1GLXCHOOSEVISUAL(3G) OpenGL Manual GLXCHOOSEVISUAL(3G)
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6 glXChooseVisual - return a visual that matches specified attributes
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9 XVisualInfo* glXChooseVisual(Display * dpy, int screen,
10 int * attribList);
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13 dpy
14 Specifies the connection to the X server.
15 screen
17 Specifies the screen number.
18 attribList
20 Specifies a list of boolean attributes and integer attribute/value
21 pairs. The last attribute must be None.
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24 glXChooseVisual returns a pointer to an XVisualInfo structure
25 describing the visual that best meets a minimum specification. The
26 boolean GLX attributes of the visual that is returned will match the
27 specified values, and the integer GLX attributes will meet or exceed
28 the specified minimum values. If all other attributes are equivalent,
29 then TrueColor and PseudoColor visuals have priority over DirectColor
30 and StaticColor visuals, respectively. If no conforming visual exists,
31 NULL is returned. To free the data returned by this function, use
32 XFree.
33 All boolean GLX attributes default to False except GLX_USE_GL, which
35 defaults to True. All integer GLX attributes default to zero. Default
36 specifications are superseded by attributes included in attribList.
37 Boolean attributes included in attribList are understood to be True.
38 Integer attributes and enumerated type attributes are followed
39 immediately by the corresponding desired or minimum value. The list
40 must be terminated with None.
41 The interpretations of the various GLX visual attributes are as
43 follows:
44 GLX_USE_GL
46 Ignored. Only visuals that can be rendered with GLX are considered.
47 GLX_BUFFER_SIZE
49 Must be followed by a nonnegative integer that indicates the
50 desired color index buffer size. The smallest index buffer of at
51 least the specified size is preferred. Ignored if GLX_RGBA is
52 asserted.
53 GLX_LEVEL
55 Must be followed by an integer buffer-level specification. This
56 specification is honored exactly. Buffer level zero corresponds to
57 the main frame buffer of the display. Buffer level one is the first
58 overlay frame buffer, level two the second overlay frame buffer,
59 and so on. Negative buffer levels correspond to underlay frame
60 buffers.
61 GLX_RGBA
63 If present, only TrueColor and DirectColor visuals are considered.
64 Otherwise, only PseudoColor and StaticColor visuals are considered.
65 GLX_DOUBLEBUFFER
67 If present, only double-buffered visuals are considered. Otherwise,
68 only single-buffered visuals are considered.
69 GLX_STEREO
71 If present, only stereo visuals are considered. Otherwise, only
72 monoscopic visuals are considered.
73 GLX_AUX_BUFFERS
75 Must be followed by a nonnegative integer that indicates the
76 desired number of auxiliary buffers. Visuals with the smallest
77 number of auxiliary buffers that meets or exceeds the specified
78 number are preferred.
79 GLX_RED_SIZE
81 Must be followed by a nonnegative minimum size specification. If
82 this value is zero, the smallest available red buffer is preferred.
83 Otherwise, the largest available red buffer of at least the minimum
84 size is preferred.
85 GLX_GREEN_SIZE
87 Must be followed by a nonnegative minimum size specification. If
88 this value is zero, the smallest available green buffer is
89 preferred. Otherwise, the largest available green buffer of at
90 least the minimum size is preferred.
91 GLX_BLUE_SIZE
93 Must be followed by a nonnegative minimum size specification. If
94 this value is zero, the smallest available blue buffer is
95 preferred. Otherwise, the largest available blue buffer of at least
96 the minimum size is preferred.
97 GLX_ALPHA_SIZE
99 Must be followed by a nonnegative minimum size specification. If
100 this value is zero, the smallest available alpha buffer is
101 preferred. Otherwise, the largest available alpha buffer of at
102 least the minimum size is preferred.
103 GLX_DEPTH_SIZE
105 Must be followed by a nonnegative minimum size specification. If
106 this value is zero, visuals with no depth buffer are preferred.
107 Otherwise, the largest available depth buffer of at least the
108 minimum size is preferred.
109 GLX_STENCIL_SIZE
111 Must be followed by a nonnegative integer that indicates the
112 desired number of stencil bitplanes. The smallest stencil buffer of
113 at least the specified size is preferred. If the desired value is
114 zero, visuals with no stencil buffer are preferred.
115 GLX_ACCUM_RED_SIZE
117 Must be followed by a nonnegative minimum size specification. If
118 this value is zero, visuals with no red accumulation buffer are
119 preferred. Otherwise, the largest possible red accumulation buffer
120 of at least the minimum size is preferred.
121 GLX_ACCUM_GREEN_SIZE
123 Must be followed by a nonnegative minimum size specification. If
124 this value is zero, visuals with no green accumulation buffer are
125 preferred. Otherwise, the largest possible green accumulation
126 buffer of at least the minimum size is preferred.
127 GLX_ACCUM_BLUE_SIZE
129 Must be followed by a nonnegative minimum size specification. If
130 this value is zero, visuals with no blue accumulation buffer are
131 preferred. Otherwise, the largest possible blue accumulation buffer
132 of at least the minimum size is preferred.
133 GLX_ACCUM_ALPHA_SIZE
135 Must be followed by a nonnegative minimum size specification. If
136 this value is zero, visuals with no alpha accumulation buffer are
137 preferred. Otherwise, the largest possible alpha accumulation
138 buffer of at least the minimum size is preferred.
139
141 attribList =
142 {GLX_RGBA, GLX_RED_SIZE, 4, GLX_GREEN_SIZE, 4, GLX_BLUE_SIZE, 4,
143 None};
144 Specifies a single-buffered RGB visual in the normal frame buffer, not
146 an overlay or underlay buffer. The returned visual supports at least
147 four bits each of red, green, and blue, and possibly no bits of alpha.
148 It does not support color index mode, double-buffering, or stereo
149 display. It may or may not have one or more auxiliary color buffers, a
150 depth buffer, a stencil buffer, or an accumulation buffer.
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153 XVisualInfo is defined in Xutil.h. It is a structure that includes
154 visual, visualID, screen, and depth elements.
155 glXChooseVisual is implemented as a client-side utility using only
157 XGetVisualInfo and glXGetConfig(). Calls to these two routines can be
158 used to implement selection algorithms other than the generic one
159 implemented by glXChooseVisual.
160 GLX implementations are strongly discouraged, but not proscribed, from
162 changing the selection algorithm used by glXChooseVisual. Therefore,
163 selections may change from release to release of the client-side
164 library.
165 There is no direct filter for picking only visuals that support
167 GLXPixmaps. GLXPixmaps are supported for visuals whose GLX_BUFFER_SIZE
168 is one of the pixmap depths supported by the X server.
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171 NULL is returned if an undefined GLX attribute is encountered in
172 attribList.
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175 glXCreateContext(), glXGetConfig()
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178 Copyright © 1991-2006 Silicon Graphics, Inc. This document is licensed
179 under the SGI Free Software B License. For details, see
180 http://oss.sgi.com/projects/FreeB/.
181
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184opengl.org 06/10/2014 GLXCHOOSEVISUAL(3G)