[cogl] avoid touching fb matrix stack directly

[Robert Bragg <rbragg src gnome org>]

commit 652c8c31cfdd98ef38803b88325d76aee187ea5e
Author: Robert Bragg <robert linux intel com>
Date:   Sun Nov 20 18:50:29 2011 +0000

    avoid touching fb matrix stack directly
    
    This ensures we don't touch a framebuffer's matrix stack directly if we
    are also relying on _cogl_framebuffer_flush_state(). We want to get to
    the point where we can set dirty flags against framebuffer state at the
    point it changes but that means we can't allow direct access to the
    matrix stack. _cogl_texture_draw_and_read() has now been changed so it
    uses cogl_framebuffer_ methods to update the matrix stacks including
    adding new internal _cogl_framebuffer_push/pop_projection() functions
    that allow us to set transient projections.
    
    Reviewed-by: Neil Roberts <neil linux intel com>

 cogl/cogl-framebuffer-private.h |    6 ++++++
 cogl/cogl-framebuffer.c         |   21 +++++++++++++++++++++
 cogl/cogl-texture.c             |   24 +++++++++---------------
 3 files changed, 36 insertions(+), 15 deletions(-)
---
diff --git a/cogl/cogl-framebuffer-private.h b/cogl/cogl-framebuffer-private.h
index e168b6e..6499c80 100644
--- a/cogl/cogl-framebuffer-private.h
+++ b/cogl/cogl-framebuffer-private.h
@@ -334,4 +334,10 @@ _cogl_blit_framebuffer (unsigned int src_x,
                         unsigned int width,
                         unsigned int height);
 
+void
+_cogl_framebuffer_push_projection (CoglFramebuffer *framebuffer);
+
+void
+_cogl_framebuffer_pop_projection (CoglFramebuffer *framebuffer);
+
 #endif /* __COGL_FRAMEBUFFER_PRIVATE_H */
diff --git a/cogl/cogl-framebuffer.c b/cogl/cogl-framebuffer.c
index f5cc877..c372963 100644
--- a/cogl/cogl-framebuffer.c
+++ b/cogl/cogl-framebuffer.c
@@ -1916,6 +1916,27 @@ cogl_framebuffer_orthographic (CoglFramebuffer *framebuffer,
 }
 
 void
+_cogl_framebuffer_push_projection (CoglFramebuffer *framebuffer)
+{
+  CoglMatrixStack *projection_stack =
+    _cogl_framebuffer_get_projection_stack (framebuffer);
+  _cogl_matrix_stack_push (projection_stack);
+
+  framebuffer->context->current_draw_buffer_changes |=
+    COGL_FRAMEBUFFER_STATE_PROJECTION;
+}
+
+void
+_cogl_framebuffer_pop_projection (CoglFramebuffer *framebuffer)
+{
+  CoglMatrixStack *projection_stack =
+    _cogl_framebuffer_get_projection_stack (framebuffer);
+  _cogl_matrix_stack_pop (projection_stack);
+  framebuffer->context->current_draw_buffer_changes |=
+    COGL_FRAMEBUFFER_STATE_PROJECTION;
+}
+
+void
 cogl_framebuffer_get_modelview_matrix (CoglFramebuffer *framebuffer,
                                        CoglMatrix *matrix)
 {
diff --git a/cogl/cogl-texture.c b/cogl/cogl-texture.c
index 23fcf8c..a072d91 100644
--- a/cogl/cogl-texture.c
+++ b/cogl/cogl-texture.c
@@ -874,8 +874,6 @@ _cogl_texture_draw_and_read (CoglTexture *texture,
   CoglFramebuffer *framebuffer;
   float viewport[4];
   CoglBitmap *alpha_bmp;
-  CoglMatrixStack *projection_stack;
-  CoglMatrixStack *modelview_stack;
   int target_width = _cogl_bitmap_get_width (target_bmp);
   int target_height = _cogl_bitmap_get_height (target_bmp);
   int target_rowstride = _cogl_bitmap_get_rowstride (target_bmp);
@@ -896,18 +894,14 @@ _cogl_texture_draw_and_read (CoglTexture *texture,
    * works)
    */
 
-  projection_stack = _cogl_framebuffer_get_projection_stack (framebuffer);
-  _cogl_matrix_stack_push (projection_stack);
-  _cogl_matrix_stack_load_identity (projection_stack);
-  _cogl_matrix_stack_ortho (projection_stack,
-                            0, viewport[2],
-                            viewport[3], 0,
-                            0,
-                            100);
+  _cogl_framebuffer_push_projection (framebuffer);
+  cogl_framebuffer_orthographic (framebuffer,
+                                 0, 0,
+                                 viewport[2], viewport[3],
+                                 0, 100);
 
-  modelview_stack = _cogl_framebuffer_get_modelview_stack (framebuffer);
-  _cogl_matrix_stack_push (modelview_stack);
-  _cogl_matrix_stack_load_identity (modelview_stack);
+  cogl_framebuffer_push_matrix (framebuffer);
+  cogl_framebuffer_identity_matrix (framebuffer);
 
   /* Direct copy operation */
 
@@ -999,8 +993,8 @@ _cogl_texture_draw_and_read (CoglTexture *texture,
     }
 
   /* Restore old state */
-  _cogl_matrix_stack_pop (modelview_stack);
-  _cogl_matrix_stack_pop (projection_stack);
+  cogl_framebuffer_pop_matrix (framebuffer);
+  _cogl_framebuffer_pop_projection (framebuffer);
 
   /* restore the original pipeline */
   cogl_pop_source ();