Add an SDL2 winsys

This adds an alternate version of the SDL winsys using the SDL 2 API.
The two versions are mutually exclusive and share the same
CoglWinsysID. Version 2 of SDL fits a little bit better with Cogl
because it supports multiple windows and the video subsystem can be
initialised entirely independently of the rest of the subsystems.

The SDL2 winsys creates an invisible dummy window in order to bind the
GL context after creating the Cogl display. This is similar to how the
X11 winsys's work.

SDL2 seems to support compiling with support for both GL and GLES.
However there doesn't seem to be a way to select between the two
backends outside of SDL. In fact if you do compile them both in it
seems to break down because it will always try to use the window
system functions from the GLES backend because those are filled in
second in the vtable. However when creating the window it will always
prefer to use the GL function to choose a visual. This function gets
confused because the GL backend has not been initialised at that
point. The Cogl backend therefore just leaves it up to SDL to pick a
sensible backend. It will then verify that it picked a GL library
which matches the Cogl driver by checking the string from
glGetString(GL_VERSION).

Reviewed-by: Robert Bragg <robert@linux.intel.com>

(cherry picked from commit 6cb5ab4135)
This commit is contained in:
Neil Roberts 2012-06-14 14:42:16 +01:00 committed by Robert Bragg
parent 9a1f0c4098
commit 17c818a9a7
7 changed files with 596 additions and 7 deletions

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@ -471,6 +471,13 @@ cogl_sources_c += \
$(srcdir)/winsys/cogl-winsys-sdl.c \
$(srcdir)/cogl-sdl.c
endif
if SUPPORT_SDL2
cogl_experimental_h += $(srcdir)/cogl-sdl.h
cogl_sources_c += \
$(srcdir)/winsys/cogl-winsys-sdl-private.h \
$(srcdir)/winsys/cogl-winsys-sdl2.c \
$(srcdir)/cogl-sdl.c
endif
EXTRA_DIST += stb_image.c

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@ -31,13 +31,13 @@
#include "cogl-renderer-private.h"
void
cogl_sdl_renderer_set_event_type (CoglRenderer *renderer, uint8_t type)
cogl_sdl_renderer_set_event_type (CoglRenderer *renderer, int type)
{
renderer->sdl_event_type_set = TRUE;
renderer->sdl_event_type = type;
}
uint8_t
int
cogl_sdl_renderer_get_event_type (CoglRenderer *renderer)
{
_COGL_RETURN_VAL_IF_FAIL (renderer->sdl_event_type_set, SDL_USEREVENT);
@ -46,7 +46,7 @@ cogl_sdl_renderer_get_event_type (CoglRenderer *renderer)
}
CoglContext *
cogl_sdl_context_new (uint8_t type, GError **error)
cogl_sdl_context_new (int type, GError **error)
{
CoglRenderer *renderer = cogl_renderer_new ();
CoglDisplay *display;

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@ -123,7 +123,7 @@ G_BEGIN_DECLS
* Stability: unstable
*/
CoglContext *
cogl_sdl_context_new (uint8_t type, GError **error);
cogl_sdl_context_new (int type, GError **error);
/**
* cogl_sdl_renderer_set_event_type:
@ -147,7 +147,7 @@ cogl_sdl_context_new (uint8_t type, GError **error);
* Stability: unstable
*/
void
cogl_sdl_renderer_set_event_type (CoglRenderer *renderer, uint8_t type);
cogl_sdl_renderer_set_event_type (CoglRenderer *renderer, int type);
/**
* cogl_sdl_renderer_get_event_type:
@ -161,7 +161,7 @@ cogl_sdl_renderer_set_event_type (CoglRenderer *renderer, uint8_t type);
* Since: 2.0
* Stability: unstable
*/
uint8_t
int
cogl_sdl_renderer_get_event_type (CoglRenderer *renderer);
/**

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@ -0,0 +1,415 @@
/*
* Cogl
*
* An object oriented GL/GLES Abstraction/Utility Layer
*
* Copyright (C) 2011, 2012 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/>.
*
*
* Authors:
* Neil Roberts <neil@linux.intel.com>
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <SDL.h>
#include "cogl-renderer-private.h"
#include "cogl-display-private.h"
#include "cogl-framebuffer-private.h"
#include "cogl-swap-chain-private.h"
#include "cogl-onscreen-template-private.h"
#include "cogl-context-private.h"
#include "cogl-onscreen-private.h"
#include "cogl-winsys-sdl-private.h"
typedef struct _CoglContextSdl2
{
SDL_Window *current_window;
} CoglContextSdl2;
typedef struct _CoglRendererSdl2
{
int stub;
} CoglRendererSdl2;
typedef struct _CoglDisplaySdl2
{
SDL_Window *dummy_window;
SDL_GLContext *context;
} CoglDisplaySdl2;
typedef struct _CoglOnscreenSdl2
{
SDL_Window *window;
} CoglOnscreenSdl2;
static CoglFuncPtr
_cogl_winsys_renderer_get_proc_address (CoglRenderer *renderer,
const char *name)
{
return SDL_GL_GetProcAddress (name);
}
static void
_cogl_winsys_renderer_disconnect (CoglRenderer *renderer)
{
SDL_VideoQuit ();
g_slice_free (CoglRendererSdl2, renderer->winsys);
}
static CoglBool
_cogl_winsys_renderer_connect (CoglRenderer *renderer,
GError **error)
{
if (SDL_VideoInit (NULL) < 0)
{
g_set_error (error, COGL_WINSYS_ERROR,
COGL_WINSYS_ERROR_INIT,
"SDL_Init failed: %s",
SDL_GetError ());
return FALSE;
}
renderer->winsys = g_slice_new0 (CoglRendererSdl2);
return TRUE;
}
static void
_cogl_winsys_display_destroy (CoglDisplay *display)
{
CoglDisplaySdl2 *sdl_display = display->winsys;
_COGL_RETURN_IF_FAIL (sdl_display != NULL);
if (sdl_display->context)
SDL_GL_DeleteContext (sdl_display->context);
if (sdl_display->dummy_window)
SDL_DestroyWindow (sdl_display->dummy_window);
g_slice_free (CoglDisplaySdl2, display->winsys);
display->winsys = NULL;
}
static void
set_gl_attribs_from_framebuffer_config (CoglFramebufferConfig *config)
{
SDL_GL_SetAttribute (SDL_GL_RED_SIZE, 1);
SDL_GL_SetAttribute (SDL_GL_GREEN_SIZE, 1);
SDL_GL_SetAttribute (SDL_GL_BLUE_SIZE, 1);
SDL_GL_SetAttribute (SDL_GL_DEPTH_SIZE, 1);
SDL_GL_SetAttribute (SDL_GL_STENCIL_SIZE,
config->need_stencil ? 1 : 0);
SDL_GL_SetAttribute (SDL_GL_DOUBLEBUFFER,
config->swap_chain->length > 1 ? 1 : 0);
SDL_GL_SetAttribute (SDL_GL_ALPHA_SIZE,
config->swap_chain->has_alpha ? 1 : 0);
}
static CoglBool
_cogl_winsys_display_setup (CoglDisplay *display,
GError **error)
{
CoglDisplaySdl2 *sdl_display;
const char * (* get_string_func) (GLenum name);
const char *gl_version;
_COGL_RETURN_VAL_IF_FAIL (display->winsys == NULL, FALSE);
sdl_display = g_slice_new0 (CoglDisplaySdl2);
display->winsys = sdl_display;
set_gl_attribs_from_framebuffer_config (&display->onscreen_template->config);
if (display->renderer->driver == COGL_DRIVER_GLES1)
SDL_GL_SetAttribute (SDL_GL_CONTEXT_MAJOR_VERSION, 1);
else if (display->renderer->driver == COGL_DRIVER_GLES2)
SDL_GL_SetAttribute (SDL_GL_CONTEXT_MAJOR_VERSION, 2);
/* Create a dummy 1x1 window that never gets display so that we can
* create a GL context */
sdl_display->dummy_window = SDL_CreateWindow ("",
0, 0, /* x/y */
1, 1, /* w/h */
SDL_WINDOW_OPENGL |
SDL_WINDOW_HIDDEN);
if (sdl_display->dummy_window == NULL)
{
g_set_error (error, COGL_WINSYS_ERROR,
COGL_WINSYS_ERROR_INIT,
"SDL_CreateWindow failed: %s",
SDL_GetError ());
goto error;
}
sdl_display->context = SDL_GL_CreateContext (sdl_display->dummy_window);
if (sdl_display->context == NULL)
{
g_set_error (error, COGL_WINSYS_ERROR,
COGL_WINSYS_ERROR_INIT,
"SDL_GL_CreateContext failed: %s",
SDL_GetError ());
goto error;
}
/* SDL doesn't seem to provide a way to select between GL and GLES
* and instead it will just pick one itself. We can at least try to
* verify that it picked the one we were expecting by looking at the
* GL version string */
get_string_func = SDL_GL_GetProcAddress ("glGetString");
gl_version = get_string_func (GL_VERSION);
switch (display->renderer->driver)
{
case COGL_DRIVER_GL:
/* The first character of the version string will be a digit if
* it's normal GL */
if (!g_ascii_isdigit (gl_version[0]))
{
g_set_error (error, COGL_WINSYS_ERROR,
COGL_WINSYS_ERROR_INIT,
"The GL driver was requested but SDL is using GLES");
goto error;
}
break;
case COGL_DRIVER_GLES2:
if (!g_str_has_prefix (gl_version, "OpenGL ES 2"))
{
g_set_error (error, COGL_WINSYS_ERROR,
COGL_WINSYS_ERROR_INIT,
"The GLES2 driver was requested but SDL is "
"not using GLES2");
goto error;
}
break;
case COGL_DRIVER_GLES1:
if (!g_str_has_prefix (gl_version, "OpenGL ES 1"))
{
g_set_error (error, COGL_WINSYS_ERROR,
COGL_WINSYS_ERROR_INIT,
"The GLES1 driver was requested but SDL is "
"not using GLES1");
goto error;
}
break;
default:
g_assert_not_reached ();
}
return TRUE;
error:
_cogl_winsys_display_destroy (display);
return FALSE;
}
static CoglBool
_cogl_winsys_context_init (CoglContext *context, GError **error)
{
CoglRenderer *renderer = context->display->renderer;
context->winsys = g_new0 (CoglContextSdl2, 1);
if (G_UNLIKELY (renderer->sdl_event_type_set == FALSE))
g_error ("cogl_sdl_renderer_set_event_type() or cogl_sdl_context_new() "
"must be called during initialization");
if (!_cogl_context_update_features (context, error))
return FALSE;
if (SDL_GL_GetSwapInterval () != -1)
COGL_FLAGS_SET (context->winsys_features,
COGL_WINSYS_FEATURE_SWAP_REGION_THROTTLE,
TRUE);
return TRUE;
}
static void
_cogl_winsys_context_deinit (CoglContext *context)
{
g_free (context->winsys);
}
static void
_cogl_winsys_onscreen_bind (CoglOnscreen *onscreen)
{
CoglFramebuffer *fb = COGL_FRAMEBUFFER (onscreen);
CoglContext *context = fb->context;
CoglContextSdl2 *sdl_context = context->winsys;
CoglDisplaySdl2 *sdl_display = context->display->winsys;
CoglOnscreenSdl2 *sdl_onscreen = onscreen->winsys;
if (sdl_context->current_window == sdl_onscreen->window)
return;
SDL_GL_MakeCurrent (sdl_onscreen->window, sdl_display->context);
sdl_context->current_window = sdl_onscreen->window;
/* It looks like SDL just directly calls a glXSwapInterval function
* when this is called. This may be provided by either the EXT
* extension, the SGI extension or the Mesa extension. The SGI
* extension is per context so we can't just do this once when the
* framebuffer is allocated. See the comments in the GLX winsys for
* more info. */
if (COGL_FLAGS_GET (context->winsys_features,
COGL_WINSYS_FEATURE_SWAP_REGION_THROTTLE))
{
CoglFramebuffer *fb = COGL_FRAMEBUFFER (onscreen);
SDL_GL_SetSwapInterval (fb->config.swap_throttled ? 1 : 0);
}
}
static void
_cogl_winsys_onscreen_deinit (CoglOnscreen *onscreen)
{
CoglOnscreenSdl2 *sdl_onscreen = onscreen->winsys;
if (sdl_onscreen->window != NULL)
{
CoglContext *context = COGL_FRAMEBUFFER (onscreen)->context;
CoglContextSdl2 *sdl_context = context->winsys;
if (sdl_context->current_window == sdl_onscreen->window)
sdl_context->current_window = NULL;
SDL_DestroyWindow (sdl_onscreen->window);
sdl_onscreen->window = NULL;
}
g_slice_free (CoglOnscreenSdl2, sdl_onscreen);
onscreen->winsys = NULL;
}
static CoglBool
_cogl_winsys_onscreen_init (CoglOnscreen *onscreen,
GError **error)
{
CoglFramebuffer *framebuffer = COGL_FRAMEBUFFER (onscreen);
CoglOnscreenSdl2 *sdl_onscreen;
SDL_Window *window;
int width, height;
width = cogl_framebuffer_get_width (framebuffer);
height = cogl_framebuffer_get_height (framebuffer);
window = SDL_CreateWindow ("" /* title */,
0, 0, /* x/y */
width, height,
SDL_WINDOW_OPENGL |
SDL_WINDOW_HIDDEN);
if (window == NULL)
{
g_set_error (error, COGL_WINSYS_ERROR,
COGL_WINSYS_ERROR_CREATE_ONSCREEN,
"SDL_CreateWindow failed: %s",
SDL_GetError ());
return FALSE;
}
onscreen->winsys = g_slice_new (CoglOnscreenSdl2);
sdl_onscreen = onscreen->winsys;
sdl_onscreen->window = window;
return TRUE;
}
static void
_cogl_winsys_onscreen_swap_buffers (CoglOnscreen *onscreen)
{
CoglOnscreenSdl2 *sdl_onscreen = onscreen->winsys;
SDL_GL_SwapWindow (sdl_onscreen->window);
}
static void
_cogl_winsys_onscreen_update_swap_throttled (CoglOnscreen *onscreen)
{
CoglContext *context = COGL_FRAMEBUFFER (onscreen)->context;
CoglContextSdl2 *sdl_context = context->winsys;
CoglOnscreenSdl2 *sdl_onscreen = onscreen->winsys;
if (sdl_context->current_window != sdl_onscreen->window)
return;
sdl_context->current_window = NULL;
_cogl_winsys_onscreen_bind (onscreen);
}
static void
_cogl_winsys_onscreen_set_visibility (CoglOnscreen *onscreen,
CoglBool visibility)
{
CoglOnscreenSdl2 *sdl_onscreen = onscreen->winsys;
if (visibility)
SDL_ShowWindow (sdl_onscreen->window);
else
SDL_HideWindow (sdl_onscreen->window);
}
const CoglWinsysVtable *
_cogl_winsys_sdl_get_vtable (void)
{
static CoglBool vtable_inited = FALSE;
static CoglWinsysVtable vtable;
/* It would be nice if we could use C99 struct initializers here
like the GLX backend does. However this code is more likely to be
compiled using Visual Studio which (still!) doesn't support them
so we initialize it in code instead */
if (!vtable_inited)
{
memset (&vtable, 0, sizeof (vtable));
vtable.id = COGL_WINSYS_ID_SDL;
vtable.name = "SDL";
vtable.renderer_get_proc_address = _cogl_winsys_renderer_get_proc_address;
vtable.renderer_connect = _cogl_winsys_renderer_connect;
vtable.renderer_disconnect = _cogl_winsys_renderer_disconnect;
vtable.display_setup = _cogl_winsys_display_setup;
vtable.display_destroy = _cogl_winsys_display_destroy;
vtable.context_init = _cogl_winsys_context_init;
vtable.context_deinit = _cogl_winsys_context_deinit;
vtable.onscreen_init = _cogl_winsys_onscreen_init;
vtable.onscreen_deinit = _cogl_winsys_onscreen_deinit;
vtable.onscreen_bind = _cogl_winsys_onscreen_bind;
vtable.onscreen_swap_buffers = _cogl_winsys_onscreen_swap_buffers;
vtable.onscreen_update_swap_throttled =
_cogl_winsys_onscreen_update_swap_throttled;
vtable.onscreen_set_visibility = _cogl_winsys_onscreen_set_visibility;
vtable_inited = TRUE;
}
return &vtable;
}

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@ -748,6 +748,30 @@ AS_IF([test "x$enable_sdl" = "xyes"],
[SUPPORT_SDL=no])
AM_CONDITIONAL(SUPPORT_SDL, [test "x$SUPPORT_SDL" = "xyes"])
AC_ARG_ENABLE(
[sdl2],
[AC_HELP_STRING([--enable-sdl2=@<:@no/yes@:>@], [Enable SDL2 support @<:@default=no@:>@])],
[],
[enable_sdl2=no])
AS_IF([test "x$enable_sdl2" = "xyes"],
[
PKG_CHECK_MODULES([SDL2],
[sdl2],
[],
[AC_MSG_ERROR([SDL2 support requested but SDL2 not found])])
SUPPORT_SDL2=yes
GL_WINSYS_APIS="$GL_WINSYS_APIS sdl2"
COGL_PKG_REQUIRES="$COGL_PKG_REQUIRES sdl2"
COGL_DEFINES_SYMBOLS="$COGL_DEFINES_SYMBOLS COGL_HAS_SDL_SUPPORT"
],
[SUPPORT_SDL2=no])
AM_CONDITIONAL(SUPPORT_SDL2, [test "x$SUPPORT_SDL2" = "xyes"])
AS_IF([test "x$SUPPORT_SDL2" = "xyes" -a "x$SUPPORT_SDL" = "xyes"],
[AC_MSG_ERROR([The SDL1 and SDL2 winsyses are currently mutually exclusive])])
EGL_PLATFORM_COUNT=0
AC_ARG_ENABLE(
@ -890,7 +914,7 @@ AC_ARG_ENABLE(
[xlib-egl-platform],
[AC_HELP_STRING([--enable-xlib-egl-platform=@<:@no/yes@:>@], [Enable support for the Xlib egl platform @<:@default=auto@:>@])],
[],
AS_IF([test "x$enable_gles1" = "xyes" -o "x$enable_gles2" = "xyes" && test "x$SUPPORT_SDL_GLES" != "xyes" && test $EGL_PLATFORM_COUNT -eq 0],
AS_IF([test "x$enable_gles1" = "xyes" -o "x$enable_gles2" = "xyes" && test "x$SUPPORT_SDL_GLES" != "xyes" && test "x$SUPPORT_SDL2" != "xyes" && test $EGL_PLATFORM_COUNT -eq 0],
[enable_xlib_egl_platform=yes], [enable_xlib_egl_platform=no])
)
AS_IF([test "x$enable_xlib_egl_platform" = "xyes"],

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@ -63,6 +63,12 @@ cogl_sdl_hello_SOURCES = cogl-sdl-hello.c
cogl_sdl_hello_LDADD = $(common_ldadd)
endif
if SUPPORT_SDL2
programs += cogl-sdl2-hello
cogl_sdl2_hello_SOURCES = cogl-sdl2-hello.c
cogl_sdl2_hello_LDADD = $(common_ldadd)
endif
cogl_gles2_context_SOURCES = cogl-gles2-context.c
cogl_gles2_context_LDADD = $(common_ldadd)

137
examples/cogl-sdl2-hello.c Normal file
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@ -0,0 +1,137 @@
#include <cogl/cogl.h>
#include <glib.h>
#include <stdio.h>
#include <SDL.h>
/* This short example is just to demonstrate mixing SDL with Cogl as a
simple way to get portable support for events */
typedef struct Data
{
CoglPrimitive *triangle;
CoglPipeline *pipeline;
float center_x, center_y;
CoglFramebuffer *fb;
CoglBool quit;
CoglBool redraw_queued;
} Data;
static CoglBool
redraw (Data *data)
{
CoglFramebuffer *fb = data->fb;
cogl_framebuffer_clear4f (fb, COGL_BUFFER_BIT_COLOR, 0, 0, 0, 1);
cogl_framebuffer_push_matrix (fb);
cogl_framebuffer_translate (fb, data->center_x, -data->center_y, 0.0f);
cogl_framebuffer_draw_primitive (fb, data->pipeline, data->triangle);
cogl_framebuffer_pop_matrix (fb);
cogl_onscreen_swap_buffers (COGL_ONSCREEN (fb));
return FALSE;
}
static void
handle_event (Data *data, SDL_Event *event)
{
switch (event->type)
{
case SDL_WINDOWEVENT:
switch (event->window.event)
{
case SDL_WINDOWEVENT_EXPOSED:
data->redraw_queued = TRUE;
break;
case SDL_WINDOWEVENT_CLOSE:
data->quit = TRUE;
break;
}
break;
case SDL_MOUSEMOTION:
{
int width =
cogl_framebuffer_get_width (COGL_FRAMEBUFFER (data->fb));
int height =
cogl_framebuffer_get_height (COGL_FRAMEBUFFER (data->fb));
data->center_x = event->motion.x * 2.0f / width - 1.0f;
data->center_y = event->motion.y * 2.0f / height - 1.0f;
data->redraw_queued = TRUE;
}
break;
case SDL_QUIT:
data->quit = TRUE;
break;
}
}
int
main (int argc, char **argv)
{
CoglContext *ctx;
CoglOnscreen *onscreen;
GError *error = NULL;
CoglVertexP2C4 triangle_vertices[] = {
{0, 0.7, 0xff, 0x00, 0x00, 0x80},
{-0.7, -0.7, 0x00, 0xff, 0x00, 0xff},
{0.7, -0.7, 0x00, 0x00, 0xff, 0xff}
};
Data data;
SDL_Event event;
ctx = cogl_sdl_context_new (SDL_USEREVENT, &error);
if (!ctx)
{
fprintf (stderr, "Failed to create context: %s\n", error->message);
return 1;
}
onscreen = cogl_onscreen_new (ctx, 800, 600);
data.fb = COGL_FRAMEBUFFER (onscreen);
data.center_x = 0.0f;
data.center_y = 0.0f;
data.quit = FALSE;
cogl_onscreen_show (onscreen);
data.triangle = cogl_primitive_new_p2c4 (ctx, COGL_VERTICES_MODE_TRIANGLES,
3, triangle_vertices);
data.pipeline = cogl_pipeline_new (ctx);
data.redraw_queued = TRUE;
while (!data.quit)
{
while (!data.quit)
{
if (!SDL_PollEvent (&event))
{
if (data.redraw_queued)
break;
cogl_sdl_idle (ctx);
if (!SDL_WaitEvent (&event))
{
fprintf (stderr, "Error waiting for SDL events");
return 1;
}
}
handle_event (&data, &event);
cogl_sdl_handle_event (ctx, &event);
}
data.redraw_queued = redraw (&data);
}
cogl_object_unref (ctx);
return 0;
}