Cache dst LUTs in SkColorSpaceXform

src/core/SkColorSpace.cpp

 /*
  * Copyright 2016 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkColorSpace.h"
 #include "SkColorSpace_Base.h"
 #include "SkColorSpacePriv.h"
+#include "SkColorSpaceXform_Base.h"
 #include "SkOnce.h"
 #include "SkPoint3.h"
 
 bool SkColorSpacePrimaries::toXYZD50(SkMatrix44* toXYZ_D50) const {
     if (!is_zero_to_one(fRX) || !is_zero_to_one(fRY) ||
         !is_zero_to_one(fGX) || !is_zero_to_one(fGY) ||
         !is_zero_to_one(fBX) || !is_zero_to_one(fBY) ||
         !is_zero_to_one(fWX) || !is_zero_to_one(fWY))
     {
         return false;
@@ skipping 291 matching lines @@
             // simply give them back a transform to sRGB gamut.
             SkDEBUGFAIL("Non-invertible XYZ matrix, defaulting to sRGB");
             SkMatrix44 srgbToxyzD50(SkMatrix44::kUninitialized_Constructor);
             srgbToxyzD50.set3x3RowMajorf(gSRGB_toXYZD50);
             srgbToxyzD50.invert(&fFromXYZD50);
         }
     });
     return fFromXYZD50;
 }
 
+void SkColorSpace_Base::toDstGammaTables(const uint8_t* tables[3], sk_sp<SkData>* storage,
+                                         int numTables) const {
+    fToDstGammaOnce([this, numTables] {
+        const bool gammasAreMatching = numTables <= 1;
+        fDstStorage =
+                SkData::MakeUninitialized(numTables * SkColorSpaceXform_Base::kDstGammaTableSize);
+        SkColorSpaceXform_Base::BuildDstGammaTables(fToDstGammaTables,
+                                                    (uint8_t*) fDstStorage->writable_data(), this,
+                                                    gammasAreMatching);
+    });
+
+    *storage = fDstStorage;
+    tables[0] = fToDstGammaTables[0];
+    tables[1] = fToDstGammaTables[1];
+    tables[2] = fToDstGammaTables[2];
+}
+
 ///////////////////////////////////////////////////////////////////////////////////////////////////
 
 enum Version {
     k0_Version, // Initial version, header + flags for matrix and profile
 };
 
 struct ColorSpaceHeader {
     /**
      *  It is only valid to set zero or one flags.
      *  Setting multiple flags is invalid.
@@ skipping 287 matching lines @@
                 return false;
             }
 
             // It is unlikely that we will reach this case.
             sk_sp<SkData> srcData = src->serialize();
             sk_sp<SkData> dstData = dst->serialize();
             return srcData->size() == dstData->size() &&
                    0 == memcmp(srcData->data(), dstData->data(), srcData->size());
     }
 }