Keep track of identity SkMatrix44s
This keeps a bool on SkMatrix44 indicating if we know for sure that the matrix
is identity, similar to the TypeMask on SkMatrix. This is useful to early-out
of potentially expensive matrix math at the cost of some memory.
Review URL: https://codereview.appspot.com/6854113
git-svn-id: http://skia.googlecode.com/svn/trunk@6620 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/include/utils/SkMatrix44.h b/include/utils/SkMatrix44.h
index 03daac4..67486b3 100644
--- a/include/utils/SkMatrix44.h
+++ b/include/utils/SkMatrix44.h
@@ -124,6 +124,7 @@
SkASSERT((unsigned)row <= 3);
SkASSERT((unsigned)col <= 3);
fMat[col][row] = value;
+ fIdentity = false;
}
double getDouble(int row, int col) const {
@@ -260,6 +261,8 @@
[3][2] = tz
*/
SkMScalar fMat[4][4];
+
+ bool fIdentity;
};
#endif