upstream-doc/man2/xhtml/glMapGrid.xml

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   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>glMapGrid</title><meta name="generator" content="DocBook XSL Stylesheets V1.73.2" /></head><body><div class="refentry" lang="en" xml:lang="en"><a id="glMapGrid"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>glMapGrid — define a one- or two-dimensional mesh</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">glMapGrid1d</b>(</code></td><td>GLint  </td><td><var class="pdparam">un</var>, </td></tr><tr><td> </td><td>GLdouble  </td><td><var class="pdparam">u1</var>, </td></tr><tr><td> </td><td>GLdouble  </td><td><var class="pdparam">u2</var><code>)</code>;</td></tr></table></div><div class="funcsynopsis"><table border="0" summary="Function synopsis" cellspacing="0" cellpadding="0"><tr><td><code class="funcdef">void <b class="fsfunc">glMapGrid1f</b>(</code></td><td>GLint  </td><td><var class="pdparam">un</var>, </td></tr><tr><td> </td><td>GLfloat  </td><td><var class="pdparam">u1</var>, </td></tr><tr><td> </td><td>GLfloat  </td><td><var class="pdparam">u2</var><code>)</code>;</td></tr></table></div><div class="funcsynopsis"><table border="0" summary="Function synopsis" cellspacing="0" cellpadding="0"><tr><td><code class="funcdef">void <b class="fsfunc">glMapGrid2d</b>(</code></td><td>GLint  </td><td><var class="pdparam">un</var>, </td></tr><tr><td> </td><td>GLdouble  </td><td><var class="pdparam">u1</var>, </td></tr><tr><td> </td><td>GLdouble  </td><td><var class="pdparam">u2</var>, </td></tr><tr><td> </td><td>GLint  </td><td><var class="pdparam">vn</var>, </td></tr><tr><td> </td><td>GLdouble  </td><td><var class="pdparam">v1</var>, </td></tr><tr><td> </td><td>GLdouble  </td><td><var class="pdparam">v2</var><code>)</code>;</td></tr></table></div><div class="funcsynopsis"><table border="0" summary="Function synopsis" cellspacing="0" cellpadding="0"><tr><td><code class="funcdef">void <b class="fsfunc">glMapGrid2f</b>(</code></td><td>GLint  </td><td><var class="pdparam">un</var>, </td></tr><tr><td> </td><td>GLfloat  </td><td><var class="pdparam">u1</var>, </td></tr><tr><td> </td><td>GLfloat  </td><td><var class="pdparam">u2</var>, </td></tr><tr><td> </td><td>GLint  </td><td><var class="pdparam">vn</var>, </td></tr><tr><td> </td><td>GLfloat  </td><td><var class="pdparam">v1</var>, </td></tr><tr><td> </td><td>GLfloat  </td><td><var class="pdparam">v2</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>un</code></em></span></dt><dd><p>
   4                     Specifies the number of partitions in the grid range interval
   5                     [<em class="parameter"><code>u1</code></em>, <em class="parameter"><code>u2</code></em>].
   6                     Must be positive.
   7                 </p></dd><dt><span class="term"><em class="parameter"><code>u1</code></em>, </span><span class="term"><em class="parameter"><code>u2</code></em></span></dt><dd><p>
   8                     Specify the mappings for integer grid domain values
   9                     <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
  10
  11                         <mml:mrow>
  12                             <mml:mi mathvariant="italic">i</mml:mi>
  13                             <mml:mo>=</mml:mo>
  14                             <mml:mn>0</mml:mn>
  15                         </mml:mrow>
  16                     </mml:math>
  17                     and
  18                     <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
  19
  20                         <mml:mrow>
  21                             <mml:mi mathvariant="italic">i</mml:mi>
  22                             <mml:mo>=</mml:mo>
  23                             <mml:mi mathvariant="italic">un</mml:mi>
  24                         </mml:mrow>
  25                     </mml:math>.
  26                 </p></dd><dt><span class="term"><em class="parameter"><code>vn</code></em></span></dt><dd><p>
  27                     Specifies the number of partitions in the grid range interval
  28                     [<em class="parameter"><code>v1</code></em>, <em class="parameter"><code>v2</code></em>]
  29                     (<code class="function">glMapGrid2</code> only).
  30                 </p></dd><dt><span class="term"><em class="parameter"><code>v1</code></em>, </span><span class="term"><em class="parameter"><code>v2</code></em></span></dt><dd><p>
  31                     Specify the mappings for integer grid domain values
  32                     <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
  33
  34                         <mml:mrow>
  35                             <mml:mi mathvariant="italic">j</mml:mi>
  36                             <mml:mo>=</mml:mo>
  37                             <mml:mn>0</mml:mn>
  38                         </mml:mrow>
  39                     </mml:math>
  40                     and
  41                     <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
  42
  43                         <mml:mrow>
  44                             <mml:mi mathvariant="italic">j</mml:mi>
  45                             <mml:mo>=</mml:mo>
  46                             <mml:mi mathvariant="italic">vn</mml:mi>
  47                         </mml:mrow>
  48                     </mml:math>
  49                     (<code class="function">glMapGrid2</code> only).
  50                 </p></dd></dl></div></div><div class="refsect1" lang="en" xml:lang="en"><a id="description"></a><h2>Description</h2><p>
  51             <code class="function">glMapGrid</code> and <a class="citerefentry" href="glEvalMesh.xml"><span class="citerefentry"><span class="refentrytitle">glEvalMesh</span></span></a> are used together to efficiently
  52             generate and evaluate a series of evenly-spaced map domain values.
  53             <a class="citerefentry" href="glEvalMesh.xml"><span class="citerefentry"><span class="refentrytitle">glEvalMesh</span></span></a> steps through the integer domain
  54             of a one- or two-dimensional grid,
  55             whose range is the domain of the evaluation maps specified by
  56             <a class="citerefentry" href="glMap1.xml"><span class="citerefentry"><span class="refentrytitle">glMap1</span></span></a> and <a class="citerefentry" href="glMap2.xml"><span class="citerefentry"><span class="refentrytitle">glMap2</span></span></a>.
  57         </p><p>
  58             <code class="function">glMapGrid1</code> and <code class="function">glMapGrid2</code> specify the linear grid mappings
  59             between the
  60             <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">i</mml:mi></mml:math>
  61             (or
  62             <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">i</mml:mi></mml:math>
  63             and
  64             <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">j</mml:mi></mml:math>)
  65             integer grid coordinates,
  66             to the
  67             <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">u</mml:mi></mml:math>
  68             (or
  69             <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">u</mml:mi></mml:math>
  70             and
  71             <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">v</mml:mi></mml:math>)
  72             floating-point evaluation map coordinates.
  73             See <a class="citerefentry" href="glMap1.xml"><span class="citerefentry"><span class="refentrytitle">glMap1</span></span></a> and <a class="citerefentry" href="glMap2.xml"><span class="citerefentry"><span class="refentrytitle">glMap2</span></span></a> for details of how
  74             <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">u</mml:mi></mml:math>
  75             and
  76             <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">v</mml:mi></mml:math>
  77             coordinates
  78             are evaluated.
  79         </p><p>
  80             <code class="function">glMapGrid1</code> specifies a single linear mapping
  81             such that integer grid coordinate 0 maps exactly to <em class="parameter"><code>u1</code></em>,
  82             and integer grid coordinate <em class="parameter"><code>un</code></em> maps exactly to <em class="parameter"><code>u2</code></em>.
  83             All other integer grid coordinates
  84             <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">i</mml:mi></mml:math>
  85             are mapped so that
  86         </p><p>
  87             </p><div class="informalequation"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
  88
  89                 <mml:mrow>
  90                     <mml:mi mathvariant="italic">u</mml:mi>
  91                     <mml:mo>=</mml:mo>
  92                     <mml:mrow>
  93                         <mml:mfrac>
  94                             <mml:mrow>
  95                                 <mml:mi mathvariant="italic">i</mml:mi>
  96                                 <mml:mo>⁡</mml:mo>
  97                                 <mml:mfenced open="(" close=")">
  98                                     <mml:mrow>
  99                                         <mml:mi mathvariant="italic">u2</mml:mi>
 100                                         <mml:mo>-</mml:mo>
 101                                         <mml:mi mathvariant="italic">u1</mml:mi>
 102                                     </mml:mrow>
 103                                 </mml:mfenced>
 104                             </mml:mrow>
 105                             <mml:mi mathvariant="italic">un</mml:mi>
 106                         </mml:mfrac>
 107                         <mml:mo>+</mml:mo>
 108                         <mml:mi mathvariant="italic">u1</mml:mi>
 109                     </mml:mrow>
 110                 </mml:mrow>
 111             </mml:math></div><p>
 112         </p><p>
 113             <code class="function">glMapGrid2</code> specifies two such linear mappings.
 114             One maps integer grid coordinate
 115             <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
 116
 117                 <mml:mrow>
 118                     <mml:mi mathvariant="italic">i</mml:mi>
 119                     <mml:mo>=</mml:mo>
 120                     <mml:mn>0</mml:mn>
 121                 </mml:mrow>
 122             </mml:math>
 123             exactly to <em class="parameter"><code>u1</code></em>,
 124             and integer grid coordinate
 125             <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
 126
 127                 <mml:mrow>
 128                     <mml:mi mathvariant="italic">i</mml:mi>
 129                     <mml:mo>=</mml:mo>
 130                     <mml:mi mathvariant="italic">un</mml:mi>
 131                 </mml:mrow>
 132             </mml:math>
 133             exactly to <em class="parameter"><code>u2</code></em>.
 134             The other maps integer grid coordinate
 135             <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
 136
 137                 <mml:mrow>
 138                     <mml:mi mathvariant="italic">j</mml:mi>
 139                     <mml:mo>=</mml:mo>
 140                     <mml:mn>0</mml:mn>
 141                 </mml:mrow>
 142             </mml:math>
 143             exactly to <em class="parameter"><code>v1</code></em>,
 144             and integer grid coordinate
 145             <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
 146
 147                 <mml:mrow>
 148                     <mml:mi mathvariant="italic">j</mml:mi>
 149                     <mml:mo>=</mml:mo>
 150                     <mml:mi mathvariant="italic">vn</mml:mi>
 151                 </mml:mrow>
 152             </mml:math>
 153             exactly to <em class="parameter"><code>v2</code></em>.
 154             Other integer grid coordinates
 155             <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">i</mml:mi></mml:math>
 156             and
 157             <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">j</mml:mi></mml:math>
 158             are mapped such that
 159         </p><p>
 160             </p><div class="informalequation"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
 161
 162                 <mml:mrow>
 163                     <mml:mi mathvariant="italic">u</mml:mi>
 164                     <mml:mo>=</mml:mo>
 165                     <mml:mrow>
 166                         <mml:mfrac>
 167                             <mml:mrow>
 168                                 <mml:mi mathvariant="italic">i</mml:mi>
 169                                 <mml:mo>⁡</mml:mo>
 170                                 <mml:mfenced open="(" close=")">
 171                                     <mml:mrow>
 172                                         <mml:mi mathvariant="italic">u2</mml:mi>
 173                                         <mml:mo>-</mml:mo>
 174                                         <mml:mi mathvariant="italic">u1</mml:mi>
 175                                     </mml:mrow>
 176                                 </mml:mfenced>
 177                             </mml:mrow>
 178                             <mml:mi mathvariant="italic">un</mml:mi>
 179                         </mml:mfrac>
 180                         <mml:mo>+</mml:mo>
 181                         <mml:mi mathvariant="italic">u1</mml:mi>
 182                     </mml:mrow>
 183                 </mml:mrow>
 184             </mml:math></div><p>
 185         </p><p>
 186             </p><div class="informalequation"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
 187
 188                 <mml:mrow>
 189                     <mml:mi mathvariant="italic">v</mml:mi>
 190                     <mml:mo>=</mml:mo>
 191                     <mml:mrow>
 192                         <mml:mfrac>
 193                             <mml:mrow>
 194                                 <mml:mi mathvariant="italic">j</mml:mi>
 195                                 <mml:mo>⁡</mml:mo>
 196                                 <mml:mfenced open="(" close=")">
 197                                     <mml:mrow>
 198                                         <mml:mi mathvariant="italic">v2</mml:mi>
 199                                         <mml:mo>-</mml:mo>
 200                                         <mml:mi mathvariant="italic">v1</mml:mi>
 201                                     </mml:mrow>
 202                                 </mml:mfenced>
 203                             </mml:mrow>
 204                             <mml:mi mathvariant="italic">vn</mml:mi>
 205                         </mml:mfrac>
 206                         <mml:mo>+</mml:mo>
 207                         <mml:mi mathvariant="italic">v1</mml:mi>
 208                     </mml:mrow>
 209                 </mml:mrow>
 210             </mml:math></div><p>
 211         </p><p>
 212             The mappings specified by <code class="function">glMapGrid</code> are used identically by
 213             <a class="citerefentry" href="glEvalMesh.xml"><span class="citerefentry"><span class="refentrytitle">glEvalMesh</span></span></a> and <a class="citerefentry" href="glEvalPoint.xml"><span class="citerefentry"><span class="refentrytitle">glEvalPoint</span></span></a>.
 214         </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="errors"></a><h2>Errors</h2><p>
 215             <code class="constant">GL_INVALID_VALUE</code> is generated if either <em class="parameter"><code>un</code></em> or <em class="parameter"><code>vn</code></em> is not
 216             positive.
 217         </p><p>
 218             <code class="constant">GL_INVALID_OPERATION</code> is generated if <code class="function">glMapGrid</code>
 219             is executed between the execution of <a class="citerefentry" href="glBegin.xml"><span class="citerefentry"><span class="refentrytitle">glBegin</span></span></a>
 220             and the corresponding execution of <a class="citerefentry" href="glEnd.xml"><span class="citerefentry"><span class="refentrytitle">glEnd</span></span></a>.
 221         </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="associatedgets"></a><h2>Associated Gets</h2><p>
 222             <a class="citerefentry" href="glGet.xml"><span class="citerefentry"><span class="refentrytitle">glGet</span></span></a> with argument <code class="constant">GL_MAP1_GRID_DOMAIN</code>
 223         </p><p>
 224             <a class="citerefentry" href="glGet.xml"><span class="citerefentry"><span class="refentrytitle">glGet</span></span></a> with argument <code class="constant">GL_MAP2_GRID_DOMAIN</code>
 225         </p><p>
 226             <a class="citerefentry" href="glGet.xml"><span class="citerefentry"><span class="refentrytitle">glGet</span></span></a> with argument <code class="constant">GL_MAP1_GRID_SEGMENTS</code>
 227         </p><p>
 228             <a class="citerefentry" href="glGet.xml"><span class="citerefentry"><span class="refentrytitle">glGet</span></span></a> with argument <code class="constant">GL_MAP2_GRID_SEGMENTS</code>
 229         </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="seealso"></a><h2>See Also</h2><p>
 230             <a class="citerefentry" href="glEvalCoord.xml"><span class="citerefentry"><span class="refentrytitle">glEvalCoord</span></span></a>,
 231             <a class="citerefentry" href="glEvalMesh.xml"><span class="citerefentry"><span class="refentrytitle">glEvalMesh</span></span></a>,
 232             <a class="citerefentry" href="glEvalPoint.xml"><span class="citerefentry"><span class="refentrytitle">glEvalPoint</span></span></a>,
 233             <a class="citerefentry" href="glMap1.xml"><span class="citerefentry"><span class="refentrytitle">glMap1</span></span></a>,
 234             <a class="citerefentry" href="glMap2.xml"><span class="citerefentry"><span class="refentrytitle">glMap2</span></span></a>
 235         </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="Copyright"></a><h2>Copyright</h2><p>
 236             Copyright <span class="trademark"></span>© 1991-2006
 237             Silicon Graphics, Inc. This document is licensed under the SGI
 238             Free Software B License. For details, see
 239             <a class="ulink" href="http://oss.sgi.com/projects/FreeB/" target="_top">http://oss.sgi.com/projects/FreeB/</a>.
 240         </p></div></div></body></html>