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4 Reference Pages
</title><meta name=
"generator" content=
"DocBook XSL Stylesheets V1.69.1" /></head><body><div class=
"refentry" lang=
"en" xml:
lang=
"en"><a id=
"glViewportIndexed"></a><div class=
"titlepage"></div><div class=
"refnamediv"><h2>Name
</h2><p>glViewportIndexed — set a specified viewport
</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">glViewportIndexedf
</b>(
</code></td><td>GLuint
</td><td><var class=
"pdparam">index
</var>,
</td></tr><tr><td> </td><td>GLfloat
</td><td><var class=
"pdparam">x
</var>,
</td></tr><tr><td> </td><td>GLfloat
</td><td><var class=
"pdparam">y
</var>,
</td></tr><tr><td> </td><td>GLfloat
</td><td><var class=
"pdparam">w
</var>,
</td></tr><tr><td> </td><td>GLfloat
</td><td><var class=
"pdparam">h
</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">glViewportIndexedfv
</b>(
</code></td><td>GLuint
</td><td><var class=
"pdparam">index
</var>,
</td></tr><tr><td> </td><td>const GLfloat *
</td><td><var class=
"pdparam">v
</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>index
</code></em></span></dt><dd><p>
5 Specify the first viewport to set.
6 </p></dd><dt><span class=
"term"><em class=
"parameter"><code>x
</code></em>,
</span><span class=
"term"><em class=
"parameter"><code>y
</code></em></span></dt><dd><p>
7 For
<code class=
"function">glViewportIndexedf
</code>, specifies the lower left corner of
8 the viewport rectangle, in pixels. The initial value is (
0,
0).
9 </p></dd><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>
10 For
<code class=
"function">glViewportIndexedf
</code>, specifies the width and height
12 When a GL context is first attached to a window,
13 <em class=
"parameter"><code>width
</code></em> and
<em class=
"parameter"><code>height
</code></em> are set to the dimensions of that
15 </p></dd><dt><span class=
"term"><em class=
"parameter"><code>v
</code></em></span></dt><dd><p>
16 For
<code class=
"function">glViewportIndexedfv
</code>, specifies the address of an array containing the viewport parameters.
17 </p></dd></dl></div></div><div class=
"refsect1" lang=
"en" xml:
lang=
"en"><a id=
"description"></a><h2>Description
</h2><p>
18 <code class=
"function">glViewportIndexedf
</code> and
<code class=
"function">glViewportIndexedfv
</code>
19 specify the parameters for a single viewport.
20 <em class=
"parameter"><code>index
</code></em> specifies the index of the viewport
22 <em class=
"parameter"><code>index
</code></em> must be less than the value of
<code class=
"constant">GL_MAX_VIEWPORTS
</code>.
23 For
<code class=
"function">glViewportIndexedf
</code>,
<em class=
"parameter"><code>x
</code></em>,
<em class=
"parameter"><code>y
</code></em>,
24 <em class=
"parameter"><code>w
</code></em>, and
<em class=
"parameter"><code>h
</code></em> specify the left, bottom, width and height
25 of the viewport in pixels, respectively.
26 For
<code class=
"function">glViewportIndexedfv
</code>,
<em class=
"parameter"><code>v
</code></em> contains the address of an array of floating
27 point values specifying the
28 left (
<mml:math xmlns:
mml=
"http://www.w3.org/1998/Math/MathML" overflow=
"scroll"><mml:mi mathvariant=
"italic">x
</mml:mi></mml:math>),
29 bottom (
<mml:math xmlns:
mml=
"http://www.w3.org/1998/Math/MathML" overflow=
"scroll"><mml:mi mathvariant=
"italic">y
</mml:mi></mml:math>),
30 width (
<mml:math xmlns:
mml=
"http://www.w3.org/1998/Math/MathML" overflow=
"scroll"><mml:mi mathvariant=
"italic">w
</mml:mi></mml:math>),
31 and height (
<mml:math xmlns:
mml=
"http://www.w3.org/1998/Math/MathML" overflow=
"scroll"><mml:mi mathvariant=
"italic">h
</mml:mi></mml:math>)
32 of each viewport, in that order.
<mml:math xmlns:
mml=
"http://www.w3.org/1998/Math/MathML" overflow=
"scroll"><mml:mi mathvariant=
"italic">x
</mml:mi></mml:math>
33 and
<mml:math xmlns:
mml=
"http://www.w3.org/1998/Math/MathML" overflow=
"scroll"><mml:mi mathvariant=
"italic">y
</mml:mi></mml:math> give
34 the location of the viewport's lower left corner, and
35 <mml:math xmlns:
mml=
"http://www.w3.org/1998/Math/MathML" overflow=
"scroll"><mml:mi mathvariant=
"italic">w
</mml:mi></mml:math>
36 and
<mml:math xmlns:
mml=
"http://www.w3.org/1998/Math/MathML" overflow=
"scroll"><mml:mi mathvariant=
"italic">h
</mml:mi></mml:math>
37 give the width and height of the viewport, respectively.
38 The viewport specifies the affine transformation of
39 <mml:math xmlns:
mml=
"http://www.w3.org/1998/Math/MathML" overflow=
"scroll"><mml:mi mathvariant=
"italic">x
</mml:mi></mml:math>
41 <mml:math xmlns:
mml=
"http://www.w3.org/1998/Math/MathML" overflow=
"scroll"><mml:mi mathvariant=
"italic">y
</mml:mi></mml:math>
43 normalized device coordinates to window coordinates.
45 <mml:math xmlns:
mml=
"http://www.w3.org/1998/Math/MathML" overflow=
"scroll">
47 <mml:mfenced open=
"(" close=
")">
48 <mml:msub><mml:mi mathvariant=
"italic">x
</mml:mi>
49 <mml:mi mathvariant=
"italic">nd
</mml:mi>
51 <mml:msub><mml:mi mathvariant=
"italic">y
</mml:mi>
52 <mml:mi mathvariant=
"italic">nd
</mml:mi>
56 be normalized device coordinates.
57 Then the window coordinates
58 <mml:math xmlns:
mml=
"http://www.w3.org/1998/Math/MathML" overflow=
"scroll">
60 <mml:mfenced open=
"(" close=
")">
61 <mml:msub><mml:mi mathvariant=
"italic">x
</mml:mi>
62 <mml:mi mathvariant=
"italic">w
</mml:mi>
64 <mml:msub><mml:mi mathvariant=
"italic">y
</mml:mi>
65 <mml:mi mathvariant=
"italic">w
</mml:mi>
69 are computed as follows:
71 </p><div class=
"informalequation"><mml:math xmlns:
mml=
"http://www.w3.org/1998/Math/MathML" overflow=
"scroll">
74 <mml:msub><mml:mi mathvariant=
"italic">x
</mml:mi>
75 <mml:mi mathvariant=
"italic">w
</mml:mi>
79 <mml:mfenced open=
"(" close=
")">
81 <mml:msub><mml:mi mathvariant=
"italic">x
</mml:mi>
82 <mml:mi mathvariant=
"italic">nd
</mml:mi>
89 <mml:mfenced open=
"(" close=
")">
91 <mml:mi mathvariant=
"italic">width
</mml:mi>
96 <mml:mi mathvariant=
"italic">x
</mml:mi>
101 </p><div class=
"informalequation"><mml:math xmlns:
mml=
"http://www.w3.org/1998/Math/MathML" overflow=
"scroll">
104 <mml:msub><mml:mi mathvariant=
"italic">y
</mml:mi>
105 <mml:mi mathvariant=
"italic">w
</mml:mi>
109 <mml:mfenced open=
"(" close=
")">
111 <mml:msub><mml:mi mathvariant=
"italic">y
</mml:mi>
112 <mml:mi mathvariant=
"italic">nd
</mml:mi>
119 <mml:mfenced open=
"(" close=
")">
121 <mml:mi mathvariant=
"italic">height
</mml:mi>
126 <mml:mi mathvariant=
"italic">y
</mml:mi>
131 The location of the viewport's bottom left corner, given by
132 (
<mml:math xmlns:
mml=
"http://www.w3.org/1998/Math/MathML" overflow=
"scroll"><mml:mi mathvariant=
"italic">x
</mml:mi></mml:math>,
<mml:math xmlns:
mml=
"http://www.w3.org/1998/Math/MathML" overflow=
"scroll"><mml:mi mathvariant=
"italic">y
</mml:mi></mml:math>)
133 is clamped to be within the implementaiton-dependent viewport bounds range.
134 The viewport bounds range [
<mml:math xmlns:
mml=
"http://www.w3.org/1998/Math/MathML" overflow=
"scroll"><mml:mi mathvariant=
"italic">min
</mml:mi></mml:math>,
<mml:math xmlns:
mml=
"http://www.w3.org/1998/Math/MathML" overflow=
"scroll"><mml:mi mathvariant=
"italic">max
</mml:mi></mml:math>]
135 can be determined by calling
<a href=
"glGet.xml"><span class=
"citerefentry"><span class=
"refentrytitle">glGet
</span></span></a> with argument
136 <code class=
"constant">GL_VIEWPORT_BOUNDS_RANGE
</code>.
137 Viewport width and height are silently clamped
138 to a range that depends on the implementation.
139 To query this range, call
<a href=
"glGet.xml"><span class=
"citerefentry"><span class=
"refentrytitle">glGet
</span></span></a> with argument
140 <code class=
"constant">GL_MAX_VIEWPORT_DIMS
</code>.
142 The precision with which the GL interprets the floating point viewport bounds is implementation-dependent
143 and may be determined by querying the impementation-defined constant
<code class=
"constant">GL_VIEWPORT_SUBPIXEL_BITS
</code>.
145 Calling
<code class=
"function">glViewportIndexedfv
</code> is equivalent to calling
<a href=
"glViewportArray.xml"><span class=
"citerefentry"><span class=
"refentrytitle">glViewportArray
</span></span></a>
146 with
<em class=
"parameter"><code>first
</code></em> set to
<em class=
"parameter"><code>index
</code></em>,
<em class=
"parameter"><code>count
</code></em> set to
147 1 and
<em class=
"parameter"><code>v
</code></em> passsed directly.
<code class=
"function">glViewportIndexedf
</code> is equivalent
149 </p><pre class=
"programlisting"> void glViewportIndexedf(GLuint index, GLfloat x, GLfloat y, GLfloat w, GLfloat h)
151 const float v[
4] = { x, y, w, h };
152 glViewportArrayv(index,
1, v);
153 }
</pre></div><div class=
"refsect1" lang=
"en" xml:
lang=
"en"><a id=
"errors"></a><h2>Errors
</h2><p>
154 <code class=
"constant">GL_INVALID_VALUE
</code> is generated if
<em class=
"parameter"><code>index
</code></em> is greater than or equal to
155 the value of
<code class=
"constant">GL_MAX_VIEWPORTS
</code>.
157 <code class=
"constant">GL_INVALID_VALUE
</code> is generated if either
<em class=
"parameter"><code>width
</code></em> or
<em class=
"parameter"><code>height
</code></em> is negative.
158 </p></div><div class=
"refsect1" lang=
"en" xml:
lang=
"en"><a id=
"associatedgets"></a><h2>Associated Gets
</h2><p>
159 <a href=
"glGet.xml"><span class=
"citerefentry"><span class=
"refentrytitle">glGet
</span></span></a> with argument
<code class=
"constant">GL_VIEWPORT
</code>
161 <a href=
"glGet.xml"><span class=
"citerefentry"><span class=
"refentrytitle">glGet
</span></span></a> with argument
<code class=
"constant">GL_MAX_VIEWPORT_DIMS
</code>
163 <a href=
"glGet.xml"><span class=
"citerefentry"><span class=
"refentrytitle">glGet
</span></span></a> with argument
<code class=
"constant">GL_VIEWPORT_BOUNDS_RANGE
</code>
165 <a href=
"glGet.xml"><span class=
"citerefentry"><span class=
"refentrytitle">glGet
</span></span></a> with argument
<code class=
"constant">GL_VIEWPORT_SUBPIXEL_BITS
</code>
166 </p></div><div class=
"refsect1" lang=
"en" xml:
lang=
"en"><a id=
"seealso"></a><h2>See Also
</h2><p>
167 <a href=
"glDepthRange.xml"><span class=
"citerefentry"><span class=
"refentrytitle">glDepthRange
</span></span></a>,
168 <a href=
"glViewport.xml"><span class=
"citerefentry"><span class=
"refentrytitle">glViewport
</span></span></a>,
169 <a href=
"glViewportArray.xml"><span class=
"citerefentry"><span class=
"refentrytitle">glViewportArray
</span></span></a>
170 </p></div><div class=
"refsect1" lang=
"en" xml:
lang=
"en"><a id=
"Copyright"></a><h2>Copyright
</h2><p>
171 Copyright
<span class=
"trademark"></span>©
2010 Khronos Group.
172 This material may be distributed subject to the terms and conditions set forth in
173 the Open Publication License, v
1.0,
8 June
1999.
174 <a href=
"http://opencontent.org/openpub/" target=
"_top">http://opencontent.org/openpub/
</a>.
175 </p></div></div></body></html>