framebuffer: Add CoglFramebuffer clip stack methods

This adds CoglFramebuffer methods for accessing the clip stack. We plan
on making some optimizations to how framebuffer state is flushed which
will require us to track when a framebuffer's clip state has changed.

This api also ties in to the longer term goal of removing the need for a
default global CoglContext since these methods are all implicitly
related to a specific context via their framebuffer argument.

Reviewed-by: Neil Roberts <neil@linux.intel.com>

cogl/cogl-framebuffer.c

@@ -1981,3 +1981,93 @@ cogl_framebuffer_set_projection_matrix (CoglFramebuffer *framebuffer,
 
   _COGL_MATRIX_DEBUG_PRINT (matrix);
 }
+
+void
+cogl_framebuffer_push_scissor_clip (CoglFramebuffer *framebuffer,
+                                    int x,
+                                    int y,
+                                    int width,
+                                    int height)
+{
+  CoglClipState *clip_state = _cogl_framebuffer_get_clip_state (framebuffer);
+
+  clip_state->stacks->data =
+    _cogl_clip_stack_push_window_rectangle (clip_state->stacks->data,
+                                            x, y, width, height);
+}
+
+void
+cogl_framebuffer_push_rectangle_clip (CoglFramebuffer *framebuffer,
+                                      float x_1,
+                                      float y_1,
+                                      float x_2,
+                                      float y_2)
+{
+  CoglClipState *clip_state = _cogl_framebuffer_get_clip_state (framebuffer);
+  CoglMatrix modelview_matrix;
+
+  cogl_framebuffer_get_modelview_matrix (framebuffer, &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);
+}
+
+void
+cogl_framebuffer_push_path_clip (CoglFramebuffer *framebuffer,
+                                 CoglPath *path)
+{
+  CoglClipState *clip_state = _cogl_framebuffer_get_clip_state (framebuffer);
+  CoglMatrix modelview_matrix;
+
+  cogl_framebuffer_get_modelview_matrix (framebuffer, &modelview_matrix);
+
+  clip_state->stacks->data =
+    _cogl_clip_stack_push_from_path (clip_state->stacks->data,
+                                     path,
+                                     &modelview_matrix);
+}
+
+void
+cogl_framebuffer_push_primitive_clip (CoglFramebuffer *framebuffer,
+                                      CoglPrimitive *primitive,
+                                      float bounds_x1,
+                                      float bounds_y1,
+                                      float bounds_x2,
+                                      float bounds_y2)
+{
+  CoglClipState *clip_state = _cogl_framebuffer_get_clip_state (framebuffer);
+  CoglMatrix modelview_matrix;
+
+  cogl_get_modelview_matrix (&modelview_matrix);
+
+  clip_state->stacks->data =
+    _cogl_clip_stack_push_primitive (clip_state->stacks->data,
+                                     primitive,
+                                     bounds_x1, bounds_y1,
+                                     bounds_x2, bounds_y2,
+                                     &modelview_matrix);
+}
+
+void
+cogl_framebuffer_pop_clip (CoglFramebuffer *framebuffer)
+{
+  CoglClipState *clip_state = _cogl_framebuffer_get_clip_state (framebuffer);
+
+  clip_state->stacks->data = _cogl_clip_stack_pop (clip_state->stacks->data);
+}
+
+void
+_cogl_framebuffer_save_clip_stack (CoglFramebuffer *framebuffer)
+{
+  CoglClipState *clip_state = _cogl_framebuffer_get_clip_state (framebuffer);
+  _cogl_clip_state_save_clip_stack (clip_state);
+}
+
+void
+_cogl_framebuffer_restore_clip_stack (CoglFramebuffer *framebuffer)
+{
+  CoglClipState *clip_state = _cogl_framebuffer_get_clip_state (framebuffer);
+  _cogl_clip_state_restore_clip_stack (clip_state);
+}