1 files changed, 17 insertions, 6 deletions
diff --git a/src/shaders/SkShader.cpp b/src/shaders/SkShader.cpp
index 265f22beaa..f3ffd26ef4 100644
--- a/src/shaders/SkShader.cpp
+++ b/src/shaders/SkShader.cpp
@@ -67,15 +67,26 @@ void SkShaderBase::flatten(SkWriteBuffer& buffer) const {
     }
 }
 
+SkTCopyOnFirstWrite<SkMatrix>
+SkShaderBase::totalLocalMatrix(const SkMatrix* preLocalMatrix,
+                               const SkMatrix* postLocalMatrix) const {
+    SkTCopyOnFirstWrite<SkMatrix> m(fLocalMatrix);
+
+    if (preLocalMatrix) {
+        m.writable()->preConcat(*preLocalMatrix);
+    }
+
+    if (postLocalMatrix) {
+        m.writable()->postConcat(*postLocalMatrix);
+    }
+
+    return m;
+}
+
 bool SkShaderBase::computeTotalInverse(const SkMatrix& ctm,
                                        const SkMatrix* outerLocalMatrix,
                                        SkMatrix* totalInverse) const {
-    SkMatrix total = SkMatrix::Concat(ctm, fLocalMatrix);
-    if (outerLocalMatrix) {
-        total.preConcat(*outerLocalMatrix);
-    }
-
-    return total.invert(totalInverse);
+    return SkMatrix::Concat(ctm, *this->totalLocalMatrix(outerLocalMatrix)).invert(totalInverse);
 }
 
 bool SkShaderBase::asLuminanceColor(SkColor* colorPtr) const {