HCoop / clinton / guile-figl.git / blame
| Commit | Line | Data |
|---|---|---|
| 7faf1d71 AW |
1 | <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "xhtml1-transitional.dtd"> |
| 2 | <!-- saved from url=(0013)about:internet --> | |
| 3 | <?xml-stylesheet type="text/xsl" href="mathml.xsl"?><html xmlns="http://www.w3.org/1999/xhtml" xmlns:pref="http://www.w3.org/2002/Math/preference" pref:renderer="mathplayer-dl"><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /><title>gluNurbsCurve</title><meta name="generator" content="DocBook XSL Stylesheets V1.73.2" /></head><body><div class="refentry" lang="en" xml:lang="en"><a id="gluNurbsCurve"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>gluNurbsCurve — define the shape of a NURBS curve</p></div><div class="refsynopsisdiv"><h2>C Specification</h2><div class="funcsynopsis"><table border="0" summary="Function synopsis" cellspacing="0" cellpadding="0"><tr><td><code class="funcdef">void <b class="fsfunc">gluNurbsCurve</b>(</code></td><td>GLUnurbs* </td><td><var class="pdparam">nurb</var>, </td></tr><tr><td> </td><td>GLint </td><td><var class="pdparam">knotCount</var>, </td></tr><tr><td> </td><td>GLfloat * </td><td><var class="pdparam">knots</var>, </td></tr><tr><td> </td><td>GLint </td><td><var class="pdparam">stride</var>, </td></tr><tr><td> </td><td>GLfloat * </td><td><var class="pdparam">control</var>, </td></tr><tr><td> </td><td>GLint </td><td><var class="pdparam">order</var>, </td></tr><tr><td> </td><td>GLenum </td><td><var class="pdparam">type</var><code>)</code>;</td></tr></table></div></div><div class="refsect1" lang="en" xml:lang="en"><a id="parameters"></a><h2>Parameters</h2><div class="variablelist"><dl><dt><span class="term"><em class="parameter"><code>nurb</code></em></span></dt><dd><p> | |
| 4 | Specifies the NURBS object (created with <a class="citerefentry" href="gluNewNurbsRenderer.xml"><span class="citerefentry"><span class="refentrytitle">gluNewNurbsRenderer</span></span></a>). | |
| 5 | </p></dd><dt><span class="term"><em class="parameter"><code>knotCount</code></em></span></dt><dd><p> | |
| 6 | Specifies the number of knots in <em class="parameter"><code>knots</code></em>. | |
| 7 | <em class="parameter"><code>knotCount</code></em> equals the number of control points plus the order. | |
| 8 | </p></dd><dt><span class="term"><em class="parameter"><code>knots</code></em></span></dt><dd><p> | |
| 9 | Specifies an array of <em class="parameter"><code>knotCount</code></em> nondecreasing knot values. | |
| 10 | </p></dd><dt><span class="term"><em class="parameter"><code>stride</code></em></span></dt><dd><p> | |
| 11 | Specifies the offset (as a number of single-precision floating-point values) | |
| 12 | between successive curve control points. | |
| 13 | </p></dd><dt><span class="term"><em class="parameter"><code>control</code></em></span></dt><dd><p> | |
| 14 | Specifies a pointer to an array of control points. The coordinates must | |
| 15 | agree with <em class="parameter"><code>type</code></em>, specified below. | |
| 16 | </p></dd><dt><span class="term"><em class="parameter"><code>order</code></em></span></dt><dd><p> | |
| 17 | Specifies the order of the NURBS curve. <em class="parameter"><code>order</code></em> equals degree + 1, hence | |
| 18 | a cubic curve has an order of 4. | |
| 19 | </p></dd><dt><span class="term"><em class="parameter"><code>type</code></em></span></dt><dd><p> | |
| 20 | Specifies the type of the curve. If this curve is defined within a | |
| 21 | <a class="citerefentry" href="gluBeginCurve.xml"><span class="citerefentry"><span class="refentrytitle">gluBeginCurve</span></span></a>/<a class="citerefentry" href="gluEndCurve.xml"><span class="citerefentry"><span class="refentrytitle">gluEndCurve</span></span></a> pair, then | |
| 22 | the type can be any of the valid | |
| 23 | one-dimensional evaluator types (such as <code class="constant">GLU_MAP1_VERTEX_3</code> or | |
| 24 | <code class="constant">GLU_MAP1_COLOR_4</code>). Between a <a class="citerefentry" href="gluBeginTrim.xml"><span class="citerefentry"><span class="refentrytitle">gluBeginTrim</span></span></a>/<a class="citerefentry" href="gluEndTrim.xml"><span class="citerefentry"><span class="refentrytitle">gluEndTrim</span></span></a> pair, | |
| 25 | the only valid types are <code class="constant">GLU_MAP1_TRIM_2</code> and <code class="constant">GLU_MAP1_TRIM_3</code>. | |
| 26 | </p></dd></dl></div></div><div class="refsect1" lang="en" xml:lang="en"><a id="description"></a><h2>Description</h2><p> | |
| 27 | Use <code class="function">gluNurbsCurve</code> to describe a NURBS curve. | |
| 28 | </p><p> | |
| 29 | When <code class="function">gluNurbsCurve</code> appears between a <a class="citerefentry" href="gluBeginCurve.xml"><span class="citerefentry"><span class="refentrytitle">gluBeginCurve</span></span></a>/<a class="citerefentry" href="gluEndCurve.xml"><span class="citerefentry"><span class="refentrytitle">gluEndCurve</span></span></a> pair, it is | |
| 30 | used to describe a curve to be rendered. | |
| 31 | Positional, texture, and color coordinates are associated | |
| 32 | by presenting each as a separate <code class="function">gluNurbsCurve</code> between a | |
| 33 | <a class="citerefentry" href="gluBeginCurve.xml"><span class="citerefentry"><span class="refentrytitle">gluBeginCurve</span></span></a>/<a class="citerefentry" href="gluEndCurve.xml"><span class="citerefentry"><span class="refentrytitle">gluEndCurve</span></span></a> pair. No more than | |
| 34 | one call to <code class="function">gluNurbsCurve</code> for each of color, position, and texture | |
| 35 | data can be made within a single <a class="citerefentry" href="gluBeginCurve.xml"><span class="citerefentry"><span class="refentrytitle">gluBeginCurve</span></span></a>/<a class="citerefentry" href="gluEndCurve.xml"><span class="citerefentry"><span class="refentrytitle">gluEndCurve</span></span></a> | |
| 36 | pair. Exactly one call must be made to describe the position of the | |
| 37 | curve (a <em class="parameter"><code>type</code></em> of <code class="constant">GLU_MAP1_VERTEX_3</code> or <code class="constant">GLU_MAP1_VERTEX_4</code>). | |
| 38 | </p><p> | |
| 39 | When <code class="function">gluNurbsCurve</code> appears between a <a class="citerefentry" href="gluBeginTrim.xml"><span class="citerefentry"><span class="refentrytitle">gluBeginTrim</span></span></a>/<a class="citerefentry" href="gluEndTrim.xml"><span class="citerefentry"><span class="refentrytitle">gluEndTrim</span></span></a> pair, it is | |
| 40 | used to describe a trimming curve on a NURBS surface. If <em class="parameter"><code>type</code></em> is | |
| 41 | <code class="constant">GLU_MAP1_TRIM_2</code>, then it describes a curve in two-dimensional (<span class="emphasis"><em>u</em></span> | |
| 42 | and <span class="emphasis"><em>v</em></span>) | |
| 43 | parameter space. If it is <code class="constant">GLU_MAP1_TRIM_3</code>, then it describes a | |
| 44 | curve in two-dimensional homogeneous (<span class="emphasis"><em>u</em></span>, <span class="emphasis"><em>v</em></span>, and <span class="emphasis"><em>w</em></span>) | |
| 45 | parameter space. | |
| 46 | See the <a class="citerefentry" href="gluBeginTrim.xml"><span class="citerefentry"><span class="refentrytitle">gluBeginTrim</span></span></a> reference page for more discussion about trimming | |
| 47 | curves. | |
| 48 | </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="example"></a><h2>Example</h2><p> | |
| 49 | The following commands render a textured NURBS curve with normals: | |
| 50 | </p><pre class="programlisting"> | |
| 51 | gluBeginCurve(nobj); | |
| 52 | gluNurbsCurve(nobj, ..., GL_MAP1_TEXTURE_COORD_2); | |
| 53 | gluNurbsCurve(nobj, ..., GL_MAP1_NORMAL); | |
| 54 | gluNurbsCurve(nobj, ..., GL_MAP1_VERTEX_4); | |
| 55 | gluEndCurve(nobj); | |
| 56 | </pre><p> | |
| 57 | </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="notes"></a><h2>Notes</h2><p> | |
| 58 | To define trim curves that stitch well, use <a class="citerefentry" href="gluPwlCurve.xml"><span class="citerefentry"><span class="refentrytitle">gluPwlCurve</span></span></a>. | |
| 59 | </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="seealso"></a><h2>See Also</h2><p> | |
| 60 | <a class="citerefentry" href="gluBeginCurve.xml"><span class="citerefentry"><span class="refentrytitle">gluBeginCurve</span></span></a>, | |
| 61 | <a class="citerefentry" href="gluBeginTrim.xml"><span class="citerefentry"><span class="refentrytitle">gluBeginTrim</span></span></a>, | |
| 62 | <a class="citerefentry" href="gluNewNurbsRenderer.xml"><span class="citerefentry"><span class="refentrytitle">gluNewNurbsRenderer</span></span></a>, | |
| 63 | <a class="citerefentry" href="gluPwlCurve.xml"><span class="citerefentry"><span class="refentrytitle">gluPwlCurve</span></span></a> | |
| 64 | </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="Copyright"></a><h2>Copyright</h2><p> | |
| 65 | Copyright <span class="trademark"></span>© 1991-2006 | |
| 66 | Silicon Graphics, Inc. This document is licensed under the SGI | |
| 67 | Free Software B License. For details, see | |
| 68 | <a class="ulink" href="http://oss.sgi.com/projects/FreeB/" target="_top">http://oss.sgi.com/projects/FreeB/</a>. | |
| 69 | </p></div></div></body></html> |