Add SkColorSpaceXform to the public API

include/core/SkColorSpaceXform.h

Index: include/core/SkColorSpaceXform.h
diff --git a/src/core/SkColorSpaceXform.h b/include/core/SkColorSpaceXform.h
similarity index 50%
rename from src/core/SkColorSpaceXform.h
rename to include/core/SkColorSpaceXform.h
index bb99071fe03388057c63e30327ca95bdb6ba23b5..15b3d49ee4a224d68cb6341c6bb9867768ade476 100644
--- a/src/core/SkColorSpaceXform.h
+++ b/include/core/SkColorSpaceXform.h
@@ -8,10 +8,10 @@
 #ifndef SkColorSpaceXform_DEFINED
 #define SkColorSpaceXform_DEFINED
 
-#include "SkColorSpace.h"
-#include "SkColorSpace_Base.h"
 #include "SkImageInfo.h"
 
+class SkColorSpace;
+
 class SkColorSpaceXform : SkNoncopyable {
 public:
 
@@ -24,7 +24,7 @@ public:
      */
     static std::unique_ptr<SkColorSpaceXform> New(SkColorSpace* srcSpace, SkColorSpace* dstSpace);
 
-    enum ColorFormat : uint8_t {
+    enum ColorFormat {
         kRGBA_8888_ColorFormat,
         kBGRA_8888_ColorFormat,
         kRGBA_F16_ColorFormat,
@@ -34,6 +34,9 @@ public:
     /**
      *  Apply the color conversion to a |src| buffer, storing the output in the |dst| buffer.
      *
+     *  F16 and F32 are only supported as dst color formats, and only when the dst color space
+     *  is linear.  This function will return false in unsupported cases.
+     *
      *  @param dst            Stored in the format described by |dstColorFormat|
      *  @param src            Stored in the format described by |srcColorFormat|
      *  @param len            Number of pixels in the buffers
@@ -46,57 +49,19 @@ public:
      *                        kOpaque   optimization hint, |dst| alphas set to 1
      *
      */
-    virtual void apply(void* dst, const uint32_t* src, int len, ColorFormat dstColorFormat,
-                       ColorFormat srcColorFormat, SkAlphaType alphaType) const = 0;
-
-    virtual ~SkColorSpaceXform() {}
-};
-
-enum SrcGamma {
-    kLinear_SrcGamma,
-    kTable_SrcGamma,
-};
-
-enum DstGamma {
-    kLinear_DstGamma,
-    kSRGB_DstGamma,
-    k2Dot2_DstGamma,
-    kTable_DstGamma,
-};
+    bool apply(ColorFormat dstFormat, void* dst, ColorFormat srcFormat, const void* src, int count,
+               SkAlphaType alphaType) const {
+        return this->onApply(dstFormat, dst, srcFormat, src, count, alphaType);
+    }
 
-enum ColorSpaceMatch {
-    kNone_ColorSpaceMatch,
-    kGamut_ColorSpaceMatch,
-    kFull_ColorSpaceMatch,
-};
-
-template <SrcGamma kSrc, DstGamma kDst, ColorSpaceMatch kCSM>
-class SkColorSpaceXform_Base : public SkColorSpaceXform {
-public:
-
-    void apply(void* dst, const uint32_t* src, int len, ColorFormat dstColorFormat,
-               ColorFormat srcColorFormat, SkAlphaType alphaType) const override;
-
-    static constexpr int      kDstGammaTableSize = 1024;
 
-private:
-    SkColorSpaceXform_Base(SkColorSpace* srcSpace, const SkMatrix44& srcToDst,
-                           SkColorSpace* dstSpace);
-
-    sk_sp<SkColorLookUpTable> fColorLUT;
-
-    // Contain pointers into storage or pointers into precomputed tables.
-    const float*              fSrcGammaTables[3];
-    const uint8_t*            fDstGammaTables[3];
-    SkAutoMalloc              fStorage;
+    virtual ~SkColorSpaceXform() {}
 
-    float                     fSrcToDst[16];
+protected:
+    virtual bool onApply(ColorFormat dstFormat, void* dst, ColorFormat srcFormat, const void* src,
+                         int count, SkAlphaType alphaType) const = 0;
 
-    friend class SkColorSpaceXform;
-    friend std::unique_ptr<SkColorSpaceXform> SlowIdentityXform(SkColorSpace* space);
+    SkColorSpaceXform() {}
 };
 
-// For testing.  Bypasses opts for when src and dst color spaces are equal.
-std::unique_ptr<SkColorSpaceXform> SlowIdentityXform(SkColorSpace* space);
-
 #endif