onscreen: Get device and window handle for onscreens

This adds a new method which returns the device and window handle for
onscreen framebuffers. Renderdoc uses those handles to target what it
is going to capture.

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/4061>

cogl/cogl/cogl-onscreen.c

@@ -516,3 +516,16 @@ cogl_onscreen_get_frame_counter (CoglOnscreen *onscreen)
 
   return priv->frame_counter;
 }
+
+gboolean
+cogl_onscreen_get_window_handles (CoglOnscreen *onscreen,
+                                  gpointer     *device_out,
+                                  gpointer     *window_out)
+{
+  CoglOnscreenClass *klass = COGL_ONSCREEN_GET_CLASS (onscreen);
+
+  if (!klass->get_window_handles)
+      return FALSE;
+
+  return klass->get_window_handles (onscreen, device_out, window_out);
+}

cogl/cogl/cogl-onscreen.h

@@ -78,6 +78,10 @@ struct _CoglOnscreenClass
                                GError        **error);
 
   int (* get_buffer_age) (CoglOnscreen *onscreen);
+
+  gboolean (* get_window_handles) (CoglOnscreen *onscreen,
+                                   gpointer     *device_out,
+                                   gpointer     *window_out);
 };
 
 /**
@@ -402,4 +406,9 @@ cogl_onscreen_remove_frame_callback (CoglOnscreen *onscreen,
 COGL_EXPORT int64_t
 cogl_onscreen_get_frame_counter (CoglOnscreen *onscreen);
 
+COGL_EXPORT gboolean
+cogl_onscreen_get_window_handles (CoglOnscreen *onscreen,
+                                  gpointer     *device_out,
+                                  gpointer     *window_out);
+
 G_END_DECLS

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

@@ -528,6 +528,26 @@ cogl_onscreen_glx_get_buffer_age (CoglOnscreen *onscreen)
   return age;
 }
 
+static gboolean
+cogl_onscreen_glx_get_window_handles (CoglOnscreen *onscreen,
+                                      gpointer     *device_out,
+                                      gpointer     *window_out)
+{
+  CoglOnscreenGlx *onscreen_glx = COGL_ONSCREEN_GLX (onscreen);
+  CoglFramebuffer *framebuffer = COGL_FRAMEBUFFER (onscreen);
+  CoglContext *cogl_context = cogl_framebuffer_get_context (framebuffer);
+  CoglXlibRenderer *xlib_renderer =
+    _cogl_xlib_renderer_get_data (cogl_context->display->renderer);
+  GLXDrawable drawable;
+
+  drawable = onscreen_glx->glxwin ? onscreen_glx->glxwin : onscreen_glx->xwin;
+
+  *device_out = xlib_renderer->xdpy;
+  *window_out = (gpointer) drawable;
+
+  return TRUE;
+}
+
 static void
 cogl_onscreen_glx_flush_notification (CoglOnscreen *onscreen)
 {
@@ -1067,4 +1087,5 @@ cogl_onscreen_glx_class_init (CoglOnscreenGlxClass *klass)
     cogl_onscreen_glx_swap_buffers_with_damage;
   onscreen_class->swap_region = cogl_onscreen_glx_swap_region;
   onscreen_class->get_buffer_age = cogl_onscreen_glx_get_buffer_age;
+  onscreen_class->get_window_handles = cogl_onscreen_glx_get_window_handles;
 }

cogl/cogl/winsys/cogl-onscreen-xlib.c

@@ -170,6 +170,22 @@ cogl_onscreen_xlib_allocate (CoglFramebuffer  *framebuffer,
   return parent_class->allocate (framebuffer, error);
 }
 
+static gboolean
+cogl_onscreen_xlib_get_window_handles (CoglOnscreen *onscreen,
+                                       gpointer     *device_out,
+                                       gpointer     *window_out)
+{
+  CoglOnscreenXlib *onscreen_xlib = COGL_ONSCREEN_XLIB (onscreen);
+  CoglFramebuffer *framebuffer = COGL_FRAMEBUFFER (onscreen);
+  CoglContext *cogl_context = cogl_framebuffer_get_context (framebuffer);
+  CoglDisplayEGL *cogl_display_egl = cogl_context->display->winsys;
+
+  *device_out = cogl_display_egl->egl_context;
+  *window_out = (gpointer) onscreen_xlib->xwin;
+
+  return TRUE;
+}
+
 static void
 cogl_onscreen_xlib_dispose (GObject *object)
 {
@@ -259,8 +275,10 @@ cogl_onscreen_xlib_class_init (CoglOnscreenXlibClass *klass)
 {
   GObjectClass *object_class = G_OBJECT_CLASS (klass);
   CoglFramebufferClass *framebuffer_class = COGL_FRAMEBUFFER_CLASS (klass);
+  CoglOnscreenClass *onscreen_class = COGL_ONSCREEN_CLASS (klass);
 
   object_class->dispose = cogl_onscreen_xlib_dispose;
 
   framebuffer_class->allocate = cogl_onscreen_xlib_allocate;
+  onscreen_class->get_window_handles = cogl_onscreen_xlib_get_window_handles;
 }

src/backends/native/meta-onscreen-native.c

@@ -1734,6 +1734,32 @@ meta_onscreen_native_direct_scanout (CoglOnscreen   *onscreen,
   return TRUE;
 }
 
+static gboolean
+meta_onscreen_native_get_window_handles (CoglOnscreen *onscreen,
+                                         gpointer     *device_out,
+                                         gpointer     *window_out)
+{
+  MetaOnscreenNative *onscreen_native = META_ONSCREEN_NATIVE (onscreen);
+  CoglFramebuffer *framebuffer = COGL_FRAMEBUFFER (onscreen);
+  CoglContext *cogl_context = cogl_framebuffer_get_context (framebuffer);
+  CoglDisplayEGL *cogl_display_egl = cogl_context->display->winsys;
+  gpointer window = NULL;
+
+  if (onscreen_native->gbm.surface)
+    window = onscreen_native->gbm.surface;
+#ifdef HAVE_EGL_DEVICE
+  else if (onscreen_native->egl.stream)
+    window = onscreen_native->egl.stream;
+#endif
+
+  if (!window)
+    return FALSE;
+
+  *device_out = cogl_display_egl->egl_context;
+  *window_out = window;
+  return TRUE;
+}
+
 static void
 add_onscreen_frame_info (MetaCrtc *crtc)
 {
@@ -2944,6 +2970,7 @@ meta_onscreen_native_class_init (MetaOnscreenNativeClass *klass)
   onscreen_class->swap_buffers_with_damage =
     meta_onscreen_native_swap_buffers_with_damage;
   onscreen_class->direct_scanout = meta_onscreen_native_direct_scanout;
+  onscreen_class->get_window_handles = meta_onscreen_native_get_window_handles;
 
   blit_source_quark = g_quark_from_static_string ("Blit source");
 }