[cogl] Adds cogl_framebuffer_identity_matrix

[Robert Bragg <rbragg src gnome org>]

commit 5ca78668afcbdca0d4b82e0db060e93276f3fd3d
Author: Robert Bragg <robert linux intel com>
Date:   Sun Nov 20 18:42:58 2011 +0000

    Adds cogl_framebuffer_identity_matrix
    
    This adds a cogl_framebuffer_identity_matrix() method that can be used
    to reset the current modelview matrix to the identity matrix.
    
    Reviewed-by: Neil Roberts <neil linux intel com>

 cogl/cogl-framebuffer.c |    8 ++++++++
 cogl/cogl-framebuffer.h |   14 ++++++++++++++
 2 files changed, 22 insertions(+), 0 deletions(-)
---
diff --git a/cogl/cogl-framebuffer.c b/cogl/cogl-framebuffer.c
index bc64106..f5cc877 100644
--- a/cogl/cogl-framebuffer.c
+++ b/cogl/cogl-framebuffer.c
@@ -1798,6 +1798,14 @@ cogl_framebuffer_pop_matrix (CoglFramebuffer *framebuffer)
 }
 
 void
+cogl_framebuffer_identity_matrix (CoglFramebuffer *framebuffer)
+{
+  CoglMatrixStack *modelview_stack =
+    _cogl_framebuffer_get_modelview_stack (framebuffer);
+  _cogl_matrix_stack_load_identity (modelview_stack);
+}
+
+void
 cogl_framebuffer_scale (CoglFramebuffer *framebuffer,
                         float x,
                         float y,
diff --git a/cogl/cogl-framebuffer.h b/cogl/cogl-framebuffer.h
index b86d273..c39350d 100644
--- a/cogl/cogl-framebuffer.h
+++ b/cogl/cogl-framebuffer.h
@@ -152,6 +152,20 @@ cogl_framebuffer_push_matrix (CoglFramebuffer *framebuffer);
 void
 cogl_framebuffer_pop_matrix (CoglFramebuffer *framebuffer);
 
+#define cogl_framebuffer_identity_matrix \
+  cogl_framebuffer_identity_matrix_EXP
+/**
+ * cogl_framebuffer_identity_matrix:
+ * @framebuffer: A #CoglFramebuffer pointer
+ *
+ * Resets the current model-view matrix to the identity matrix.
+ *
+ * Since: 1.10
+ * Stability: unstable
+ */
+void
+cogl_framebuffer_identity_matrix (CoglFramebuffer *framebuffer);
+
 #define cogl_framebuffer_scale cogl_framebuffer_scale_EXP
 /**
  * cogl_framebuffer_scale: