rename upstream-man-pages to upstream-doc
[clinton/guile-figl.git] / upstream-doc / manglsl / textureLod.xml
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1<?xml version="1.0" encoding="UTF-8"?>\r
2<!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook MathML Module V1.1b1//EN"\r
3 "http://www.oasis-open.org/docbook/xml/mathml/1.1CR1/dbmathml.dtd">\r
4<refentry id="textureLod">\r
5 <refmeta>\r
6 <refmetainfo>\r
7 <copyright>\r
8 <year>2011</year>\r
9 <holder>Khronos Group</holder>\r
10 </copyright>\r
11 </refmetainfo>\r
12 <refentrytitle>textureLod</refentrytitle>\r
13 <manvolnum>3G</manvolnum>\r
14 </refmeta>\r
15 <refnamediv>\r
16 <refname>textureLod</refname>\r
17 <refpurpose>perform a texture lookup with explicit level-of-detail</refpurpose>\r
18 </refnamediv>\r
19 <refsynopsisdiv><title>Declaration</title>\r
20 <funcsynopsis>\r
21 <funcprototype>\r
22 <funcdef>gvec4 <function>textureLod</function></funcdef>\r
23 <paramdef>gsampler1D <parameter>sampler</parameter></paramdef>\r
24 <paramdef>float <parameter>P</parameter></paramdef>\r
25 <paramdef>float <parameter>lod</parameter></paramdef>\r
26 </funcprototype>\r
27 <funcprototype>\r
28 <funcdef>gvec4 <function>textureLod</function></funcdef>\r
29 <paramdef>gsampler2D <parameter>sampler</parameter></paramdef>\r
30 <paramdef>vec2 <parameter>P</parameter></paramdef>\r
31 <paramdef>float <parameter>lod</parameter></paramdef>\r
32 </funcprototype>\r
33 <funcprototype>\r
34 <funcdef>gvec4 <function>textureLod</function></funcdef>\r
35 <paramdef>gsampler3D <parameter>sampler</parameter></paramdef>\r
36 <paramdef>vec3 <parameter>P</parameter></paramdef>\r
37 <paramdef>float <parameter>lod</parameter></paramdef>\r
38 </funcprototype>\r
39 <funcprototype>\r
40 <funcdef>gvec4 <function>textureLod</function></funcdef>\r
41 <paramdef>gsamplerCube <parameter>sampler</parameter></paramdef>\r
42 <paramdef>vec3 <parameter>P</parameter></paramdef>\r
43 <paramdef>float <parameter>lod</parameter></paramdef>\r
44 </funcprototype>\r
45 <funcprototype>\r
46 <funcdef>float <function>textureLod</function></funcdef>\r
47 <paramdef>sampler1DShadow <parameter>sampler</parameter></paramdef>\r
48 <paramdef>vec3 <parameter>P</parameter></paramdef>\r
49 <paramdef>float <parameter>lod</parameter></paramdef>\r
50 </funcprototype>\r
51 <funcprototype>\r
52 <funcdef>float <function>textureLod</function></funcdef>\r
53 <paramdef>sampler2DShadow <parameter>sampler</parameter></paramdef>\r
54 <paramdef>vec4 <parameter>P</parameter></paramdef>\r
55 <paramdef>float <parameter>lod</parameter></paramdef>\r
56 </funcprototype>\r
57 <funcprototype>\r
58 <funcdef>gvec4 <function>textureLod</function></funcdef>\r
59 <paramdef>gsampler1DArray <parameter>sampler</parameter></paramdef>\r
60 <paramdef>vec2 <parameter>P</parameter></paramdef>\r
61 <paramdef>float <parameter>lod</parameter></paramdef>\r
62 </funcprototype>\r
63 <funcprototype>\r
64 <funcdef>gvec4 <function>textureLod</function></funcdef>\r
65 <paramdef>gsampler2DArray <parameter>sampler</parameter></paramdef>\r
66 <paramdef>vec3 <parameter>P</parameter></paramdef>\r
67 <paramdef>float <parameter>lod</parameter></paramdef>\r
68 </funcprototype>\r
69 <funcprototype>\r
70 <funcdef>float <function>textureLod</function></funcdef>\r
71 <paramdef>sampler1DArrayShadow <parameter>sampler</parameter></paramdef>\r
72 <paramdef>vec3 <parameter>P</parameter></paramdef>\r
73 <paramdef>float <parameter>lod</parameter></paramdef>\r
74 </funcprototype>\r
75 <funcprototype>\r
76 <funcdef>gvec4 <function>textureLod</function></funcdef>\r
77 <paramdef>gsamplerCubeArray <parameter>sampler</parameter></paramdef>\r
78 <paramdef>vec4 <parameter>P</parameter></paramdef>\r
79 <paramdef>float <parameter>lod</parameter></paramdef>\r
80 </funcprototype>\r
81 </funcsynopsis>\r
82 </refsynopsisdiv>\r
83 <refsect1 id="parameters"><title>Parameters</title>\r
84 <variablelist>\r
85 <varlistentry>\r
86 <term><parameter>sampler</parameter></term>\r
87 <listitem>\r
88 <para>\r
89 Specifies the sampler to which the texture from which texels will be retrieved is bound.\r
90 </para>\r
91 </listitem>\r
92 </varlistentry>\r
93 <varlistentry>\r
94 <term><parameter>P</parameter></term>\r
95 <listitem>\r
96 <para>\r
97 Specifies the texture coordinates at which texture will be sampled.\r
98 </para>\r
99 </listitem>\r
100 </varlistentry>\r
101 <varlistentry>\r
102 <term><parameter>lod</parameter></term>\r
103 <listitem>\r
104 <para>\r
105 Specifies the explicit level-of-detail\r
106 </para>\r
107 </listitem>\r
108 </varlistentry>\r
109 </variablelist>\r
110 </refsect1>\r
111 <refsect1 id="description"><title>Description</title>\r
112 <para>\r
113 <function>textureLod</function> performs a texture lookup at coordinate <parameter>P</parameter> from the\r
114 texture bound to <parameter>sampler</parameter> with an explicit level-of-detail as specified in <parameter>lod</parameter>.\r
115 <parameter>lod</parameter> specifies\r
116 <inlineequation><mml:math><mml:msub><mml:mi>&lambda;</mml:mi><mml:mi>base</mml:mi></mml:msub></mml:math></inlineequation>\r
117 and sets the partial derivatives as follows:\r
118 </para>\r
119 <para>\r
120 <inlineequation><mml:math>\r
121 <mml:mtable rowalign='center'>\r
122 <mml:mtr>\r
123 <mml:mtd>\r
124 <mml:mrow>\r
125 <mml:mfrac>\r
126 <mml:mrow>\r
127 <mml:mi>&delta;</mml:mi>\r
128 <mml:mi>u</mml:mi>\r
129 </mml:mrow>\r
130 <mml:mrow>\r
131 <mml:mi>&delta;</mml:mi>\r
132 <mml:mi>x</mml:mi>\r
133 </mml:mrow>\r
134 </mml:mfrac>\r
135 <mml:mo>=</mml:mo>\r
136 <mml:mn>0</mml:mn>\r
137 <mml:mo>,</mml:mo>\r
138 </mml:mrow>\r
139 </mml:mtd>\r
140 <mml:mtd>\r
141 <mml:mrow>\r
142 <mml:mfrac>\r
143 <mml:mrow>\r
144 <mml:mi>&delta;</mml:mi>\r
145 <mml:mi>v</mml:mi>\r
146 </mml:mrow>\r
147 <mml:mrow>\r
148 <mml:mi>&delta;</mml:mi>\r
149 <mml:mi>x</mml:mi>\r
150 </mml:mrow>\r
151 </mml:mfrac>\r
152 <mml:mo>=</mml:mo>\r
153 <mml:mn>0</mml:mn>\r
154 <mml:mo>,</mml:mo>\r
155 </mml:mrow>\r
156 </mml:mtd>\r
157 <mml:mtd>\r
158 <mml:mrow>\r
159 <mml:mfrac>\r
160 <mml:mrow>\r
161 <mml:mi>&delta;</mml:mi>\r
162 <mml:mi>w</mml:mi>\r
163 </mml:mrow>\r
164 <mml:mrow>\r
165 <mml:mi>&delta;</mml:mi>\r
166 <mml:mi>x</mml:mi>\r
167 </mml:mrow>\r
168 </mml:mfrac>\r
169 <mml:mo>=</mml:mo>\r
170 <mml:mn>0</mml:mn>\r
171 </mml:mrow>\r
172 </mml:mtd>\r
173 </mml:mtr>\r
174 <mml:mtr>\r
175 <mml:mtd>\r
176 <mml:mrow>\r
177 <mml:mfrac>\r
178 <mml:mrow>\r
179 <mml:mi>&delta;</mml:mi>\r
180 <mml:mi>u</mml:mi>\r
181 </mml:mrow>\r
182 <mml:mrow>\r
183 <mml:mi>&delta;</mml:mi>\r
184 <mml:mi>y</mml:mi>\r
185 </mml:mrow>\r
186 </mml:mfrac>\r
187 <mml:mo>=</mml:mo>\r
188 <mml:mn>0</mml:mn>\r
189 <mml:mo>,</mml:mo>\r
190 </mml:mrow>\r
191 </mml:mtd>\r
192 <mml:mtd>\r
193 <mml:mrow>\r
194 <mml:mfrac>\r
195 <mml:mrow>\r
196 <mml:mi>&delta;</mml:mi>\r
197 <mml:mi>v</mml:mi>\r
198 </mml:mrow>\r
199 <mml:mrow>\r
200 <mml:mi>&delta;</mml:mi>\r
201 <mml:mi>y</mml:mi>\r
202 </mml:mrow>\r
203 </mml:mfrac>\r
204 <mml:mo>=</mml:mo>\r
205 <mml:mn>0</mml:mn>\r
206 <mml:mo>,</mml:mo>\r
207 </mml:mrow>\r
208 </mml:mtd>\r
209 <mml:mtd>\r
210 <mml:mrow>\r
211 <mml:mfrac>\r
212 <mml:mrow>\r
213 <mml:mi>&delta;</mml:mi>\r
214 <mml:mi>w</mml:mi>\r
215 </mml:mrow>\r
216 <mml:mrow>\r
217 <mml:mi>&delta;</mml:mi>\r
218 <mml:mi>y</mml:mi>\r
219 </mml:mrow>\r
220 </mml:mfrac>\r
221 <mml:mo>=</mml:mo>\r
222 <mml:mn>0</mml:mn>\r
223 </mml:mrow>\r
224 </mml:mtd>\r
225 </mml:mtr>\r
226 </mml:mtable>\r
227 </mml:math></inlineequation>\r
228 </para>\r
229 </refsect1>\r
230 <refsect1 id="versions"><title>Version Support</title>\r
231 <informaltable frame="topbot">\r
232 #VARTABLECOLS#\r
233 <thead>\r
234 #FUNCTABLEHEADER#\r
235 <row>\r
236 <entry>textureLod</entry>#newin13#\r
237 </row>\r
238 <row>\r
239 <entry>textureLod (gsampler2DRect{Shadow})</entry>#newin14#\r
240 </row>\r
241 <row>\r
242 <entry>textureLod (gsamplerCubeArray)</entry>#newin40#\r
243 </row>\r
244 </thead>\r
245 </tgroup>\r
246 </informaltable>\r
247 </refsect1>\r
248 <refsect1 id="seealso"><title>See Also</title>\r
249 <para>\r
250 <citerefentry><refentrytitle>texelFetch</refentrytitle></citerefentry>,\r
251 <citerefentry><refentrytitle>texelFetchOffset</refentrytitle></citerefentry>,\r
252 <citerefentry><refentrytitle>texture</refentrytitle></citerefentry>,\r
253 <citerefentry><refentrytitle>textureGather</refentrytitle></citerefentry>,\r
254 <citerefentry><refentrytitle>textureGatherOffset</refentrytitle></citerefentry>,\r
255 <citerefentry><refentrytitle>textureGatherOffsets</refentrytitle></citerefentry>,\r
256 <citerefentry><refentrytitle>textureGrad</refentrytitle></citerefentry>,\r
257 <citerefentry><refentrytitle>textureGradOffset</refentrytitle></citerefentry>,\r
258 <citerefentry><refentrytitle>textureLodOffset</refentrytitle></citerefentry>,\r
259 <citerefentry><refentrytitle>textureOffset</refentrytitle></citerefentry>,\r
260 <citerefentry><refentrytitle>textureProj</refentrytitle></citerefentry>,\r
261 <citerefentry><refentrytitle>textureProjGrad</refentrytitle></citerefentry>,\r
262 <citerefentry><refentrytitle>textureProjGradOffset</refentrytitle></citerefentry>,\r
263 <citerefentry><refentrytitle>textureProjLod</refentrytitle></citerefentry>,\r
264 <citerefentry><refentrytitle>textureProjLodOffset</refentrytitle></citerefentry>,\r
265 <citerefentry><refentrytitle>textureProjOffset</refentrytitle></citerefentry>,\r
266 <citerefentry><refentrytitle>textureQueryLod</refentrytitle></citerefentry>,\r
267 <citerefentry><refentrytitle>textureSize</refentrytitle></citerefentry>\r
268 </para>\r
269 </refsect1>\r
270 <refsect1 id="Copyright"><title>Copyright</title>\r
271 <para>\r
272 Copyright <trademark class="copyright"></trademark> 2011 Khronos Group. \r
273 This material may be distributed subject to the terms and conditions set forth in \r
274 the Open Publication License, v 1.0, 8 June 1999.\r
275 <ulink url="http://opencontent.org/openpub/">http://opencontent.org/openpub/</ulink>.\r
276 </para>\r
277 </refsect1>\r
278</refentry>\r