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

Testing consisted of:
 1) ninja -C out/Debug gm && gm -i resources --match mandrill_512 -w /tmp/gm
 2) notice that gm didn't segfault
 3) look in /tmp/gm and see a bunch of handsome monkeys

BUG=skia:1517
R=humper@google.com

Review URL: https://codereview.chromium.org/22801016

git-svn-id: http://skia.googlecode.com/svn/trunk@10917 2bbb7eff-a529-9590-31e7-b0007b416f81

4 files changed, 42 insertions, 22 deletions

diff --git a/src/core/SkBitmapFilter.cpp b/src/core/SkBitmapFilter.cpp
index 5128d9b5dc..c607e6814b 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);
+}
+
+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;
     }
 }
diff --git a/src/core/SkBitmapProcState.cpp b/src/core/SkBitmapProcState.cpp
index b48f8384c9..390582d161 100644
--- a/src/core/SkBitmapProcState.cpp
+++ b/src/core/SkBitmapProcState.cpp
@@ -376,8 +376,7 @@ bool SkBitmapProcState::chooseProcs(const SkMatrix& inv, const SkPaint& paint) {
 
         SkASSERT(fInvType > SkMatrix::kTranslate_Mask);
 
-        fShaderProc32 = this->chooseBitmapFilterProc();
-        if (!fShaderProc32) {
+        if (!this->setBitmapFilterProcs()) {
             fFilterLevel = SkPaint::kLow_FilterLevel;
         }
     }
@@ -404,7 +403,7 @@ bool SkBitmapProcState::chooseProcs(const SkMatrix& inv, const SkPaint& paint) {
 
     // No need to do this if we're doing HQ sampling; if filter quality is
     // still set to HQ by the time we get here, then we must have installed
-    // the shader proc above and can skip all this.
+    // the shader procs above and can skip all this.
 
     if (fFilterLevel < SkPaint::kHigh_FilterLevel) {
 
diff --git a/src/core/SkBitmapProcState.h b/src/core/SkBitmapProcState.h
index e138ed2698..3a1d7bad62 100644
--- a/src/core/SkBitmapProcState.h
+++ b/src/core/SkBitmapProcState.h
@@ -166,7 +166,9 @@ private:
 
     SkBitmapFilter* fBitmapFilter;
 
-    ShaderProc32 chooseBitmapFilterProc();
+    // If supported, sets fShaderProc32 and fShaderProc16 and returns true,
+    // otherwise returns false.
+    bool setBitmapFilterProcs();
 
     // Return false if we failed to setup for fast translate (e.g. overflow)
     bool setupForTranslate();
@@ -208,9 +210,9 @@ void S32_opaque_D32_filter_DX(const SkBitmapProcState& s, const uint32_t xy[],
 void S32_alpha_D32_filter_DX(const SkBitmapProcState& s, const uint32_t xy[],
                              int count, SkPMColor colors[]);
 void S32_opaque_D32_filter_DXDY(const SkBitmapProcState& s,
-                           const uint32_t xy[], int count, SkPMColor colors[]);
+                                const uint32_t xy[], int count, SkPMColor colors[]);
 void S32_alpha_D32_filter_DXDY(const SkBitmapProcState& s,
-                           const uint32_t xy[], int count, SkPMColor colors[]);
+                               const uint32_t xy[], int count, SkPMColor colors[]);
 void ClampX_ClampY_filter_scale(const SkBitmapProcState& s, uint32_t xy[],
                                 int count, int x, int y);
 void ClampX_ClampY_nofilter_scale(const SkBitmapProcState& s, uint32_t xy[],
@@ -220,10 +222,12 @@ void ClampX_ClampY_filter_affine(const SkBitmapProcState& s,
 void ClampX_ClampY_nofilter_affine(const SkBitmapProcState& s,
                                    uint32_t xy[], int count, int x, int y);
 void S32_D16_filter_DX(const SkBitmapProcState& s,
-                                   const uint32_t* xy, int count, uint16_t* colors);
+                       const uint32_t* xy, int count, uint16_t* colors);
 
-void highQualityFilter(const SkBitmapProcState &s, int x, int y,
-                   SkPMColor *SK_RESTRICT colors, int count);
+void highQualityFilter32(const SkBitmapProcState &s, int x, int y,
+                         SkPMColor *SK_RESTRICT colors, int count);
+void highQualityFilter16(const SkBitmapProcState &s, int x, int y,
+                         uint16_t *SK_RESTRICT colors, int count);
 
 
 #endif
diff --git a/src/opts/opts_check_SSE2.cpp b/src/opts/opts_check_SSE2.cpp
index 9b6f775d9a..8d43390a22 100644
--- a/src/opts/opts_check_SSE2.cpp
+++ b/src/opts/opts_check_SSE2.cpp
@@ -155,7 +155,7 @@ void SkBitmapProcState::platformProcs() {
             fMatrixProc = ClampX_ClampY_nofilter_affine_SSE2;
         }
         if (c_hqfilter_sse) {
-            if (fShaderProc32 == highQualityFilter) {
+            if (fShaderProc32 == highQualityFilter32) {
                 fShaderProc32 = highQualityFilter_SSE2;
             }
         }