Differentiate between sRGBGamma and 2Dot2Gamma

src/codec/SkPngCodec.cpp

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkBitmap.h"
 #include "SkCodecPriv.h"
 #include "SkColorPriv.h"
-#include "SkColorSpace.h"
+#include "SkColorSpace_Base.h"
 #include "SkColorTable.h"
 #include "SkMath.h"
 #include "SkOpts.h"
 #include "SkPngCodec.h"
 #include "SkSize.h"
 #include "SkStream.h"
 #include "SkSwizzler.h"
 #include "SkTemplates.h"
 #include "SkUtils.h"
 
@@ skipping 202 matching lines @@
             toXYZD50[i] = png_fixed_point_to_float(XYZ[i]);
         }
 
         if (PNG_INFO_gAMA == png_get_gAMA_fixed(png_ptr, info_ptr, &gamma)) {
             float value = png_inverted_fixed_point_to_float(gamma);
             gammas[0] = value;
             gammas[1] = value;
             gammas[2] = value;
 
         } else {
             // Default to sRGB (gamma = 2.2f) if the image has color space information,

[Brian Osman, 2016/06/14 21:55:38]

Now that we're distinguishing between 2.2 and sRGB, does it make sense to
default to actual sRGB in this case, rather than 2.2? (ie, return
SkColorSpace::NewRGB(kSRGB_GammaNamed, mat)) ?

[msarett, 2016/06/14 22:59:11]

Yes I think so!  Done.

Might make sense to default to whichever we can do faster, though I don't know
what that is yet.  If it's a tie, I'd go sRGB.

             // but does not specify gamma.
             gammas[0] = 2.2f;
             gammas[1] = 2.2f;
             gammas[2] = 2.2f;
         }
 
         SkMatrix44 mat(SkMatrix44::kUninitialized_Constructor);
         mat.set3x3ColMajorf(toXYZD50);
-        return SkColorSpace::NewRGB(gammas, mat);
+        return SkColorSpace_Base::NewRGB(gammas, mat);
     }
 
     // Last, check for gamma.
     if (PNG_INFO_gAMA == png_get_gAMA_fixed(png_ptr, info_ptr, &gamma)) {
 
         // Guess a default value for cHRM?  Or should we just give up?
         // Here we use the identity matrix as a default.
 
         // Set the gammas.
         float value = png_inverted_fixed_point_to_float(gamma);
         gammas[0] = value;
         gammas[1] = value;
         gammas[2] = value;
 
-        return SkColorSpace::NewRGB(gammas, SkMatrix44::I());
+        return SkColorSpace_Base::NewRGB(gammas, SkMatrix44::I());
     }
 
 #endif // LIBPNG >= 1.6
 
     // Finally, what should we do if there is no color space information in the PNG?
     // The specification says that this indicates "gamma is unknown" and that the
     // "color is device dependent".  I'm assuming we can represent this with NULL.
     // But should we guess sRGB?  Most images are sRGB, even if they don't specify.
     return nullptr;
 }
@@ skipping 538 matching lines @@
     SkCodec* outCodec;
     if (read_header(stream, chunkReader, &outCodec, nullptr, nullptr)) {
         // Codec has taken ownership of the stream.
         SkASSERT(outCodec);
         streamDeleter.release();
         return outCodec;
     }
 
     return nullptr;
 }