1 /*
2  * Copyright © 2016 Red Hat, Inc.
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
21  * DEALINGS IN THE SOFTWARE.
22  *
23  * Authors:
24  *	Adam Jackson <ajax@redhat.com>
25  */
26 
27 #ifndef GLAMOR_EGL_H
28 #define GLAMOR_EGL_H
29 
30 #define MESA_EGL_NO_X11_HEADERS
31 #define EGL_NO_X11
32 #include <epoxy/gl.h>
33 #include <epoxy/egl.h>
34 #include <glamor_egl_ext.h>
35 
36 /*
37  * Create an EGLDisplay from a native display type. This is a little quirky
38  * for a few reasons.
39  *
40  * 1: GetPlatformDisplayEXT and GetPlatformDisplay are the API you want to
41  * use, but have different function signatures in the third argument; this
42  * happens not to matter for us, at the moment, but it means epoxy won't alias
43  * them together.
44  *
45  * 2: epoxy 1.3 and earlier don't understand EGL client extensions, which
46  * means you can't call "eglGetPlatformDisplayEXT" directly, as the resolver
47  * will crash.
48  *
49  * 3: You can't tell whether you have EGL 1.5 at this point, because
50  * eglQueryString(EGL_VERSION) is a property of the display, which we don't
51  * have yet. So you have to query for extensions no matter what. Fortunately
52  * epoxy_has_egl_extension _does_ let you query for client extensions, so
53  * we don't have to write our own extension string parsing.
54  *
55  * 4. There is no EGL_KHR_platform_base to complement the EXT one, thus one
56  * needs to know EGL 1.5 is supported in order to use the eglGetPlatformDisplay
57  * function pointer.
58  * We can workaround this (circular dependency) by probing for the EGL 1.5
59  * platform extensions (EGL_KHR_platform_gbm and friends) yet it doesn't seem
60  * like mesa will be able to adverise these (even though it can do EGL 1.5).
61  */
62 static inline EGLDisplay
glamor_egl_get_display(EGLint type,void * native)63 glamor_egl_get_display(EGLint type, void *native)
64 {
65     /* In practise any EGL 1.5 implementation would support the EXT extension */
66     if (epoxy_has_egl_extension(NULL, "EGL_EXT_platform_base")) {
67         PFNEGLGETPLATFORMDISPLAYEXTPROC getPlatformDisplayEXT =
68             (void *) eglGetProcAddress("eglGetPlatformDisplayEXT");
69         if (getPlatformDisplayEXT)
70             return getPlatformDisplayEXT(type, native, NULL);
71     }
72 
73     /* Welp, everything is awful. */
74     return eglGetDisplay(native);
75 }
76 
77 #endif
78