[cogl] framebuffer: track fb color mask like other fb state

[Robert Bragg <rbragg src gnome org>]

commit cf4b228fc0cc00041ce0b73ff21522eb03f961c5
Author: Robert Bragg <robert linux intel com>
Date:   Mon Nov 21 17:58:45 2011 +0000

    framebuffer: track fb color mask like other fb state
    
    We should not be deciding whether we need to really update the GL color
    mask state at the point where a new framebuffer has been pushed, we
    should be waiting until we have really been asked to flush some
    framebuffer state otherwise we may do redundant work if multiple
    framebuffers are pushed/popped before something is really drawn.
    
    This integrates the color mask state tracking with the design we have
    for handling most of the other framebuffer state so we benefit from the
    optimizations for minimizing the cost of _cogl_framebuffer_flush_state()
    
    Reviewed-by: Neil Roberts <neil linux intel com>

 cogl/cogl-framebuffer-private.h |    6 +++-
 cogl/cogl-framebuffer.c         |   54 ++++++++++++++++++++++++++------------
 2 files changed, 41 insertions(+), 19 deletions(-)
---
diff --git a/cogl/cogl-framebuffer-private.h b/cogl/cogl-framebuffer-private.h
index 7fbab5c..9fbf54b 100644
--- a/cogl/cogl-framebuffer-private.h
+++ b/cogl/cogl-framebuffer-private.h
@@ -71,7 +71,8 @@ typedef enum _CoglFramebufferStateIndex
   COGL_FRAMEBUFFER_STATE_INDEX_DITHER     = 3,
   COGL_FRAMEBUFFER_STATE_INDEX_MODELVIEW  = 4,
   COGL_FRAMEBUFFER_STATE_INDEX_PROJECTION = 5,
-  COGL_FRAMEBUFFER_STATE_INDEX_MAX        = 6
+  COGL_FRAMEBUFFER_STATE_INDEX_COLOR_MASK = 6,
+  COGL_FRAMEBUFFER_STATE_INDEX_MAX        = 7
 } CoglFramebufferStateIndex;
 
 typedef enum _CoglFramebufferState
@@ -81,7 +82,8 @@ typedef enum _CoglFramebufferState
   COGL_FRAMEBUFFER_STATE_CLIP       = 1<<2,
   COGL_FRAMEBUFFER_STATE_DITHER     = 1<<3,
   COGL_FRAMEBUFFER_STATE_MODELVIEW  = 1<<4,
-  COGL_FRAMEBUFFER_STATE_PROJECTION = 1<<5
+  COGL_FRAMEBUFFER_STATE_PROJECTION = 1<<5,
+  COGL_FRAMEBUFFER_STATE_COLOR_MASK = 1<<6
 } CoglFramebufferState;
 
 #define COGL_FRAMEBUFFER_STATE_ALL ((1<<COGL_FRAMEBUFFER_STATE_INDEX_MAX) - 1)
diff --git a/cogl/cogl-framebuffer.c b/cogl/cogl-framebuffer.c
index 539032c..5ed3b5e 100644
--- a/cogl/cogl-framebuffer.c
+++ b/cogl/cogl-framebuffer.c
@@ -1108,17 +1108,6 @@ notify_buffers_changed (CoglFramebuffer *old_draw_buffer,
 
   if (old_draw_buffer && new_draw_buffer)
     {
-      /* If the two draw framebuffers have a different color mask then
-         we need to ensure the logic ops are reflushed the next time
-         something is drawn */
-      if (cogl_framebuffer_get_color_mask (old_draw_buffer) !=
-          cogl_framebuffer_get_color_mask (new_draw_buffer))
-        {
-          ctx->current_pipeline_changes_since_flush |=
-            COGL_PIPELINE_STATE_LOGIC_OPS;
-          ctx->current_pipeline_age--;
-        }
-
       /* If we're switching from onscreen to offscreen and the last
          flush pipeline is using backface culling then we also need to
          reflush the cull face state because the winding order of the
@@ -1429,6 +1418,17 @@ _cogl_framebuffer_compare_projection_state (CoglFramebuffer *a,
 }
 
 static unsigned long
+_cogl_framebuffer_compare_color_mask_state (CoglFramebuffer *a,
+                                            CoglFramebuffer *b)
+{
+  if (cogl_framebuffer_get_color_mask (a) !=
+      cogl_framebuffer_get_color_mask (b))
+    return COGL_FRAMEBUFFER_STATE_COLOR_MASK;
+  else
+    return 0;
+}
+
+static unsigned long
 _cogl_framebuffer_compare (CoglFramebuffer *a,
                            CoglFramebuffer *b,
                            unsigned long state)
@@ -1468,6 +1468,10 @@ _cogl_framebuffer_compare (CoglFramebuffer *a,
           differences |=
             _cogl_framebuffer_compare_projection_state (a, b);
           break;
+        case COGL_FRAMEBUFFER_STATE_INDEX_COLOR_MASK:
+          differences |=
+            _cogl_framebuffer_compare_color_mask_state (a, b);
+          break;
         default:
           g_warn_if_reached ();
         }
@@ -1547,6 +1551,20 @@ _cogl_framebuffer_flush_projection_state (CoglFramebuffer *framebuffer)
                                   COGL_MATRIX_PROJECTION);
 }
 
+static void
+_cogl_framebuffer_flush_color_mask_state (CoglFramebuffer *framebuffer)
+{
+  CoglContext *context = framebuffer->context;
+
+  /* The color mask state is really owned by a CoglPipeline so to
+   * ensure the color mask is updated the next time we draw something
+   * we need to make sure the logic ops for the pipeline are
+   * re-flushed... */
+  context->current_pipeline_changes_since_flush |=
+    COGL_PIPELINE_STATE_LOGIC_OPS;
+  context->current_pipeline_age--;
+}
+
 void
 _cogl_framebuffer_flush_state (CoglFramebuffer *draw_buffer,
                                CoglFramebuffer *read_buffer,
@@ -1647,6 +1665,9 @@ _cogl_framebuffer_flush_state (CoglFramebuffer *draw_buffer,
         case COGL_FRAMEBUFFER_STATE_INDEX_PROJECTION:
           _cogl_framebuffer_flush_projection_state (draw_buffer);
           break;
+        case COGL_FRAMEBUFFER_STATE_INDEX_COLOR_MASK:
+          _cogl_framebuffer_flush_color_mask_state (draw_buffer);
+          break;
         default:
           g_warn_if_reached ();
         }
@@ -1699,15 +1720,14 @@ void
 cogl_framebuffer_set_color_mask (CoglFramebuffer *framebuffer,
                                  CoglColorMask color_mask)
 {
-  _COGL_GET_CONTEXT (ctx, NO_RETVAL);
+  /* XXX: Currently color mask changes don't go through the journal */
+  _cogl_framebuffer_flush_journal (framebuffer);
 
-  cogl_flush (); /* XXX: Currently color mask changes don't go through the journal */
   framebuffer->color_mask = color_mask;
 
-  /* Make sure the ColorMask is updated when the next primitive is drawn */
-  ctx->current_pipeline_changes_since_flush |=
-    COGL_PIPELINE_STATE_LOGIC_OPS;
-  ctx->current_pipeline_age--;
+  if (framebuffer->context->current_draw_buffer == framebuffer)
+    framebuffer->context->current_draw_buffer_changes |=
+      COGL_FRAMEBUFFER_STATE_COLOR_MASK;
 }
 
 gboolean