upstream-doc/man3/xhtml/glDrawRangeElements.xml

   1 <?xml version="1.0" encoding="UTF-8"?>
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   3 <!-- saved from url=(0013)about:internet -->
   4 <?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" /><link rel="stylesheet" type="text/css" href="opengl-man.css" /><title>glDrawRangeElements</title><meta name="generator" content="DocBook XSL Stylesheets V1.69.1" /></head><body><div class="refentry" lang="en" xml:lang="en"><a id="glDrawRangeElements"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>glDrawRangeElements — render primitives from array data</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">glDrawRangeElements</b>(</code></td><td>GLenum  </td><td><var class="pdparam">mode</var>, </td></tr><tr><td> </td><td>GLuint  </td><td><var class="pdparam">start</var>, </td></tr><tr><td> </td><td>GLuint  </td><td><var class="pdparam">end</var>, </td></tr><tr><td> </td><td>GLsizei  </td><td><var class="pdparam">count</var>, </td></tr><tr><td> </td><td>GLenum  </td><td><var class="pdparam">type</var>, </td></tr><tr><td> </td><td>const GLvoid *  </td><td><var class="pdparam">indices</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>mode</code></em></span></dt><dd><p>
   5                     Specifies what kind of primitives to render.
   6                     Symbolic constants
   7                     <code class="constant">GL_POINTS</code>,
   8                     <code class="constant">GL_LINE_STRIP</code>,
   9                     <code class="constant">GL_LINE_LOOP</code>,
  10                     <code class="constant">GL_LINES</code>,
  11                     <code class="constant">GL_LINE_STRIP_ADJACENCY</code>,
  12                     <code class="constant">GL_LINES_ADJACENCY</code>,
  13                     <code class="constant">GL_TRIANGLE_STRIP</code>,
  14                     <code class="constant">GL_TRIANGLE_FAN</code>,
  15                     <code class="constant">GL_TRIANGLES</code>,
  16                     <code class="constant">GL_TRIANGLE_STRIP_ADJACENCY</code> and
  17                     <code class="constant">GL_TRIANGLES_ADJACENCY</code>
  18                     are accepted.
  19                 </p></dd><dt><span class="term"><em class="parameter"><code>start</code></em></span></dt><dd><p>
  20                     Specifies the minimum array index contained in <em class="parameter"><code>indices</code></em>.
  21                 </p></dd><dt><span class="term"><em class="parameter"><code>end</code></em></span></dt><dd><p>
  22                     Specifies the maximum array index contained in <em class="parameter"><code>indices</code></em>.
  23                 </p></dd><dt><span class="term"><em class="parameter"><code>count</code></em></span></dt><dd><p>
  24                     Specifies the number of elements to be rendered.
  25                 </p></dd><dt><span class="term"><em class="parameter"><code>type</code></em></span></dt><dd><p>
  26                     Specifies the type of the values in <em class="parameter"><code>indices</code></em>. Must be one of
  27                     <code class="constant">GL_UNSIGNED_BYTE</code>, <code class="constant">GL_UNSIGNED_SHORT</code>, or
  28                     <code class="constant">GL_UNSIGNED_INT</code>.
  29                 </p></dd><dt><span class="term"><em class="parameter"><code>indices</code></em></span></dt><dd><p>
  30                     Specifies a pointer to the location where the indices are stored.
  31                 </p></dd></dl></div></div><div class="refsect1" lang="en" xml:lang="en"><a id="description"></a><h2>Description</h2><p>
  32             <code class="function">glDrawRangeElements</code> is a restricted form of <a href="glDrawElements.xml"><span class="citerefentry"><span class="refentrytitle">glDrawElements</span></span></a>. <em class="parameter"><code>mode</code></em>, <em class="parameter"><code>start</code></em>, <em class="parameter"><code>end</code></em>,
  33             and <em class="parameter"><code>count</code></em> match the corresponding arguments to <a href="glDrawElements.xml"><span class="citerefentry"><span class="refentrytitle">glDrawElements</span></span></a>, with
  34             the additional constraint that all values in the arrays <em class="parameter"><code>count</code></em> must lie
  35             between <em class="parameter"><code>start</code></em> and <em class="parameter"><code>end</code></em>, inclusive.
  36         </p><p>
  37             Implementations denote recommended maximum amounts of vertex and
  38             index data,
  39             which may be queried by calling <a href="glGet.xml"><span class="citerefentry"><span class="refentrytitle">glGet</span></span></a> with argument
  40             <code class="constant">GL_MAX_ELEMENTS_VERTICES</code> and <code class="constant">GL_MAX_ELEMENTS_INDICES</code>.
  41             If
  42             <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
  43
  44                 <mml:mrow>
  45                     <mml:mi mathvariant="italic">end</mml:mi>
  46                     <mml:mo>-</mml:mo>
  47                     <mml:mi mathvariant="italic">start</mml:mi>
  48                     <mml:mo>+</mml:mo>
  49                     <mml:mn>1</mml:mn>
  50                 </mml:mrow>
  51             </mml:math>
  52             is greater than the value of
  53             <code class="constant">GL_MAX_ELEMENTS_VERTICES</code>, or if <em class="parameter"><code>count</code></em> is greater than the value of
  54             <code class="constant">GL_MAX_ELEMENTS_INDICES</code>, then the call may operate at reduced
  55             performance.  There is no requirement that all vertices in the range
  56             <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
  57
  58                 <mml:mfenced open="[" close="]">
  59                     <mml:mi mathvariant="italic">start</mml:mi>
  60                     <mml:mi mathvariant="italic">end</mml:mi>
  61                 </mml:mfenced>
  62             </mml:math>
  63             be referenced.  However, the implementation may
  64             partially process unused vertices, reducing performance from what could
  65             be achieved with an optimal index set.
  66         </p><p>
  67             When <code class="function">glDrawRangeElements</code> is called, it uses <em class="parameter"><code>count</code></em> sequential elements from an
  68             enabled array, starting at <em class="parameter"><code>start</code></em> to construct a sequence of
  69             geometric primitives. <em class="parameter"><code>mode</code></em> specifies what kind of primitives are
  70             constructed, and how the array elements construct these primitives. If
  71             more than one array is enabled, each is used.
  72         </p><p>
  73             Vertex attributes that are modified by <code class="function">glDrawRangeElements</code> have an
  74             unspecified value after <code class="function">glDrawRangeElements</code> returns. Attributes that aren't
  75             modified maintain their previous values.
  76         </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="notes"></a><h2>Notes</h2><p>
  77             <code class="constant">GL_LINE_STRIP_ADJACENCY</code>,
  78             <code class="constant">GL_LINES_ADJACENCY</code>,
  79             <code class="constant">GL_TRIANGLE_STRIP_ADJACENCY</code> and
  80             <code class="constant">GL_TRIANGLES_ADJACENCY</code>
  81             are available only if the GL version is 3.2 or greater.
  82         </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="errors"></a><h2>Errors</h2><p>
  83             It is an error for indices to lie outside the range
  84             <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
  85
  86                 <mml:mfenced open="[" close="]">
  87                     <mml:mi mathvariant="italic">start</mml:mi>
  88                     <mml:mi mathvariant="italic">end</mml:mi>
  89                 </mml:mfenced>
  90             </mml:math>,
  91             but implementations may not check for this situation. Such indices
  92             cause implementation-dependent behavior.
  93         </p><p>
  94             <code class="constant">GL_INVALID_ENUM</code> is generated if <em class="parameter"><code>mode</code></em> is not an accepted value.
  95         </p><p>
  96             <code class="constant">GL_INVALID_VALUE</code> is generated if <em class="parameter"><code>count</code></em> is negative.
  97         </p><p>
  98             <code class="constant">GL_INVALID_VALUE</code> is generated if
  99             <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
 100
 101                 <mml:mrow>
 102                     <mml:mi mathvariant="italic">end</mml:mi>
 103                     <mml:mo>&lt;</mml:mo>
 104                     <mml:mi mathvariant="italic">start</mml:mi>
 105                 </mml:mrow>
 106             </mml:math>.
 107         </p><p>
 108             <code class="constant">GL_INVALID_OPERATION</code> is generated if a geometry shader is active and <em class="parameter"><code>mode</code></em>
 109             is incompatible with the input primitive type of the geometry shader in the currently installed program object.
 110         </p><p>
 111             <code class="constant">GL_INVALID_OPERATION</code> is generated if a non-zero buffer object name is bound to an
 112             enabled array or the element array and the buffer object's data store is currently mapped.
 113         </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="associatedgets"></a><h2>Associated Gets</h2><p>
 114             <a href="glGet.xml"><span class="citerefentry"><span class="refentrytitle">glGet</span></span></a> with argument <code class="constant">GL_MAX_ELEMENTS_VERTICES</code>
 115         </p><p>
 116             <a href="glGet.xml"><span class="citerefentry"><span class="refentrytitle">glGet</span></span></a> with argument <code class="constant">GL_MAX_ELEMENTS_INDICES</code>
 117         </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="seealso"></a><h2>See Also</h2><p>
 118             <a href="glDrawArrays.xml"><span class="citerefentry"><span class="refentrytitle">glDrawArrays</span></span></a>,
 119             <a href="glDrawElements.xml"><span class="citerefentry"><span class="refentrytitle">glDrawElements</span></span></a>,
 120             <a href="glDrawElementsBaseVertex.xml"><span class="citerefentry"><span class="refentrytitle">glDrawElementsBaseVertex</span></span></a>
 121         </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="Copyright"></a><h2>Copyright</h2><p>
 122             Copyright <span class="trademark"></span>© 1991-2006
 123             Silicon Graphics, Inc. This document is licensed under the SGI
 124             Free Software B License. For details, see
 125             <a href="http://oss.sgi.com/projects/FreeB/" target="_top">http://oss.sgi.com/projects/FreeB/</a>.
 126         </p></div></div></body></html>