Implement highQualityFilter16 so GM doesn't crash when you give it resources.

src/core/SkBitmapFilter.cpp

Index: src/core/SkBitmapFilter.cpp
diff --git a/src/core/SkBitmapFilter.cpp b/src/core/SkBitmapFilter.cpp
index 5128d9b5dc7a3843508db023dd0811b90ce1eea9..c607e6814b2fbb55b291b4f62c159d131cd38f48 100644
--- a/src/core/SkBitmapFilter.cpp
+++ b/src/core/SkBitmapFilter.cpp
@@ -22,9 +22,10 @@
 // the image is rotated or has some other complex transformation applied.
 // Scaled images will usually be rescaled directly before rasterization.
 
-void highQualityFilter(const SkBitmapProcState& s, int x, int y,
-                   SkPMColor* SK_RESTRICT colors, int count) {
+namespace {
 
+template <typename Color, typename ColorPacker>
+void highQualityFilter(ColorPacker pack, const SkBitmapProcState& s, int x, int y, Color* SK_RESTRICT colors, int count) {
     const int maxX = s.fBitmap->width() - 1;
     const int maxY = s.fBitmap->height() - 1;
 
@@ -70,12 +71,27 @@ void highQualityFilter(const SkBitmapProcState& s, int x, int y,
         int g = SkClampMax(SkScalarRoundToInt(fg), a);
         int b = SkClampMax(SkScalarRoundToInt(fb), a);
 
-        *colors++ = SkPackARGB32(a, r, g, b);
+        *colors++ = pack(a, r, g, b);
 
         x++;
     }
 }
 
+uint16_t PackTo565(int /*a*/, int r, int g, int b) {
+    return SkPack888ToRGB16(r, g, b);
+}
+
+}  // namespace
+
+void highQualityFilter32(const SkBitmapProcState& s, int x, int y, SkPMColor* SK_RESTRICT colors, int count) {
+    highQualityFilter(&SkPackARGB32, s, x, y, colors, count);

[reed1, 2013/08/26 13:51:27]

Have we confirmed that SkPackARGB32 got inlined (same with PackTo565? I presume
so, but just want to make sure.

+}
+
+void highQualityFilter16(const SkBitmapProcState& s, int x, int y, uint16_t* SK_RESTRICT colors, int count) {
+    highQualityFilter(&PackTo565, s, x, y, colors, count);
+}
+
+
 SK_CONF_DECLARE(const char *, c_bitmapFilter, "bitmap.filter", "mitchell", "Which scanline bitmap filter to use [mitchell, lanczos, hamming, gaussian, triangle, box]");
 
 SkBitmapFilter *SkBitmapFilter::Allocate() {
@@ -98,34 +114,35 @@ SkBitmapFilter *SkBitmapFilter::Allocate() {
     return NULL;
 }
 
-SkBitmapProcState::ShaderProc32
-SkBitmapProcState::chooseBitmapFilterProc() {
-
+bool SkBitmapProcState::setBitmapFilterProcs() {
     if (fFilterLevel != SkPaint::kHigh_FilterLevel) {
-        return NULL;
+        return false;
     }
 
     if (fAlphaScale != 256) {
-        return NULL;
+        return false;
     }
 
     // TODO: consider supporting other configs (e.g. 565, A8)
     if (fBitmap->config() != SkBitmap::kARGB_8888_Config) {
-        return NULL;
+        return false;
     }
 
     // TODO: consider supporting repeat and mirror
     if (SkShader::kClamp_TileMode != fTileModeX || SkShader::kClamp_TileMode != fTileModeY) {
-        return NULL;
+        return false;
     }
 
+    // TODO: is this right?  do we want fBitmapFilter allocated even if we can't set shader procs?
     if (fInvType & (SkMatrix::kAffine_Mask | SkMatrix::kScale_Mask)) {
         fBitmapFilter = SkBitmapFilter::Allocate();
     }
 
     if (fInvType & SkMatrix::kScale_Mask) {
-        return highQualityFilter;
+        fShaderProc32 = highQualityFilter32;
+        fShaderProc16 = highQualityFilter16;
+        return true;
     } else {
-        return NULL;
+        return false;
     }
 }