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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>glRenderMode</title><meta name="generator" content="DocBook XSL Stylesheets V1.73.2" /></head><body><div class="refentry" lang="en" xml:lang="en"><a id="glRenderMode"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>glRenderMode — set rasterization mode</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">GLint <b class="fsfunc">glRenderMode</b>(</code></td><td>GLenum </td><td><var class="pdparam">mode</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>mode</code></em></span></dt><dd><p> | |
4 | Specifies the rasterization mode. | |
5 | Three values are accepted: | |
6 | <code class="constant">GL_RENDER</code>, | |
7 | <code class="constant">GL_SELECT</code>, and | |
8 | <code class="constant">GL_FEEDBACK</code>. | |
9 | The initial value is <code class="constant">GL_RENDER</code>. | |
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">glRenderMode</code> sets the rasterization mode. | |
12 | It takes one argument, | |
13 | <em class="parameter"><code>mode</code></em>, | |
14 | which can assume one of three predefined values: | |
15 | </p><div class="variablelist"><dl><dt><span class="term"><code class="constant">GL_RENDER</code></span></dt><dd><p> | |
16 | Render mode. Primitives are rasterized, | |
17 | producing pixel fragments, | |
18 | which are written into the frame buffer. | |
19 | This is the normal mode | |
20 | and also the default mode. | |
21 | </p></dd><dt><span class="term"><code class="constant">GL_SELECT</code></span></dt><dd><p> | |
22 | Selection mode. | |
23 | No pixel fragments are produced, | |
24 | and no change to the frame buffer contents is made. | |
25 | Instead, | |
26 | a record of the names of primitives that would have been drawn | |
27 | if the render mode had been <code class="constant">GL_RENDER</code> is returned in a select buffer, | |
28 | which must be created (see <a class="citerefentry" href="glSelectBuffer.xml"><span class="citerefentry"><span class="refentrytitle">glSelectBuffer</span></span></a>) before selection mode | |
29 | is entered. | |
30 | </p></dd><dt><span class="term"><code class="constant">GL_FEEDBACK</code></span></dt><dd><p> | |
31 | Feedback mode. | |
32 | No pixel fragments are produced, | |
33 | and no change to the frame buffer contents is made. | |
34 | Instead, | |
35 | the coordinates and attributes of vertices that would have been drawn | |
36 | if the render mode had been <code class="constant">GL_RENDER</code> is returned in a feedback buffer, | |
37 | which must be created (see <a class="citerefentry" href="glFeedbackBuffer.xml"><span class="citerefentry"><span class="refentrytitle">glFeedbackBuffer</span></span></a>) before feedback mode | |
38 | is entered. | |
39 | </p></dd></dl></div><p> | |
40 | The return value of <code class="function">glRenderMode</code> is determined by the render mode at the time | |
41 | <code class="function">glRenderMode</code> is called, | |
42 | rather than by <em class="parameter"><code>mode</code></em>. | |
43 | The values returned for the three render modes are as follows: | |
44 | </p><div class="variablelist"><dl><dt><span class="term"><code class="constant">GL_RENDER</code></span></dt><dd><p> | |
45 | 0. | |
46 | </p></dd><dt><span class="term"><code class="constant">GL_SELECT</code></span></dt><dd><p> | |
47 | The number of hit records transferred to the select buffer. | |
48 | </p></dd><dt><span class="term"><code class="constant">GL_FEEDBACK</code></span></dt><dd><p> | |
49 | The number of values (not vertices) transferred to the feedback buffer. | |
50 | </p></dd></dl></div><p> | |
51 | See the <a class="citerefentry" href="glSelectBuffer.xml"><span class="citerefentry"><span class="refentrytitle">glSelectBuffer</span></span></a> and <a class="citerefentry" href="glFeedbackBuffer.xml"><span class="citerefentry"><span class="refentrytitle">glFeedbackBuffer</span></span></a> reference pages for | |
52 | more details concerning selection and feedback operation. | |
53 | </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="notes"></a><h2>Notes</h2><p> | |
54 | If an error is generated, | |
55 | <code class="function">glRenderMode</code> returns 0 regardless of the current render mode. | |
56 | </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="errors"></a><h2>Errors</h2><p> | |
57 | <code class="constant">GL_INVALID_ENUM</code> is generated if <em class="parameter"><code>mode</code></em> is not one of the three | |
58 | accepted values. | |
59 | </p><p> | |
60 | <code class="constant">GL_INVALID_OPERATION</code> is generated if <a class="citerefentry" href="glSelectBuffer.xml"><span class="citerefentry"><span class="refentrytitle">glSelectBuffer</span></span></a> is called | |
61 | while the render mode is <code class="constant">GL_SELECT</code>, | |
62 | or if <code class="function">glRenderMode</code> is called with argument <code class="constant">GL_SELECT</code> before | |
63 | <a class="citerefentry" href="glSelectBuffer.xml"><span class="citerefentry"><span class="refentrytitle">glSelectBuffer</span></span></a> is called at least once. | |
64 | </p><p> | |
65 | <code class="constant">GL_INVALID_OPERATION</code> is generated if <a class="citerefentry" href="glFeedbackBuffer.xml"><span class="citerefentry"><span class="refentrytitle">glFeedbackBuffer</span></span></a> is called | |
66 | while the render mode is <code class="constant">GL_FEEDBACK</code>, | |
67 | or if <code class="function">glRenderMode</code> is called with argument <code class="constant">GL_FEEDBACK</code> before | |
68 | <a class="citerefentry" href="glFeedbackBuffer.xml"><span class="citerefentry"><span class="refentrytitle">glFeedbackBuffer</span></span></a> is called at least once. | |
69 | </p><p> | |
70 | <code class="constant">GL_INVALID_OPERATION</code> is generated if <code class="function">glRenderMode</code> | |
71 | is executed between the execution of <a class="citerefentry" href="glBegin.xml"><span class="citerefentry"><span class="refentrytitle">glBegin</span></span></a> | |
72 | and the corresponding execution of <a class="citerefentry" href="glEnd.xml"><span class="citerefentry"><span class="refentrytitle">glEnd</span></span></a>. | |
73 | </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="associatedgets"></a><h2>Associated Gets</h2><p> | |
74 | <a class="citerefentry" href="glGet.xml"><span class="citerefentry"><span class="refentrytitle">glGet</span></span></a> with argument <code class="constant">GL_RENDER_MODE</code> | |
75 | </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="seealso"></a><h2>See Also</h2><p> | |
76 | <a class="citerefentry" href="glFeedbackBuffer.xml"><span class="citerefentry"><span class="refentrytitle">glFeedbackBuffer</span></span></a>, | |
77 | <a class="citerefentry" href="glInitNames.xml"><span class="citerefentry"><span class="refentrytitle">glInitNames</span></span></a>, | |
78 | <a class="citerefentry" href="glLoadName.xml"><span class="citerefentry"><span class="refentrytitle">glLoadName</span></span></a>, | |
79 | <a class="citerefentry" href="glPassThrough.xml"><span class="citerefentry"><span class="refentrytitle">glPassThrough</span></span></a>, | |
80 | <a class="citerefentry" href="glPushName.xml"><span class="citerefentry"><span class="refentrytitle">glPushName</span></span></a>, | |
81 | <a class="citerefentry" href="glSelectBuffer.xml"><span class="citerefentry"><span class="refentrytitle">glSelectBuffer</span></span></a> | |
82 | </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="Copyright"></a><h2>Copyright</h2><p> | |
83 | Copyright <span class="trademark"></span>© 1991-2006 | |
84 | Silicon Graphics, Inc. This document is licensed under the SGI | |
85 | Free Software B License. For details, see | |
86 | <a class="ulink" href="http://oss.sgi.com/projects/FreeB/" target="_top">http://oss.sgi.com/projects/FreeB/</a>. | |
87 | </p></div></div></body></html> |