Sketch SkPMFloat

src/core/SkPMFloat.h

+#ifndef SkPM_DEFINED
+#define SkPM_DEFINED
+
+#include "SkTypes.h"
+#include "SkColor.h"
+
+// As usual, there are two ways to increase alignment... the MSVC way and the everyone-else way.
+#ifdef _MSC_VER
+    #define ALIGN(N) __declspec(align(N))
+#else
+    #define ALIGN(N) __attribute__((aligned(N)))
+#endif
+
+// A pre-multiplied color in the same order as SkPMColor storing each component as a float.
+struct ALIGN(16) SkPMFloat {
+    float fColor[4];
+
+    float a() const { return fColor[SK_A32_SHIFT / 8]; }
+    float r() const { return fColor[SK_R32_SHIFT / 8]; }
+    float g() const { return fColor[SK_G32_SHIFT / 8]; }
+    float b() const { return fColor[SK_B32_SHIFT / 8]; }
+
+    void setA(float val) { fColor[SK_A32_SHIFT / 8] = val; }
+    void setR(float val) { fColor[SK_R32_SHIFT / 8] = val; }
+    void setG(float val) { fColor[SK_G32_SHIFT / 8] = val; }
+    void setB(float val) { fColor[SK_B32_SHIFT / 8] = val; }
+
+    void set(SkPMColor);
+
+    SkPMColor     get() const;  // May SkASSERT(this->sane()).
+    SkPMColor clamped() const;  // Will clamp all values to [0,1], then may SkASSERT(this->sane()).
+
+    bool sane() const {

[reed1, 2015/02/19 22:14:49]

bikeshed: isValid(), isLegal(), isClamped() ?

[mtklein, 2015/02/19 22:48:35]

Done.

+        return this->a() >= 0 && this->a() <= 1 &&
+               this->r() >= 0 && this->r() <= 1 &&

[reed1, 2015/02/19 22:14:50]

can replace the 2nd test on r() with r() <= a() and remove the additional check
at the bottom. i.e. only 8 checks are needed total.

[mtklein, 2015/02/19 22:48:35]

Oh, nice.  Done.

+               this->g() >= 0 && this->g() <= 1 &&
+               this->b() >= 0 && this->b() <= 1 &&
+               this->r() <= this->a() &&
+               this->g() <= this->a() &&
+               this->b() <= this->a();
+    }
+};
+#undef ALIGN
+
+#if SK_CPU_SSE_LEVEL >= SK_CPU_SSE_LEVEL_SSE2
+    #include "../opts/SkPMFloat_SSE2.h"
+#elif defined(__ARM_NEON__)
+    #include "../opts/SkPMFloat_neon.h"
+#else
+    #include "../opts/SkPMFloat_none.h"
+#endif
+
+#endif//SkPM_DEFINED