1GLRENDERMODE(3G)                 OpenGL Manual                GLRENDERMODE(3G)
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NAME

6       glRenderMode - set rasterization mode
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C SPECIFICATION

9       GLint glRenderMode(GLenum mode);
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PARAMETERS

12       mode
13           Specifies the rasterization mode. Three values are accepted:
14           GL_RENDER, GL_SELECT, and GL_FEEDBACK. The initial value is
15           GL_RENDER.
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DESCRIPTION

18       glRenderMode sets the rasterization mode. It takes one argument, mode,
19       which can assume one of three predefined values:
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21       GL_RENDER
22           Render mode. Primitives are rasterized, producing pixel fragments,
23           which are written into the frame buffer. This is the normal mode
24           and also the default mode.
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26       GL_SELECT
27           Selection mode. No pixel fragments are produced, and no change to
28           the frame buffer contents is made. Instead, a record of the names
29           of primitives that would have been drawn if the render mode had
30           been GL_RENDER is returned in a select buffer, which must be
31           created (see glSelectBuffer()) before selection mode is entered.
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33       GL_FEEDBACK
34           Feedback mode. No pixel fragments are produced, and no change to
35           the frame buffer contents is made. Instead, the coordinates and
36           attributes of vertices that would have been drawn if the render
37           mode had been GL_RENDER is returned in a feedback buffer, which
38           must be created (see glFeedbackBuffer()) before feedback mode is
39           entered.
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41       The return value of glRenderMode is determined by the render mode at
42       the time glRenderMode is called, rather than by mode. The values
43       returned for the three render modes are as follows:
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45       GL_RENDER
46           0.
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48       GL_SELECT
49           The number of hit records transferred to the select buffer.
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51       GL_FEEDBACK
52           The number of values (not vertices) transferred to the feedback
53           buffer.
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55       See the glSelectBuffer() and glFeedbackBuffer() reference pages for
56       more details concerning selection and feedback operation.
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NOTES

59       If an error is generated, glRenderMode returns 0 regardless of the
60       current render mode.
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ERRORS

63       GL_INVALID_ENUM is generated if mode is not one of the three accepted
64       values.
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66       GL_INVALID_OPERATION is generated if glSelectBuffer() is called while
67       the render mode is GL_SELECT, or if glRenderMode is called with
68       argument GL_SELECT before glSelectBuffer() is called at least once.
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70       GL_INVALID_OPERATION is generated if glFeedbackBuffer() is called while
71       the render mode is GL_FEEDBACK, or if glRenderMode is called with
72       argument GL_FEEDBACK before glFeedbackBuffer() is called at least once.
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74       GL_INVALID_OPERATION is generated if glRenderMode is executed between
75       the execution of glBegin() and the corresponding execution of glEnd().
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ASSOCIATED GETS

78       glGet() with argument GL_RENDER_MODE
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SEE ALSO

81       glFeedbackBuffer(), glInitNames(), glLoadName(), glPassThrough(),
82       glPushName(), glSelectBuffer()
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85       Copyright © 1991-2006 Silicon Graphics, Inc. This document is licensed
86       under the SGI Free Software B License. For details, see
87       http://oss.sgi.com/projects/FreeB/.
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AUTHORS

90       opengl.org
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94opengl.org                        06/10/2014                  GLRENDERMODE(3G)
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