Add SkColorSpacePrimaries to help with making D50 matrices

src/core/SkColorSpace.cpp

Index: src/core/SkColorSpace.cpp
diff --git a/src/core/SkColorSpace.cpp b/src/core/SkColorSpace.cpp
index 647795fb65d37533a649c9e1bc6e85a3b29a136d..4b08d4b76d4498e5c4c9189ef74e7e474e2f7549 100644
--- a/src/core/SkColorSpace.cpp
+++ b/src/core/SkColorSpace.cpp
@@ -132,6 +132,44 @@ sk_sp<SkColorSpace> SkColorSpace::NewRGB(GammaNamed gammaNamed, const SkMatrix44
     }
 }
 
+sk_sp<SkColorSpace> SkColorSpace::NewRGB(const SkTransferFn& coeffs, const SkMatrix44& toXYZD50) {
+    // TODO: Check if coeffs match sRGB, 2.2, or linear.
+    // TODO: Make sure coefficients describe a valid curve.  Return nullptr if they don't.
+    void* memory = sk_malloc_throw(sizeof(SkGammas) + sizeof(SkTransferFn));
+    sk_sp<SkGammas> gammas = sk_sp<SkGammas>(new (memory) SkGammas());
+    void* storage = SkTAddOffset<void>(memory, sizeof(SkGammas));
+     memcpy(storage, &coeffs, sizeof(SkTransferFn));
+     gammas->fRedType = SkGammas::Type::kParam_Type;
+     gammas->fGreenType = SkGammas::Type::kParam_Type;
+     gammas->fBlueType = SkGammas::Type::kParam_Type;
+
+     SkGammas::Data data;
+     data.fParamOffset = 0;
+     gammas->fRedData = data;
+     gammas->fGreenData = data;
+     gammas->fBlueData = data;
+     return sk_sp<SkColorSpace>(new SkColorSpace_Base(nullptr, kNonStandard_SkGammaNamed,
+                                                      std::move(gammas), toXYZD50, nullptr));
+}
+
+sk_sp<SkColorSpace> SkColorSpace::NewRGB(GammaNamed gammaNamed, const SkPrimaries& primaries) {
+    SkMatrix44 toXYZD50(SkMatrix44::kUninitialized_Constructor);
+    if (!PrimariesToXYZD50(&toXYZD50, primaries)) {
+        return nullptr;
+    }
+
+    return NewRGB(gammaNamed, toXYZD50);
+}
+
+sk_sp<SkColorSpace> SkColorSpace::NewRGB(const SkTransferFn& coeffs, const SkPrimaries& primaries) {
+    SkMatrix44 toXYZD50(SkMatrix44::kUninitialized_Constructor);
+    if (!PrimariesToXYZD50(&toXYZD50, primaries)) {
+        return nullptr;
+    }
+
+    return NewRGB(coeffs, toXYZD50);
+}
+
 static SkColorSpace* gAdobeRGB;
 static SkColorSpace* gSRGB;
 
@@ -270,6 +308,15 @@ size_t SkColorSpace::writeToMemory(void* memory) const {
                 return sizeof(ColorSpaceHeader) + 12 * sizeof(float);
             }
             default:
+                // TODO: This case gets trickier.  The code below exists because I allow
+                //       SkPngCodec to call a constructor with float gammas.
+                //       I think the best thing to do would be:
+                //       (1) Fix SkPngCodec to call one of the new constructors.
+                //       (2) Handle serializing the parametric gammas here.
+                // TODO: In a separate CL, remove the idea of "exponential" gammas.
+                //       These can be consumed by the parametric case.  Maybe this CL
+                //       should land first.
+
                 // Otherwise, write the gamma values and the matrix.
                 if (memory) {
                     *((ColorSpaceHeader*) memory) =
@@ -369,6 +416,8 @@ sk_sp<SkColorSpace> SkColorSpace::Deserialize(const void* data, size_t length) {
             return NewICC(data, profileSize);
         }
         case ColorSpaceHeader::kFloatGamma_Flag: {
+            // TODO: This needs to be fixed to match the new version of serialize().
+
             if (length < 15 * sizeof(float)) {
                 return nullptr;
             }
@@ -420,6 +469,7 @@ bool SkColorSpace::Equals(const SkColorSpace* src, const SkColorSpace* dst) {
             if (as_CSB(src)->fGammaNamed != as_CSB(dst)->fGammaNamed) {
                 return false;
             }
+            // This should still work :).
 
             // It is unlikely that we will reach this case.
             sk_sp<SkData> srcData = src->serialize();