[mutter] cursor-renderer/native: Let the backend realize cursor sprite itself

[Jonas Ådahl <jadahl src gnome org>]

commit ea05d2af49acd9e4e88698e8515598e4fdcccf02
Author: Jonas Ådahl <jadahl gmail com>
Date:   Wed May 2 16:56:53 2018 +0200

    cursor-renderer/native: Let the backend realize cursor sprite itself
    
    It knows better when it's needed. For now, just do it just as before,
    before drawing. Eventually, we can conditionalize where to realize
    depending on the cursor sprite position.
    
    https://gitlab.gnome.org/GNOME/mutter/issues/77

 src/backends/meta-cursor-renderer.c               | 10 ----
 src/backends/meta-cursor-renderer.h               |  5 --
 src/backends/meta-cursor-sprite-xcursor.c         |  5 --
 src/backends/native/meta-cursor-renderer-native.c | 69 ++++++++++++++++-------
 src/wayland/meta-wayland-cursor-surface.c         | 10 ----
 5 files changed, 49 insertions(+), 50 deletions(-)
---
diff --git a/src/backends/meta-cursor-renderer.c b/src/backends/meta-cursor-renderer.c
index bf10d5e2b..ae398730f 100644
--- a/src/backends/meta-cursor-renderer.c
+++ b/src/backends/meta-cursor-renderer.c
@@ -283,13 +283,3 @@ meta_cursor_renderer_get_cursor (MetaCursorRenderer *renderer)
 
   return priv->displayed_cursor;
 }
-
-void
-meta_cursor_renderer_realize_cursor_sprite (MetaCursorRenderer *renderer,
-                                            MetaCursorSprite   *cursor_sprite)
-{
-  MetaCursorRendererClass *renderer_class = META_CURSOR_RENDERER_GET_CLASS (renderer);
-
-  if (renderer_class->realize_cursor_sprite)
-    renderer_class->realize_cursor_sprite (renderer, cursor_sprite);
-}
diff --git a/src/backends/meta-cursor-renderer.h b/src/backends/meta-cursor-renderer.h
index 82581995f..830d16ef6 100644
--- a/src/backends/meta-cursor-renderer.h
+++ b/src/backends/meta-cursor-renderer.h
@@ -40,8 +40,6 @@ struct _MetaCursorRendererClass
 
   gboolean (* update_cursor) (MetaCursorRenderer *renderer,
                               MetaCursorSprite   *cursor_sprite);
-  void (* realize_cursor_sprite) (MetaCursorRenderer *renderer,
-                                  MetaCursorSprite   *cursor_sprite);
 };
 
 MetaCursorRenderer * meta_cursor_renderer_new (void);
@@ -60,9 +58,6 @@ MetaCursorSprite * meta_cursor_renderer_get_cursor (MetaCursorRenderer *renderer
 ClutterRect meta_cursor_renderer_calculate_rect (MetaCursorRenderer *renderer,
                                                  MetaCursorSprite   *cursor_sprite);
 
-void meta_cursor_renderer_realize_cursor_sprite (MetaCursorRenderer *renderer,
-                                                 MetaCursorSprite   *cursor_sprite);
-
 void meta_cursor_renderer_emit_painted (MetaCursorRenderer *renderer,
                                         MetaCursorSprite   *cursor_sprite);
 
diff --git a/src/backends/meta-cursor-sprite-xcursor.c b/src/backends/meta-cursor-sprite-xcursor.c
index bd5d6a94a..49d10b94c 100644
--- a/src/backends/meta-cursor-sprite-xcursor.c
+++ b/src/backends/meta-cursor-sprite-xcursor.c
@@ -20,7 +20,6 @@
 
 #include "backends/meta-cursor-sprite-xcursor.h"
 
-#include "backends/meta-backend-private.h"
 #include "backends/meta-cursor.h"
 #include "backends/meta-cursor-renderer.h"
 #include "clutter/clutter.h"
@@ -118,8 +117,6 @@ static void
 load_from_current_xcursor_image (MetaCursorSpriteXcursor *sprite_xcursor)
 {
   MetaCursorSprite *sprite = META_CURSOR_SPRITE (sprite_xcursor);
-  MetaBackend *backend = meta_get_backend ();
-  MetaCursorRenderer *renderer = meta_backend_get_cursor_renderer (backend);
   XcursorImage *xc_image;
   int width, height, rowstride;
   CoglPixelFormat cogl_format;
@@ -160,8 +157,6 @@ load_from_current_xcursor_image (MetaCursorSpriteXcursor *sprite_xcursor)
                                   xc_image->xhot, xc_image->yhot);
 
   g_clear_pointer (&texture, cogl_object_unref);
-
-  meta_cursor_renderer_realize_cursor_sprite (renderer, sprite);
 }
 
 void
diff --git a/src/backends/native/meta-cursor-renderer-native.c 
b/src/backends/native/meta-cursor-renderer-native.c
index 310200bc4..fcecea126 100644
--- a/src/backends/native/meta-cursor-renderer-native.c
+++ b/src/backends/native/meta-cursor-renderer-native.c
@@ -119,6 +119,10 @@ static GQuark quark_cursor_renderer_native_gpu_data = 0;
 
 G_DEFINE_TYPE_WITH_PRIVATE (MetaCursorRendererNative, meta_cursor_renderer_native, 
META_TYPE_CURSOR_RENDERER);
 
+static void
+realize_cursor_sprite (MetaCursorRenderer *renderer,
+                       MetaCursorSprite   *cursor_sprite);
+
 static MetaCursorNativeGpuState *
 get_cursor_gpu_state (MetaCursorNativePrivate *cursor_priv,
                       MetaGpuKms              *gpu_kms);
@@ -675,7 +679,7 @@ meta_cursor_renderer_native_update_cursor (MetaCursorRenderer *renderer,
     meta_cursor_renderer_native_get_instance_private (native);
 
   if (cursor_sprite)
-    meta_cursor_sprite_realize_texture (cursor_sprite);
+    realize_cursor_sprite (renderer, cursor_sprite);
 
   maybe_schedule_cursor_sprite_animation_frame (native, cursor_sprite);
 
@@ -717,6 +721,24 @@ ensure_cursor_gpu_state (MetaCursorNativePrivate *cursor_priv,
   return cursor_gpu_state;
 }
 
+static void
+on_cursor_sprite_texture_changed (MetaCursorSprite *cursor_sprite)
+{
+  MetaCursorNativePrivate *cursor_priv = get_cursor_priv (cursor_sprite);
+  GHashTableIter iter;
+  MetaCursorNativeGpuState *cursor_gpu_state;
+
+  g_hash_table_iter_init (&iter, cursor_priv->gpu_states);
+  while (g_hash_table_iter_next (&iter, NULL, (gpointer *) &cursor_gpu_state))
+    {
+      guint pending_bo;
+      pending_bo = get_pending_cursor_sprite_gbm_bo_index (cursor_gpu_state);
+      g_clear_pointer (&cursor_gpu_state->bos[pending_bo],
+                       (GDestroyNotify) gbm_bo_destroy);
+      cursor_gpu_state->pending_bo_state = META_CURSOR_GBM_BO_STATE_INVALIDATED;
+    }
+}
+
 static void
 cursor_priv_free (MetaCursorNativePrivate *cursor_priv)
 {
@@ -749,6 +771,9 @@ ensure_cursor_priv (MetaCursorSprite *cursor_sprite)
                            cursor_priv,
                            (GDestroyNotify) cursor_priv_free);
 
+  g_signal_connect (cursor_sprite, "texture-changed",
+                    G_CALLBACK (on_cursor_sprite_texture_changed), NULL);
+
   return cursor_priv;
 }
 
@@ -816,26 +841,31 @@ load_cursor_sprite_gbm_buffer_for_gpu (MetaCursorRendererNative *native,
     }
 }
 
-static void
-invalidate_pending_cursor_sprite_gbm_bo (MetaCursorSprite *cursor_sprite,
-                                         MetaGpuKms       *gpu_kms)
+static gboolean
+is_cursor_hw_state_valid (MetaCursorSprite *cursor_sprite,
+                          MetaGpuKms       *gpu_kms)
 {
   MetaCursorNativePrivate *cursor_priv;
   MetaCursorNativeGpuState *cursor_gpu_state;
-  guint pending_bo;
 
   cursor_priv = get_cursor_priv (cursor_sprite);
   if (!cursor_priv)
-    return;
+    return FALSE;
 
   cursor_gpu_state = get_cursor_gpu_state (cursor_priv, gpu_kms);
   if (!cursor_gpu_state)
-    return;
+    return FALSE;
 
-  pending_bo = get_pending_cursor_sprite_gbm_bo_index (cursor_gpu_state);
-  g_clear_pointer (&cursor_gpu_state->bos[pending_bo],
-                   (GDestroyNotify) gbm_bo_destroy);
-  cursor_gpu_state->pending_bo_state = META_CURSOR_GBM_BO_STATE_INVALIDATED;
+  switch (cursor_gpu_state->pending_bo_state)
+    {
+    case META_CURSOR_GBM_BO_STATE_SET:
+    case META_CURSOR_GBM_BO_STATE_NONE:
+      return TRUE;
+    case META_CURSOR_GBM_BO_STATE_INVALIDATED:
+      return FALSE;
+    }
+
+  g_assert_not_reached ();
 }
 
 #ifdef HAVE_WAYLAND
@@ -858,10 +888,8 @@ realize_cursor_sprite_from_wl_buffer_for_gpu (MetaCursorRenderer      *renderer,
   if (!cursor_renderer_gpu_data || cursor_renderer_gpu_data->hw_cursor_broken)
     return;
 
-  /* Destroy any previous pending cursor buffer; we'll always either fail (which
-   * should unset, or succeed, which will set new buffer.
-   */
-  invalidate_pending_cursor_sprite_gbm_bo (cursor_sprite, gpu_kms);
+  if (is_cursor_hw_state_valid (cursor_sprite, gpu_kms))
+    return;
 
   texture = meta_cursor_sprite_get_cogl_texture (cursor_sprite);
   width = cogl_texture_get_width (texture);
@@ -990,7 +1018,8 @@ realize_cursor_sprite_from_xcursor_for_gpu (MetaCursorRenderer      *renderer,
   if (!cursor_renderer_gpu_data || cursor_renderer_gpu_data->hw_cursor_broken)
     return;
 
-  invalidate_pending_cursor_sprite_gbm_bo (cursor_sprite, gpu_kms);
+  if (is_cursor_hw_state_valid (cursor_sprite, gpu_kms))
+    return;
 
   load_cursor_sprite_gbm_buffer_for_gpu (native,
                                          gpu_kms,
@@ -1027,9 +1056,11 @@ realize_cursor_sprite_from_xcursor (MetaCursorRenderer      *renderer,
 }
 
 static void
-meta_cursor_renderer_native_realize_cursor_sprite (MetaCursorRenderer *renderer,
-                                                   MetaCursorSprite   *cursor_sprite)
+realize_cursor_sprite (MetaCursorRenderer *renderer,
+                       MetaCursorSprite   *cursor_sprite)
 {
+  meta_cursor_sprite_realize_texture (cursor_sprite);
+
   if (META_IS_CURSOR_SPRITE_XCURSOR (cursor_sprite))
     {
       MetaCursorSpriteXcursor *sprite_xcursor =
@@ -1056,8 +1087,6 @@ meta_cursor_renderer_native_class_init (MetaCursorRendererNativeClass *klass)
 
   object_class->finalize = meta_cursor_renderer_native_finalize;
   renderer_class->update_cursor = meta_cursor_renderer_native_update_cursor;
-  renderer_class->realize_cursor_sprite =
-    meta_cursor_renderer_native_realize_cursor_sprite;
 
   quark_cursor_sprite = g_quark_from_static_string ("-meta-cursor-native");
   quark_cursor_renderer_native_gpu_data =
diff --git a/src/wayland/meta-wayland-cursor-surface.c b/src/wayland/meta-wayland-cursor-surface.c
index 7b7d63c28..d08af9e8c 100644
--- a/src/wayland/meta-wayland-cursor-surface.c
+++ b/src/wayland/meta-wayland-cursor-surface.c
@@ -71,16 +71,6 @@ update_cursor_sprite_texture (MetaWaylandCursorSurface *cursor_surface)
                                       buffer->texture,
                                       priv->hot_x * surface->scale,
                                       priv->hot_y * surface->scale);
-
-      if (priv->buffer)
-        {
-          g_assert (priv->buffer == buffer);
-          meta_cursor_renderer_realize_cursor_sprite (priv->cursor_renderer,
-                                                      cursor_sprite);
-
-          meta_wayland_surface_unref_buffer_use_count (surface);
-          g_clear_object (&priv->buffer);
-        }
     }
   else
     {