Swizzler changes Index8 and 565

src/codec/SkSwizzler.h

Index: src/codec/SkSwizzler.h
diff --git a/src/codec/SkSwizzler.h b/src/codec/SkSwizzler.h
index 63afbf73bc3d75717f20dc8650f64e3f54d29425..80be80cb19ffe178f237b8309ae55437bfa58e71 100644
--- a/src/codec/SkSwizzler.h
+++ b/src/codec/SkSwizzler.h
@@ -61,7 +61,7 @@ public:
     static bool IsOpaque(ResultAlpha r) {
         return kOpaque_ResultAlpha == r;
     }
-    
+
     /*
      *
      * Constructs the proper result code based on accumulated alpha masks
@@ -128,6 +128,27 @@ public:
                                       const SkImageInfo&, void* dst,
                                       size_t dstRowBytes,
                                       SkImageGenerator::ZeroInitialized);
+
+    /**
+     * Fill the remainder of the destination with a single color
+     * @param y            The starting row for the fill.
+     * @param colorOrIndex The value to fill with - may be a color or an index.
+     *                     It will be an index in the case where the encoded image was

[scroggo, 2015/04/09 14:53:48]

This seems like extraneous information. What this should tell us is what this
function will do with these parameters. I think what you really want to say is
something like the following:

If dstInfo.colorType() is kIndex8, colorOrIndex is assumed to be a uint8_t
index, and colorTable is ignored. Each 8-bit pixel will be set to (uint8_t)
index.

If dstInfo.colorType() is kN32, colorOrIndex is treated differently depending on
whether colorTable is NULL:

  A NULL colorTable means colorOrIndex is treated as an SkPMColor (premul or
  unpremul, depending on dstInfo.alphaType()). Each 4-byte pixel will be set to
  colorOrIndex.

  A non-NULL colorTable means colorOrIndex is treated as a uint8_t index into
  the colorTable. i.e. each 4-byte pixel will be set to
  colorTable[(uint8_t) colorOrIndex].

Other SkColorTypes are not supported.

[msarett, 2015/04/09 16:26:32]

Very well said.

+     *                     stored in an indexed format.  If we are decoding to kIndex8
+     *                     we will fill with the index directly.  If we are decoding to
+     *                     kN32, we will use the index to look up the color that we are
+     *                     to fill with.  If the input is an index, it will be treated
+     *                     as a uint8_t.
+     *                     We recognize that the input is not an index if we are
+     *                     decoding to kN32 and the input color table is NULL.  In this
+     *                     case, we assume the input is an SkPMColor and fill with it
+     *                     directly.
+     * @param colorTable   a non-NULL colorTable indicates that the input is an index
+     *                     even if the dst color type is not an index type
+     */
+    static void Fill(void* dst, const SkImageInfo& dstInfo, size_t dstRowBytes, uint32_t y,
+            uint32_t colorOrIndex, SkPMColor* colorTable);
+
     /**
      *  Swizzle the next line. Call height times, once for each row of source.
      *  @param src The next row of the source data.
@@ -156,6 +177,7 @@ public:
      *  destination?
      */
     void setDstRow(void* dst) { fDstRow = dst; }
+
 private:
 
 #ifdef SK_DEBUG