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>glPixelZoom
</title><meta name=
"generator" content=
"DocBook XSL Stylesheets V1.73.2" /></head><body><div class=
"refentry" lang=
"en" xml:
lang=
"en"><a id=
"glPixelZoom"></a><div class=
"titlepage"></div><div class=
"refnamediv"><h2>Name
</h2><p>glPixelZoom — specify the pixel zoom factors
</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">glPixelZoom
</b>(
</code></td><td>GLfloat
</td><td><var class=
"pdparam">xfactor
</var>,
</td></tr><tr><td> </td><td>GLfloat
</td><td><var class=
"pdparam">yfactor
</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>xfactor
</code></em>,
</span><span class=
"term"><em class=
"parameter"><code>yfactor
</code></em></span></dt><dd><p>
5 <mml:math xmlns:
mml=
"http://www.w3.org/1998/Math/MathML" overflow=
"scroll"><mml:mi mathvariant=
"italic">x
</mml:mi></mml:math>
7 <mml:math xmlns:
mml=
"http://www.w3.org/1998/Math/MathML" overflow=
"scroll"><mml:mi mathvariant=
"italic">y
</mml:mi></mml:math>
8 zoom factors for pixel write operations.
9 </p></dd></dl></div></div><div class=
"refsect1" lang=
"en" xml:
lang=
"en"><a id=
"description"></a><h2>Description
</h2><p>
10 <code class=
"function">glPixelZoom
</code> specifies values for the
11 <mml:math xmlns:
mml=
"http://www.w3.org/1998/Math/MathML" overflow=
"scroll"><mml:mi mathvariant=
"italic">x
</mml:mi></mml:math>
13 <mml:math xmlns:
mml=
"http://www.w3.org/1998/Math/MathML" overflow=
"scroll"><mml:mi mathvariant=
"italic">y
</mml:mi></mml:math>
15 During the execution of
<a class=
"citerefentry" href=
"glDrawPixels.xml"><span class=
"citerefentry"><span class=
"refentrytitle">glDrawPixels
</span></span></a> or
<a class=
"citerefentry" href=
"glCopyPixels.xml"><span class=
"citerefentry"><span class=
"refentrytitle">glCopyPixels
</span></span></a>,
17 (
<mml:math xmlns:
mml=
"http://www.w3.org/1998/Math/MathML" overflow=
"scroll">
19 <mml:mi mathvariant=
"italic">xr
</mml:mi>
21 <mml:math xmlns:
mml=
"http://www.w3.org/1998/Math/MathML" overflow=
"scroll">
23 <mml:mi mathvariant=
"italic">yr
</mml:mi>
25 is the current raster position,
26 and a given element is in the
27 <mml:math xmlns:
mml=
"http://www.w3.org/1998/Math/MathML" overflow=
"scroll"><mml:mi mathvariant=
"italic">m
</mml:mi></mml:math>th
29 <mml:math xmlns:
mml=
"http://www.w3.org/1998/Math/MathML" overflow=
"scroll"><mml:mi mathvariant=
"italic">n
</mml:mi></mml:math>th
30 column of the pixel rectangle,
31 then pixels whose centers are in the rectangle with corners at
33 (
<mml:math xmlns:
mml=
"http://www.w3.org/1998/Math/MathML" overflow=
"scroll">
36 <mml:mi mathvariant=
"italic">xr
</mml:mi>
39 <mml:mi mathvariant=
"italic">n
</mml:mi>
41 <mml:mi mathvariant=
"italic">xfactor
</mml:mi>
45 <mml:math xmlns:
mml=
"http://www.w3.org/1998/Math/MathML" overflow=
"scroll">
48 <mml:mi mathvariant=
"italic">yr
</mml:mi>
51 <mml:mi mathvariant=
"italic">m
</mml:mi>
53 <mml:mi mathvariant=
"italic">yfactor
</mml:mi>
58 (
<mml:math xmlns:
mml=
"http://www.w3.org/1998/Math/MathML" overflow=
"scroll">
61 <mml:mi mathvariant=
"italic">xr
</mml:mi>
64 <mml:mfenced open=
"(" close=
")">
66 <mml:mi mathvariant=
"italic">n
</mml:mi>
72 <mml:mi mathvariant=
"italic">xfactor
</mml:mi>
76 <mml:math xmlns:
mml=
"http://www.w3.org/1998/Math/MathML" overflow=
"scroll">
79 <mml:mi mathvariant=
"italic">yr
</mml:mi>
82 <mml:mfenced open=
"(" close=
")">
84 <mml:mi mathvariant=
"italic">m
</mml:mi>
90 <mml:mi mathvariant=
"italic">yfactor
</mml:mi>
95 are candidates for replacement.
96 Any pixel whose center lies on the bottom or left edge of this rectangular
97 region is also modified.
99 Pixel zoom factors are not limited to positive values.
100 Negative zoom factors reflect the resulting image about the current
102 </p></div><div class=
"refsect1" lang=
"en" xml:
lang=
"en"><a id=
"errors"></a><h2>Errors
</h2><p>
103 <code class=
"constant">GL_INVALID_OPERATION
</code> is generated if
<code class=
"function">glPixelZoom
</code>
104 is executed between the execution of
<a class=
"citerefentry" href=
"glBegin.xml"><span class=
"citerefentry"><span class=
"refentrytitle">glBegin
</span></span></a>
105 and the corresponding execution of
<a class=
"citerefentry" href=
"glEnd.xml"><span class=
"citerefentry"><span class=
"refentrytitle">glEnd
</span></span></a>.
106 </p></div><div class=
"refsect1" lang=
"en" xml:
lang=
"en"><a id=
"associatedgets"></a><h2>Associated Gets
</h2><p>
107 <a class=
"citerefentry" href=
"glGet.xml"><span class=
"citerefentry"><span class=
"refentrytitle">glGet
</span></span></a> with argument
<code class=
"constant">GL_ZOOM_X
</code>
109 <a class=
"citerefentry" href=
"glGet.xml"><span class=
"citerefentry"><span class=
"refentrytitle">glGet
</span></span></a> with argument
<code class=
"constant">GL_ZOOM_Y
</code>
110 </p></div><div class=
"refsect1" lang=
"en" xml:
lang=
"en"><a id=
"seealso"></a><h2>See Also
</h2><p>
111 <a class=
"citerefentry" href=
"glCopyPixels.xml"><span class=
"citerefentry"><span class=
"refentrytitle">glCopyPixels
</span></span></a>,
112 <a class=
"citerefentry" href=
"glDrawPixels.xml"><span class=
"citerefentry"><span class=
"refentrytitle">glDrawPixels
</span></span></a>
113 </p></div><div class=
"refsect1" lang=
"en" xml:
lang=
"en"><a id=
"Copyright"></a><h2>Copyright
</h2><p>
114 Copyright
<span class=
"trademark"></span>©
1991-
2006
115 Silicon Graphics, Inc. This document is licensed under the SGI
116 Free Software B License. For details, see
117 <a class=
"ulink" href=
"http://oss.sgi.com/projects/FreeB/" target=
"_top">http://oss.sgi.com/projects/FreeB/
</a>.
118 </p></div></div></body></html>