Make SkColorSpace a public API

include/core/SkColorSpace.h

 /*
  * Copyright 2016 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkColorSpace_DEFINED
 #define SkColorSpace_DEFINED
 
-// Some terms

[msarett, 2016/05/20 15:36:07]

I don't feel strongly about removing these comments - just seems like they might
belong somewhere else.

-//
-//  PCS : Profile Connection Space : where color number values have an absolute meaning.
-//        Part of the work float is to convert colors to and from this space...
-//        src_linear_unit_floats --> PCS --> PCS' --> dst_linear_unit_floats
-//
-// Some nice documents
-//
-// http://www.cambridgeincolour.com/tutorials/color-space-conversion.htm
-// https://www.w3.org/Graphics/Color/srgb
-// http://www.poynton.com/notes/colour_and_gamma/ColorFAQ.html
-//
-
 #include "SkMatrix44.h"
 #include "SkRefCnt.h"
 #include "../private/SkTemplates.h"
 
 struct SkColorLookUpTable;
 struct SkGammaCurve;
 struct SkGammas;
 
 class SkColorSpace : public SkRefCnt {
 public:
 
+    /**
+     *  Common, named profiles that we can recognize.
+     */
     enum Named {
         kUnknown_Named,
         kSRGB_Named,
         kAdobeRGB_Named,
     };
 
     /**
-     *  Given the src gamma and a transform from src gamut to D50_XYZ, return a SkColorSpace.
+     *  Create an SkColorSpace from the src gamma and a transform from src gamut to D50 XYZ.
      */
     static sk_sp<SkColorSpace> NewRGB(float gammas[3], const SkMatrix44& toXYZD50);
 
+    /**
+     *  Create a common, named SkColorSpace.
+     */
     static sk_sp<SkColorSpace> NewNamed(Named);
+
+    /**
+     *  Create an SkColorSpace from an ICC profile.
+     */
     static sk_sp<SkColorSpace> NewICC(const void*, size_t);
 
     /**
-     *  Used only by test code.
+     *  Used interally.
      */
     SkGammas* gammas() const { return fGammas.get(); }
 
+    /**
+     *  Returns the matrix used to transform src gamut to XYZ D50.
+     */
     SkMatrix44 xyz() const { return fToXYZD50; }
+
+    /**
+     *  Returns profile name or kUnknown if it does not match one of our known profiles.
+     */
     Named named() const { return fNamed; }

[reed1, 2016/05/20 21:10:44]

do we need this guy?

[msarett, 2016/05/23 14:03:48]

Not right now, I'm deleting it because no one is using it.

Since we go to the trouble of checking if the xyz values match srgb (or adobe
rgb) at create time, it may make sense to expose that info to the client at some
point (so they don't also have to check).

-    uint32_t uniqueID() const { return fUniqueID; }
 

[reed1, 2016/05/20 21:10:44]

Do we have an idea for the srgb-like query we're gonna want?

e.g.

bool isGammaCloseTo2Dot2() const;

[msarett, 2016/05/23 14:03:48]

Yeah I had an idea.  I'll pull it in from another CL.  It returns an enum
(rather than a bool), so we can say "2.2", "linear", or "complicated".

For images, we don't really need the "linear" so the bool would be fine, but I
think that other sources may be linear?

 private:
 
     static bool LoadGammas(SkGammaCurve* gammas, uint32_t num, const uint8_t* src, size_t len);
 
     static bool LoadColorLUT(SkColorLookUpTable* colorLUT, uint32_t inputChannels,
                              uint32_t outputChannels, const uint8_t* src, size_t len);
 
     static bool LoadA2B0(SkColorLookUpTable* colorLUT, SkGammaCurve*, SkMatrix44* toXYZ,
                          const uint8_t* src, size_t len);
 
     SkColorSpace(sk_sp<SkGammas> gammas, const SkMatrix44& toXYZ, Named);
 
     SkColorSpace(SkColorLookUpTable* colorLUT, sk_sp<SkGammas> gammas, const SkMatrix44& toXYZ);
 
     SkAutoTDelete<SkColorLookUpTable> fColorLUT;
     sk_sp<SkGammas>                   fGammas;
     const SkMatrix44                  fToXYZD50;
-
-    const uint32_t                    fUniqueID;
     const Named                       fNamed;
 };
 
 #endif