Minimize computeTotalInverse()'s inputs

The helper doesn't need a full context rec - it only looks at the CTM
and external local matrix.  Pass these explicitly instead.
Change-Id: I6a5884f65cd383c2df0e8d83c9086789bd96f345
Reviewed-on: https://skia-review.googlesource.com/15870
Reviewed-by: Mike Klein <mtklein@chromium.org>
Commit-Queue: Florin Malita <fmalita@chromium.org>

3 files changed, 10 insertions, 13 deletions

diff --git a/src/core/SkBitmapProcShader.cpp b/src/core/SkBitmapProcShader.cpp
index 3472bf0638..b7bd39c197 100644
--- a/src/core/SkBitmapProcShader.cpp
+++ b/src/core/SkBitmapProcShader.cpp
@@ -205,7 +205,7 @@ SkShader::Context* SkBitmapProcLegacyShader::MakeContext(
 {
     SkMatrix totalInverse;
     // Do this first, so we know the matrix can be inverted.
-    if (!shader.computeTotalInverse(rec, &totalInverse)) {
+    if (!shader.computeTotalInverse(*rec.fMatrix, rec.fLocalMatrix, &totalInverse)) {
         return nullptr;
     }
 
diff --git a/src/core/SkShader.cpp b/src/core/SkShader.cpp
index f6865d9a31..203209799f 100644
--- a/src/core/SkShader.cpp
+++ b/src/core/SkShader.cpp
@@ -70,10 +70,12 @@ void SkShader::flatten(SkWriteBuffer& buffer) const {
     }
 }
 
-bool SkShader::computeTotalInverse(const ContextRec& rec, SkMatrix* totalInverse) const {
-    SkMatrix total = SkMatrix::Concat(*rec.fMatrix, fLocalMatrix);
-    if (rec.fLocalMatrix) {
-        total.preConcat(*rec.fLocalMatrix);
+bool SkShader::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);
@@ -92,7 +94,7 @@ bool SkShader::asLuminanceColor(SkColor* colorPtr) const {
 }
 
 SkShader::Context* SkShader::makeContext(const ContextRec& rec, SkArenaAlloc* alloc) const {
-    if (!this->computeTotalInverse(rec, nullptr)) {
+    if (!this->computeTotalInverse(*rec.fMatrix, rec.fLocalMatrix, nullptr)) {
         return nullptr;
     }
     return this->onMakeContext(rec, alloc);
@@ -103,7 +105,7 @@ SkShader::Context::Context(const SkShader& shader, const ContextRec& rec)
 {
     // Because the context parameters must be valid at this point, we know that the matrix is
     // invertible.
-    SkAssertResult(fShader.computeTotalInverse(rec, &fTotalInverse));
+    SkAssertResult(fShader.computeTotalInverse(*rec.fMatrix, rec.fLocalMatrix, &fTotalInverse));
     fTotalInverseClass = (uint8_t)ComputeMatrixClass(fTotalInverse);
 
     fPaintAlpha = rec.fPaint->getAlpha();
diff --git a/src/effects/gradients/SkGradientShader.cpp b/src/effects/gradients/SkGradientShader.cpp
index 9ecc84ec65..0c8eacdf46 100644
--- a/src/effects/gradients/SkGradientShader.cpp
+++ b/src/effects/gradients/SkGradientShader.cpp
@@ -353,12 +353,7 @@ bool SkGradientShaderBase::onAppendStages(
     const SkMatrix* localM) const
 {
     SkMatrix matrix;
-    if (!this->computeTotalInverse(ContextRec(paint,
-                                              ctm,
-                                              localM,
-                                              ContextRec::kPM4f_DstType, // doesn't matter here
-                                              dstCS),
-                                   &matrix)) {
+    if (!this->computeTotalInverse(ctm, localM, &matrix)) {
         return false;
     }