Refactor explicit inverse calculation in SkImageShader::onAppendStages()

We have SkShaderBase::computeTotalInverse() which does exactly that.

Change-Id: I77695f9261d700c3ac25fe94250b798e6edfc25d
Reviewed-on: https://skia-review.googlesource.com/105000
Commit-Queue: Mike Klein <mtklein@chromium.org>
Reviewed-by: Mike Klein <mtklein@chromium.org>

1 files changed, 2 insertions, 6 deletions

diff --git a/src/shaders/SkImageShader.cpp b/src/shaders/SkImageShader.cpp
index 22c3b7633b..1f77158206 100644
--- a/src/shaders/SkImageShader.cpp
+++ b/src/shaders/SkImageShader.cpp
@@ -282,12 +282,8 @@ bool SkImageShader::onAppendStages(const StageRec& rec) const {
     SkRasterPipeline* p = rec.fPipeline;
     SkArenaAlloc* alloc = rec.fAlloc;
 
-    auto matrix = SkMatrix::Concat(rec.fCTM, this->getLocalMatrix());
-    if (rec.fLocalM) {
-        matrix.preConcat(*rec.fLocalM);
-    }
-
-    if (!matrix.invert(&matrix)) {
+    SkMatrix matrix;
+    if (!this->computeTotalInverse(rec.fCTM, rec.fLocalM, &matrix)) {
         return false;
     }
     auto quality = rec.fPaint.getFilterQuality();