upstream-man-pages/man2/xhtml/glBitmap.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>glBitmap</title><meta name="generator" content="DocBook XSL Stylesheets V1.73.2" /></head><body><div class="refentry" lang="en" xml:lang="en"><a id="glBitmap"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>glBitmap — draw a bitmap</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">glBitmap</b>(</code></td><td>GLsizei  </td><td><var class="pdparam">width</var>, </td></tr><tr><td> </td><td>GLsizei  </td><td><var class="pdparam">height</var>, </td></tr><tr><td> </td><td>GLfloat  </td><td><var class="pdparam">xorig</var>, </td></tr><tr><td> </td><td>GLfloat  </td><td><var class="pdparam">yorig</var>, </td></tr><tr><td> </td><td>GLfloat  </td><td><var class="pdparam">xmove</var>, </td></tr><tr><td> </td><td>GLfloat  </td><td><var class="pdparam">ymove</var>, </td></tr><tr><td> </td><td>const GLubyte *  </td><td><var class="pdparam">bitmap</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>width</code></em>, </span><span class="term"><em class="parameter"><code>height</code></em></span></dt><dd><p>
   4                     Specify the pixel width and height of the bitmap image.
   5                 </p></dd><dt><span class="term"><em class="parameter"><code>xorig</code></em>, </span><span class="term"><em class="parameter"><code>yorig</code></em></span></dt><dd><p>
   6                     Specify the location of the origin in the bitmap image.
   7                     The origin is measured from the lower left corner of the bitmap,
   8                     with right and up being the positive axes.
   9                 </p></dd><dt><span class="term"><em class="parameter"><code>xmove</code></em>, </span><span class="term"><em class="parameter"><code>ymove</code></em></span></dt><dd><p>
  10                     Specify the <span class="emphasis"><em>x</em></span> and <span class="emphasis"><em>y</em></span> offsets to be added to the current raster position
  11                     after the bitmap is drawn.
  12                 </p></dd><dt><span class="term"><em class="parameter"><code>bitmap</code></em></span></dt><dd><p>
  13                     Specifies the address of the bitmap image.
  14                 </p></dd></dl></div></div><div class="refsect1" lang="en" xml:lang="en"><a id="description"></a><h2>Description</h2><p>
  15             A bitmap is a binary image.
  16             When drawn,
  17             the bitmap is positioned relative to the current raster position,
  18             and frame buffer pixels corresponding to 1's in the bitmap are
  19             written using the current raster color or index.
  20             Frame buffer pixels corresponding to 0's in the bitmap are not modified.
  21         </p><p>
  22             <code class="function">glBitmap</code> takes seven arguments.
  23             The first pair specifies the width and height of the bitmap image.
  24             The second pair specifies the location of the bitmap origin relative
  25             to the lower left corner of the bitmap image.
  26             The third pair of arguments specifies <span class="emphasis"><em>x</em></span> and <span class="emphasis"><em>y</em></span> offsets to be added
  27             to the current raster position after the bitmap has been drawn.
  28             The final argument is a pointer to the bitmap image itself.
  29         </p><p>
  30             If a non-zero named buffer object is bound to the <code class="constant">GL_PIXEL_UNPACK_BUFFER</code> target
  31             (see <a class="citerefentry" href="glBindBuffer.xml"><span class="citerefentry"><span class="refentrytitle">glBindBuffer</span></span></a>) while a bitmap image is
  32             specified, <em class="parameter"><code>bitmap</code></em> is treated as a byte offset into the buffer object's data store.
  33         </p><p>
  34             The bitmap image is interpreted like image data for the <a class="citerefentry" href="glDrawPixels.xml"><span class="citerefentry"><span class="refentrytitle">glDrawPixels</span></span></a>
  35             command,
  36             with <em class="parameter"><code>width</code></em> and <em class="parameter"><code>height</code></em> corresponding to the width and height arguments
  37             of that command,
  38             and with <span class="emphasis"><em>type</em></span> set to <code class="constant">GL_BITMAP</code>
  39             and <span class="emphasis"><em>format</em></span> set to <code class="constant">GL_COLOR_INDEX</code>.
  40             Modes specified using <a class="citerefentry" href="glPixelStore.xml"><span class="citerefentry"><span class="refentrytitle">glPixelStore</span></span></a> affect the
  41             interpretation of bitmap image data;
  42             modes specified using <a class="citerefentry" href="glPixelTransfer.xml"><span class="citerefentry"><span class="refentrytitle">glPixelTransfer</span></span></a> do not.
  43         </p><p>
  44             If the current raster position is invalid, <code class="function">glBitmap</code> is ignored.
  45             Otherwise,
  46             the lower left corner of the bitmap image is positioned at the window coordinates
  47         </p><p>
  48             <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
  49
  50                 <mml:mrow>
  51                     <mml:msub><mml:mi mathvariant="italic">x</mml:mi>
  52                     <mml:mi mathvariant="italic">w</mml:mi>
  53                     </mml:msub>
  54                     <mml:mo>=</mml:mo>
  55                     <mml:mfenced open="&#x230A;" close="&#x230B;">
  56                         <mml:mrow>
  57                             <mml:msub><mml:mi mathvariant="italic">x</mml:mi>
  58                             <mml:mi mathvariant="italic">r</mml:mi>
  59                             </mml:msub>
  60                             <mml:mo>-</mml:mo>
  61                             <mml:msub><mml:mi mathvariant="italic">x</mml:mi>
  62                             <mml:mi mathvariant="italic">o</mml:mi>
  63                             </mml:msub>
  64                         </mml:mrow>
  65                     </mml:mfenced>
  66                 </mml:mrow>
  67             </mml:math>
  68         </p><p>
  69             <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
  70
  71                 <mml:mrow>
  72                     <mml:msub><mml:mi mathvariant="italic">y</mml:mi>
  73                     <mml:mi mathvariant="italic">w</mml:mi>
  74                     </mml:msub>
  75                     <mml:mo>=</mml:mo>
  76                     <mml:mfenced open="&#x230A;" close="&#x230B;">
  77                         <mml:mrow>
  78                             <mml:msub><mml:mi mathvariant="italic">y</mml:mi>
  79                             <mml:mi mathvariant="italic">r</mml:mi>
  80                             </mml:msub>
  81                             <mml:mo>-</mml:mo>
  82                             <mml:msub><mml:mi mathvariant="italic">y</mml:mi>
  83                             <mml:mi mathvariant="italic">o</mml:mi>
  84                             </mml:msub>
  85                         </mml:mrow>
  86                     </mml:mfenced>
  87                 </mml:mrow>
  88             </mml:math>
  89         </p><p>
  90             where
  91             <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
  92
  93                 <mml:mfenced open="(" close=")">
  94                     <mml:msub><mml:mi mathvariant="italic">x</mml:mi>
  95                     <mml:mi mathvariant="italic">r</mml:mi>
  96                     </mml:msub>
  97                     <mml:msub><mml:mi mathvariant="italic">y</mml:mi>
  98                     <mml:mi mathvariant="italic">r</mml:mi>
  99                     </mml:msub>
 100                 </mml:mfenced>
 101             </mml:math>
 102             is the raster position
 103             and
 104             <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
 105
 106                 <mml:mfenced open="(" close=")">
 107                     <mml:msub><mml:mi mathvariant="italic">x</mml:mi>
 108                     <mml:mi mathvariant="italic">o</mml:mi>
 109                     </mml:msub>
 110                     <mml:msub><mml:mi mathvariant="italic">y</mml:mi>
 111                     <mml:mi mathvariant="italic">o</mml:mi>
 112                     </mml:msub>
 113                 </mml:mfenced>
 114             </mml:math>
 115             is the bitmap origin.
 116             Fragments are then generated for each pixel corresponding to a 1 (one)
 117             in the bitmap image.
 118             These fragments are generated using the current raster <span class="emphasis"><em>z</em></span> coordinate,
 119             color or color index, and current raster texture coordinates.
 120             They are then treated just as if they had been generated
 121             by a point, line, or polygon,
 122             including texture mapping,
 123             fogging,
 124             and all per-fragment operations such as alpha and depth testing.
 125         </p><p>
 126             After the bitmap has been drawn,
 127             the <span class="emphasis"><em>x</em></span> and <span class="emphasis"><em>y</em></span> coordinates of the current raster position are offset by
 128             <em class="parameter"><code>xmove</code></em> and <em class="parameter"><code>ymove</code></em>.
 129             No change is made to the <span class="emphasis"><em>z</em></span> coordinate of the current raster position,
 130             or to the current raster color, texture coordinates, or index.
 131         </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="notes"></a><h2>Notes</h2><p>
 132             To set a valid raster position outside the viewport, first set a valid
 133             raster position inside the viewport, then call <code class="function">glBitmap</code> with NULL
 134             as the <em class="parameter"><code>bitmap</code></em> parameter and with <em class="parameter"><code>xmove</code></em> and <em class="parameter"><code>ymove</code></em> set to
 135             the offsets of the new raster position. This technique is useful when
 136             panning an image around the viewport.
 137         </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="errors"></a><h2>Errors</h2><p>
 138             <code class="constant">GL_INVALID_VALUE</code> is generated if <em class="parameter"><code>width</code></em> or <em class="parameter"><code>height</code></em> is negative.
 139         </p><p>
 140             <code class="constant">GL_INVALID_OPERATION</code> is generated if a non-zero buffer object name is bound to the
 141             <code class="constant">GL_PIXEL_UNPACK_BUFFER</code> target and the buffer object's data store is currently mapped.
 142         </p><p>
 143             <code class="constant">GL_INVALID_OPERATION</code> is generated if a non-zero buffer object name is bound to the
 144             <code class="constant">GL_PIXEL_UNPACK_BUFFER</code> target and the data would be unpacked from the buffer
 145             object such that the memory reads required would exceed the data store size.
 146         </p><p>
 147             <code class="constant">GL_INVALID_OPERATION</code> is generated if <code class="function">glBitmap</code>
 148             is executed between the execution of <a class="citerefentry" href="glBegin.xml"><span class="citerefentry"><span class="refentrytitle">glBegin</span></span></a> and the corresponding execution of
 149             <a class="citerefentry" href="glEnd.xml"><span class="citerefentry"><span class="refentrytitle">glEnd</span></span></a>.
 150         </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="associatedgets"></a><h2>Associated Gets</h2><p>
 151             <a class="citerefentry" href="glGet.xml"><span class="citerefentry"><span class="refentrytitle">glGet</span></span></a> with argument <code class="constant">GL_CURRENT_RASTER_POSITION</code>
 152         </p><p>
 153             <a class="citerefentry" href="glGet.xml"><span class="citerefentry"><span class="refentrytitle">glGet</span></span></a> with argument <code class="constant">GL_CURRENT_RASTER_COLOR</code>
 154         </p><p>
 155             <a class="citerefentry" href="glGet.xml"><span class="citerefentry"><span class="refentrytitle">glGet</span></span></a> with argument <code class="constant">GL_CURRENT_RASTER_SECONDARY_COLOR</code>
 156         </p><p>
 157             <a class="citerefentry" href="glGet.xml"><span class="citerefentry"><span class="refentrytitle">glGet</span></span></a> with argument <code class="constant">GL_CURRENT_RASTER_DISTANCE</code>
 158         </p><p>
 159             <a class="citerefentry" href="glGet.xml"><span class="citerefentry"><span class="refentrytitle">glGet</span></span></a> with argument <code class="constant">GL_CURRENT_RASTER_INDEX</code>
 160         </p><p>
 161             <a class="citerefentry" href="glGet.xml"><span class="citerefentry"><span class="refentrytitle">glGet</span></span></a> with argument <code class="constant">GL_CURRENT_RASTER_TEXTURE_COORDS</code>
 162         </p><p>
 163             <a class="citerefentry" href="glGet.xml"><span class="citerefentry"><span class="refentrytitle">glGet</span></span></a> with argument <code class="constant">GL_CURRENT_RASTER_POSITION_VALID</code>
 164         </p><p>
 165             <a class="citerefentry" href="glGet.xml"><span class="citerefentry"><span class="refentrytitle">glGet</span></span></a> with argument <code class="constant">GL_PIXEL_UNPACK_BUFFER_BINDING</code>
 166         </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="seealso"></a><h2>See Also</h2><p>
 167             <a class="citerefentry" href="glBindBuffer.xml"><span class="citerefentry"><span class="refentrytitle">glBindBuffer</span></span></a>,
 168             <a class="citerefentry" href="glDrawPixels.xml"><span class="citerefentry"><span class="refentrytitle">glDrawPixels</span></span></a>,
 169             <a class="citerefentry" href="glPixelStore.xml"><span class="citerefentry"><span class="refentrytitle">glPixelStore</span></span></a>,
 170             <a class="citerefentry" href="glPixelTransfer.xml"><span class="citerefentry"><span class="refentrytitle">glPixelTransfer</span></span></a>,
 171             <a class="citerefentry" href="glRasterPos.xml"><span class="citerefentry"><span class="refentrytitle">glRasterPos</span></span></a>,
 172             <a class="citerefentry" href="glWindowPos.xml"><span class="citerefentry"><span class="refentrytitle">glWindowPos</span></span></a>
 173         </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="Copyright"></a><h2>Copyright</h2><p>
 174             Copyright <span class="trademark"></span>© 1991-2006
 175             Silicon Graphics, Inc. This document is licensed under the SGI
 176             Free Software B License. For details, see
 177             <a class="ulink" href="http://oss.sgi.com/projects/FreeB/" target="_top">http://oss.sgi.com/projects/FreeB/</a>.
 178         </p></div></div></body></html>