Commit | Line | Data |
---|---|---|
7faf1d71 AW |
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>glDepthRange</title><meta name="generator" content="DocBook XSL Stylesheets V1.73.2" /></head><body><div class="refentry" lang="en" xml:lang="en"><a id="glDepthRange"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>glDepthRange — specify mapping of depth values from normalized device coordinates to window coordinates</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">glDepthRange</b>(</code></td><td>GLclampd </td><td><var class="pdparam">nearVal</var>, </td></tr><tr><td> </td><td>GLclampd </td><td><var class="pdparam">farVal</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>nearVal</code></em></span></dt><dd><p> | |
4 | Specifies the mapping of the near clipping plane to window coordinates. | |
5 | The initial value is 0. | |
6 | </p></dd><dt><span class="term"><em class="parameter"><code>farVal</code></em></span></dt><dd><p> | |
7 | Specifies the mapping of the far clipping plane to window coordinates. | |
8 | The initial value is 1. | |
9 | </p></dd></dl></div></div><div class="refsect1" lang="en" xml:lang="en"><a id="description"></a><h2>Description</h2><p> | |
10 | After clipping and division by <span class="emphasis"><em>w</em></span>, | |
11 | depth coordinates range from | |
12 | <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> | |
13 | ||
14 | <mml:mn>-1</mml:mn> | |
15 | </mml:math> | |
16 | to 1, | |
17 | corresponding to the near and far clipping planes. | |
18 | <code class="function">glDepthRange</code> specifies a linear mapping of the normalized depth coordinates | |
19 | in this range to window depth coordinates. | |
20 | Regardless of the actual depth buffer implementation, | |
21 | window coordinate depth values are treated as though they range | |
22 | from 0 through 1 (like color components). | |
23 | Thus, | |
24 | the values accepted by <code class="function">glDepthRange</code> are both clamped to this range | |
25 | before they are accepted. | |
26 | </p><p> | |
27 | The setting of (0,1) maps the near plane to 0 and | |
28 | the far plane to 1. | |
29 | With this mapping, | |
30 | the depth buffer range is fully utilized. | |
31 | </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="notes"></a><h2>Notes</h2><p> | |
32 | It is not necessary that <em class="parameter"><code>nearVal</code></em> be less than <em class="parameter"><code>farVal</code></em>. | |
33 | Reverse mappings such as | |
34 | <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> | |
35 | ||
36 | <mml:mrow> | |
37 | <mml:mi mathvariant="italic">nearVal</mml:mi> | |
38 | <mml:mo>=</mml:mo> | |
39 | <mml:mn>1</mml:mn> | |
40 | </mml:mrow> | |
41 | </mml:math>, | |
42 | and | |
43 | <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> | |
44 | ||
45 | <mml:mrow> | |
46 | <mml:mi mathvariant="italic">farVal</mml:mi> | |
47 | <mml:mo>=</mml:mo> | |
48 | <mml:mn>0</mml:mn> | |
49 | </mml:mrow> | |
50 | </mml:math> | |
51 | are acceptable. | |
52 | </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="errors"></a><h2>Errors</h2><p> | |
53 | <code class="constant">GL_INVALID_OPERATION</code> is generated if <code class="function">glDepthRange</code> | |
54 | is executed between the execution of <a class="citerefentry" href="glBegin.xml"><span class="citerefentry"><span class="refentrytitle">glBegin</span></span></a> | |
55 | and the corresponding execution of <a class="citerefentry" href="glEnd.xml"><span class="citerefentry"><span class="refentrytitle">glEnd</span></span></a>. | |
56 | </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="associatedgets"></a><h2>Associated Gets</h2><p> | |
57 | <a class="citerefentry" href="glGet.xml"><span class="citerefentry"><span class="refentrytitle">glGet</span></span></a> with argument <code class="constant">GL_DEPTH_RANGE</code> | |
58 | </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="seealso"></a><h2>See Also</h2><p> | |
59 | <a class="citerefentry" href="glDepthFunc.xml"><span class="citerefentry"><span class="refentrytitle">glDepthFunc</span></span></a>, | |
60 | <a class="citerefentry" href="glPolygonOffset.xml"><span class="citerefentry"><span class="refentrytitle">glPolygonOffset</span></span></a>, | |
61 | <a class="citerefentry" href="glViewport.xml"><span class="citerefentry"><span class="refentrytitle">glViewport</span></span></a> | |
62 | </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="Copyright"></a><h2>Copyright</h2><p> | |
63 | Copyright <span class="trademark"></span>© 1991-2006 | |
64 | Silicon Graphics, Inc. This document is licensed under the SGI | |
65 | Free Software B License. For details, see | |
66 | <a class="ulink" href="http://oss.sgi.com/projects/FreeB/" target="_top">http://oss.sgi.com/projects/FreeB/</a>. | |
67 | </p></div></div></body></html> |