Cache the inverse matrix on SkColorSpace. Rename xyz() to toXYZ().

src/core/SkColorSpaceXform.cpp

Index: src/core/SkColorSpaceXform.cpp
diff --git a/src/core/SkColorSpaceXform.cpp b/src/core/SkColorSpaceXform.cpp
index f20886af7b11bd80e29e986b2df521ac41463f8e..0b17a50d2a79a4fefc79ebebffc4034bb52c9ae5 100644
--- a/src/core/SkColorSpaceXform.cpp
+++ b/src/core/SkColorSpaceXform.cpp
@@ -446,13 +446,10 @@ static void build_gamma_tables(const T* outGammaTables[3], T* gammaTableStorage,
 
 ///////////////////////////////////////////////////////////////////////////////////////////////////
 
-static inline bool compute_gamut_xform(SkMatrix44* srcToDst, const SkMatrix44& srcToXYZ,
-                                       const SkMatrix44& dstToXYZ) {
-    if (!dstToXYZ.invert(srcToDst)) {
-        return false;
-    }
-
-    srcToDst->postConcat(srcToXYZ);
+static inline bool compute_gamut_xform(SkMatrix44* srcToDst, const SkColorSpace* src,

[msarett, 2016/09/08 15:06:07]

Thanks for integrating this change here!

Let's go ahead and make this void?

+                                       const SkColorSpace* dst) {
+    *srcToDst = as_CSB(dst)->fromXYZ();
+    srcToDst->postConcat(src->toXYZ());
     return true;
 }
 
@@ -482,7 +479,7 @@ std::unique_ptr<SkColorSpaceXform> SkColorSpaceXform::New(const sk_sp<SkColorSpa
     if (SkColorSpace::Equals(srcSpace.get(), dstSpace.get())) {
         srcToDst.setIdentity();
         csm = kFull_ColorSpaceMatch;
-    } else if (!compute_gamut_xform(&srcToDst, srcSpace->xyz(), dstSpace->xyz())) {
+    } else if (!compute_gamut_xform(&srcToDst, srcSpace.get(), dstSpace.get())) {
         return nullptr;
     } else if (is_almost_identity(srcToDst)) {
         srcToDst.setIdentity();