Skip memcpy() calls, etc. if the matrix is already the identity. Return
true/false to indicate if we're really changing the matrix or not.
---
src/mesa/math/m_matrix.c | 23 +++++++++++++++--------
src/mesa/math/m_matrix.h | 2 +-
2 files changed, 16 insertions(+), 9 deletions(-)
diff --git a/src/mesa/math/m_matrix.c b/src/mesa/math/m_matrix.c
index ecf564c..37c7612 100644
--- a/src/mesa/math/m_matrix.c
+++ b/src/mesa/math/m_matrix.c
@@ -1132,17 +1132,24 @@ _math_matrix_viewport(GLmatrix *m, const double
scale[3],
*
* Copies ::Identity into \p GLmatrix::m, and into GLmatrix::inv if not NULL.
* Sets the matrix type to identity, and clear the dirty flags.
+ * \return true if prev matrix wasn't identity, false otherwise
*/
-void
-_math_matrix_set_identity( GLmatrix *mat )
+bool
+_math_matrix_set_identity(GLmatrix *mat)
{
- memcpy( mat->m, Identity, 16*sizeof(GLfloat) );
- memcpy( mat->inv, Identity, 16*sizeof(GLfloat) );
+ if (mat->type != MATRIX_IDENTITY || mat->flags) {
+ memcpy(mat->m, Identity, 16 * sizeof(GLfloat));
+ memcpy(mat->inv, Identity, 16 * sizeof(GLfloat));
+
+ mat->type = MATRIX_IDENTITY;
+ mat->flags = 0;
- mat->type = MATRIX_IDENTITY;
- mat->flags &= ~(MAT_DIRTY_FLAGS|
- MAT_DIRTY_TYPE|
- MAT_DIRTY_INVERSE);
+ return true;
+ }
+ else {
+ /* no change */
+ return false;
+ }
}
/*@}*/
diff --git a/src/mesa/math/m_matrix.h b/src/mesa/math/m_matrix.h
index 778d716..0bb63c8 100644
--- a/src/mesa/math/m_matrix.h
+++ b/src/mesa/math/m_matrix.h
@@ -125,7 +125,7 @@ extern void
_math_matrix_viewport( GLmatrix *m, const double scale[3],
const double translate[3], double depthMax );
-extern void
+extern bool
_math_matrix_set_identity( GLmatrix *dest );
extern void
--
1.9.1
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