From 35b07f6b8394c0ca371183f9bd2709812c884754 Mon Sep 17 00:00:00 2001
From: Neil Roberts <neil@linux.intel.com>
Date: Fri, 10 Dec 2010 17:42:39 +0000
Subject: [PATCH] cogl-matrix-stack: Add _cogl_matrix_stack_has_identity_flag
This adds an internal function to quickly determine whether the top of
the matrix stack is known to be the identity matrix.
---
cogl/cogl-matrix-stack.c | 6 ++++++
cogl/cogl-matrix-stack.h | 7 +++++++
2 files changed, 13 insertions(+)
diff --git a/cogl/cogl-matrix-stack.c b/cogl/cogl-matrix-stack.c
index 7b4ad69f8..d4defd1ce 100644
--- a/cogl/cogl-matrix-stack.c
+++ b/cogl/cogl-matrix-stack.c
@@ -473,3 +473,9 @@ _cogl_matrix_stack_get_age (CoglMatrixStack *stack)
{
return stack->age;
}
+
+gboolean
+_cogl_matrix_stack_has_identity_flag (CoglMatrixStack *stack)
+{
+ return _cogl_matrix_stack_top (stack)->is_identity;
+}
diff --git a/cogl/cogl-matrix-stack.h b/cogl/cogl-matrix-stack.h
index 8efca3fed..5c8b954a1 100644
--- a/cogl/cogl-matrix-stack.h
+++ b/cogl/cogl-matrix-stack.h
@@ -110,4 +110,11 @@ _cogl_matrix_stack_dirty (CoglMatrixStack *stack);
unsigned int
_cogl_matrix_stack_get_age (CoglMatrixStack *stack);
+/* If this returns TRUE then the top of the matrix is definitely the
+ identity matrix. If it returns FALSE it may or may not be the
+ identity matrix but no expensive comparison is performed to verify
+ it. */
+gboolean
+_cogl_matrix_stack_has_identity_flag (CoglMatrixStack *stack);
+
#endif /* __COGL_MATRIX_STACK_H */