upstream-doc/man2/glDrawRangeElements.xml

   1 <?xml version="1.0" encoding="UTF-8"?>
   2 <!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook MathML Module V1.1b1//EN"
   3               "http://www.oasis-open.org/docbook/xml/mathml/1.1CR1/dbmathml.dtd">
   4 <refentry id="glDrawRangeElements">
   5     <refmeta>
   6         <refmetainfo>
   7             <copyright>
   8                 <year>1991-2006</year>
   9                 <holder>Silicon Graphics, Inc.</holder>
  10             </copyright>
  11         </refmetainfo>
  12         <refentrytitle>glDrawRangeElements</refentrytitle>
  13         <manvolnum>3G</manvolnum>
  14     </refmeta>
  15     <refnamediv>
  16         <refname>glDrawRangeElements</refname>
  17         <refpurpose>render primitives from array data</refpurpose>
  18     </refnamediv>
  19     <refsynopsisdiv><title>C Specification</title>
  20         <funcsynopsis>
  21             <funcprototype>
  22                 <funcdef>void <function>glDrawRangeElements</function></funcdef>
  23                 <paramdef>GLenum <parameter>mode</parameter></paramdef>
  24                 <paramdef>GLuint <parameter>start</parameter></paramdef>
  25                 <paramdef>GLuint <parameter>end</parameter></paramdef>
  26                 <paramdef>GLsizei <parameter>count</parameter></paramdef>
  27                 <paramdef>GLenum <parameter>type</parameter></paramdef>
  28                 <paramdef>const GLvoid * <parameter>indices</parameter></paramdef>
  29             </funcprototype>
  30         </funcsynopsis>
  31     </refsynopsisdiv>
  32     <!-- eqn: ignoring delim $$ -->
  33     <refsect1 id="parameters"><title>Parameters</title>
  34         <variablelist>
  35         <varlistentry>
  36             <term><parameter>mode</parameter></term>
  37             <listitem>
  38                 <para>
  39                     Specifies what kind of primitives to render.
  40                     Symbolic constants
  41                     <constant>GL_POINTS</constant>,
  42                     <constant>GL_LINE_STRIP</constant>,
  43                     <constant>GL_LINE_LOOP</constant>,
  44                     <constant>GL_LINES</constant>,
  45                     <constant>GL_TRIANGLE_STRIP</constant>,
  46                     <constant>GL_TRIANGLE_FAN</constant>,
  47                     <constant>GL_TRIANGLES</constant>,
  48                     <constant>GL_QUAD_STRIP</constant>,
  49                     <constant>GL_QUADS</constant>,
  50                     and <constant>GL_POLYGON</constant> are accepted.
  51                 </para>
  52             </listitem>
  53         </varlistentry>
  54         <varlistentry>
  55             <term><parameter>start</parameter></term>
  56             <listitem>
  57                 <para>
  58                     Specifies the minimum array index contained in <parameter>indices</parameter>.
  59                 </para>
  60             </listitem>
  61         </varlistentry>
  62         <varlistentry>
  63             <term><parameter>end</parameter></term>
  64             <listitem>
  65                 <para>
  66                     Specifies the maximum array index contained in <parameter>indices</parameter>.
  67                 </para>
  68             </listitem>
  69         </varlistentry>
  70         <varlistentry>
  71             <term><parameter>count</parameter></term>
  72             <listitem>
  73                 <para>
  74                     Specifies the number of elements to be rendered.
  75                 </para>
  76             </listitem>
  77         </varlistentry>
  78         <varlistentry>
  79             <term><parameter>type</parameter></term>
  80             <listitem>
  81                 <para>
  82                     Specifies the type of the values in <parameter>indices</parameter>. Must be one of
  83                     <constant>GL_UNSIGNED_BYTE</constant>, <constant>GL_UNSIGNED_SHORT</constant>, or
  84                     <constant>GL_UNSIGNED_INT</constant>.
  85                 </para>
  86             </listitem>
  87         </varlistentry>
  88         <varlistentry>
  89             <term><parameter>indices</parameter></term>
  90             <listitem>
  91                 <para>
  92                     Specifies a pointer to the location where the indices are stored.
  93                 </para>
  94             </listitem>
  95         </varlistentry>
  96         </variablelist>
  97     </refsect1>
  98     <refsect1 id="description"><title>Description</title>
  99         <para>
 100             <function>glDrawRangeElements</function> is a restricted form of <citerefentry><refentrytitle>glDrawElements</refentrytitle></citerefentry>. <parameter>mode</parameter>, <parameter>start</parameter>, <parameter>end</parameter>,
 101             and <parameter>count</parameter> match the corresponding arguments to <citerefentry><refentrytitle>glDrawElements</refentrytitle></citerefentry>, with
 102             the additional constraint that all values in the arrays <parameter>count</parameter> must lie
 103             between <parameter>start</parameter> and <parameter>end</parameter>, inclusive.
 104         </para>
 105         <para>
 106             Implementations denote recommended maximum amounts of vertex and
 107             index data,
 108             which may be queried by calling <citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with argument
 109             <constant>GL_MAX_ELEMENTS_VERTICES</constant> and <constant>GL_MAX_ELEMENTS_INDICES</constant>.
 110             If
 111             <inlineequation><mml:math>
 112                 <!-- eqn: end  -  start  +  1:-->
 113                 <mml:mrow>
 114                     <mml:mi mathvariant="italic">end</mml:mi>
 115                     <mml:mo>-</mml:mo>
 116                     <mml:mi mathvariant="italic">start</mml:mi>
 117                     <mml:mo>+</mml:mo>
 118                     <mml:mn>1</mml:mn>
 119                 </mml:mrow>
 120             </mml:math></inlineequation>
 121             is greater than the value of
 122             <constant>GL_MAX_ELEMENTS_VERTICES</constant>, or if <parameter>count</parameter> is greater than the value of
 123             <constant>GL_MAX_ELEMENTS_INDICES</constant>, then the call may operate at reduced
 124             performance.  There is no requirement that all vertices in the range
 125             <inlineequation><mml:math>
 126                 <!-- eqn: [start, end]:-->
 127                 <mml:mfenced open="[" close="]">
 128                     <mml:mi mathvariant="italic">start</mml:mi>
 129                     <mml:mi mathvariant="italic">end</mml:mi>
 130                 </mml:mfenced>
 131             </mml:math></inlineequation>
 132             be referenced.  However, the implementation may
 133             partially process unused vertices, reducing performance from what could
 134             be achieved with an optimal index set.
 135         </para>
 136         <para>
 137             When <function>glDrawRangeElements</function> is called, it uses <parameter>count</parameter> sequential elements from an
 138             enabled array, starting at <parameter>start</parameter> to construct a sequence of
 139             geometric primitives. <parameter>mode</parameter> specifies what kind of primitives are
 140             constructed, and how the array elements construct these primitives. If
 141             more than one array is enabled, each is used. If
 142             <constant>GL_VERTEX_ARRAY</constant> is not enabled, no geometric primitives are
 143             constructed.
 144         </para>
 145         <para>
 146             Vertex attributes that are modified by <function>glDrawRangeElements</function> have an
 147             unspecified value after <function>glDrawRangeElements</function> returns. For example, if
 148             <constant>GL_COLOR_ARRAY</constant> is enabled, the value of the current color is
 149             undefined after <function>glDrawRangeElements</function> executes. Attributes that aren't
 150             modified maintain their previous values.
 151         </para>
 152     </refsect1>
 153     <refsect1 id="notes"><title>Notes</title>
 154         <para>
 155             <function>glDrawRangeElements</function> is available only if the GL version is 1.2 or greater.
 156         </para>
 157         <para>
 158             <function>glDrawRangeElements</function> is included in display lists. If <function>glDrawRangeElements</function> is entered into a
 159             display list,
 160             the necessary array data (determined by the array pointers and
 161             enables) is also
 162             entered into the display list. Because the array pointers and
 163             enables are client-side state, their values affect display lists
 164             when the lists are created, not when the lists are executed.
 165         </para>
 166     </refsect1>
 167     <refsect1 id="errors"><title>Errors</title>
 168         <para>
 169             It is an error for indices to lie outside the range
 170             <inlineequation><mml:math>
 171                 <!-- eqn: [start, end]:-->
 172                 <mml:mfenced open="[" close="]">
 173                     <mml:mi mathvariant="italic">start</mml:mi>
 174                     <mml:mi mathvariant="italic">end</mml:mi>
 175                 </mml:mfenced>
 176             </mml:math></inlineequation>,
 177             but implementations may not check for this situation. Such indices
 178             cause implementation-dependent behavior.
 179         </para>
 180         <para>
 181             <constant>GL_INVALID_ENUM</constant> is generated if <parameter>mode</parameter> is not an accepted value.
 182         </para>
 183         <para>
 184             <constant>GL_INVALID_VALUE</constant> is generated if <parameter>count</parameter> is negative.
 185         </para>
 186         <para>
 187             <constant>GL_INVALID_VALUE</constant> is generated if
 188             <inlineequation><mml:math>
 189                 <!-- eqn: end < start:-->
 190                 <mml:mrow>
 191                     <mml:mi mathvariant="italic">end</mml:mi>
 192                     <mml:mo>&lt;</mml:mo>
 193                     <mml:mi mathvariant="italic">start</mml:mi>
 194                 </mml:mrow>
 195             </mml:math></inlineequation>.
 196         </para>
 197         <para>
 198             <constant>GL_INVALID_OPERATION</constant> is generated if a non-zero buffer object name is bound to an
 199             enabled array or the element array and the buffer object's data store is currently mapped.
 200         </para>
 201         <para>
 202             <constant>GL_INVALID_OPERATION</constant> is generated if <function>glDrawRangeElements</function> is executed between
 203             the execution of <citerefentry><refentrytitle>glBegin</refentrytitle></citerefentry> and the corresponding <citerefentry><refentrytitle>glEnd</refentrytitle></citerefentry>.
 204         </para>
 205     </refsect1>
 206     <refsect1 id="associatedgets"><title>Associated Gets</title>
 207         <para>
 208             <citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with argument <constant>GL_MAX_ELEMENTS_VERTICES</constant>
 209         </para>
 210         <para>
 211             <citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with argument <constant>GL_MAX_ELEMENTS_INDICES</constant>
 212         </para>
 213     </refsect1>
 214     <refsect1 id="seealso"><title>See Also</title>
 215         <para>
 216             <citerefentry><refentrytitle>glArrayElement</refentrytitle></citerefentry>,
 217             <citerefentry><refentrytitle>glColorPointer</refentrytitle></citerefentry>,
 218             <citerefentry><refentrytitle>glDrawArrays</refentrytitle></citerefentry>,
 219             <citerefentry><refentrytitle>glDrawElements</refentrytitle></citerefentry>,
 220             <citerefentry><refentrytitle>glEdgeFlagPointer</refentrytitle></citerefentry>,
 221             <citerefentry><refentrytitle>glGetPointerv</refentrytitle></citerefentry>,
 222             <citerefentry><refentrytitle>glIndexPointer</refentrytitle></citerefentry>,
 223             <citerefentry><refentrytitle>glInterleavedArrays</refentrytitle></citerefentry>,
 224             <citerefentry><refentrytitle>glNormalPointer</refentrytitle></citerefentry>,
 225             <citerefentry><refentrytitle>glSecondaryColorPointer</refentrytitle></citerefentry>,
 226             <citerefentry><refentrytitle>glTexCoordPointer</refentrytitle></citerefentry>,
 227             <citerefentry><refentrytitle>glVertexPointer</refentrytitle></citerefentry>
 228         </para>
 229     </refsect1>
 230     <refsect1 id="Copyright"><title>Copyright</title>
 231         <para>
 232             Copyright <trademark class="copyright"></trademark> 1991-2006
 233             Silicon Graphics, Inc. This document is licensed under the SGI
 234             Free Software B License. For details, see
 235             <ulink url="http://oss.sgi.com/projects/FreeB/">http://oss.sgi.com/projects/FreeB/</ulink>.
 236         </para>
 237     </refsect1>
 238 </refentry>