| 1 | <?xml version="1.0" encoding="UTF-8"?> |
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| 4 | <?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" /><link rel="stylesheet" type="text/css" href="opengl-man.css" /><title>glViewportArray - OpenGL 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="glViewportArray"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>glViewportArray — set multiple viewports</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">glViewportArrayv</b>(</code></td><td>GLuint </td><td><var class="pdparam">first</var>, </td></tr><tr><td> </td><td>GLsizei </td><td><var class="pdparam">count</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>first</code></em></span></dt><dd><p> |
| 5 | Specify the first viewport to set. |
| 6 | </p></dd><dt><span class="term"><em class="parameter"><code>count</code></em></span></dt><dd><p> |
| 7 | Specify the number of viewports to set. |
| 8 | </p></dd><dt><span class="term"><em class="parameter"><code>v</code></em></span></dt><dd><p> |
| 9 | Specify the address of an array containing the viewport parameters. |
| 10 | </p></dd></dl></div></div><div class="refsect1" lang="en" xml:lang="en"><a id="description"></a><h2>Description</h2><p> |
| 11 | <code class="function">glViewportArrayv</code> specifies the parameters for multiple viewports |
| 12 | simulataneously. <em class="parameter"><code>first</code></em> specifies the index of the first viewport |
| 13 | to modify and <em class="parameter"><code>count</code></em> specifies the number of viewports to modify. |
| 14 | <em class="parameter"><code>first</code></em> must be less than the value of <code class="constant">GL_MAX_VIEWPORTS</code>, |
| 15 | and <em class="parameter"><code>first</code></em> + <em class="parameter"><code>count</code></em> must be less than or equal to |
| 16 | the value of <code class="constant">GL_MAX_VIEWPORTS</code>. Viewports whose indices lie outside |
| 17 | the range [<em class="parameter"><code>first</code></em>, <em class="parameter"><code>first</code></em> + <em class="parameter"><code>count</code></em>) |
| 18 | are not modified. <em class="parameter"><code>v</code></em> contains the address of an array of floating |
| 19 | point values specifying the |
| 20 | left (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">x</mml:mi></mml:math>), |
| 21 | bottom (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">y</mml:mi></mml:math>), |
| 22 | width (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">w</mml:mi></mml:math>), |
| 23 | and height (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">h</mml:mi></mml:math>) |
| 24 | 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> |
| 25 | and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">y</mml:mi></mml:math> give |
| 26 | the location of the viewport's lower left corner, and |
| 27 | <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">w</mml:mi></mml:math> |
| 28 | and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">h</mml:mi></mml:math> |
| 29 | give the width and height of the viewport, respectively. |
| 30 | The viewport specifies the affine transformation of |
| 31 | <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">x</mml:mi></mml:math> |
| 32 | and |
| 33 | <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">y</mml:mi></mml:math> |
| 34 | from |
| 35 | normalized device coordinates to window coordinates. |
| 36 | Let |
| 37 | <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> |
| 38 | |
| 39 | <mml:mfenced open="(" close=")"> |
| 40 | <mml:msub><mml:mi mathvariant="italic">x</mml:mi> |
| 41 | <mml:mi mathvariant="italic">nd</mml:mi> |
| 42 | </mml:msub> |
| 43 | <mml:msub><mml:mi mathvariant="italic">y</mml:mi> |
| 44 | <mml:mi mathvariant="italic">nd</mml:mi> |
| 45 | </mml:msub> |
| 46 | </mml:mfenced> |
| 47 | </mml:math> |
| 48 | be normalized device coordinates. |
| 49 | Then the window coordinates |
| 50 | <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> |
| 51 | |
| 52 | <mml:mfenced open="(" close=")"> |
| 53 | <mml:msub><mml:mi mathvariant="italic">x</mml:mi> |
| 54 | <mml:mi mathvariant="italic">w</mml:mi> |
| 55 | </mml:msub> |
| 56 | <mml:msub><mml:mi mathvariant="italic">y</mml:mi> |
| 57 | <mml:mi mathvariant="italic">w</mml:mi> |
| 58 | </mml:msub> |
| 59 | </mml:mfenced> |
| 60 | </mml:math> |
| 61 | are computed as follows: |
| 62 | </p><p> |
| 63 | </p><div class="informalequation"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> |
| 64 | |
| 65 | <mml:mrow> |
| 66 | <mml:msub><mml:mi mathvariant="italic">x</mml:mi> |
| 67 | <mml:mi mathvariant="italic">w</mml:mi> |
| 68 | </mml:msub> |
| 69 | <mml:mo>=</mml:mo> |
| 70 | <mml:mrow> |
| 71 | <mml:mfenced open="(" close=")"> |
| 72 | <mml:mrow> |
| 73 | <mml:msub><mml:mi mathvariant="italic">x</mml:mi> |
| 74 | <mml:mi mathvariant="italic">nd</mml:mi> |
| 75 | </mml:msub> |
| 76 | <mml:mo>+</mml:mo> |
| 77 | <mml:mn>1</mml:mn> |
| 78 | </mml:mrow> |
| 79 | </mml:mfenced> |
| 80 | <mml:mo></mml:mo> |
| 81 | <mml:mfenced open="(" close=")"> |
| 82 | <mml:mfrac> |
| 83 | <mml:mi mathvariant="italic">width</mml:mi> |
| 84 | <mml:mn>2</mml:mn> |
| 85 | </mml:mfrac> |
| 86 | </mml:mfenced> |
| 87 | <mml:mo>+</mml:mo> |
| 88 | <mml:mi mathvariant="italic">x</mml:mi> |
| 89 | </mml:mrow> |
| 90 | </mml:mrow> |
| 91 | </mml:math></div><p> |
| 92 | </p><p> |
| 93 | </p><div class="informalequation"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> |
| 94 | |
| 95 | <mml:mrow> |
| 96 | <mml:msub><mml:mi mathvariant="italic">y</mml:mi> |
| 97 | <mml:mi mathvariant="italic">w</mml:mi> |
| 98 | </mml:msub> |
| 99 | <mml:mo>=</mml:mo> |
| 100 | <mml:mrow> |
| 101 | <mml:mfenced open="(" close=")"> |
| 102 | <mml:mrow> |
| 103 | <mml:msub><mml:mi mathvariant="italic">y</mml:mi> |
| 104 | <mml:mi mathvariant="italic">nd</mml:mi> |
| 105 | </mml:msub> |
| 106 | <mml:mo>+</mml:mo> |
| 107 | <mml:mn>1</mml:mn> |
| 108 | </mml:mrow> |
| 109 | </mml:mfenced> |
| 110 | <mml:mo></mml:mo> |
| 111 | <mml:mfenced open="(" close=")"> |
| 112 | <mml:mfrac> |
| 113 | <mml:mi mathvariant="italic">height</mml:mi> |
| 114 | <mml:mn>2</mml:mn> |
| 115 | </mml:mfrac> |
| 116 | </mml:mfenced> |
| 117 | <mml:mo>+</mml:mo> |
| 118 | <mml:mi mathvariant="italic">y</mml:mi> |
| 119 | </mml:mrow> |
| 120 | </mml:mrow> |
| 121 | </mml:math></div><p> |
| 122 | </p><p> |
| 123 | The location of the viewport's bottom left corner, given by |
| 124 | (<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>) |
| 125 | is clamped to be within the implementaiton-dependent viewport bounds range. |
| 126 | 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>] |
| 127 | can be determined by calling <a href="glGet.xml"><span class="citerefentry"><span class="refentrytitle">glGet</span></span></a> with argument |
| 128 | <code class="constant">GL_VIEWPORT_BOUNDS_RANGE</code>. |
| 129 | Viewport width and height are silently clamped |
| 130 | to a range that depends on the implementation. |
| 131 | To query this range, call <a href="glGet.xml"><span class="citerefentry"><span class="refentrytitle">glGet</span></span></a> with argument |
| 132 | <code class="constant">GL_MAX_VIEWPORT_DIMS</code>. |
| 133 | </p><p> |
| 134 | The precision with which the GL interprets the floating point viewport bounds is implementation-dependent |
| 135 | and may be determined by querying the impementation-defined constant <code class="constant">GL_VIEWPORT_SUBPIXEL_BITS</code>. |
| 136 | </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="errors"></a><h2>Errors</h2><p> |
| 137 | <code class="constant">GL_INVALID_VALUE</code> is generated if <em class="parameter"><code>first</code></em> is greater than or equal to |
| 138 | the value of <code class="constant">GL_MAX_VIEWPORTS</code>. |
| 139 | </p><p> |
| 140 | <code class="constant">GL_INVALID_VALUE</code> is generated if <em class="parameter"><code>first</code></em> + <em class="parameter"><code>count</code></em> |
| 141 | is greater than or equal to the value of <code class="constant">GL_MAX_VIEWPORTS</code>. |
| 142 | </p><p> |
| 143 | <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. |
| 144 | </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="associatedgets"></a><h2>Associated Gets</h2><p> |
| 145 | <a href="glGet.xml"><span class="citerefentry"><span class="refentrytitle">glGet</span></span></a> with argument <code class="constant">GL_VIEWPORT</code> |
| 146 | </p><p> |
| 147 | <a href="glGet.xml"><span class="citerefentry"><span class="refentrytitle">glGet</span></span></a> with argument <code class="constant">GL_MAX_VIEWPORT_DIMS</code> |
| 148 | </p><p> |
| 149 | <a href="glGet.xml"><span class="citerefentry"><span class="refentrytitle">glGet</span></span></a> with argument <code class="constant">GL_VIEWPORT_BOUNDS_RANGE</code> |
| 150 | </p><p> |
| 151 | <a href="glGet.xml"><span class="citerefentry"><span class="refentrytitle">glGet</span></span></a> with argument <code class="constant">GL_VIEWPORT_SUBPIXEL_BITS</code> |
| 152 | </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="seealso"></a><h2>See Also</h2><p> |
| 153 | <a href="glDepthRange.xml"><span class="citerefentry"><span class="refentrytitle">glDepthRange</span></span></a>, |
| 154 | <a href="glViewport.xml"><span class="citerefentry"><span class="refentrytitle">glViewport</span></span></a>, |
| 155 | <a href="glViewportIndexed.xml"><span class="citerefentry"><span class="refentrytitle">glViewportIndexed</span></span></a> |
| 156 | </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="Copyright"></a><h2>Copyright</h2><p> |
| 157 | Copyright <span class="trademark"></span>© 2010 Khronos Group. |
| 158 | This material may be distributed subject to the terms and conditions set forth in |
| 159 | the Open Publication License, v 1.0, 8 June 1999. |
| 160 | <a href="http://opencontent.org/openpub/" target="_top">http://opencontent.org/openpub/</a>. |
| 161 | </p></div></div></body></html> |