disable 32A->565 + alpha for now, until it handles src-alpha==0 as a noop

git-svn-id: http://skia.googlecode.com/svn/trunk@525 2bbb7eff-a529-9590-31e7-b0007b416f81

2 files changed, 14 insertions, 34 deletions

diff --git a/src/core/SkBlitRow_D16.cpp b/src/core/SkBlitRow_D16.cpp
index 07c42ceb0b..72c9d527dc 100644
--- a/src/core/SkBlitRow_D16.cpp
+++ b/src/core/SkBlitRow_D16.cpp
@@ -63,27 +63,16 @@ static void S32A_D565_Blend(uint16_t* SK_RESTRICT dst,
     SkASSERT(255 > alpha);
     
     if (count > 0) {
-        int src_scale = SkAlpha255To256(alpha);
         do {
             SkPMColor sc = *src++;
             SkPMColorAssert(sc);
-            if (sc)
-            {
+            if (sc) {
                 uint16_t dc = *dst;
-                unsigned sa = SkGetPackedA32(sc);
-                unsigned dr, dg, db;
-                
-                if (sa == 255) {
-                    dr = SkAlphaBlend(SkPacked32ToR16(sc), SkGetPackedR16(dc), src_scale);
-                    dg = SkAlphaBlend(SkPacked32ToG16(sc), SkGetPackedG16(dc), src_scale);
-                    db = SkAlphaBlend(SkPacked32ToB16(sc), SkGetPackedB16(dc), src_scale);
-                } else {
-                    unsigned dst_scale = 255 - SkAlphaMul(sa, src_scale);
-                    dr = (SkPacked32ToR16(sc) * src_scale + SkGetPackedR16(dc) * dst_scale) >> 8;
-                    dg = (SkPacked32ToG16(sc) * src_scale + SkGetPackedG16(dc) * dst_scale) >> 8;
-                    db = (SkPacked32ToB16(sc) * src_scale + SkGetPackedB16(dc) * dst_scale) >> 8;
-                }
-                *dst = SkPackRGB16(dr, dg, db);
+                unsigned dst_scale = 255 - SkMulDiv255Round(SkGetPackedA32(sc), alpha);
+                unsigned dr = SkMulS16(SkPacked32ToR16(sc), alpha) + SkMulS16(SkGetPackedR16(dc), dst_scale);
+                unsigned dg = SkMulS16(SkPacked32ToG16(sc), alpha) + SkMulS16(SkGetPackedG16(dc), dst_scale);
+                unsigned db = SkMulS16(SkPacked32ToB16(sc), alpha) + SkMulS16(SkGetPackedB16(dc), dst_scale);
+                *dst = SkPackRGB16(SkDiv255Round(dr), SkDiv255Round(dg), SkDiv255Round(db));
             }
             dst += 1;
         } while (--count != 0);
diff --git a/src/opts/SkBlitRow_opts_arm.cpp b/src/opts/SkBlitRow_opts_arm.cpp
index 78fc907606..5b6ce7effc 100644
--- a/src/opts/SkBlitRow_opts_arm.cpp
+++ b/src/opts/SkBlitRow_opts_arm.cpp
@@ -281,23 +281,13 @@ static void S32A_D565_Blend_neon(uint16_t* SK_RESTRICT dst,
     if (count > 0) {
         do {
             SkPMColor sc = *src++;
-            if (sc)
-            {
+            if (sc) {
                 uint16_t dc = *dst;
-                unsigned sa = SkGetPackedA32(sc);
-                unsigned dr, dg, db;
-                
-                if (sa == 255) {
-                    dr = SkAlphaBlend(SkPacked32ToR16(sc), SkGetPackedR16(dc), alpha);
-                    dg = SkAlphaBlend(SkPacked32ToG16(sc), SkGetPackedG16(dc), alpha);
-                    db = SkAlphaBlend(SkPacked32ToB16(sc), SkGetPackedB16(dc), alpha);
-                } else {
-                    unsigned dst_scale = 255 - SkAlphaMul(sa, alpha);
-                    dr = (SkPacked32ToR16(sc) * alpha + SkGetPackedR16(dc) * dst_scale) >> 8;
-                    dg = (SkPacked32ToG16(sc) * alpha + SkGetPackedG16(dc) * dst_scale) >> 8;
-                    db = (SkPacked32ToB16(sc) * alpha + SkGetPackedB16(dc) * dst_scale) >> 8;
-                }
-                *dst = SkPackRGB16(dr, dg, db);
+                unsigned dst_scale = 255 - SkMulDiv255Round(SkGetPackedA32(sc), alpha);
+                unsigned dr = SkMulS16(SkPacked32ToR16(sc), alpha) + SkMulS16(SkGetPackedR16(dc), dst_scale);
+                unsigned dg = SkMulS16(SkPacked32ToG16(sc), alpha) + SkMulS16(SkGetPackedG16(dc), dst_scale);
+                unsigned db = SkMulS16(SkPacked32ToB16(sc), alpha) + SkMulS16(SkGetPackedB16(dc), dst_scale);
+                *dst = SkPackRGB16(SkDiv255Round(dr), SkDiv255Round(dg), SkDiv255Round(db));
             }
             dst += 1;
         } while (--count != 0);
@@ -988,7 +978,8 @@ static const SkBlitRow::Proc platform_565_procs[] = {
     S32_D565_Opaque_PROC,
     S32_D565_Blend_PROC,
     S32A_D565_Opaque_PROC,
-    S32A_D565_Blend_PROC,
+    // fails to treat src==0 as a no-op. see BlitRowTest.cpp
+    NULL,   // S32A_D565_Blend_PROC,
     
     // dither
     S32_D565_Opaque_Dither_PROC,