1/*
2 * Copyright © 2013 Intel Corporation
3 *
4 * Permission is hereby granted, free of charge, to any person obtaining a
5 * copy of this software and associated documentation files (the "Software"),
6 * to deal in the Software without restriction, including without limitation
7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8 * and/or sell copies of the Software, and to permit persons to whom the
9 * Software is furnished to do so, subject to the following conditions:
10 *
11 * The above copyright notice and this permission notice (including the next
12 * paragraph) shall be included in all copies or substantial portions of the
13 * Software.
14 *
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
21 * IN THE SOFTWARE.
22 */
23
24#include <assert.h>
25#include <string.h>
26#include <stdio.h>
27
28#include "dispatch_common.h"
29
30/**
31 * If we can determine the GLX version from the current context, then
32 * return that, otherwise return a version that will just send us on
33 * to dlsym() or get_proc_address().
34 */
35int
36epoxy_conservative_glx_version(void)
37{
38 Display *dpy = glXGetCurrentDisplay();
39 GLXContext ctx = glXGetCurrentContext();
40 int screen;
41
42 if (!dpy || !ctx)
43 return 14;
44
45 glXQueryContext(dpy, ctx, GLX_SCREEN, &screen);
46
47 return epoxy_glx_version(dpy, screen);
48}
49
50
51/**
52 * @brief Returns the version of GLX we are using
53 *
54 * The version is encoded as:
55 *
56 * ```
57 *
58 * version = major * 10 + minor
59 *
60 * ```
61 *
62 * So it can be easily used for version comparisons.
63 *
64 * @param dpy The X11 display
65 * @param screen The X11 screen
66 *
67 * @return The encoded version of GLX we are using
68 *
69 * @see epoxy_gl_version()
70 */
71int
72epoxy_glx_version(Display *dpy, int screen)
73{
74 int server_major, server_minor;
75 int client_major, client_minor;
76 int server, client;
77 const char *version_string;
78 int ret;
79
80 version_string = glXQueryServerString(dpy, screen, GLX_VERSION);
81 if (!version_string)
82 return 0;
83
84 ret = sscanf(s: version_string, format: "%d.%d", &server_major, &server_minor);
85 assert(ret == 2);
86 server = server_major * 10 + server_minor;
87
88 version_string = glXGetClientString(dpy, GLX_VERSION);
89 if (!version_string)
90 return 0;
91
92 ret = sscanf(s: version_string, format: "%d.%d", &client_major, &client_minor);
93 assert(ret == 2);
94 client = client_major * 10 + client_minor;
95
96 if (client < server)
97 return client;
98 else
99 return server;
100}
101
102/**
103 * If we can determine the GLX extension support from the current
104 * context, then return that, otherwise give the answer that will just
105 * send us on to get_proc_address().
106 */
107bool
108epoxy_conservative_has_glx_extension(const char *ext)
109{
110 Display *dpy = glXGetCurrentDisplay();
111 GLXContext ctx = glXGetCurrentContext();
112 int screen;
113
114 if (!dpy || !ctx)
115 return true;
116
117 glXQueryContext(dpy, ctx, GLX_SCREEN, &screen);
118
119 return epoxy_has_glx_extension(dpy, screen, extension: ext);
120}
121
122/**
123 * @brief Returns true if the given GLX extension is supported in the current context.
124 *
125 * @param dpy The X11 display
126 * @param screen The X11 screen
127 * @param extension The name of the GLX extension
128 *
129 * @return `true` if the extension is available
130 *
131 * @see epoxy_has_gl_extension()
132 * @see epoxy_has_egl_extension()
133 */
134bool
135epoxy_has_glx_extension(Display *dpy, int screen, const char *ext)
136{
137 /* No, you can't just use glXGetClientString or
138 * glXGetServerString() here. Those each tell you about one half
139 * of what's needed for an extension to be supported, and
140 * glXQueryExtensionsString() is what gives you the intersection
141 * of the two.
142 */
143 return epoxy_extension_in_string(glXQueryExtensionsString(dpy, screen), ext);
144}
145
146/**
147 * @brief Checks whether GLX is available.
148 *
149 * @param dpy The X11 display
150 *
151 * @return `true` if GLX is available
152 *
153 * @newin{1,4}
154 */
155bool
156epoxy_has_glx(Display *dpy)
157{
158#if !PLATFORM_HAS_GLX
159 return false;
160#else
161 if (epoxy_load_glx(false, true)) {
162 Bool (* pf_glXQueryExtension) (Display *, int *, int *);
163 int error_base, event_base;
164
165 pf_glXQueryExtension = epoxy_conservative_glx_dlsym(name: "glXQueryExtension", false);
166 if (pf_glXQueryExtension && pf_glXQueryExtension(dpy, &error_base, &event_base))
167 return true;
168 }
169
170 return false;
171#endif /* !PLATFORM_HAS_GLX */
172}
173

source code of gtk/subprojects/libepoxy/src/dispatch_glx.c