Add cogl_sdl_onscreen_get_window()

This adds a function to get a pointer to the SDL_Window associated
with a CoglOnscreen when using the SDL2 winsys.

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

(cherry picked from commit 071f4b80daa8a2f967746a30b3acf014d74f781a)

cogl/cogl-sdl.h

@@ -29,6 +29,7 @@
 #define __COGL_SDL_H__
 
 #include <cogl/cogl-context.h>
+#include <cogl/cogl-onscreen.h>
 #include <SDL.h>
 
 #ifdef _MSC_VER
@@ -202,6 +203,22 @@ cogl_sdl_handle_event (CoglContext *context, SDL_Event *event);
 void
 cogl_sdl_idle (CoglContext *context);
 
+#if SDL_MAJOR_VERSION >= 2
+
+/**
+ * cogl_sdl_onscreen_get_window:
+ * @onscreen: A #CoglOnscreen
+ *
+ * Returns the underlying SDL_Window associated with an onscreen framebuffer.
+ *
+ * Since: 2.0
+ * Stability: unstable
+ */
+SDL_Window *
+cogl_sdl_onscreen_get_window (CoglOnscreen *onscreen);
+
+#endif /* SDL_MAJOR_VERSION */
+
 G_END_DECLS
 
 #endif /* __COGL_SDL_H__ */

cogl/winsys/cogl-winsys-sdl2.c

@@ -38,6 +38,7 @@
 #include "cogl-onscreen-private.h"
 #include "cogl-winsys-sdl-private.h"
 #include "cogl-error-private.h"
+#include "cogl-sdl.h"
 
 typedef struct _CoglContextSdl2
 {
@@ -510,6 +511,21 @@ _cogl_winsys_poll_dispatch (CoglContext *context,
     }
 }
 
+SDL_Window *
+cogl_sdl_onscreen_get_window (CoglOnscreen *onscreen)
+{
+  CoglOnscreenSdl2 *sdl_onscreen;
+
+  _COGL_RETURN_VAL_IF_FAIL (cogl_is_onscreen (onscreen), NULL);
+
+  if (!cogl_framebuffer_allocate (COGL_FRAMEBUFFER (onscreen), NULL))
+    return NULL;
+
+  sdl_onscreen = onscreen->winsys;
+
+  return sdl_onscreen->window;
+}
+
 const CoglWinsysVtable *
 _cogl_winsys_sdl_get_vtable (void)
 {

doc/reference/cogl-2.0-experimental/cogl-2.0-experimental-sections.txt

@@ -822,4 +822,5 @@ cogl_sdl_renderer_set_event_type
 cogl_sdl_renderer_get_event_type
 cogl_sdl_handle_event
 cogl_sdl_idle
+cogl_sdl_onscreen_get_window
 </SECTION>