mutter/cogl/cogl-glx-renderer-private.h

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/*
* Cogl
*
* An object oriented GL/GLES Abstraction/Utility Layer
*
* Copyright (C) 2011 Intel Corporation.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library. If not, see
* <http://www.gnu.org/licenses/>.
*
*
*/
#ifndef __COGL_RENDERER_GLX_PRIVATE_H
#define __COGL_RENDERER_GLX_PRIVATE_H
Dynamically load the GL or GLES library The GL or GLES library is now dynamically loaded by the CoglRenderer so that it can choose between GL, GLES1 and GLES2 at runtime. The library is loaded by the renderer because it needs to be done before calling eglInitialize. There is a new environment variable called COGL_DRIVER to choose between gl, gles1 or gles2. The #ifdefs for HAVE_COGL_GL, HAVE_COGL_GLES and HAVE_COGL_GLES2 have been changed so that they don't assume the ifdefs are mutually exclusive. They haven't been removed entirely so that it's possible to compile the GLES backends without the the enums from the GL headers. When using GLX the winsys additionally dynamically loads libGL because that also contains the GLX API. It can't be linked in directly because that would probably conflict with the GLES API if the EGL is selected. When compiling with EGL support the library links directly to libEGL because it doesn't contain any GL API so it shouldn't have any conflicts. When building for WGL or OSX Cogl still directly links against the GL API so there is a #define in config.h so that Cogl won't try to dlopen the library. Cogl-pango previously had a #ifdef to detect when the GL backend is used so that it can sneakily pass GL_QUADS to cogl_vertex_buffer_draw. This is now changed so that it queries the CoglContext for the backend. However to get this to work Cogl now needs to export the _cogl_context_get_default symbol and cogl-pango needs some extra -I flags to so that it can include cogl-context-private.h
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#include <gmodule.h>
#include "cogl-object-private.h"
#include "cogl-xlib-renderer-private.h"
typedef struct _CoglGLXRenderer
{
int glx_major;
int glx_minor;
int glx_error_base;
int glx_event_base;
CoglBool is_direct;
/* Vblank stuff */
int dri_fd;
Dynamically load the GL or GLES library The GL or GLES library is now dynamically loaded by the CoglRenderer so that it can choose between GL, GLES1 and GLES2 at runtime. The library is loaded by the renderer because it needs to be done before calling eglInitialize. There is a new environment variable called COGL_DRIVER to choose between gl, gles1 or gles2. The #ifdefs for HAVE_COGL_GL, HAVE_COGL_GLES and HAVE_COGL_GLES2 have been changed so that they don't assume the ifdefs are mutually exclusive. They haven't been removed entirely so that it's possible to compile the GLES backends without the the enums from the GL headers. When using GLX the winsys additionally dynamically loads libGL because that also contains the GLX API. It can't be linked in directly because that would probably conflict with the GLES API if the EGL is selected. When compiling with EGL support the library links directly to libEGL because it doesn't contain any GL API so it shouldn't have any conflicts. When building for WGL or OSX Cogl still directly links against the GL API so there is a #define in config.h so that Cogl won't try to dlopen the library. Cogl-pango previously had a #ifdef to detect when the GL backend is used so that it can sneakily pass GL_QUADS to cogl_vertex_buffer_draw. This is now changed so that it queries the CoglContext for the backend. However to get this to work Cogl now needs to export the _cogl_context_get_default symbol and cogl-pango needs some extra -I flags to so that it can include cogl-context-private.h
2011-07-07 15:44:56 -04:00
/* GModule pointing to libGL which we use to get glX functions out of */
GModule *libgl_module;
Query glX* functions before getting the context to fix GL3 driver The GL3 context is created using the glXCreateContextAttribs function which is part of the GLX_ARB_create_context extension. However previously the function pointers from GLX extensions were only retrieved once the GL context is created. That meant that the GL3 context creation function would always assume that the extension is not supported so it would always fail. This patch changes it to query the functions when the renderer is set up instead. The base winsys feature flags that are determined while querying the functions are stored in a member of CoglGLXRenderer. These are then copied to the CoglContext when it is initialised. The spec for glXGetProcAddress says that the functions returned are context-independent. That implies that it is safe to call it without binding a context although that is not explicitly stated as far as I can tell. A big of googling finds this DRI documentation which says it can be used without a context: http://dri.freedesktop.org/wiki/glXGetProcAddressNeverReturnsNULL And also this code sample: http://www.opengl.org/wiki/Tutorial:_OpenGL_3.0_Context_Creation_%28GLX%29 One point that makes me concerned that this might not always work in practice is that the code in SDL2 to create a GL3 context first creates a dummy GL2 context in order to have something bound before it calls glXGetProcAddress. I think this may just be a misunderstanding based on how wglGetProcAddress works however. Reviewed-by: Robert Bragg <robert@linux.intel.com> (cherry picked from commit 04a7aca9a98e84e43ac5559305a1358112902e30)
2012-12-12 14:58:35 -05:00
/* Copy of the winsys features that are based purely on the
* information we can get without using a GL context. We want to
* determine this before we have a context so that we can use the
* function pointers from the extensions earlier. This is necessary
* to use the glXCreateContextAttribs function. */
unsigned long base_winsys_features
[COGL_FLAGS_N_LONGS_FOR_SIZE (COGL_WINSYS_FEATURE_N_FEATURES)];
CoglFeatureFlags legacy_feature_flags;
Dynamically load the GL or GLES library The GL or GLES library is now dynamically loaded by the CoglRenderer so that it can choose between GL, GLES1 and GLES2 at runtime. The library is loaded by the renderer because it needs to be done before calling eglInitialize. There is a new environment variable called COGL_DRIVER to choose between gl, gles1 or gles2. The #ifdefs for HAVE_COGL_GL, HAVE_COGL_GLES and HAVE_COGL_GLES2 have been changed so that they don't assume the ifdefs are mutually exclusive. They haven't been removed entirely so that it's possible to compile the GLES backends without the the enums from the GL headers. When using GLX the winsys additionally dynamically loads libGL because that also contains the GLX API. It can't be linked in directly because that would probably conflict with the GLES API if the EGL is selected. When compiling with EGL support the library links directly to libEGL because it doesn't contain any GL API so it shouldn't have any conflicts. When building for WGL or OSX Cogl still directly links against the GL API so there is a #define in config.h so that Cogl won't try to dlopen the library. Cogl-pango previously had a #ifdef to detect when the GL backend is used so that it can sneakily pass GL_QUADS to cogl_vertex_buffer_draw. This is now changed so that it queries the CoglContext for the backend. However to get this to work Cogl now needs to export the _cogl_context_get_default symbol and cogl-pango needs some extra -I flags to so that it can include cogl-context-private.h
2011-07-07 15:44:56 -04:00
/* Function pointers for core GLX functionality. We can't just link
against these directly because we need to conditionally load
libGL when we are using GLX so that it won't conflict with a GLES
Query glX* functions before getting the context to fix GL3 driver The GL3 context is created using the glXCreateContextAttribs function which is part of the GLX_ARB_create_context extension. However previously the function pointers from GLX extensions were only retrieved once the GL context is created. That meant that the GL3 context creation function would always assume that the extension is not supported so it would always fail. This patch changes it to query the functions when the renderer is set up instead. The base winsys feature flags that are determined while querying the functions are stored in a member of CoglGLXRenderer. These are then copied to the CoglContext when it is initialised. The spec for glXGetProcAddress says that the functions returned are context-independent. That implies that it is safe to call it without binding a context although that is not explicitly stated as far as I can tell. A big of googling finds this DRI documentation which says it can be used without a context: http://dri.freedesktop.org/wiki/glXGetProcAddressNeverReturnsNULL And also this code sample: http://www.opengl.org/wiki/Tutorial:_OpenGL_3.0_Context_Creation_%28GLX%29 One point that makes me concerned that this might not always work in practice is that the code in SDL2 to create a GL3 context first creates a dummy GL2 context in order to have something bound before it calls glXGetProcAddress. I think this may just be a misunderstanding based on how wglGetProcAddress works however. Reviewed-by: Robert Bragg <robert@linux.intel.com> (cherry picked from commit 04a7aca9a98e84e43ac5559305a1358112902e30)
2012-12-12 14:58:35 -05:00
library if we are using EGL + GLES. These are just the functions
that we want to use before calling glXGetProcAddress */
Dynamically load the GL or GLES library The GL or GLES library is now dynamically loaded by the CoglRenderer so that it can choose between GL, GLES1 and GLES2 at runtime. The library is loaded by the renderer because it needs to be done before calling eglInitialize. There is a new environment variable called COGL_DRIVER to choose between gl, gles1 or gles2. The #ifdefs for HAVE_COGL_GL, HAVE_COGL_GLES and HAVE_COGL_GLES2 have been changed so that they don't assume the ifdefs are mutually exclusive. They haven't been removed entirely so that it's possible to compile the GLES backends without the the enums from the GL headers. When using GLX the winsys additionally dynamically loads libGL because that also contains the GLX API. It can't be linked in directly because that would probably conflict with the GLES API if the EGL is selected. When compiling with EGL support the library links directly to libEGL because it doesn't contain any GL API so it shouldn't have any conflicts. When building for WGL or OSX Cogl still directly links against the GL API so there is a #define in config.h so that Cogl won't try to dlopen the library. Cogl-pango previously had a #ifdef to detect when the GL backend is used so that it can sneakily pass GL_QUADS to cogl_vertex_buffer_draw. This is now changed so that it queries the CoglContext for the backend. However to get this to work Cogl now needs to export the _cogl_context_get_default symbol and cogl-pango needs some extra -I flags to so that it can include cogl-context-private.h
2011-07-07 15:44:56 -04:00
Bool
(* glXQueryExtension) (Display *dpy, int *errorb, int *event);
const char *
(* glXQueryExtensionsString) (Display *dpy, int screen);
Bool
(* glXQueryVersion) (Display *dpy, int *maj, int *min);
void *
(* glXGetProcAddress) (const GLubyte *procName);
int
(* glXQueryDrawable) (Display *dpy, GLXDrawable drawable,
int attribute, unsigned int *value);
/* Function pointers for GLX specific extensions */
Query glX* functions before getting the context to fix GL3 driver The GL3 context is created using the glXCreateContextAttribs function which is part of the GLX_ARB_create_context extension. However previously the function pointers from GLX extensions were only retrieved once the GL context is created. That meant that the GL3 context creation function would always assume that the extension is not supported so it would always fail. This patch changes it to query the functions when the renderer is set up instead. The base winsys feature flags that are determined while querying the functions are stored in a member of CoglGLXRenderer. These are then copied to the CoglContext when it is initialised. The spec for glXGetProcAddress says that the functions returned are context-independent. That implies that it is safe to call it without binding a context although that is not explicitly stated as far as I can tell. A big of googling finds this DRI documentation which says it can be used without a context: http://dri.freedesktop.org/wiki/glXGetProcAddressNeverReturnsNULL And also this code sample: http://www.opengl.org/wiki/Tutorial:_OpenGL_3.0_Context_Creation_%28GLX%29 One point that makes me concerned that this might not always work in practice is that the code in SDL2 to create a GL3 context first creates a dummy GL2 context in order to have something bound before it calls glXGetProcAddress. I think this may just be a misunderstanding based on how wglGetProcAddress works however. Reviewed-by: Robert Bragg <robert@linux.intel.com> (cherry picked from commit 04a7aca9a98e84e43ac5559305a1358112902e30)
2012-12-12 14:58:35 -05:00
#define COGL_WINSYS_FEATURE_BEGIN(a, b, c, d, e, f, g)
#define COGL_WINSYS_FEATURE_FUNCTION(ret, name, args) \
Query glX* functions before getting the context to fix GL3 driver The GL3 context is created using the glXCreateContextAttribs function which is part of the GLX_ARB_create_context extension. However previously the function pointers from GLX extensions were only retrieved once the GL context is created. That meant that the GL3 context creation function would always assume that the extension is not supported so it would always fail. This patch changes it to query the functions when the renderer is set up instead. The base winsys feature flags that are determined while querying the functions are stored in a member of CoglGLXRenderer. These are then copied to the CoglContext when it is initialised. The spec for glXGetProcAddress says that the functions returned are context-independent. That implies that it is safe to call it without binding a context although that is not explicitly stated as far as I can tell. A big of googling finds this DRI documentation which says it can be used without a context: http://dri.freedesktop.org/wiki/glXGetProcAddressNeverReturnsNULL And also this code sample: http://www.opengl.org/wiki/Tutorial:_OpenGL_3.0_Context_Creation_%28GLX%29 One point that makes me concerned that this might not always work in practice is that the code in SDL2 to create a GL3 context first creates a dummy GL2 context in order to have something bound before it calls glXGetProcAddress. I think this may just be a misunderstanding based on how wglGetProcAddress works however. Reviewed-by: Robert Bragg <robert@linux.intel.com> (cherry picked from commit 04a7aca9a98e84e43ac5559305a1358112902e30)
2012-12-12 14:58:35 -05:00
ret (APIENTRY * name) args;
#define COGL_WINSYS_FEATURE_END()
#include "cogl-winsys-glx-feature-functions.h"
#undef COGL_WINSYS_FEATURE_BEGIN
#undef COGL_WINSYS_FEATURE_FUNCTION
#undef COGL_WINSYS_FEATURE_END
} CoglGLXRenderer;
#endif /* __COGL_RENDERER_GLX_PRIVATE_H */