cogl-clip-stack: Don't allocate a separate struct for CoglClipStack

Instead of having a separate CoglHandle for CoglClipStack the code is
now expected to directly hold a pointer to the top entry on the
stack. The empty stack is then the NULL pointer. This saves an
allocation when we want to copy the stack because we can just take a
reference on a stack entry. The idea is that this will make it
possible to store the clip stack in the journal without any extra
allocations.

The _cogl_get_clip_stack and set functions now take a CoglClipStack
pointer instead of a handle so it would no longer make sense to make
them public. However I think the only reason we would have wanted that
in the first place would be to save the clip state between switching
FBOs and that is no longer necessary.

1 files changed, 20 insertions, 35 deletions

diff --git a/cogl/cogl-clip-state.c b/cogl/cogl-clip-state.c
index 317089ef..18850e09 100644
--- a/cogl/cogl-clip-state.c
+++ b/cogl/cogl-clip-state.c
@@ -48,7 +48,6 @@ cogl_clip_push_window_rectangle (int x_offset,
 {
   CoglFramebuffer *framebuffer;
   CoglClipState *clip_state;
-  CoglHandle stack;
 
   _COGL_GET_CONTEXT (ctx, NO_RETVAL);
 
@@ -59,10 +58,10 @@ cogl_clip_push_window_rectangle (int x_offset,
   framebuffer = _cogl_get_framebuffer ();
   clip_state = _cogl_framebuffer_get_clip_state (framebuffer);
 
-  stack = clip_state->stacks->data;
-
-  _cogl_clip_stack_push_window_rectangle (stack, x_offset, y_offset,
-                                          width, height);
+  clip_state->stacks->data =
+    _cogl_clip_stack_push_window_rectangle (clip_state->stacks->data,
+                                            x_offset, y_offset,
+                                            width, height);
 
   clip_state->stack_dirty = TRUE;
 }
@@ -135,7 +134,6 @@ cogl_clip_push_rectangle (float x_1,
 {
   CoglFramebuffer *framebuffer;
   CoglClipState *clip_state;
-  CoglHandle stack;
   CoglMatrix modelview_matrix;
 
   _COGL_GET_CONTEXT (ctx, NO_RETVAL);
@@ -152,12 +150,12 @@ cogl_clip_push_rectangle (float x_1,
   framebuffer = _cogl_get_framebuffer ();
   clip_state = _cogl_framebuffer_get_clip_state (framebuffer);
 
-  stack = clip_state->stacks->data;
-
   cogl_get_modelview_matrix (&modelview_matrix);
 
-  _cogl_clip_stack_push_rectangle (stack, x_1, y_1, x_2, y_2,
-                                   &modelview_matrix);
+  clip_state->stacks->data =
+    _cogl_clip_stack_push_rectangle (clip_state->stacks->data,
+                                     x_1, y_1, x_2, y_2,
+                                     &modelview_matrix);
 
   clip_state->stack_dirty = TRUE;
 }
@@ -180,7 +178,6 @@ cogl_clip_push_from_path_preserve (void)
 {
   CoglFramebuffer *framebuffer;
   CoglClipState *clip_state;
-  CoglHandle stack;
   CoglMatrix modelview_matrix;
 
   _COGL_GET_CONTEXT (ctx, NO_RETVAL);
@@ -192,12 +189,11 @@ cogl_clip_push_from_path_preserve (void)
   framebuffer = _cogl_get_framebuffer ();
   clip_state = _cogl_framebuffer_get_clip_state (framebuffer);
 
-  stack = clip_state->stacks->data;
-
   cogl_get_modelview_matrix (&modelview_matrix);
 
-  _cogl_clip_stack_push_from_path (stack, cogl_get_path (),
-                                   &modelview_matrix);
+  clip_state->stacks->data =
+    _cogl_clip_stack_push_from_path (clip_state->stacks->data, cogl_get_path (),
+                                     &modelview_matrix);
 
   clip_state->stack_dirty = TRUE;
 }
@@ -213,15 +209,11 @@ cogl_clip_push_from_path (void)
 static void
 _cogl_clip_pop_real (CoglClipState *clip_state)
 {
-  CoglHandle stack;
-
   /* We don't log clip stack changes in the journal so we must flush
    * it before making modifications */
   _cogl_journal_flush ();
 
-  stack = clip_state->stacks->data;
-
-  _cogl_clip_stack_pop (stack);
+  clip_state->stacks->data = _cogl_clip_stack_pop (clip_state->stacks->data);
 
   clip_state->stack_dirty = TRUE;
 }
@@ -243,7 +235,7 @@ cogl_clip_pop (void)
 void
 _cogl_clip_state_flush (CoglClipState *clip_state)
 {
-  CoglHandle stack;
+  CoglClipStack *stack;
 
   if (!clip_state->stack_dirty)
     return;
@@ -277,15 +269,11 @@ cogl_clip_ensure (void)
 static void
 _cogl_clip_stack_save_real (CoglClipState *clip_state)
 {
-  CoglHandle stack;
-
   /* We don't log clip stack changes in the journal so we must flush
    * it before making modifications */
   _cogl_journal_flush ();
 
-  stack = _cogl_clip_stack_new ();
-
-  clip_state->stacks = g_slist_prepend (clip_state->stacks, stack);
+  clip_state->stacks = g_slist_prepend (clip_state->stacks, NULL);
   clip_state->stack_dirty = TRUE;
 }
 
@@ -316,7 +304,7 @@ _cogl_clip_stack_restore_real (CoglClipState *clip_state)
 
   stack = clip_state->stacks->data;
 
-  cogl_handle_unref (stack);
+  _cogl_clip_stack_unref (stack);
 
   /* Revert to an old stack */
   clip_state->stacks = g_slist_delete_link (clip_state->stacks,
@@ -365,7 +353,7 @@ _cogl_clip_state_dirty (CoglClipState *clip_state)
   clip_state->stack_dirty = TRUE;
 }
 
-CoglHandle
+CoglClipStack *
 _cogl_get_clip_stack (void)
 {
   CoglFramebuffer *framebuffer;
@@ -380,21 +368,18 @@ _cogl_get_clip_stack (void)
 }
 
 void
-_cogl_set_clip_stack (CoglHandle handle)
+_cogl_set_clip_stack (CoglClipStack *stack)
 {
   CoglFramebuffer *framebuffer;
   CoglClipState *clip_state;
 
   _COGL_GET_CONTEXT (ctx, NO_RETVAL);
 
-  if (handle == COGL_INVALID_HANDLE)
-    return;
-
   framebuffer = _cogl_get_framebuffer ();
   clip_state = _cogl_framebuffer_get_clip_state (framebuffer);
 
   /* Replace the top of the stack of stacks */
-  cogl_handle_ref (handle);
-  cogl_handle_unref (clip_state->stacks->data);
-  clip_state->stacks->data = handle;
+  _cogl_clip_stack_ref (stack);
+  _cogl_clip_stack_unref (clip_state->stacks->data);
+  clip_state->stacks->data = stack;
 }