefun void gluNextContour tess type |
3c9b6116 AW |
1409 | Mark the beginning of another contour. |
1410 | ||
8925f36f AW |
1411 | @table @asis |
1412 | @item @var{tess} | |
1413 | Specifies the tessellation object (created with @code{gluNewTess}). | |
1414 | ||
1415 | @item @var{type} | |
1416 | Specifies the type of the contour being defined. Valid values are | |
1417 | @code{GLU_EXTERIOR}, @code{GLU_INTERIOR}, @code{GLU_UNKNOWN}, | |
1418 | @code{GLU_CCW}, and @code{GLU_CW}. | |
1419 | ||
1420 | @end table | |
1421 | ||
8925f36f AW |
1422 | @code{gluNextContour} is used in describing polygons with multiple |
1423 | contours. After the first contour has been described through a series of | |
1424 | @code{gluTessVertex} calls, a @code{gluNextContour} call indicates that | |
1425 | the previous contour is complete and that the next contour is about to | |
1426 | begin. Another series of @code{gluTessVertex} calls is then used to | |
1427 | describe the new contour. This process can be repeated until all | |
1428 | contours have been described. | |
1429 | ||
1430 | @var{type} defines what type of contour follows. The legal contour types | |
1431 | are as follows: | |
1432 | ||
1433 | @table @asis | |
1434 | @item @code{GLU_EXTERIOR} | |
1435 | An exterior contour defines an exterior boundary of the polygon. | |
1436 | ||
1437 | @item @code{GLU_INTERIOR} | |
1438 | An interior contour defines an interior boundary of the polygon (such as | |
1439 | a hole). | |
1440 | ||
1441 | @item @code{GLU_UNKNOWN} | |
1442 | An unknown contour is analyzed by the library to determine if it is | |
1443 | interior or exterior. | |
1444 | ||
1445 | @item @code{GLU_CCW}, | |
1446 | @item @code{GLU_CW} | |
1447 | The first @code{GLU_CCW} or @code{GLU_CW} contour defined is considered | |
1448 | to be exterior. All other contours are considered to be exterior if they | |
1449 | are oriented in the same direction (clockwise or counterclockwise) as | |
1450 | the first contour, and interior if they are not. | |
1451 | ||
1452 | @end table | |
1453 | ||
1454 | If one contour is of type @code{GLU_CCW} or @code{GLU_CW}, then all | |
1455 | contours must be of the same type (if they are not, then all | |
1456 | @code{GLU_CCW} and @code{GLU_CW} contours will be changed to | |
1457 | @code{GLU_UNKNOWN}). | |
1458 | ||
1459 | Note that there is no real difference between the @code{GLU_CCW} and | |
1460 | @code{GLU_CW} contour types. | |
1461 | ||
1462 | Before the first contour is described, @code{gluNextContour} can be | |
1463 | called to define the type of the first contour. If @code{gluNextContour} | |
1464 | is not called before the first contour, then the first contour is marked | |
1465 | @code{GLU_EXTERIOR}. | |
1466 | ||
1467 | This command is obsolete and is provided for backward compatibility | |
1468 | only. Calls to @code{gluNextContour} are mapped to | |
1469 | @code{gluTessEndContour} followed by @code{gluTessBeginContour}. | |
1470 | ||
bb894c9d | 1471 | @end deftypefun |
8925f36f | 1472 | |
bb894c9d | 1473 | @deftypefun void gluNurbsCallbackDataEXT nurb userData |
3c9b6116 AW |
1474 | Set a user data pointer. |
1475 | ||
8925f36f AW |
1476 | @table @asis |
1477 | @item @var{nurb} | |
1478 | Specifies the NURBS object (created with @code{gluNewNurbsRenderer}). | |
1479 | ||
1480 | @item @var{userData} | |
1481 | Specifies a pointer to the user's data. | |
1482 | ||
1483 | @end table | |
1484 | ||
8925f36f AW |
1485 | @code{gluNurbsCallbackDataEXT} is used to pass a pointer to the |
1486 | application's data to NURBS tessellator. A copy of this pointer will be | |
1487 | passed by the tessellator in the NURBS callback functions (set by | |
1488 | @code{gluNurbsCallback}). | |
1489 | ||
bb894c9d | 1490 | @end deftypefun |
8925f36f | 1491 | |
bb894c9d | 1492 | @deftypefun void gluNurbsCallbackData nurb userData |
3c9b6116 AW |
1493 | Set a user data pointer. |
1494 | ||
8925f36f AW |
1495 | @table @asis |
1496 | @item @var{nurb} | |
1497 | Specifies the NURBS object (created with @code{gluNewNurbsRenderer}). | |
1498 | ||
1499 | @item @var{userData} | |
1500 | Specifies a pointer to the user's data. | |
1501 | ||
1502 | @end table | |
1503 | ||
8925f36f AW |
1504 | @code{gluNurbsCallbackData} is used to pass a pointer to the |
1505 | application's data to NURBS tessellator. A copy of this pointer will be | |
1506 | passed by the tessellator in the NURBS callback functions (set by | |
1507 | @code{gluNurbsCallback}). | |
1508 | ||
bb894c9d | 1509 | @end deftypefun |
8925f36f | 1510 | |
bb894c9d | 1511 | @deftypefun void gluNurbsCallback nurb which CallBackFunc |
3c9b6116 AW |
1512 | Define a callback for a NURBS object. |
1513 | ||
8925f36f AW |
1514 | @table @asis |
1515 | @item @var{nurb} | |
1516 | Specifies the NURBS object (created with @code{gluNewNurbsRenderer}). | |
1517 | ||
1518 | @item @var{which} | |
1519 | Specifies the callback being defined. Valid values are | |
1520 | @code{GLU_NURBS_BEGIN}, @code{GLU_NURBS_VERTEX}, | |
1521 | @code{GLU_NURBS_NORMAL}, @code{GLU_NURBS_COLOR}, | |
1522 | @code{GLU_NURBS_TEXTURE_COORD}, @code{GLU_NURBS_END}, | |
1523 | @code{GLU_NURBS_BEGIN_DATA}, @code{GLU_NURBS_VERTEX_DATA}, | |
1524 | @code{GLU_NURBS_NORMAL_DATA}, @code{GLU_NURBS_COLOR_DATA}, | |
1525 | @code{GLU_NURBS_TEXTURE_COORD_DATA}, @code{GLU_NURBS_END_DATA}, and | |
1526 | @code{GLU_NURBS_ERROR}. | |
1527 | ||
1528 | @item @var{CallBackFunc} | |
1529 | Specifies the function that the callback calls. | |
1530 | ||
1531 | @end table | |
1532 | ||
8925f36f AW |
1533 | @code{gluNurbsCallback} is used to define a callback to be used by a |
1534 | NURBS object. If the specified callback is already defined, then it is | |
1535 | replaced. If @var{CallBackFunc} is NULL, then this callback will not get | |
1536 | invoked and the related data, if any, will be lost. | |
1537 | ||
1538 | Except the error callback, these callbacks are used by NURBS tessellator | |
1539 | (when @code{GLU_NURBS_MODE} is set to be @code{GLU_NURBS_TESSELLATOR}) | |
1540 | to return back the OpenGL polygon primitives resulting from the | |
1541 | tessellation. Note that there are two versions of each callback: one | |
1542 | with a user data pointer and one without. If both versions for a | |
1543 | particular callback are specified then the callback with the user data | |
1544 | pointer will be used. Note that ``userData'' is a copy of the pointer | |
1545 | that was specified at the last call to @code{gluNurbsCallbackData}. | |
1546 | ||
1547 | The error callback function is effective no matter which value that | |
1548 | @code{GLU_NURBS_MODE} is set to. All other callback functions are | |
1549 | effective only when @code{GLU_NURBS_MODE} is set to | |
1550 | @code{GLU_NURBS_TESSELLATOR}. | |
1551 | ||
1552 | The legal callbacks are as follows: | |
1553 | ||
1554 | @table @asis | |
1555 | @item @code{GLU_NURBS_BEGIN} | |
1556 | ||
1557 | ||
1558 | The begin callback indicates the start of a primitive. The function | |
1559 | takes a single argument of type GLenum, which can be one of | |
1560 | @code{GLU_LINES}, @code{GLU_LINE_STRIP}, @code{GLU_TRIANGLE_FAN}, | |
1561 | @code{GLU_TRIANGLE_STRIP}, @code{GLU_TRIANGLES}, or | |
1562 | @code{GLU_QUAD_STRIP}. The default begin callback function is NULL. The | |
1563 | function prototype for this callback looks like: | |
1564 | ||
1565 | @item @code{GLU_NURBS_BEGIN_DATA} | |
1566 | ||
1567 | ||
1568 | The same as the @code{GLU_NURBS_BEGIN} callback except that it takes an | |
1569 | additional pointer argument. This pointer is a copy of the pointer that | |
1570 | was specified at the last call to @code{gluNurbsCallbackData}. The | |
1571 | default callback function is NULL. The function prototype for this | |
1572 | callback function looks like: | |
1573 | ||
1574 | @item @code{GLU_NURBS_VERTEX} | |
1575 | ||
1576 | ||
1577 | The vertex callback indicates a vertex of the primitive. The coordinates | |
1578 | of the vertex are stored in the parameter ``vertex''. All the generated | |
1579 | vertices have dimension 3; that is, homogeneous coordinates have been | |
1580 | transformed into affine coordinates. The default vertex callback | |
1581 | function is NULL. The function prototype for this callback function | |
1582 | looks like: | |
1583 | ||
1584 | @item @code{GLU_NURBS_VERTEX_DATA} | |
1585 | ||
1586 | ||
1587 | This is the same as the @code{GLU_NURBS_VERTEX} callback, except that it | |
1588 | takes an additional pointer argument. This pointer is a copy of the | |
1589 | pointer that was specified at the last call to | |
1590 | @code{gluNurbsCallbackData}. The default callback function is NULL. The | |
1591 | function prototype for this callback function looks like: | |
1592 | ||
1593 | @item @code{GLU_NURBS_NORMAL} | |
1594 | ||
1595 | ||
1596 | The normal callback is invoked as the vertex normal is generated. The | |
1597 | components of the normal are stored in the parameter ``normal.'' In the | |
1598 | case of a NURBS curve, the callback function is effective only when the | |
1599 | user provides a normal map (@code{GLU_MAP1_NORMAL}). In the case of a | |
1600 | NURBS surface, if a normal map (@code{GLU_MAP2_NORMAL}) is provided, | |
1601 | then the generated normal is computed from the normal map. If a normal | |
1602 | map is not provided, then a surface normal is computed in a manner | |
1603 | similar to that described for evaluators when @code{GLU_AUTO_NORMAL} is | |
1604 | enabled. The default normal callback function is NULL. The function | |
1605 | prototype for this callback function looks like: | |
1606 | ||
1607 | @item @code{GLU_NURBS_NORMAL_DATA} | |
1608 | ||
1609 | ||
1610 | The same as the @code{GLU_NURBS_NORMAL} callback except that it takes an | |
1611 | additional pointer argument. This pointer is a copy of the pointer that | |
1612 | was specified at the last call to @code{gluNurbsCallbackData}. The | |
1613 | default callback function is NULL. The function prototype for this | |
1614 | callback function looks like: | |
1615 | ||
1616 | @item @code{GLU_NURBS_COLOR} | |
1617 | ||
1618 | ||
1619 | The color callback is invoked as the color of a vertex is generated. The | |
1620 | components of the color are stored in the parameter ``color.'' This | |
1621 | callback is effective only when the user provides a color map | |
1622 | (@code{GLU_MAP1_COLOR_4} or @code{GLU_MAP2_COLOR_4}). ``color'' contains | |
1623 | four components: R, G, B, A. The default color callback function is | |
1624 | NULL. The prototype for this callback function looks like: | |
1625 | ||
1626 | @item @code{GLU_NURBS_COLOR_DATA} | |
1627 | ||
1628 | ||
1629 | The same as the @code{GLU_NURBS_COLOR} callback except that it takes an | |
1630 | additional pointer argument. This pointer is a copy of the pointer that | |
1631 | was specified at the last call to @code{gluNurbsCallbackData}. The | |
1632 | default callback function is NULL. The function prototype for this | |
1633 | callback function looks like: | |
1634 | ||
1635 | @item @code{GLU_NURBS_TEXTURE_COORD} | |
1636 | ||
1637 | ||
1638 | The texture callback is invoked as the texture coordinates of a vertex | |
1639 | are generated. These coordinates are stored in the parameter | |
1640 | ``texCoord.'' The number of texture coordinates can be 1, 2, 3, or 4 | |
1641 | depending on which type of texture map is specified | |
1642 | (@code{GLU_MAP1_TEXTURE_COORD_1}, @code{GLU_MAP1_TEXTURE_COORD_2}, | |
1643 | @code{GLU_MAP1_TEXTURE_COORD_3}, @code{GLU_MAP1_TEXTURE_COORD_4}, | |
1644 | @code{GLU_MAP2_TEXTURE_COORD_1}, @code{GLU_MAP2_TEXTURE_COORD_2}, | |
1645 | @code{GLU_MAP2_TEXTURE_COORD_3}, @code{GLU_MAP2_TEXTURE_COORD_4}). If no | |
1646 | texture map is specified, this callback function will not be called. The | |
1647 | default texture callback function is NULL. The function prototype for | |
1648 | this callback function looks like: | |
1649 | ||
1650 | @item @code{GLU_NURBS_TEXTURE_COORD_DATA} | |
1651 | ||
1652 | ||
1653 | This is the same as the @code{GLU_NURBS_TEXTURE_COORD} callback, except | |
1654 | that it takes an additional pointer argument. This pointer is a copy of | |
1655 | the pointer that was specified at the last call to | |
1656 | @code{gluNurbsCallbackData}. The default callback function is NULL. The | |
1657 | function prototype for this callback function looks like: | |
1658 | ||
1659 | @item @code{GLU_NURBS_END} | |
1660 | ||
1661 | ||
1662 | The end callback is invoked at the end of a primitive. The default end | |
1663 | callback function is NULL. The function prototype for this callback | |
1664 | function looks like: | |
1665 | ||
1666 | @item @code{GLU_NURBS_END_DATA} | |
1667 | ||
1668 | ||
1669 | This is the same as the @code{GLU_NURBS_END} callback, except that it | |
1670 | takes an additional pointer argument. This pointer is a copy of the | |
1671 | pointer that was specified at the last call to | |
1672 | @code{gluNurbsCallbackData}. The default callback function is NULL. The | |
1673 | function prototype for this callback function looks like: | |
1674 | ||
1675 | @item @code{GLU_NURBS_ERROR} | |
1676 | ||
1677 | ||
1678 | The error function is called when an error is encountered. Its single | |
1679 | argument is of type GLenum, and it indicates the specific error that | |
1680 | occurred. There are 37 errors unique to NURBS, named | |
1681 | @code{GLU_NURBS_ERROR1} through @code{GLU_NURBS_ERROR37}. Character | |
1682 | strings describing these errors can be retrieved with | |
1683 | @code{gluErrorString}. | |
1684 | ||
1685 | @end table | |
1686 | ||
1687 | @example | |
1688 | ||
1689 | void begin( GLenum type ); | |
1690 | @end example | |
1691 | ||
1692 | @example | |
1693 | ||
1694 | void beginData(GLenum type, void *userData); | |
1695 | @end example | |
1696 | ||
1697 | @example | |
1698 | ||
1699 | void vertex( GLfloat *vertex ); | |
1700 | @end example | |
1701 | ||
1702 | @example | |
1703 | ||
1704 | void vertexData( GLfloat *vertex, void *userData ); | |
1705 | @end example | |
1706 | ||
1707 | @example | |
1708 | ||
1709 | void normal( GLfloat *normal ); | |
1710 | @end example | |
1711 | ||
1712 | @example | |
1713 | ||
1714 | void normalData( GLfloat *normal, void *userData ); | |
1715 | @end example | |
1716 | ||
1717 | @example | |
1718 | ||
1719 | void color( GLfloat *color ); | |
1720 | @end example | |
1721 | ||
1722 | @example | |
1723 | ||
1724 | void colorData( GLfloat *color, void *userData ); | |
1725 | @end example | |
1726 | ||
1727 | @example | |
1728 | ||
1729 | void texCoord( GLfloat *texCoord ); | |
1730 | @end example | |
1731 | ||
1732 | @example | |
1733 | ||
1734 | void texCoordData( GLfloat *texCoord, void *userData ); | |
1735 | @end example | |
1736 | ||
1737 | @example | |
1738 | ||
1739 | void end( void ); | |
1740 | @end example | |
1741 | ||
1742 | @example | |
1743 | ||
1744 | void endData( void *userData ); | |
1745 | @end example | |
1746 | ||
bb894c9d | 1747 | @end deftypefun |
8925f36f | 1748 | |
bb894c9d | 1749 | @deftypefun void gluNurbsCurve nurb knotCount knots stride control order type |
3c9b6116 AW |
1750 | Define the shape of a NURBS curve. |
1751 | ||
8925f36f AW |
1752 | @table @asis |
1753 | @item @var{nurb} | |
1754 | Specifies the NURBS object (created with @code{gluNewNurbsRenderer}). | |
1755 | ||
1756 | @item @var{knotCount} | |
1757 | Specifies the number of knots in @var{knots}. @var{knotCount} equals the | |
1758 | number of control points plus the order. | |
1759 | ||
1760 | @item @var{knots} | |
1761 | Specifies an array of @var{knotCount} nondecreasing knot values. | |
1762 | ||
1763 | @item @var{stride} | |
1764 | Specifies the offset (as a number of single-precision floating-point | |
1765 | values) between successive curve control points. | |
1766 | ||
1767 | @item @var{control} | |
1768 | Specifies a pointer to an array of control points. The coordinates must | |
1769 | agree with @var{type}, specified below. | |
1770 | ||
1771 | @item @var{order} | |
1772 | Specifies the order of the NURBS curve. @var{order} equals degree + 1, | |
1773 | hence a cubic curve has an order of 4. | |
1774 | ||
1775 | @item @var{type} | |
1776 | Specifies the type of the curve. If this curve is defined within a | |
1777 | @code{gluBeginCurve}/@code{gluEndCurve} pair, then the type can be any | |
1778 | of the valid one-dimensional evaluator types (such as | |
1779 | @code{GLU_MAP1_VERTEX_3} or @code{GLU_MAP1_COLOR_4}). Between a | |
1780 | @code{gluBeginTrim}/@code{gluEndTrim} pair, the only valid types are | |
1781 | @code{GLU_MAP1_TRIM_2} and @code{GLU_MAP1_TRIM_3}. | |
1782 | ||
1783 | @end table | |
1784 | ||
8925f36f AW |
1785 | Use @code{gluNurbsCurve} to describe a NURBS curve. |
1786 | ||
1787 | When @code{gluNurbsCurve} appears between a | |
1788 | @code{gluBeginCurve}/@code{gluEndCurve} pair, it is used to describe a | |
1789 | curve to be rendered. Positional, texture, and color coordinates are | |
1790 | associated by presenting each as a separate @code{gluNurbsCurve} between | |
1791 | a @code{gluBeginCurve}/@code{gluEndCurve} pair. No more than one call to | |
1792 | @code{gluNurbsCurve} for each of color, position, and texture data can | |
1793 | be made within a single @code{gluBeginCurve}/@code{gluEndCurve} pair. | |
1794 | Exactly one call must be made to describe the position of the curve (a | |
1795 | @var{type} of @code{GLU_MAP1_VERTEX_3} or @code{GLU_MAP1_VERTEX_4}). | |
1796 | ||
1797 | When @code{gluNurbsCurve} appears between a | |
1798 | @code{gluBeginTrim}/@code{gluEndTrim} pair, it is used to describe a | |
1799 | trimming curve on a NURBS surface. If @var{type} is | |
1800 | @code{GLU_MAP1_TRIM_2}, then it describes a curve in two-dimensional | |
1801 | (@var{u} and @var{v}) parameter space. If it is @code{GLU_MAP1_TRIM_3}, | |
1802 | then it describes a curve in two-dimensional homogeneous (@var{u}, | |
1803 | @var{v}, and @var{w}) parameter space. See the @code{gluBeginTrim} | |
1804 | reference page for more discussion about trimming curves. | |
1805 | ||
bb894c9d | 1806 | @end deftypefun |
8925f36f | 1807 | |
bb894c9d | 1808 | @deftypefun void gluNurbsProperty nurb property value |
3c9b6116 AW |
1809 | Set a NURBS property. |
1810 | ||
8925f36f AW |
1811 | @table @asis |
1812 | @item @var{nurb} | |
1813 | Specifies the NURBS object (created with @code{gluNewNurbsRenderer}). | |
1814 | ||
1815 | @item @var{property} | |
1816 | Specifies the property to be set. Valid values are | |
1817 | @code{GLU_SAMPLING_TOLERANCE}, @code{GLU_DISPLAY_MODE}, | |
1818 | @code{GLU_CULLING}, @code{GLU_AUTO_LOAD_MATRIX}, | |
1819 | @code{GLU_PARAMETRIC_TOLERANCE}, @code{GLU_SAMPLING_METHOD}, | |
1820 | @code{GLU_U_STEP}, @code{GLU_V_STEP}, or @code{GLU_NURBS_MODE}. | |
1821 | ||
1822 | @item @var{value} | |
1823 | Specifies the value of the indicated property. It may be a numeric value | |
1824 | or one of @code{GLU_OUTLINE_POLYGON}, @code{GLU_FILL}, | |
1825 | @code{GLU_OUTLINE_PATCH}, @code{GLU_TRUE}, @code{GLU_FALSE}, | |
1826 | @code{GLU_PATH_LENGTH}, @code{GLU_PARAMETRIC_ERROR}, | |
1827 | @code{GLU_DOMAIN_DISTANCE}, @code{GLU_NURBS_RENDERER}, or | |
1828 | @code{GLU_NURBS_TESSELLATOR}. | |
1829 | ||
1830 | @end table | |
1831 | ||
8925f36f AW |
1832 | @code{gluNurbsProperty} is used to control properties stored in a NURBS |
1833 | object. These properties affect the way that a NURBS curve is rendered. | |
1834 | The accepted values for @var{property} are as follows: | |
1835 | ||
1836 | @table @asis | |
1837 | @item @code{GLU_NURBS_MODE} | |
1838 | @var{value} should be set to be either @code{GLU_NURBS_RENDERER} or | |
1839 | @code{GLU_NURBS_TESSELLATOR}. When set to @code{GLU_NURBS_RENDERER}, | |
1840 | NURBS objects are tessellated into OpenGL primitives and sent to the | |
1841 | pipeline for rendering. When set to @code{GLU_NURBS_TESSELLATOR}, NURBS | |
1842 | objects are tessellated into OpenGL primitives but the vertices, | |
1843 | normals, colors, and/or textures are retrieved back through a callback | |
1844 | interface (see @code{gluNurbsCallback}). This allows the user to cache | |
1845 | the tessellated results for further processing. The initial value is | |
1846 | @code{GLU_NURBS_RENDERER}. | |
1847 | ||
1848 | @item @code{GLU_SAMPLING_METHOD} | |
1849 | Specifies how a NURBS surface should be tessellated. @var{value} may be | |
1850 | one of @code{GLU_PATH_LENGTH}, @code{GLU_PARAMETRIC_ERROR}, | |
1851 | @code{GLU_DOMAIN_DISTANCE}, @code{GLU_OBJECT_PATH_LENGTH}, or | |
1852 | @code{GLU_OBJECT_PARAMETRIC_ERROR}. When set to @code{GLU_PATH_LENGTH}, | |
1853 | the surface is rendered so that the maximum length, in pixels, of the | |
1854 | edges of the tessellation polygons is no greater than what is specified | |
1855 | by @code{GLU_SAMPLING_TOLERANCE}. | |
1856 | ||
1857 | @code{GLU_PARAMETRIC_ERROR} specifies that the surface is rendered in | |
1858 | such a way that the value specified by @code{GLU_PARAMETRIC_TOLERANCE} | |
1859 | describes the maximum distance, in pixels, between the tessellation | |
1860 | polygons and the surfaces they approximate. | |
1861 | ||
1862 | @code{GLU_DOMAIN_DISTANCE} allows users to specify, in parametric | |
1863 | coordinates, how many sample points per unit length are taken in | |
1864 | @var{u}, @var{v} direction. | |
1865 | ||
1866 | @code{GLU_OBJECT_PATH_LENGTH} is similar to @code{GLU_PATH_LENGTH} | |
1867 | except that it is view independent; that is, the surface is rendered so | |
1868 | that the maximum length, in object space, of edges of the tessellation | |
1869 | polygons is no greater than what is specified by | |
1870 | @code{GLU_SAMPLING_TOLERANCE}. | |
1871 | ||
1872 | @code{GLU_OBJECT_PARAMETRIC_ERROR} is similar to | |
1873 | @code{GLU_PARAMETRIC_ERROR} except that it is view independent; that is, | |
1874 | the surface is rendered in such a way that the value specified by | |
1875 | @code{GLU_PARAMETRIC_TOLERANCE} describes the maximum distance, in | |
1876 | object space, between the tessellation polygons and the surfaces they | |
1877 | approximate. | |
1878 | ||
1879 | The initial value of @code{GLU_SAMPLING_METHOD} is | |
1880 | @code{GLU_PATH_LENGTH}. | |
1881 | ||
1882 | @item @code{GLU_SAMPLING_TOLERANCE} | |
1883 | Specifies the maximum length, in pixels or in object space length unit, | |
1884 | to use when the sampling method is set to @code{GLU_PATH_LENGTH} or | |
1885 | @code{GLU_OBJECT_PATH_LENGTH}. The NURBS code is conservative when | |
1886 | rendering a curve or surface, so the actual length can be somewhat | |
1887 | shorter. The initial value is 50.0 pixels. | |
1888 | ||
1889 | @item @code{GLU_PARAMETRIC_TOLERANCE} | |
1890 | Specifies the maximum distance, in pixels or in object space length | |
1891 | unit, to use when the sampling method is @code{GLU_PARAMETRIC_ERROR} or | |
1892 | @code{GLU_OBJECT_PARAMETRIC_ERROR}. The initial value is 0.5. | |
1893 | ||
1894 | @item @code{GLU_U_STEP} | |
1895 | Specifies the number of sample points per unit length taken along the | |
1896 | @var{u} axis in parametric coordinates. It is needed when | |
1897 | @code{GLU_SAMPLING_METHOD} is set to @code{GLU_DOMAIN_DISTANCE}. The | |
1898 | initial value is 100. | |
1899 | ||
1900 | @item @code{GLU_V_STEP} | |
1901 | Specifies the number of sample points per unit length taken along the | |
1902 | @var{v} axis in parametric coordinate. It is needed when | |
1903 | @code{GLU_SAMPLING_METHOD} is set to @code{GLU_DOMAIN_DISTANCE}. The | |
1904 | initial value is 100. | |
1905 | ||
1906 | @item @code{GLU_DISPLAY_MODE} | |
1907 | @var{value} can be set to @code{GLU_OUTLINE_POLYGON}, @code{GLU_FILL}, | |
1908 | or @code{GLU_OUTLINE_PATCH}. When @code{GLU_NURBS_MODE} is set to be | |
1909 | @code{GLU_NURBS_RENDERER}, @var{value} defines how a NURBS surface | |
1910 | should be rendered. When @var{value} is set to @code{GLU_FILL}, the | |
1911 | surface is rendered as a set of polygons. When @var{value} is set to | |
1912 | @code{GLU_OUTLINE_POLYGON}, the NURBS library draws only the outlines of | |
1913 | the polygons created by tessellation. When @var{value} is set to | |
1914 | @code{GLU_OUTLINE_PATCH} just the outlines of patches and trim curves | |
1915 | defined by the user are drawn. | |
1916 | ||
1917 | When @code{GLU_NURBS_MODE} is set to be @code{GLU_NURBS_TESSELLATOR}, | |
1918 | @var{value} defines how a NURBS surface should be tessellated. When | |
1919 | @code{GLU_DISPLAY_MODE} is set to @code{GLU_FILL} or | |
1920 | @code{GLU_OUTLINE_POLYGON}, the NURBS surface is tessellated into OpenGL | |
1921 | triangle primitives that can be retrieved back through callback | |
1922 | functions. If @code{GLU_DISPLAY_MODE} is set to | |
1923 | @code{GLU_OUTLINE_PATCH}, only the outlines of the patches and trim | |
1924 | curves are generated as a sequence of line strips that can be retrieved | |
1925 | back through callback functions. | |
1926 | ||
1927 | The initial value is @code{GLU_FILL}. | |
1928 | ||
1929 | @item @code{GLU_CULLING} | |
1930 | @var{value} is a boolean value that, when set to @code{GLU_TRUE}, | |
1931 | indicates that a NURBS curve should be discarded prior to tessellation | |
1932 | if its control points lie outside the current viewport. The initial | |
1933 | value is @code{GLU_FALSE}. | |
1934 | ||
1935 | @item @code{GLU_AUTO_LOAD_MATRIX} | |
1936 | @var{value} is a boolean value. When set to @code{GLU_TRUE}, the NURBS | |
1937 | code downloads the projection matrix, the modelview matrix, and the | |
1938 | viewport from the GL server to compute sampling and culling matrices for | |
1939 | each NURBS curve that is rendered. Sampling and culling matrices are | |
1940 | required to determine the tessellation of a NURBS surface into line | |
1941 | segments or polygons and to cull a NURBS surface if it lies outside the | |
1942 | viewport. | |
1943 | ||
1944 | If this mode is set to @code{GLU_FALSE}, then the program needs to | |
1945 | provide a projection matrix, a modelview matrix, and a viewport for the | |
1946 | NURBS renderer to use to construct sampling and culling matrices. This | |
1947 | can be done with the @code{gluLoadSamplingMatrices} function. This mode | |
1948 | is initially set to @code{GLU_TRUE}. Changing it from @code{GLU_TRUE} to | |
1949 | @code{GLU_FALSE} does not affect the sampling and culling matrices until | |
1950 | @code{gluLoadSamplingMatrices} is called. | |
1951 | ||
1952 | @end table | |
1953 | ||
bb894c9d | 1954 | @end deftypefun |
8925f36f | 1955 | |
bb894c9d | 1956 | @deftypefun void gluNurbsSurface nurb sKnotCount sKnots tKnotCount tKnots sStride tStride control sOrder tOrder type |
3c9b6116 AW |
1957 | Define the shape of a NURBS surface. |
1958 | ||
8925f36f AW |
1959 | @table @asis |
1960 | @item @var{nurb} | |
1961 | Specifies the NURBS object (created with @code{gluNewNurbsRenderer}). | |
1962 | ||
1963 | @item @var{sKnotCount} | |
1964 | Specifies the number of knots in the parametric @var{u} direction. | |
1965 | ||
1966 | @item @var{sKnots} | |
1967 | Specifies an array of @var{sKnotCount} nondecreasing knot values in the | |
1968 | parametric @var{u} direction. | |
1969 | ||
1970 | @item @var{tKnotCount} | |
1971 | Specifies the number of knots in the parametric @var{v} direction. | |
1972 | ||
1973 | @item @var{tKnots} | |
1974 | Specifies an array of @var{tKnotCount} nondecreasing knot values in the | |
1975 | parametric @var{v} direction. | |
1976 | ||
1977 | @item @var{sStride} | |
1978 | Specifies the offset (as a number of single-precision floating-point | |
1979 | values) between successive control points in the parametric @var{u} | |
1980 | direction in @var{control}. | |
1981 | ||
1982 | @item @var{tStride} | |
1983 | Specifies the offset (in single-precision floating-point values) between | |
1984 | successive control points in the parametric @var{v} direction in | |
1985 | @var{control}. | |
1986 | ||
1987 | @item @var{control} | |
1988 | Specifies an array containing control points for the NURBS surface. The | |
1989 | offsets between successive control points in the parametric @var{u} and | |
1990 | @var{v} directions are given by @var{sStride} and @var{tStride}. | |
1991 | ||
1992 | @item @var{sOrder} | |
1993 | Specifies the order of the NURBS surface in the parametric @var{u} | |
1994 | direction. The order is one more than the degree, hence a surface that | |
1995 | is cubic in @var{u} has a @var{u} order of 4. | |
1996 | ||
1997 | @item @var{tOrder} | |
1998 | Specifies the order of the NURBS surface in the parametric @var{v} | |
1999 | direction. The order is one more than the degree, hence a surface that | |
2000 | is cubic in @var{v} has a @var{v} order of 4. | |
2001 | ||
2002 | @item @var{type} | |
2003 | Specifies type of the surface. @var{type} can be any of the valid | |
2004 | two-dimensional evaluator types (such as @code{GLU_MAP2_VERTEX_3} or | |
2005 | @code{GLU_MAP2_COLOR_4}). | |
2006 | ||
2007 | @end table | |
2008 | ||
8925f36f AW |
2009 | Use @code{gluNurbsSurface} within a NURBS (Non-Uniform Rational |
2010 | B-Spline) surface definition to describe the shape of a NURBS surface | |
2011 | (before any trimming). To mark the beginning of a NURBS surface | |
2012 | definition, use the @code{gluBeginSurface} command. To mark the end of a | |
2013 | NURBS surface definition, use the @code{gluEndSurface} command. Call | |
2014 | @code{gluNurbsSurface} within a NURBS surface definition only. | |
2015 | ||
2016 | Positional, texture, and color coordinates are associated with a surface | |
2017 | by presenting each as a separate @code{gluNurbsSurface} between a | |
2018 | @code{gluBeginSurface}/@code{gluEndSurface} pair. No more than one call | |
2019 | to @code{gluNurbsSurface} for each of color, position, and texture data | |
2020 | can be made within a single @code{gluBeginSurface}/@code{gluEndSurface} | |
2021 | pair. Exactly one call must be made to describe the position of the | |
2022 | surface (a @var{type} of @code{GLU_MAP2_VERTEX_3} or | |
2023 | @code{GLU_MAP2_VERTEX_4}). | |
2024 | ||
2025 | A NURBS surface can be trimmed by using the commands | |
2026 | @code{gluNurbsCurve} and @code{gluPwlCurve} between calls to | |
2027 | @code{gluBeginTrim} and @code{gluEndTrim}. | |
2028 | ||
2029 | Note that a @code{gluNurbsSurface} with @var{sKnotCount} knots in the | |
2030 | @var{u} direction and @var{tKnotCount} knots in the @var{v} direction | |
2031 | with orders @var{sOrder} and @var{tOrder} must have (@var{sKnotCount} - | |
3c9b6116 AW |
2032 | @var{sOrder}) @r{@var{times}} (@var{tKnotCount} - @var{tOrder}) control |
2033 | points. | |
8925f36f | 2034 | |
bb894c9d | 2035 | @end deftypefun |
8925f36f | 2036 | |
bb894c9d | 2037 | @deftypefun void gluOrtho2D left right bottom top |
3c9b6116 AW |
2038 | Define a 2D orthographic projection matrix. |
2039 | ||
8925f36f AW |
2040 | @table @asis |
2041 | @item @var{left} | |
2042 | @itemx @var{right} | |
2043 | Specify the coordinates for the left and right vertical clipping planes. | |
2044 | ||
2045 | @item @var{bottom} | |
2046 | @itemx @var{top} | |
2047 | Specify the coordinates for the bottom and top horizontal clipping | |
2048 | planes. | |
2049 | ||
2050 | @end table | |
2051 | ||
8925f36f | 2052 | @code{gluOrtho2D} sets up a two-dimensional orthographic viewing region. |
3c9b6116 AW |
2053 | This is equivalent to calling @code{glOrtho} with @r{@var{near}=-1} and |
2054 | @r{@var{far}=1}. | |
8925f36f | 2055 | |
bb894c9d | 2056 | @end deftypefun |
8925f36f | 2057 | |
bb894c9d | 2058 | @deftypefun void gluPartialDisk quad inner outer slices loops start sweep |
3c9b6116 AW |
2059 | Draw an arc of a disk. |
2060 | ||
8925f36f AW |
2061 | @table @asis |
2062 | @item @var{quad} | |
2063 | Specifies a quadrics object (created with @code{gluNewQuadric}). | |
2064 | ||
2065 | @item @var{inner} | |
2066 | Specifies the inner radius of the partial disk (can be 0). | |
2067 | ||
2068 | @item @var{outer} | |
2069 | Specifies the outer radius of the partial disk. | |
2070 | ||
2071 | @item @var{slices} | |
2072 | Specifies the number of subdivisions around the @var{z} axis. | |
2073 | ||
2074 | @item @var{loops} | |
2075 | Specifies the number of concentric rings about the origin into which the | |
2076 | partial disk is subdivided. | |
2077 | ||
2078 | @item @var{start} | |
2079 | Specifies the starting angle, in degrees, of the disk portion. | |
2080 | ||
2081 | @item @var{sweep} | |
2082 | Specifies the sweep angle, in degrees, of the disk portion. | |
2083 | ||
2084 | @end table | |
2085 | ||
3c9b6116 AW |
2086 | @code{gluPartialDisk} renders a partial disk on the @r{@var{z}=0} plane. |
2087 | A partial disk is similar to a full disk, except that only the subset of | |
2088 | the disk from @var{start} through @var{start} + @var{sweep} is included | |
2089 | (where 0 degrees is along the +\f2y\f axis, 90 degrees along the | |
2090 | +@var{x} axis, 180 degrees along the \-@var{y} axis, and 270 degrees | |
8925f36f AW |
2091 | along the \-@var{x} axis). |
2092 | ||
2093 | The partial disk has a radius of @var{outer} and contains a concentric | |
2094 | circular hole with a radius of @var{inner}. If @var{inner} is 0, then no | |
2095 | hole is generated. The partial disk is subdivided around the @var{z} | |
2096 | axis into slices (like pizza slices) and also about the @var{z} axis | |
2097 | into rings (as specified by @var{slices} and @var{loops}, respectively). | |
2098 | ||
2099 | With respect to orientation, the +@var{z} side of the partial disk is | |
2100 | considered to be outside (see @code{gluQuadricOrientation}). This means | |
2101 | that if the orientation is set to @code{GLU_OUTSIDE}, then any normals | |
2102 | generated point along the +@var{z} axis. Otherwise, they point along the | |
2103 | \-@var{z} axis. | |
2104 | ||
2105 | If texturing is turned on (with @code{gluQuadricTexture}), texture | |
2106 | coordinates are generated linearly such that where | |
3c9b6116 AW |
2107 | @r{@var{r}=@var{outer}}, the value at (@var{r}, 0, 0) is (1.0, 0.5), at |
2108 | (0, @var{r}, 0) it is (0.5, 1.0), at (\-@var{r}, 0, 0) it is (0.0, 0.5), | |
2109 | and at (0, \-@var{r}, 0) it is (0.5, 0.0). | |
8925f36f | 2110 | |
bb894c9d | 2111 | @end deftypefun |
8925f36f | 2112 | |
bb894c9d | 2113 | @deftypefun void gluPerspective fovy aspect zNear zFar |
3c9b6116 AW |
2114 | Set up a perspective projection matrix. |
2115 | ||
8925f36f AW |
2116 | @table @asis |
2117 | @item @var{fovy} | |
2118 | Specifies the field of view angle, in degrees, in the @var{y} direction. | |
2119 | ||
2120 | @item @var{aspect} | |
2121 | Specifies the aspect ratio that determines the field of view in the | |
2122 | @var{x} direction. The aspect ratio is the ratio of @var{x} (width) to | |
2123 | @var{y} (height). | |
2124 | ||
2125 | @item @var{zNear} | |
2126 | Specifies the distance from the viewer to the near clipping plane | |
2127 | (always positive). | |
2128 | ||
2129 | @item @var{zFar} | |
2130 | Specifies the distance from the viewer to the far clipping plane (always | |
2131 | positive). | |
2132 | ||
2133 | @end table | |
2134 | ||
8925f36f AW |
2135 | @code{gluPerspective} specifies a viewing frustum into the world |
2136 | coordinate system. In general, the aspect ratio in @code{gluPerspective} | |
2137 | should match the aspect ratio of the associated viewport. For example, | |
3c9b6116 AW |
2138 | @r{@var{aspect}=2.0} means the viewer's angle of view is twice as wide |
2139 | in @var{x} as it is in @var{y}. If the viewport is twice as wide as it | |
2140 | is tall, it displays the image without distortion. | |
8925f36f AW |
2141 | |
2142 | The matrix generated by @code{gluPerspective} is multipled by the | |
2143 | current matrix, just as if @code{glMultMatrix} were called with the | |
2144 | generated matrix. To load the perspective matrix onto the current matrix | |
2145 | stack instead, precede the call to @code{gluPerspective} with a call to | |
2146 | @code{glLoadIdentity}. | |
2147 | ||
2148 | Given @var{f} defined as follows: | |
2149 | ||
3c9b6116 | 2150 | @r{@var{f}=@var{cotangent}(@var{fovy}/2,)} The generated matrix is |
8925f36f | 2151 | |
3c9b6116 | 2152 | @r{((@var{f}/@var{aspect} 0 0 0), (0 @var{f} 0 0), (0 0 |
8925f36f AW |
2153 | @var{zFar}+@var{zNear},/@var{zNear}-@var{zFar}, |
2154 | 2×@var{zFar}×@var{zNear},/@var{zNear}-@var{zFar},), (0 0 -1 0),)} | |
2155 | ||
bb894c9d | 2156 | @end deftypefun |
8925f36f | 2157 | |
bb894c9d | 2158 | @deftypefun void gluPickMatrix x y delX delY viewport |
3c9b6116 AW |
2159 | Define a picking region. |
2160 | ||
8925f36f AW |
2161 | @table @asis |
2162 | @item @var{x} | |
2163 | @itemx @var{y} | |
2164 | Specify the center of a picking region in window coordinates. | |
2165 | ||
2166 | @item @var{delX} | |
2167 | @itemx @var{delY} | |
2168 | Specify the width and height, respectively, of the picking region in | |
2169 | window coordinates. | |
2170 | ||
2171 | @item @var{viewport} | |
2172 | Specifies the current viewport (as from a @code{glGetIntegerv} call). | |
2173 | ||
2174 | @end table | |
2175 | ||
8925f36f AW |
2176 | @code{gluPickMatrix} creates a projection matrix that can be used to |
2177 | restrict drawing to a small region of the viewport. This is typically | |
2178 | useful to determine what objects are being drawn near the cursor. Use | |
2179 | @code{gluPickMatrix} to restrict drawing to a small region around the | |
2180 | cursor. Then, enter selection mode (with @code{glRenderMode}) and | |
2181 | rerender the scene. All primitives that would have been drawn near the | |
2182 | cursor are identified and stored in the selection buffer. | |
2183 | ||
2184 | The matrix created by @code{gluPickMatrix} is multiplied by the current | |
2185 | matrix just as if @code{glMultMatrix} is called with the generated | |
2186 | matrix. To effectively use the generated pick matrix for picking, first | |
2187 | call @code{glLoadIdentity} to load an identity matrix onto the | |
2188 | perspective matrix stack. Then call @code{gluPickMatrix}, and, finally, | |
2189 | call a command (such as @code{gluPerspective}) to multiply the | |
2190 | perspective matrix by the pick matrix. | |
2191 | ||
2192 | When using @code{gluPickMatrix} to pick NURBS, be careful to turn off | |
2193 | the NURBS property @code{GLU_AUTO_LOAD_MATRIX}. If | |
2194 | @code{GLU_AUTO_LOAD_MATRIX} is not turned off, then any NURBS surface | |
2195 | rendered is subdivided differently with the pick matrix than the way it | |
2196 | was subdivided without the pick matrix. | |
2197 | ||
bb894c9d | 2198 | @end deftypefun |
8925f36f | 2199 | |
bb894c9d | 2200 | @deftypefun GLint gluProject objX objY objZ model proj view winX winY winZ |
3c9b6116 AW |
2201 | Map object coordinates to window coordinates. |
2202 | ||
8925f36f AW |
2203 | @table @asis |
2204 | @item @var{objX} | |
2205 | @itemx @var{objY} | |
2206 | @itemx @var{objZ} | |
2207 | Specify the object coordinates. | |
2208 | ||
2209 | @item @var{model} | |
2210 | Specifies the current modelview matrix (as from a @code{glGetDoublev} | |
2211 | call). | |
2212 | ||
2213 | @item @var{proj} | |
2214 | Specifies the current projection matrix (as from a @code{glGetDoublev} | |
2215 | call). | |
2216 | ||
2217 | @item @var{view} | |
2218 | Specifies the current viewport (as from a @code{glGetIntegerv} call). | |
2219 | ||
2220 | @item @var{winX} | |
2221 | @itemx @var{winY} | |
2222 | @itemx @var{winZ} | |
2223 | Return the computed window coordinates. | |
2224 | ||
2225 | @end table | |
2226 | ||
8925f36f AW |
2227 | @code{gluProject} transforms the specified object coordinates into |
2228 | window coordinates using @var{model}, @var{proj}, and @var{view}. The | |
2229 | result is stored in @var{winX}, @var{winY}, and @var{winZ}. A return | |
2230 | value of @code{GLU_TRUE} indicates success, a return value of | |
2231 | @code{GLU_FALSE} indicates failure. | |
2232 | ||
2233 | To compute the coordinates, let | |
3c9b6116 AW |
2234 | @r{@var{v}=(@var{objX},@var{objY}@var{objZ}1.0)} represented as a matrix |
2235 | with 4 rows and 1 column. Then @code{gluProject} computes @r{@var{v}^″} | |
2236 | as follows: | |
8925f36f | 2237 | |
3c9b6116 | 2238 | @r{@var{v}^″=@var{P}×@var{M}×@var{v}} |
8925f36f | 2239 | |
3c9b6116 AW |
2240 | where @r{@var{P}} is the current projection matrix @var{proj} and |
2241 | @r{@var{M}} is the current modelview matrix @var{model} (both | |
2242 | represented as @r{4×4} matrices in column-major order). | |
8925f36f AW |
2243 | |
2244 | The window coordinates are then computed as follows: | |
2245 | ||
3c9b6116 AW |
2246 | @r{@var{winX}=@var{view}(0,)+@var{view}(2,)×(@var{v}^″(0,)+1,)/2}@r{@var{winY}=@var{view}(1,)+@var{view}(3,)×(@var{v}^″(1,)+1,)/2} |
2247 | @r{@var{winZ}=(@var{v}^″(2,)+1,)/2} | |
8925f36f AW |
2248 | |
2249 | ||
2250 | ||
bb894c9d | 2251 | @end deftypefun |
8925f36f | 2252 | |
bb894c9d | 2253 | @deftypefun void gluPwlCurve nurb count data stride type |
3c9b6116 AW |
2254 | Describe a piecewise linear NURBS trimming curve. |
2255 | ||
8925f36f AW |
2256 | @table @asis |
2257 | @item @var{nurb} | |
2258 | Specifies the NURBS object (created with @code{gluNewNurbsRenderer}). | |
2259 | ||
2260 | @item @var{count} | |
2261 | Specifies the number of points on the curve. | |
2262 | ||
2263 | @item @var{data} | |
2264 | Specifies an array containing the curve points. | |
2265 | ||
2266 | @item @var{stride} | |
2267 | Specifies the offset (a number of single-precision floating-point | |
2268 | values) between points on the curve. | |
2269 | ||
2270 | @item @var{type} | |
2271 | Specifies the type of curve. Must be either @code{GLU_MAP1_TRIM_2} or | |
2272 | @code{GLU_MAP1_TRIM_3}. | |
2273 | ||
2274 | @end table | |
2275 | ||
8925f36f AW |
2276 | @code{gluPwlCurve} describes a piecewise linear trimming curve for a |
2277 | NURBS surface. A piecewise linear curve consists of a list of | |
2278 | coordinates of points in the parameter space for the NURBS surface to be | |
2279 | trimmed. These points are connected with line segments to form a curve. | |
2280 | If the curve is an approximation to a curve that is not piecewise | |
2281 | linear, the points should be close enough in parameter space that the | |
2282 | resulting path appears curved at the resolution used in the application. | |
2283 | ||
2284 | If @var{type} is @code{GLU_MAP1_TRIM_2}, then it describes a curve in | |
2285 | two-dimensional (@var{u} and @var{v}) parameter space. If it is | |
2286 | @code{GLU_MAP1_TRIM_3}, then it describes a curve in two-dimensional | |
2287 | homogeneous (@var{u}, @var{v}, and @var{w}) parameter space. See the | |
2288 | @code{gluBeginTrim} reference page for more information about trimming | |
2289 | curves. | |
2290 | ||
bb894c9d | 2291 | @end deftypefun |
8925f36f | 2292 | |
bb894c9d | 2293 | @deftypefun void gluQuadricCallback quad which CallBackFunc |
3c9b6116 AW |
2294 | Define a callback for a quadrics object. |
2295 | ||
8925f36f AW |
2296 | @table @asis |
2297 | @item @var{quad} | |
2298 | Specifies the quadrics object (created with @code{gluNewQuadric}). | |
2299 | ||
2300 | @item @var{which} | |
2301 | Specifies the callback being defined. The only valid value is | |
2302 | @code{GLU_ERROR}. | |
2303 | ||
2304 | @item @var{CallBackFunc} | |
2305 | Specifies the function to be called. | |
2306 | ||
2307 | @end table | |
2308 | ||
8925f36f AW |
2309 | @code{gluQuadricCallback} is used to define a new callback to be used by |
2310 | a quadrics object. If the specified callback is already defined, then it | |
2311 | is replaced. If @var{CallBackFunc} is NULL, then any existing callback | |
2312 | is erased. | |
2313 | ||
2314 | The one legal callback is @code{GLU_ERROR}: | |
2315 | ||
2316 | @table @asis | |
2317 | @item @code{GLU_ERROR} | |
2318 | The function is called when an error is encountered. Its single argument | |
2319 | is of type GLenum, and it indicates the specific error that occurred. | |
2320 | Character strings describing these errors can be retrieved with the | |
2321 | @code{gluErrorString} call. | |
2322 | ||
2323 | @end table | |
2324 | ||
bb894c9d | 2325 | @end deftypefun |
8925f36f | 2326 | |
bb894c9d | 2327 | @deftypefun void gluQuadricDrawStyle quad draw |
3c9b6116 AW |
2328 | Specify the draw style desired for quadrics. |
2329 | ||
8925f36f AW |
2330 | @table @asis |
2331 | @item @var{quad} | |
2332 | Specifies the quadrics object (created with @code{gluNewQuadric}). | |
2333 | ||
2334 | @item @var{draw} | |
2335 | Specifies the desired draw style. Valid values are @code{GLU_FILL}, | |
2336 | @code{GLU_LINE}, @code{GLU_SILHOUETTE}, and @code{GLU_POINT}. | |
2337 | ||
2338 | @end table | |
2339 | ||
8925f36f AW |
2340 | @code{gluQuadricDrawStyle} specifies the draw style for quadrics |
2341 | rendered with @var{quad}. The legal values are as follows: | |
2342 | ||
2343 | @table @asis | |
2344 | @item @code{GLU_FILL} | |
2345 | Quadrics are rendered with polygon primitives. The polygons are drawn in | |
2346 | a counterclockwise fashion with respect to their normals (as defined | |
2347 | with @code{gluQuadricOrientation}). | |
2348 | ||
2349 | @item @code{GLU_LINE} | |
2350 | Quadrics are rendered as a set of lines. | |
2351 | ||
2352 | @item @code{GLU_SILHOUETTE} | |
2353 | Quadrics are rendered as a set of lines, except that edges separating | |
2354 | coplanar faces will not be drawn. | |
2355 | ||
2356 | @item @code{GLU_POINT} | |
2357 | Quadrics are rendered as a set of points. | |
2358 | ||
2359 | @end table | |
2360 | ||
bb894c9d | 2361 | @end deftypefun |
8925f36f | 2362 | |
bb894c9d | 2363 | @deftypefun void gluQuadricNormals quad normal |
3c9b6116 AW |
2364 | Specify what kind of normals are desired for quadrics. |
2365 | ||
8925f36f AW |
2366 | @table @asis |
2367 | @item @var{quad} | |
2368 | Specifies the quadrics object (created with @code{gluNewQuadric}). | |
2369 | ||
2370 | @item @var{normal} | |
2371 | Specifies the desired type of normals. Valid values are @code{GLU_NONE}, | |
2372 | @code{GLU_FLAT}, and @code{GLU_SMOOTH}. | |
2373 | ||
2374 | @end table | |
2375 | ||
8925f36f AW |
2376 | @code{gluQuadricNormals} specifies what kind of normals are desired for |
2377 | quadrics rendered with @var{quad}. The legal values are as follows: | |
2378 | ||
2379 | @table @asis | |
2380 | @item @code{GLU_NONE} | |
2381 | No normals are generated. | |
2382 | ||
2383 | @item @code{GLU_FLAT} | |
2384 | One normal is generated for every facet of a quadric. | |
2385 | ||
2386 | @item @code{GLU_SMOOTH} | |
2387 | One normal is generated for every vertex of a quadric. This is the | |
2388 | initial value. | |
2389 | ||
2390 | @end table | |
2391 | ||
bb894c9d | 2392 | @end deftypefun |
8925f36f | 2393 | |
bb894c9d | 2394 | @deftypefun void gluQuadricOrientation quad orientation |
3c9b6116 AW |
2395 | Specify inside/outside orientation for quadrics. |
2396 | ||
8925f36f AW |
2397 | @table @asis |
2398 | @item @var{quad} | |
2399 | Specifies the quadrics object (created with @code{gluNewQuadric}). | |
2400 | ||
2401 | @item @var{orientation} | |
2402 | Specifies the desired orientation. Valid values are @code{GLU_OUTSIDE} | |
2403 | and @code{GLU_INSIDE}. | |
2404 | ||
2405 | @end table | |
2406 | ||
8925f36f AW |
2407 | @code{gluQuadricOrientation} specifies what kind of orientation is |
2408 | desired for quadrics rendered with @var{quad}. The @var{orientation} | |
2409 | values are as follows: | |
2410 | ||
2411 | @table @asis | |
2412 | @item @code{GLU_OUTSIDE} | |
2413 | Quadrics are drawn with normals pointing outward (the initial value). | |
2414 | ||
2415 | @item @code{GLU_INSIDE} | |
2416 | Quadrics are drawn with normals pointing inward. | |
2417 | ||
2418 | @end table | |
2419 | ||
2420 | Note that the interpretation of @var{outward} and @var{inward} depends | |
2421 | on the quadric being drawn. | |
2422 | ||
bb894c9d | 2423 | @end deftypefun |
8925f36f | 2424 | |
bb894c9d | 2425 | @deftypefun void gluQuadricTexture quad texture |
3c9b6116 AW |
2426 | Specify if texturing is desired for quadrics. |
2427 | ||
8925f36f AW |
2428 | @table @asis |
2429 | @item @var{quad} | |
2430 | Specifies the quadrics object (created with @code{gluNewQuadric}). | |
2431 | ||
2432 | @item @var{texture} | |
2433 | Specifies a flag indicating if texture coordinates should be generated. | |
2434 | ||
2435 | @end table | |
2436 | ||
8925f36f AW |
2437 | @code{gluQuadricTexture} specifies if texture coordinates should be |
2438 | generated for quadrics rendered with @var{quad}. If the value of | |
2439 | @var{texture} is @code{GLU_TRUE}, then texture coordinates are | |
2440 | generated, and if @var{texture} is @code{GLU_FALSE}, they are not. The | |
2441 | initial value is @code{GLU_FALSE}. | |
2442 | ||
2443 | The manner in which texture coordinates are generated depends upon the | |
2444 | specific quadric rendered. | |
2445 | ||
bb894c9d | 2446 | @end deftypefun |
8925f36f | 2447 | |
bb894c9d | 2448 | @deftypefun GLint gluScaleImage format wIn hIn typeIn dataIn wOut hOut typeOut dataOut |
3c9b6116 AW |
2449 | Scale an image to an arbitrary size. |
2450 | ||
8925f36f AW |
2451 | @table @asis |
2452 | @item @var{format} | |
2453 | Specifies the format of the pixel data. The following symbolic values | |
2454 | are valid: @code{GLU_COLOR_INDEX}, @code{GLU_STENCIL_INDEX}, | |
2455 | @code{GLU_DEPTH_COMPONENT}, @code{GLU_RED}, @code{GLU_GREEN}, | |
2456 | @code{GLU_BLUE}, @code{GLU_ALPHA}, @code{GLU_RGB}, @code{GLU_RGBA}, | |
2457 | @code{GLU_BGR}, @code{GLU_BGRA}, @code{GLU_LUMINANCE}, and | |
2458 | @code{GLU_LUMINANCE_ALPHA}. | |
2459 | ||
2460 | @item @var{wIn} | |
2461 | @itemx @var{hIn} | |
2462 | Specify in pixels the width and height, respectively, of the source | |
2463 | image. | |
2464 | ||
2465 | @item @var{typeIn} | |
2466 | Specifies the data type for @var{dataIn}. Must be one of | |
2467 | @code{GLU_UNSIGNED_BYTE}, @code{GLU_BYTE}, @code{GLU_BITMAP}, | |
2468 | @code{GLU_UNSIGNED_SHORT}, @code{GLU_SHORT}, @code{GLU_UNSIGNED_INT}, | |
2469 | @code{GLU_INT}, @code{GLU_FLOAT}, @code{GLU_UNSIGNED_BYTE_3_3_2}, | |
2470 | @code{GLU_UNSIGNED_BYTE_2_3_3_REV}, @code{GLU_UNSIGNED_SHORT_5_6_5}, | |
2471 | @code{GLU_UNSIGNED_SHORT_5_6_5_REV}, @code{GLU_UNSIGNED_SHORT_4_4_4_4}, | |
2472 | @code{GLU_UNSIGNED_SHORT_4_4_4_4_REV}, | |
2473 | @code{GLU_UNSIGNED_SHORT_5_5_5_1}, | |
2474 | @code{GLU_UNSIGNED_SHORT_1_5_5_5_REV}, @code{GLU_UNSIGNED_INT_8_8_8_8}, | |
2475 | @code{GLU_UNSIGNED_INT_8_8_8_8_REV}, @code{GLU_UNSIGNED_INT_10_10_10_2}, | |
2476 | or @code{GLU_UNSIGNED_INT_2_10_10_10_REV}. | |
2477 | ||
2478 | @item @var{dataIn} | |
2479 | Specifies a pointer to the source image. | |
2480 | ||
2481 | @item @var{wOut} | |
2482 | @itemx @var{hOut} | |
2483 | Specify the width and height, respectively, in pixels of the destination | |
2484 | image. | |
2485 | ||
2486 | @item @var{typeOut} | |
2487 | Specifies the data type for @var{dataOut}. Must be one of | |
2488 | @code{GLU_UNSIGNED_BYTE}, @code{GLU_BYTE}, @code{GLU_BITMAP}, | |
2489 | @code{GLU_UNSIGNED_SHORT}, @code{GLU_SHORT}, @code{GLU_UNSIGNED_INT}, | |
2490 | @code{GLU_INT}, @code{GLU_FLOAT}, @code{GLU_UNSIGNED_BYTE_3_3_2}, | |
2491 | @code{GLU_UNSIGNED_BYTE_2_3_3_REV}, @code{GLU_UNSIGNED_SHORT_5_6_5}, | |
2492 | @code{GLU_UNSIGNED_SHORT_5_6_5_REV}, @code{GLU_UNSIGNED_SHORT_4_4_4_4}, | |
2493 | @code{GLU_UNSIGNED_SHORT_4_4_4_4_REV}, | |
2494 | @code{GLU_UNSIGNED_SHORT_5_5_5_1}, | |
2495 | @code{GLU_UNSIGNED_SHORT_1_5_5_5_REV}, @code{GLU_UNSIGNED_INT_8_8_8_8}, | |
2496 | @code{GLU_UNSIGNED_INT_8_8_8_8_REV}, @code{GLU_UNSIGNED_INT_10_10_10_2}, | |
2497 | or @code{GLU_UNSIGNED_INT_2_10_10_10_REV}. | |
2498 | ||
2499 | @item @var{dataOut} | |
2500 | Specifies a pointer to the destination image. | |
2501 | ||
2502 | @end table | |
2503 | ||
8925f36f AW |
2504 | @code{gluScaleImage} scales a pixel image using the appropriate pixel |
2505 | store modes to unpack data from the source image and pack data into the | |
2506 | destination image. | |
2507 | ||
2508 | When shrinking an image, @code{gluScaleImage} uses a box filter to | |
2509 | sample the source image and create pixels for the destination image. | |
2510 | When magnifying an image, the pixels from the source image are linearly | |
2511 | interpolated to create the destination image. | |
2512 | ||
2513 | A return value of zero indicates success, otherwise a GLU error code is | |
2514 | returned (see @code{gluErrorString}). | |
2515 | ||
2516 | See the @code{glReadPixels} reference page for a description of the | |
2517 | acceptable values for the @var{format}, @var{typeIn}, and @var{typeOut} | |
2518 | parameters. | |
2519 | ||
8925f36f AW |
2520 | @code{GLU_INVALID_VALUE} is returned if @var{wIn}, @var{hIn}, |
2521 | @var{wOut}, or @var{hOut} is negative. | |
2522 | ||
2523 | @code{GLU_INVALID_ENUM} is returned if @var{format}, @var{typeIn}, or | |
2524 | @var{typeOut} is not legal. | |
2525 | ||
2526 | @code{GLU_INVALID_OPERATION} is returned if @var{typeIn} or | |
2527 | @var{typeOut} is @code{GLU_UNSIGNED_BYTE_3_3_2} or | |
2528 | @code{GLU_UNSIGNED_BYTE_2_3_3_REV} and @var{format} is not | |
2529 | @code{GLU_RGB}. | |
2530 | ||
2531 | @code{GLU_INVALID_OPERATION} is returned if @var{typeIn} or | |
2532 | @var{typeOut} is @code{GLU_UNSIGNED_SHORT_5_6_5} or | |
2533 | @code{GLU_UNSIGNED_SHORT_5_6_5_REV} and @var{format} is not | |
2534 | @code{GLU_RGB}. | |
2535 | ||
2536 | @code{GLU_INVALID_OPERATION} is returned if @var{typeIn} or | |
2537 | @var{typeOut} is @code{GLU_UNSIGNED_SHORT_4_4_4_4} or | |
2538 | @code{GLU_UNSIGNED_SHORT_4_4_4_4_REV} and @var{format} is neither | |
2539 | @code{GLU_RGBA} nor @code{GLU_BGRA}. | |
2540 | ||
2541 | @code{GLU_INVALID_OPERATION} is returned if @var{typeIn} or | |
2542 | @var{typeOut} is @code{GLU_UNSIGNED_SHORT_5_5_5_1} or | |
2543 | @code{GLU_UNSIGNED_SHORT_1_5_5_5_REV} and @var{format} is neither | |
2544 | @code{GLU_RGBA} nor @code{GLU_BGRA}. | |
2545 | ||
2546 | @code{GLU_INVALID_OPERATION} is returned if @var{typeIn} or | |
2547 | @var{typeOut} is @code{GLU_UNSIGNED_INT_8_8_8_8} or | |
2548 | @code{GLU_UNSIGNED_INT_8_8_8_8_REV} and @var{format} is neither | |
2549 | @code{GLU_RGBA} nor @code{GLU_BGRA}. | |
2550 | ||
2551 | @code{GLU_INVALID_OPERATION} is returned if @var{typeIn} or | |
2552 | @var{typeOut} is @code{GLU_UNSIGNED_INT_10_10_10_2} or | |
2553 | @code{GLU_UNSIGNED_INT_2_10_10_10_REV} and @var{format} is neither | |
2554 | @code{GLU_RGBA} nor @code{GLU_BGRA}. | |
2555 | ||
bb894c9d | 2556 | @end deftypefun |
8925f36f | 2557 | |
bb894c9d | 2558 | @deftypefun void gluSphere quad radius slices stacks |
3c9b6116 AW |
2559 | Draw a sphere. |
2560 | ||
8925f36f AW |
2561 | @table @asis |
2562 | @item @var{quad} | |
2563 | Specifies the quadrics object (created with @code{gluNewQuadric}). | |
2564 | ||
2565 | @item @var{radius} | |
2566 | Specifies the radius of the sphere. | |
2567 | ||
2568 | @item @var{slices} | |
2569 | Specifies the number of subdivisions around the @var{z} axis (similar to | |
2570 | lines of longitude). | |
2571 | ||
2572 | @item @var{stacks} | |
2573 | Specifies the number of subdivisions along the @var{z} axis (similar to | |
2574 | lines of latitude). | |
2575 | ||
2576 | @end table | |
2577 | ||
8925f36f AW |
2578 | @code{gluSphere} draws a sphere of the given radius centered around the |
2579 | origin. The sphere is subdivided around the @var{z} axis into slices and | |
2580 | along the @var{z} axis into stacks (similar to lines of longitude and | |
2581 | latitude). | |
2582 | ||
2583 | If the orientation is set to @code{GLU_OUTSIDE} (with | |
2584 | @code{gluQuadricOrientation}), then any normals generated point away | |
2585 | from the center of the sphere. Otherwise, they point toward the center | |
2586 | of the sphere. | |
2587 | ||
2588 | If texturing is turned on (with @code{gluQuadricTexture}), then texture | |
2589 | coordinates are generated so that @var{t} ranges from 0.0 at | |
3c9b6116 AW |
2590 | @r{@var{z}=-@var{radius}} to 1.0 at @r{@var{z}=@var{radius}} (@var{t} |
2591 | increases linearly along longitudinal lines), and @var{s} ranges from | |
2592 | 0.0 at the +@var{y} axis, to 0.25 at the +@var{x} axis, to 0.5 at the | |
2593 | \-@var{y} axis, to 0.75 at the \-@var{x} axis, and back to 1.0 at the | |
2594 | +@var{y} axis. | |
8925f36f | 2595 | |
bb894c9d | 2596 | @end deftypefun |
8925f36f | 2597 | |
bb894c9d AW |
2598 | @deftypefun void gluTessBeginContour tess |
2599 | @deftypefunx void gluTessEndContour tess | |
3c9b6116 AW |
2600 | Delimit a contour description. |
2601 | ||
8925f36f AW |
2602 | @table @asis |
2603 | @item @var{tess} | |
2604 | Specifies the tessellation object (created with @code{gluNewTess}). | |
2605 | ||
2606 | @end table | |
2607 | ||
8925f36f AW |
2608 | @code{gluTessBeginContour} and @code{gluTessEndContour} delimit the |
2609 | definition of a polygon contour. Within each | |
2610 | @code{gluTessBeginContour}/@code{gluTessEndContour} pair, there can be | |
2611 | zero or more calls to @code{gluTessVertex}. The vertices specify a | |
2612 | closed contour (the last vertex of each contour is automatically linked | |
2613 | to the first). See the @code{gluTessVertex} reference page for more | |
2614 | details. @code{gluTessBeginContour} can only be called between | |
2615 | @code{gluTessBeginPolygon} and @code{gluTessEndPolygon}. | |
2616 | ||
bb894c9d | 2617 | @end deftypefun |
8925f36f | 2618 | |
bb894c9d | 2619 | @deftypefun void gluTessBeginPolygon tess data |
3c9b6116 AW |
2620 | Delimit a polygon description. |
2621 | ||
8925f36f AW |
2622 | @table @asis |
2623 | @item @var{tess} | |
2624 | Specifies the tessellation object (created with @code{gluNewTess}). | |
2625 | ||
2626 | @item @var{data} | |
2627 | Specifies a pointer to user polygon data. | |
2628 | ||
2629 | @end table | |
2630 | ||
8925f36f AW |
2631 | @code{gluTessBeginPolygon} and @code{gluTessEndPolygon} delimit the |
2632 | definition of a convex, concave or self-intersecting polygon. Within | |
2633 | each @code{gluTessBeginPolygon}/@code{gluTessEndPolygon} pair, there | |
2634 | must be one or more calls to | |
2635 | @code{gluTessBeginContour}/@code{gluTessEndContour}. Within each | |
2636 | contour, there are zero or more calls to @code{gluTessVertex}. The | |
2637 | vertices specify a closed contour (the last vertex of each contour is | |
2638 | automatically linked to the first). See the @code{gluTessVertex}, | |
2639 | @code{gluTessBeginContour}, and @code{gluTessEndContour} reference pages | |
2640 | for more details. | |
2641 | ||
2642 | @var{data} is a pointer to a user-defined data structure. If the | |
2643 | appropriate callback(s) are specified (see @code{gluTessCallback}), then | |
2644 | this pointer is returned to the callback function(s). Thus, it is a | |
2645 | convenient way to store per-polygon information. | |
2646 | ||
2647 | Once @code{gluTessEndPolygon} is called, the polygon is tessellated, and | |
2648 | the resulting triangles are described through callbacks. See | |
2649 | @code{gluTessCallback} for descriptions of the callback functions. | |
2650 | ||
bb894c9d | 2651 | @end deftypefun |
8925f36f | 2652 | |
bb894c9d | 2653 | @deftypefun void gluTessCallback tess which CallBackFunc |
3c9b6116 AW |
2654 | Define a callback for a tessellation object. |
2655 | ||
8925f36f AW |
2656 | @table @asis |
2657 | @item @var{tess} | |
2658 | Specifies the tessellation object (created with @code{gluNewTess}). | |
2659 | ||
2660 | @item @var{which} | |
2661 | Specifies the callback being defined. The following values are valid: | |
2662 | @code{GLU_TESS_BEGIN}, @code{GLU_TESS_BEGIN_DATA}, | |
2663 | @code{GLU_TESS_EDGE_FLAG}, @code{GLU_TESS_EDGE_FLAG_DATA}, | |
2664 | @code{GLU_TESS_VERTEX}, @code{GLU_TESS_VERTEX_DATA}, | |
2665 | @code{GLU_TESS_END}, @code{GLU_TESS_END_DATA}, @code{GLU_TESS_COMBINE}, | |
2666 | @code{GLU_TESS_COMBINE_DATA}, @code{GLU_TESS_ERROR}, and | |
2667 | @code{GLU_TESS_ERROR_DATA}. | |
2668 | ||
2669 | @item @var{CallBackFunc} | |
2670 | Specifies the function to be called. | |
2671 | ||
2672 | @end table | |
2673 | ||
8925f36f AW |
2674 | @code{gluTessCallback} is used to indicate a callback to be used by a |
2675 | tessellation object. If the specified callback is already defined, then | |
2676 | it is replaced. If @var{CallBackFunc} is NULL, then the existing | |
2677 | callback becomes undefined. | |
2678 | ||
2679 | These callbacks are used by the tessellation object to describe how a | |
2680 | polygon specified by the user is broken into triangles. Note that there | |
2681 | are two versions of each callback: one with user-specified polygon data | |
2682 | and one without. If both versions of a particular callback are | |
2683 | specified, then the callback with user-specified polygon data will be | |
2684 | used. Note that the @var{polygon_data} parameter used by some of the | |
2685 | functions is a copy of the pointer that was specified when | |
2686 | @code{gluTessBeginPolygon} was called. The legal callbacks are as | |
2687 | follows: | |
2688 | ||
2689 | @table @asis | |
2690 | @item @code{GLU_TESS_BEGIN} | |
2691 | The begin callback is invoked like @code{glBegin} to indicate the start | |
2692 | of a (triangle) primitive. The function takes a single argument of type | |
2693 | GLenum. If the @code{GLU_TESS_BOUNDARY_ONLY} property is set to | |
2694 | @code{GLU_FALSE}, then the argument is set to either | |
2695 | @code{GLU_TRIANGLE_FAN}, @code{GLU_TRIANGLE_STRIP}, or | |
2696 | @code{GLU_TRIANGLES}. If the @code{GLU_TESS_BOUNDARY_ONLY} property is | |
2697 | set to @code{GLU_TRUE}, then the argument will be set to | |
2698 | @code{GLU_LINE_LOOP}. The function prototype for this callback is: | |
2699 | ||
2700 | @item @code{GLU_TESS_BEGIN_DATA} | |
2701 | The same as the @code{GLU_TESS_BEGIN} callback except that it takes an | |
2702 | additional pointer argument. This pointer is identical to the opaque | |
2703 | pointer provided when @code{gluTessBeginPolygon} was called. The | |
2704 | function prototype for this callback is: | |
2705 | ||
2706 | @item @code{GLU_TESS_EDGE_FLAG} | |
2707 | The edge flag callback is similar to @code{glEdgeFlag}. The function | |
2708 | takes a single boolean flag that indicates which edges lie on the | |
2709 | polygon boundary. If the flag is @code{GLU_TRUE}, then each vertex that | |
2710 | follows begins an edge that lies on the polygon boundary, that is, an | |
2711 | edge that separates an interior region from an exterior one. If the flag | |
2712 | is @code{GLU_FALSE}, then each vertex that follows begins an edge that | |
2713 | lies in the polygon interior. The edge flag callback (if defined) is | |
2714 | invoked before the first vertex callback. | |
2715 | ||
2716 | Since triangle fans and triangle strips do not support edge flags, the | |
2717 | begin callback is not called with @code{GLU_TRIANGLE_FAN} or | |
2718 | @code{GLU_TRIANGLE_STRIP} if a non-NULL edge flag callback is provided. | |
2719 | (If the callback is initialized to NULL, there is no impact on | |
2720 | performance). Instead, the fans and strips are converted to independent | |
2721 | triangles. The function prototype for this callback is: | |
2722 | ||
2723 | @item @code{GLU_TESS_EDGE_FLAG_DATA} | |
2724 | The same as the @code{GLU_TESS_EDGE_FLAG} callback except that it takes | |
2725 | an additional pointer argument. This pointer is identical to the opaque | |
2726 | pointer provided when @code{gluTessBeginPolygon} was called. The | |
2727 | function prototype for this callback is: | |
2728 | ||
2729 | @item @code{GLU_TESS_VERTEX} | |
2730 | The vertex callback is invoked between the begin and end callbacks. It | |
2731 | is similar to @code{glVertex}, and it defines the vertices of the | |
2732 | triangles created by the tessellation process. The function takes a | |
2733 | pointer as its only argument. This pointer is identical to the opaque | |
2734 | pointer provided by the user when the vertex was described (see | |
2735 | @code{gluTessVertex}). The function prototype for this callback is: | |
2736 | ||
2737 | @item @code{GLU_TESS_VERTEX_DATA} | |
2738 | The same as the @code{GLU_TESS_VERTEX} callback except that it takes an | |
2739 | additional pointer argument. This pointer is identical to the opaque | |
2740 | pointer provided when @code{gluTessBeginPolygon} was called. The | |
2741 | function prototype for this callback is: | |
2742 | ||
2743 | @item @code{GLU_TESS_END} | |
2744 | The end callback serves the same purpose as @code{glEnd}. It indicates | |
2745 | the end of a primitive and it takes no arguments. The function prototype | |
2746 | for this callback is: | |
2747 | ||
2748 | @item @code{GLU_TESS_END_DATA} | |
2749 | The same as the @code{GLU_TESS_END} callback except that it takes an | |
2750 | additional pointer argument. This pointer is identical to the opaque | |
2751 | pointer provided when @code{gluTessBeginPolygon} was called. The | |
2752 | function prototype for this callback is: | |
2753 | ||
2754 | @item @code{GLU_TESS_COMBINE} | |
2755 | The combine callback is called to create a new vertex when the | |
2756 | tessellation detects an intersection or wishes to merge features. The | |
2757 | function takes four arguments: an array of three elements each of type | |
2758 | GLdouble, an array of four pointers, an array of four elements each of | |
2759 | type GLfloat, and a pointer to a pointer. The prototype is: | |
2760 | ||
2761 | The vertex is defined as a linear combination of up to four existing | |
2762 | vertices, stored in @var{vertex_data}. The coefficients of the linear | |
2763 | combination are given by @var{weight}; these weights always add up to 1. | |
2764 | All vertex pointers are valid even when some of the weights are 0. | |
2765 | @var{coords} gives the location of the new vertex. | |
2766 | ||
2767 | The user must allocate another vertex, interpolate parameters using | |
2768 | @var{vertex_data} and @var{weight}, and return the new vertex pointer in | |
2769 | @var{outData}. This handle is supplied during rendering callbacks. The | |
2770 | user is responsible for freeing the memory some time after | |
2771 | @code{gluTessEndPolygon} is called. | |
2772 | ||
2773 | For example, if the polygon lies in an arbitrary plane in 3-space, and a | |
2774 | color is associated with each vertex, the @code{GLU_TESS_COMBINE} | |
2775 | callback might look like this: | |
2776 | ||
2777 | If the tessellation detects an intersection, then the | |
2778 | @code{GLU_TESS_COMBINE} or @code{GLU_TESS_COMBINE_DATA} callback (see | |
2779 | below) must be defined, and it must write a non-NULL pointer into | |
2780 | @var{dataOut}. Otherwise the @code{GLU_TESS_NEED_COMBINE_CALLBACK} error | |
2781 | occurs, and no output is generated. | |
2782 | ||
2783 | @item @code{GLU_TESS_COMBINE_DATA} | |
2784 | The same as the @code{GLU_TESS_COMBINE} callback except that it takes an | |
2785 | additional pointer argument. This pointer is identical to the opaque | |
2786 | pointer provided when @code{gluTessBeginPolygon} was called. The | |
2787 | function prototype for this callback is: | |
2788 | ||
2789 | @item @code{GLU_TESS_ERROR} | |
2790 | The error callback is called when an error is encountered. The one | |
2791 | argument is of type GLenum; it indicates the specific error that | |
2792 | occurred and will be set to one of | |
2793 | @code{GLU_TESS_MISSING_BEGIN_POLYGON}, | |
2794 | @code{GLU_TESS_MISSING_END_POLYGON}, | |
2795 | @code{GLU_TESS_MISSING_BEGIN_CONTOUR}, | |
2796 | @code{GLU_TESS_MISSING_END_CONTOUR}, @code{GLU_TESS_COORD_TOO_LARGE}, | |
2797 | @code{GLU_TESS_NEED_COMBINE_CALLBACK}, or @code{GLU_OUT_OF_MEMORY}. | |
2798 | Character strings describing these errors can be retrieved with the | |
2799 | @code{gluErrorString} call. The function prototype for this callback is: | |
2800 | ||
2801 | The GLU library will recover from the first four errors by inserting the | |
2802 | missing call(s). @code{GLU_TESS_COORD_TOO_LARGE} indicates that some | |
2803 | vertex coordinate exceeded the predefined constant | |
2804 | @code{GLU_TESS_MAX_COORD} in absolute value, and that the value has been | |
2805 | clamped. (Coordinate values must be small enough so that two can be | |
2806 | multiplied together without overflow.) | |
2807 | @code{GLU_TESS_NEED_COMBINE_CALLBACK} indicates that the tessellation | |
2808 | detected an intersection between two edges in the input data, and the | |
2809 | @code{GLU_TESS_COMBINE} or @code{GLU_TESS_COMBINE_DATA} callback was not | |
2810 | provided. No output is generated. @code{GLU_OUT_OF_MEMORY} indicates | |
2811 | that there is not enough memory so no output is generated. | |
2812 | ||
2813 | @item @code{GLU_TESS_ERROR_DATA} | |
2814 | The same as the @code{GLU_TESS_ERROR} callback except that it takes an | |
2815 | additional pointer argument. This pointer is identical to the opaque | |
2816 | pointer provided when @code{gluTessBeginPolygon} was called. The | |
2817 | function prototype for this callback is: | |
2818 | ||
2819 | @end table | |
2820 | ||
2821 | @example | |
2822 | ||
2823 | void begin( GLenum type ); | |
2824 | @end example | |
2825 | ||
2826 | @example | |
2827 | ||
2828 | void beginData( GLenum type, void *polygon_data ); | |
2829 | @end example | |
2830 | ||
2831 | @example | |
2832 | ||
2833 | void edgeFlag( GLboolean flag ); | |
2834 | @end example | |
2835 | ||
2836 | @example | |
2837 | ||
2838 | void edgeFlagData( GLboolean flag, void *polygon_data ); | |
2839 | @end example | |
2840 | ||
2841 | @example | |
2842 | ||
2843 | void vertex( void *vertex_data ); | |
2844 | @end example | |
2845 | ||
2846 | @example | |
2847 | ||
2848 | void vertexData( void *vertex_data, void *polygon_data ); | |
2849 | @end example | |
2850 | ||
2851 | @example | |
2852 | ||
2853 | void end( void ); | |
2854 | @end example | |
2855 | ||
2856 | @example | |
2857 | ||
2858 | void endData( void *polygon_data ); | |
2859 | @end example | |
2860 | ||
2861 | @example | |
2862 | ||
2863 | void combine( GLdouble coords[3], void *vertex_data[4], | |
2864 | GLfloat weight[4], void **outData ); | |
2865 | @end example | |
2866 | ||
2867 | @example | |
2868 | ||
2869 | void myCombine( GLdouble coords[3], VERTEX *d[4], | |
2870 | GLfloat w[4], VERTEX **dataOut ) | |
2871 | @{ | |
2872 | VERTEX *new = new_vertex(); | |
2873 | ||
2874 | new->x = coords[0]; | |
2875 | new->y = coords[1]; | |
2876 | new->z = coords[2]; | |
2877 | new->r = w[0]*d[0]->r + w[1]*d[1]->r + w[2]*d[2]->r + w[3]*d[3]->r; | |
2878 | new->g = w[0]*d[0]->g + w[1]*d[1]->g + w[2]*d[2]->g + w[3]*d[3]->g; | |
2879 | new->b = w[0]*d[0]->b + w[1]*d[1]->b + w[2]*d[2]->b + w[3]*d[3]->b; | |
2880 | new->a = w[0]*d[0]->a + w[1]*d[1]->a + w[2]*d[2]->a + w[3]*d[3]->a; | |
2881 | *dataOut = new; | |
2882 | @} | |
2883 | @end example | |
2884 | ||
2885 | @example | |
2886 | ||
2887 | void combineData( GLdouble coords[3], void *vertex_data[4], | |
2888 | GLfloat weight[4], void **outData, | |
2889 | void *polygon_data ); | |
2890 | @end example | |
2891 | ||
2892 | @example | |
2893 | ||
2894 | void error( GLenum errno ); | |
2895 | @end example | |
2896 | ||
2897 | @example | |
2898 | ||
2899 | void errorData( GLenum errno, void *polygon_data ); | |
2900 | @end example | |
2901 | ||
bb894c9d | 2902 | @end deftypefun |
8925f36f | 2903 | |
bb894c9d | 2904 | @deftypefun void gluTessEndPolygon tess |
3c9b6116 AW |
2905 | Delimit a polygon description. |
2906 | ||
8925f36f AW |
2907 | @table @asis |
2908 | @item @var{tess} | |
2909 | Specifies the tessellation object (created with @code{gluNewTess}). | |
2910 | ||
2911 | @end table | |
2912 | ||
8925f36f AW |
2913 | @code{gluTessBeginPolygon} and @code{gluTessEndPolygon} delimit the |
2914 | definition of a convex, concave, or self-intersecting polygon. Within | |
2915 | each @code{gluTessBeginPolygon}/@code{gluTessEndPolygon} pair, there | |
2916 | must be one or more calls to | |
2917 | @code{gluTessBeginContour}/@code{gluTessEndContour}. Within each | |
2918 | contour, there are zero or more calls to @code{gluTessVertex}. The | |
2919 | vertices specify a closed contour (the last vertex of each contour is | |
2920 | automatically linked to the first). See the @code{gluTessVertex}, | |
2921 | @code{gluTessBeginContour}, and @code{gluTessEndContour} reference pages | |
2922 | for more details. | |
2923 | ||
2924 | Once @code{gluTessEndPolygon} is called, the polygon is tessellated, and | |
2925 | the resulting triangles are described through callbacks. See | |
2926 | @code{gluTessCallback} for descriptions of the callback functions. | |
2927 | ||
bb894c9d | 2928 | @end deftypefun |
8925f36f | 2929 | |
bb894c9d | 2930 | @deftypefun void gluTessNormal tess valueX valueY valueZ |
3c9b6116 AW |
2931 | Specify a normal for a polygon. |
2932 | ||
8925f36f AW |
2933 | @table @asis |
2934 | @item @var{tess} | |
2935 | Specifies the tessellation object (created with @code{gluNewTess}). | |
2936 | ||
2937 | @item @var{valueX} | |
2938 | Specifies the first component of the normal. | |
2939 | ||
2940 | @item @var{valueY} | |
2941 | Specifies the second component of the normal. | |
2942 | ||
2943 | @item @var{valueZ} | |
2944 | Specifies the third component of the normal. | |
2945 | ||
2946 | @end table | |
2947 | ||
8925f36f AW |
2948 | @code{gluTessNormal} describes a normal for a polygon that the program |
2949 | is defining. All input data will be projected onto a plane perpendicular | |
2950 | to one of the three coordinate axes before tessellation and all output | |
2951 | triangles will be oriented CCW with respect to the normal (CW | |
2952 | orientation can be obtained by reversing the sign of the supplied | |
2953 | normal). For example, if you know that all polygons lie in the x-y | |
2954 | plane, call @code{gluTessNormal}(tess, 0.0, 0.0, 1.0) before rendering | |
2955 | any polygons. | |
2956 | ||
2957 | If the supplied normal is (0.0, 0.0, 0.0) (the initial value), the | |
2958 | normal is determined as follows. The direction of the normal, up to its | |
2959 | sign, is found by fitting a plane to the vertices, without regard to how | |
2960 | the vertices are connected. It is expected that the input data lies | |
2961 | approximately in the plane; otherwise, projection perpendicular to one | |
2962 | of the three coordinate axes may substantially change the geometry. The | |
2963 | sign of the normal is chosen so that the sum of the signed areas of all | |
2964 | input contours is nonnegative (where a CCW contour has positive area). | |
2965 | ||
2966 | The supplied normal persists until it is changed by another call to | |
2967 | @code{gluTessNormal}. | |
2968 | ||
bb894c9d | 2969 | @end deftypefun |
8925f36f | 2970 | |
bb894c9d | 2971 | @deftypefun void gluTessProperty tess which data |
3c9b6116 AW |
2972 | Set a tessellation object property. |
2973 | ||
8925f36f AW |
2974 | @table @asis |
2975 | @item @var{tess} | |
2976 | Specifies the tessellation object (created with @code{gluNewTess}). | |
2977 | ||
2978 | @item @var{which} | |
2979 | Specifies the property to be set. Valid values are | |
2980 | @code{GLU_TESS_WINDING_RULE}, @code{GLU_TESS_BOUNDARY_ONLY}, and | |
2981 | @code{GLU_TESS_TOLERANCE}. | |
2982 | ||
2983 | @item @var{data} | |
2984 | Specifies the value of the indicated property. | |
2985 | ||
2986 | @end table | |
2987 | ||
8925f36f AW |
2988 | @code{gluTessProperty} is used to control properties stored in a |
2989 | tessellation object. These properties affect the way that the polygons | |
2990 | are interpreted and rendered. The legal values for @var{which} are as | |
2991 | follows: | |
2992 | ||
2993 | @table @asis | |
2994 | @item @code{GLU_TESS_WINDING_RULE} | |
2995 | Determines which parts of the polygon are on the ``interior''. | |
2996 | @var{data} may be set to one of @code{GLU_TESS_WINDING_ODD}, | |
2997 | @code{GLU_TESS_WINDING_NONZERO}, @code{GLU_TESS_WINDING_POSITIVE}, | |
2998 | @code{GLU_TESS_WINDING_NEGATIVE}, or | |
2999 | @code{GLU_TESS_WINDING_ABS_GEQ_TWO}. | |
3000 | ||
3001 | To understand how the winding rule works, consider that the input | |
3002 | contours partition the plane into regions. The winding rule determines | |
3003 | which of these regions are inside the polygon. | |
3004 | ||
3005 | For a single contour C, the winding number of a point x is simply the | |
3006 | signed number of revolutions we make around x as we travel once around C | |
3007 | (where CCW is positive). When there are several contours, the individual | |
3008 | winding numbers are summed. This procedure associates a signed integer | |
3009 | value with each point x in the plane. Note that the winding number is | |
3010 | the same for all points in a single region. | |
3011 | ||
3012 | The winding rule classifies a region as ``inside'' if its winding number | |
3013 | belongs to the chosen category (odd, nonzero, positive, negative, or | |
3014 | absolute value of at least two). The previous GLU tessellator (prior to | |
3015 | GLU 1.2) used the ``odd'' rule. The ``nonzero'' rule is another common | |
3016 | way to define the interior. The other three rules are useful for polygon | |
3017 | CSG operations. | |
3018 | ||
3019 | @item @code{GLU_TESS_BOUNDARY_ONLY} | |
3020 | Is a boolean value (``value'' should be set to GL_TRUE or GL_FALSE). | |
3021 | When set to GL_TRUE, a set of closed contours separating the polygon | |
3022 | interior and exterior are returned instead of a tessellation. Exterior | |
3023 | contours are oriented CCW with respect to the normal; interior contours | |
3024 | are oriented CW. The @code{GLU_TESS_BEGIN} and | |
3025 | @code{GLU_TESS_BEGIN_DATA} callbacks use the type GL_LINE_LOOP for each | |
3026 | contour. | |
3027 | ||
3028 | @item @code{GLU_TESS_TOLERANCE} | |
3029 | Specifies a tolerance for merging features to reduce the size of the | |
3030 | output. For example, two vertices that are very close to each other | |
3031 | might be replaced by a single vertex. The tolerance is multiplied by the | |
3032 | largest coordinate magnitude of any input vertex; this specifies the | |
3033 | maximum distance that any feature can move as the result of a single | |
3034 | merge operation. If a single feature takes part in several merge | |
3035 | operations, the total distance moved could be larger. | |
3036 | ||
3037 | Feature merging is completely optional; the tolerance is only a hint. | |
3038 | The implementation is free to merge in some cases and not in others, or | |
3039 | to never merge features at all. The initial tolerance is 0. | |
3040 | ||
3041 | The current implementation merges vertices only if they are exactly | |
3042 | coincident, regardless of the current tolerance. A vertex is spliced | |
3043 | into an edge only if the implementation is unable to distinguish which | |
3044 | side of the edge the vertex lies on. Two edges are merged only when both | |
3045 | endpoints are identical. | |
3046 | ||
3047 | @end table | |
3048 | ||
bb894c9d | 3049 | @end deftypefun |
8925f36f | 3050 | |
bb894c9d | 3051 | @deftypefun void gluTessVertex tess location data |
3c9b6116 AW |
3052 | Specify a vertex on a polygon. |
3053 | ||
8925f36f AW |
3054 | @table @asis |
3055 | @item @var{tess} | |
3056 | Specifies the tessellation object (created with @code{gluNewTess}). | |
3057 | ||
3058 | @item @var{location} | |
3059 | Specifies the location of the vertex. | |
3060 | ||
3061 | @item @var{data} | |
3062 | Specifies an opaque pointer passed back to the program with the vertex | |
3063 | callback (as specified by @code{gluTessCallback}). | |
3064 | ||
3065 | @end table | |
3066 | ||
8925f36f AW |
3067 | @code{gluTessVertex} describes a vertex on a polygon that the program |
3068 | defines. Successive @code{gluTessVertex} calls describe a closed | |
3069 | contour. For example, to describe a quadrilateral, @code{gluTessVertex} | |
3070 | should be called four times. @code{gluTessVertex} can only be called | |
3071 | between @code{gluTessBeginContour} and @code{gluTessEndContour}. | |
3072 | ||
3073 | @var{data} normally points to a structure containing the vertex | |
3074 | location, as well as other per-vertex attributes such as color and | |
3075 | normal. This pointer is passed back to the user through the | |
3076 | @code{GLU_TESS_VERTEX} or @code{GLU_TESS_VERTEX_DATA} callback after | |
3077 | tessellation (see the @code{gluTessCallback} reference page). | |
3078 | ||
bb894c9d | 3079 | @end deftypefun |
8925f36f | 3080 | |
bb894c9d | 3081 | @deftypefun GLint gluUnProject4 winX winY winZ clipW model proj view nearVal farVal objX objY objZ objW |
3c9b6116 AW |
3082 | Map window and clip coordinates to object coordinates. |
3083 | ||
8925f36f AW |
3084 | @table @asis |
3085 | @item @var{winX} | |
3086 | @itemx @var{winY} | |
3087 | @itemx @var{winZ} | |
3088 | Specify the window coordinates to be mapped. | |
3089 | ||
3090 | @item @var{clipW} | |
3091 | Specify the clip w coordinate to be mapped. | |
3092 | ||
3093 | @item @var{model} | |
3094 | Specifies the modelview matrix (as from a @code{glGetDoublev} call). | |
3095 | ||
3096 | @item @var{proj} | |
3097 | Specifies the projection matrix (as from a @code{glGetDoublev} call). | |
3098 | ||
3099 | @item @var{view} | |
3100 | Specifies the viewport (as from a @code{glGetIntegerv} call). | |
3101 | ||
3102 | @item @var{nearVal} | |
3103 | @itemx @var{farVal} | |
3104 | Specifies the near and far planes (as from a @code{glGetDoublev} call). | |
3105 | ||
3106 | @item @var{objX} | |
3107 | @itemx @var{objY} | |
3108 | @itemx @var{objZ} | |
3109 | @itemx @var{objW} | |
3110 | Returns the computed object coordinates. | |
3111 | ||
3112 | @end table | |
3113 | ||
8925f36f AW |
3114 | @code{gluUnProject4} maps the specified window coordinatesi: @var{winX}, |
3115 | @var{winY}, and @var{winZ} and its clip w coordinate @var{clipW} into | |
3c9b6116 AW |
3116 | object coordinates @r{(@var{objX},@var{objY}@var{objZ}@var{objW})} using |
3117 | @var{model}, @var{proj}, and @var{view}. @var{clipW} can be other than 1 | |
3118 | as for vertices in @code{glFeedbackBuffer} when data type | |
8925f36f AW |
3119 | @code{GLU_4D_COLOR_TEXTURE} is returned. This also handles the case |
3120 | where the @var{nearVal} and @var{farVal} planes are different from the | |
3121 | default, 0 and 1, respectively. A return value of @code{GLU_TRUE} | |
3122 | indicates success; a return value of @code{GLU_FALSE} indicates failure. | |
3123 | ||
3124 | To compute the coordinates | |
3c9b6116 | 3125 | @r{(@var{objX},@var{objY}@var{objZ}@var{objW})}, @code{gluUnProject4} |
8925f36f AW |
3126 | multiplies the normalized device coordinates by the inverse of |
3127 | @var{model} * @var{proj} as follows: | |
3128 | ||
3c9b6116 | 3129 | @r{((@var{objX}), (@var{objY}), (@var{objZ}), |
8925f36f AW |
3130 | (@var{objW}),)=@var{INV}(@var{P}@var{M},)((2(@var{winX}-@var{view}[0,],),/@var{view}[2,],-1), |
3131 | (2(@var{winY}-@var{view}[1,],),/@var{view}[3,],-1), | |
3132 | (2(@var{winZ}-@var{nearVal},),/(@var{farVal}-@var{nearVal},),-1), | |
3133 | (@var{clipW}),)} | |
3134 | ||
3c9b6116 | 3135 | @r{@var{INV}} denotes matrix inversion. |
8925f36f AW |
3136 | |
3137 | @code{gluUnProject4} is equivalent to @code{gluUnProject} when | |
3138 | @var{clipW} is 1, @var{nearVal} is 0, and @var{farVal} is 1. | |
3139 | ||
bb894c9d | 3140 | @end deftypefun |
8925f36f | 3141 | |
bb894c9d | 3142 | @deftypefun GLint gluUnProject winX winY winZ model proj view objX objY objZ |
3c9b6116 AW |
3143 | Map window coordinates to object coordinates. |
3144 | ||
8925f36f AW |
3145 | @table @asis |
3146 | @item @var{winX} | |
3147 | @itemx @var{winY} | |
3148 | @itemx @var{winZ} | |
3149 | Specify the window coordinates to be mapped. | |
3150 | ||
3151 | @item @var{model} | |
3152 | Specifies the modelview matrix (as from a @code{glGetDoublev} call). | |
3153 | ||
3154 | @item @var{proj} | |
3155 | Specifies the projection matrix (as from a @code{glGetDoublev} call). | |
3156 | ||
3157 | @item @var{view} | |
3158 | Specifies the viewport (as from a @code{glGetIntegerv} call). | |
3159 | ||
3160 | @item @var{objX} | |
3161 | @itemx @var{objY} | |
3162 | @itemx @var{objZ} | |
3163 | Returns the computed object coordinates. | |
3164 | ||
3165 | @end table | |
3166 | ||
8925f36f AW |
3167 | @code{gluUnProject} maps the specified window coordinates into object |
3168 | coordinates using @var{model}, @var{proj}, and @var{view}. The result is | |
3169 | stored in @var{objX}, @var{objY}, and @var{objZ}. A return value of | |
3170 | @code{GLU_TRUE} indicates success; a return value of @code{GLU_FALSE} | |
3171 | indicates failure. | |
3172 | ||
3c9b6116 | 3173 | To compute the coordinates @r{(@var{objX},@var{objY}@var{objZ})}, |
8925f36f AW |
3174 | @code{gluUnProject} multiplies the normalized device coordinates by the |
3175 | inverse of @var{model} * @var{proj} as follows: | |
3176 | ||
3c9b6116 | 3177 | @r{((@var{objX}), (@var{objY}), (@var{objZ}), |
8925f36f AW |
3178 | (@var{W}),)=@var{INV}(@var{P}@var{M},)((2(@var{winX}-@var{view}[0,],),/@var{view}[2,],-1), |
3179 | (2(@var{winY}-@var{view}[1,],),/@var{view}[3,],-1), | |
3c9b6116 AW |
3180 | (2(@var{winZ},)-1), (1),)}@r{@var{INV}} denotes matrix inversion. W is |
3181 | an unused variable, included for consistent matrix notation. | |
8925f36f | 3182 | |
bb894c9d | 3183 | @end deftypefun |
8925f36f AW |
3184 | |
3185 | ||
3186 | @c %end of fragment |