SkScaledCodec class

include/codec/SkScanlineDecoder.h

Index: include/codec/SkScanlineDecoder.h
diff --git a/include/codec/SkScanlineDecoder.h b/include/codec/SkScanlineDecoder.h
index 8376e57c09d84bb48c1d7ae295ccd441a7feab48..d1cba35cce8da94fa6c0559b9f58a0970284f12a 100644
--- a/include/codec/SkScanlineDecoder.h
+++ b/include/codec/SkScanlineDecoder.h
@@ -35,7 +35,7 @@ public:
      */
     SkCodec::Result getScanlines(void* dst, int countLines, size_t rowBytes) {
         if ((rowBytes < fDstInfo.minRowBytes() && countLines > 1 ) || countLines <= 0
-                || fCurrScanline + countLines > fDstInfo.height()) {
+                || fCurrScanline + countLines > fSrcInfo.height()) {
             return SkCodec::kInvalidParameters;
         }
         const SkCodec::Result result = this->onGetScanlines(dst, countLines, rowBytes);
@@ -52,7 +52,7 @@ public:
      *  false.
      */
     SkCodec::Result skipScanlines(int countLines) {
-        if (fCurrScanline + countLines > fDstInfo.height()) {
+        if (fCurrScanline + countLines > fSrcInfo.height()) {
             // Arguably, we could just skip the scanlines which are remaining,
             // and return kSuccess. We choose to return invalid so the client
             // can catch their bug.
@@ -75,18 +75,26 @@ public:
         return this->onReallyHasAlpha();
     }
 
+    bool setSampleX(int sampleX) {

[scroggo, 2015/07/27 15:09:19]

Please add comments explaining what this does.

[emmaleer, 2015/07/27 18:31:38]

Acknowledged.

+        return this->onSetSampleX(sampleX);
+    }
+
 protected:
-    SkScanlineDecoder(const SkImageInfo& requested)
+    SkScanlineDecoder(const SkImageInfo& requested, const SkImageInfo src)

[scroggo, 2015/07/27 15:09:19]

This should be a const reference. That way we do not do a copy when passing the
parameter. (The field needs to not be a reference, and we'll still do a copy
when it is initialized.)

[emmaleer, 2015/07/27 18:31:38]

Acknowledged.

         : fDstInfo(requested)
-        , fCurrScanline(0) {}
+        , fCurrScanline(0)
+        , fSrcInfo(src) {}
 
     virtual bool onReallyHasAlpha() const { return false; }
 
+    virtual bool onSetSampleX(int SampleX){ return false; }
+
     const SkImageInfo& dstInfo() const { return fDstInfo; }
 
 private:
     const SkImageInfo   fDstInfo;
     int                 fCurrScanline;
+    const SkImageInfo   fSrcInfo;
 
     // Naive default version just calls onGetScanlines on temp memory.
     virtual SkCodec::Result onSkipScanlines(int countLines) {