SkScaledCodec class

src/codec/SkCodec_libpng.cpp

Index: src/codec/SkCodec_libpng.cpp
diff --git a/src/codec/SkCodec_libpng.cpp b/src/codec/SkCodec_libpng.cpp
index 9f9c110cc68bcc06ed9d38c7c272cdecea42341a..66d9b2cad2c5dd1da4a131a339a4f3b7a2f0a72f 100644
--- a/src/codec/SkCodec_libpng.cpp
+++ b/src/codec/SkCodec_libpng.cpp
@@ -11,6 +11,7 @@
 #include "SkColorTable.h"
 #include "SkBitmap.h"
 #include "SkMath.h"
+#include "SkScaledCodec.h"
 #include "SkScanlineDecoder.h"
 #include "SkSize.h"
 #include "SkStream.h"
@@ -473,7 +474,7 @@ SkCodec::Result SkPngCodec::initializeSwizzler(const SkImageInfo& requestedInfo,
     // Create the swizzler.  SkPngCodec retains ownership of the color table.
     const SkPMColor* colors = fColorTable ? fColorTable->readColors() : NULL;
     fSwizzler.reset(SkSwizzler::CreateSwizzler(fSrcConfig, colors, requestedInfo,
-            options.fZeroInitialized));
+                    options.fZeroInitialized, this->getInfo().width()));
     if (!fSwizzler) {
         // FIXME: CreateSwizzler could fail for another reason.
         return kUnimplemented;
@@ -599,7 +600,7 @@ public:
         , fCodec(codec)
         , fHasAlpha(false)
     {
-        fStorage.reset(dstInfo.width() * SkSwizzler::BytesPerPixel(fCodec->fSrcConfig));
+        fStorage.reset(fCodec->getInfo().width() * SkSwizzler::BytesPerPixel(fCodec->fSrcConfig));
         fSrcRow = static_cast<uint8_t*>(fStorage.get());
     }
 
@@ -655,7 +656,7 @@ public:
         , fCurrentRow(0)
         , fHeight(dstInfo.height())
     {
-        fSrcRowBytes = dstInfo.width() * SkSwizzler::BytesPerPixel(fCodec->fSrcConfig);
+        fSrcRowBytes = codec->getInfo().width() * SkSwizzler::BytesPerPixel(fCodec->fSrcConfig);
         fGarbageRow.reset(fSrcRowBytes);
         fGarbageRowPtr = static_cast<uint8_t*>(fGarbageRow.get());
     }
@@ -710,6 +711,10 @@ public:
 
     bool onReallyHasAlpha() const override { return fHasAlpha; }
 
+    bool onRequiresPostYSampling() override {
+        return true;
+    }
+
 private:
     SkAutoTDelete<SkPngCodec>   fCodec;
     bool                        fHasAlpha;
@@ -731,7 +736,9 @@ SkScanlineDecoder* SkPngCodec::onGetScanlineDecoder(const SkImageInfo& dstInfo,
     }
     // Check to see if scaling was requested.
     if (dstInfo.dimensions() != this->getInfo().dimensions()) {
-        return NULL;
+        if (!SkScaledCodec::DimensionsSupportedForSampling(this->getInfo(), dstInfo)) {
+            return NULL;
+        }
     }
     // Create a new SkPngCodec, to be owned by the scanline decoder.
     SkStream* stream = this->stream()->duplicate();