Code's more readable when SkPMFloat is an Sk4f.

src/core/SkXfermode.cpp

 
 /*
  * 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.
  */
 
 #include "SkXfermode.h"
 #include "SkXfermode_opts_SSE2.h"
@@ skipping 1218 matching lines @@
 #ifdef SK_DEBUG
     (void)pm.round();
 #endif
     return pm;
 }
 
 //  kSrcATop_Mode,  //!< [Da, Sc * Da + (1 - Sa) * Dc]
 struct SrcATop4f {
     static SkPMFloat Xfer(const SkPMFloat& src, const SkPMFloat& dst) {
         const Sk4f inv255(gInv255);
-        Sk4f s4 = src;
-        Sk4f d4 = dst;
-        return check_as_pmfloat(d4 + (s4 * Sk4f(dst.a()) - d4 * Sk4f(src.a())) * inv255);
+        return check_as_pmfloat(dst + (src * Sk4f(dst.a()) - dst * Sk4f(src.a())) * inv255);
     }
     static const bool kFoldCoverageIntoSrcAlpha = true;
     static const SkXfermode::Mode kMode = SkXfermode::kSrcATop_Mode;
 };
 
 //  kDstATop_Mode,  //!< [Sa, Sa * Dc + Sc * (1 - Da)]
 struct DstATop4f {
     static SkPMFloat Xfer(const SkPMFloat& src, const SkPMFloat& dst) {
         const Sk4f inv255(gInv255);
-        Sk4f s4 = src;
-        Sk4f d4 = dst;
-        return check_as_pmfloat(s4 + (d4 * Sk4f(src.a()) - s4 * Sk4f(dst.a())) * inv255);
+        return check_as_pmfloat(src + (dst * Sk4f(src.a()) - src * Sk4f(dst.a())) * inv255);
     }
     static const bool kFoldCoverageIntoSrcAlpha = false;
     static const SkXfermode::Mode kMode = SkXfermode::kDstATop_Mode;
 };
 
 //  kXor_Mode   [Sa + Da - 2 * Sa * Da, Sc * (1 - Da) + (1 - Sa) * Dc]
 struct Xor4f {
     static SkPMFloat Xfer(const SkPMFloat& src, const SkPMFloat& dst) {
         const Sk4f inv255(gInv255);
-        Sk4f s4 = src;
-        Sk4f d4 = dst;
-        return check_as_pmfloat(s4 + d4 - (s4 * Sk4f(dst.a()) + d4 * Sk4f(src.a())) * inv255);
+        return check_as_pmfloat(src + dst - (src * Sk4f(dst.a()) + dst * Sk4f(src.a())) * inv255);
     }
     static const bool kFoldCoverageIntoSrcAlpha = true;
     static const SkXfermode::Mode kMode = SkXfermode::kXor_Mode;
 };
 
 //  kPlus_Mode   [Sa + Da, Sc + Dc]
 struct Plus4f {
     static SkPMFloat Xfer(const SkPMFloat& src, const SkPMFloat& dst) {
-        Sk4f s4 = src;
-        Sk4f d4 = dst;
-        return check_as_pmfloat(clamp_255(s4 + d4));
+        return check_as_pmfloat(clamp_255(src + dst));
     }
     static const bool kFoldCoverageIntoSrcAlpha = true;
     static const SkXfermode::Mode kMode = SkXfermode::kPlus_Mode;
 };
 
 //  kModulate_Mode   [Sa * Da, Sc * Dc]
 struct Modulate4f {
     static SkPMFloat Xfer(const SkPMFloat& src, const SkPMFloat& dst) {
         const Sk4f inv255(gInv255);
-        Sk4f s4 = src;
-        Sk4f d4 = dst;
-        return check_as_pmfloat(s4 * d4 * inv255);
+        return check_as_pmfloat(src * dst * inv255);
     }
     static const bool kFoldCoverageIntoSrcAlpha = false;
     static const SkXfermode::Mode kMode = SkXfermode::kModulate_Mode;
 };
 
 //  kScreen_Mode   [S + D - S * D]
 struct Screen4f {
     static SkPMFloat Xfer(const SkPMFloat& src, const SkPMFloat& dst) {
         const Sk4f inv255(gInv255);
-        Sk4f s4 = src;
-        Sk4f d4 = dst;
-        return check_as_pmfloat(s4 + d4 - s4 * d4 * inv255);
+        return check_as_pmfloat(src + dst - src * dst * inv255);
     }
     static const bool kFoldCoverageIntoSrcAlpha = true;
     static const SkXfermode::Mode kMode = SkXfermode::kScreen_Mode;
 };
 
 struct Multiply4f {
     static SkPMFloat Xfer(const SkPMFloat& src, const SkPMFloat& dst) {
         const Sk4f inv255(gInv255);
         Sk4f sa = Sk4f(src.a());
         Sk4f da = Sk4f(dst.a());
@@ skipping 474 matching lines @@
         } else {
             proc16 = rec.fProc16_General;
         }
     }
     return proc16;
 }
 
 SK_DEFINE_FLATTENABLE_REGISTRAR_GROUP_START(SkXfermode)
     SK_DEFINE_FLATTENABLE_REGISTRAR_ENTRY(SkProcCoeffXfermode)
 SK_DEFINE_FLATTENABLE_REGISTRAR_GROUP_END