experiment: float color components

include/core/SkColor.h

 /*
  * Copyright 2006 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkColor_DEFINED
 #define SkColor_DEFINED
 
@@ skipping 142 matching lines @@
 /** Return a SkPMColor value from a SkColor value. This is done by multiplying the color
     components by the color's alpha, and by arranging the bytes in a configuration
     dependent order, to match the format of kARGB32 bitmaps.
 */
 SK_API SkPMColor SkPreMultiplyColor(SkColor c);
 
 /** Define a function pointer type for combining two premultiplied colors
 */
 typedef SkPMColor (*SkXfermodeProc)(SkPMColor src, SkPMColor dst);
 
+///////////////////////////////////////////////////////////////////////////////////////////////////
+
+struct SkPM4f {
+    float fVec[4];

[mtklein, 2016/01/21 17:52:36]

To be super-sweet,

struct SK_ATTRIBUTE(aligned(16)) SkPM4f {
   ...
};

This will make sure the floats are aligned when you put them on the stack.
(This is often guaranteed anyway, depending on the OS + CPU architecture.)

+};
+
 #endif