cogl/renderer: Add API to bind the right EGL API

We need to call eglBindAPI() with GLES before we setup the secondary
GPU blit. We've been lucky not really needing this, as it has been
GLES default, which is what the secondary blit uses, in order to not
depend on the default, or if we want to create the secondary blit
objects after initializing cogl, we must make sure to bind the right API
at the right time.

As we need to bind the GLES API when setting up the secondary blit, we
need to make sure that cogl gets the right API bound when that's done,
so Cogl can continue working. For this, add a "bind_api()" method on the
CoglRenderer object, that will know what API is correct to bind.

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1828>

cogl/cogl/cogl-renderer.c

@@ -774,3 +774,11 @@ cogl_renderer_create_dma_buf (CoglRenderer  *renderer,
 
   return NULL;
 }
+
+void
+cogl_renderer_bind_api (CoglRenderer *renderer)
+{
+  const CoglWinsysVtable *winsys = _cogl_renderer_get_winsys (renderer);
+
+  winsys->renderer_bind_api (renderer);
+}

cogl/cogl/cogl-renderer.h

@@ -419,6 +419,12 @@ cogl_renderer_create_dma_buf (CoglRenderer  *renderer,
                               int            height,
                               GError       **error);
 
+/**
+ * cogl_renderer_bind_api: (skip)
+ */
+COGL_EXPORT void
+cogl_renderer_bind_api (CoglRenderer *renderer);
+
 G_END_DECLS
 
 #endif /* __COGL_RENDERER_H__ */

cogl/cogl/winsys/cogl-winsys-egl.c

@@ -134,6 +134,16 @@ _cogl_winsys_renderer_disconnect (CoglRenderer *renderer)
   g_assert_not_reached ();
 }
 
+static void
+_cogl_winsys_renderer_bind_api (CoglRenderer *renderer)
+{
+  if (renderer->driver == COGL_DRIVER_GL ||
+      renderer->driver == COGL_DRIVER_GL3)
+    eglBindAPI (EGL_OPENGL_API);
+  else if (renderer->driver == COGL_DRIVER_GLES2)
+    eglBindAPI (EGL_OPENGL_ES_API);
+}
+
 /* Updates all the function pointers */
 static void
 check_egl_extensions (CoglRenderer *renderer)
@@ -364,11 +374,7 @@ try_create_context (CoglDisplay *display,
 
   g_return_val_if_fail (egl_display->egl_context == NULL, TRUE);
 
-  if (renderer->driver == COGL_DRIVER_GL ||
-      renderer->driver == COGL_DRIVER_GL3)
-    eglBindAPI (EGL_OPENGL_API);
-  else if (renderer->driver == COGL_DRIVER_GLES2)
-    eglBindAPI (EGL_OPENGL_ES_API);
+  cogl_renderer_bind_api (renderer);
 
   cogl_display_egl_determine_attributes (display,
                                          &display->onscreen_template->config,
@@ -620,6 +626,7 @@ static CoglWinsysVtable _cogl_winsys_vtable =
     .renderer_get_proc_address = _cogl_winsys_renderer_get_proc_address,
     .renderer_connect = _cogl_winsys_renderer_connect,
     .renderer_disconnect = _cogl_winsys_renderer_disconnect,
+    .renderer_bind_api = _cogl_winsys_renderer_bind_api,
     .display_setup = _cogl_winsys_display_setup,
     .display_destroy = _cogl_winsys_display_destroy,
     .context_init = _cogl_winsys_context_init,

cogl/cogl/winsys/cogl-winsys-glx.c

@@ -297,6 +297,11 @@ _cogl_winsys_renderer_outputs_changed (CoglRenderer *renderer)
   update_all_outputs (renderer);
 }
 
+static void
+_cogl_winsys_renderer_bind_api (CoglRenderer *renderer)
+{
+}
+
 static gboolean
 resolve_core_glx_functions (CoglRenderer *renderer,
                             GError **error)
@@ -1419,6 +1424,7 @@ static CoglWinsysVtable _cogl_winsys_vtable =
     .renderer_connect = _cogl_winsys_renderer_connect,
     .renderer_disconnect = _cogl_winsys_renderer_disconnect,
     .renderer_outputs_changed = _cogl_winsys_renderer_outputs_changed,
+    .renderer_bind_api = _cogl_winsys_renderer_bind_api,
     .display_setup = _cogl_winsys_display_setup,
     .display_destroy = _cogl_winsys_display_destroy,
     .context_init = _cogl_winsys_context_init,

cogl/cogl/winsys/cogl-winsys-private.h

@@ -97,6 +97,9 @@ typedef struct _CoglWinsysVtable
                               int            height,
                               GError       **error);
 
+  void
+  (*renderer_bind_api) (CoglRenderer *renderer);
+
   gboolean
   (*context_init) (CoglContext *context, GError **error);