Hash the gamut of XYZ color spaces, to speed up comparison

Also going to use this to allow caching of GrColorSpaceXforms

BUG=skia:

GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=3670

Change-Id: I56ed2dcbdddc22046263f56d68f2d6aea55547c8
Reviewed-on: https://skia-review.googlesource.com/3670
Commit-Queue: Brian Osman <brianosman@google.com>
Reviewed-by: Matt Sarett <msarett@google.com>
Reviewed-by: Brian Salomon <bsalomon@google.com>

1 files changed, 9 insertions, 5 deletions

diff --git a/src/core/SkColorSpace.cpp b/src/core/SkColorSpace.cpp
index e90254c969..ba45d9b6f4 100644
--- a/src/core/SkColorSpace.cpp
+++ b/src/core/SkColorSpace.cpp
@@ -576,16 +576,20 @@ bool SkColorSpace::Equals(const SkColorSpace* src, const SkColorSpace* dst) {
     const SkColorSpace_XYZ* srcXYZ = static_cast<const SkColorSpace_XYZ*>(src);
     const SkColorSpace_XYZ* dstXYZ = static_cast<const SkColorSpace_XYZ*>(dst);
 
+    if (srcXYZ->gammaNamed() != dstXYZ->gammaNamed()) {
+        return false;
+    }
+
     switch (srcXYZ->gammaNamed()) {
         case kSRGB_SkGammaNamed:
         case k2Dot2Curve_SkGammaNamed:
         case kLinear_SkGammaNamed:
-            return (srcXYZ->gammaNamed() == dstXYZ->gammaNamed()) &&
-                   (*srcXYZ->toXYZD50() == *dstXYZ->toXYZD50());
-        default:
-            if (srcXYZ->gammaNamed() != dstXYZ->gammaNamed()) {
-                return false;
+            if (srcXYZ->toXYZD50Hash() == dstXYZ->toXYZD50Hash()) {
+                SkASSERT(*srcXYZ->toXYZD50() == *dstXYZ->toXYZD50() && "Hash collision");
+                return true;
             }
+            return false;
+        default:
             // It is unlikely that we will reach this case.
             sk_sp<SkData> serializedSrcData = src->serialize();
             sk_sp<SkData> serializedDstData = dst->serialize();