Adding premul and 565 swizzles for bmp:

src/codec/SkCodec_libbmp.h

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkCodec.h"
 #include "SkImageInfo.h"
 #include "SkMaskSwizzler.h"
@@ skipping 57 matching lines @@
      */
     enum BitmapInputFormat {
         kStandard_BitmapInputFormat,
         kRLE_BitmapInputFormat,
         kBitMask_BitmapInputFormat,
         kUnknown_BitmapInputFormat
     };
 
     /*
      *
+     * Creates the color table
+     *
+     */
+     bool createColorTable(const SkAlphaType alphaType);

[scroggo, 2015/03/17 13:27:22]

nit: We typically do not mark enum parameters as const (only reference/pointer
parameters to objects/structs).

[msarett, 2015/03/17 16:54:06]

Done.

+
+    /*
+     *
      * Performs the bitmap decoding for bit masks input format
      *
      */
     Result decodeMask(const SkImageInfo& dstInfo, void* dst,
                       size_t dstRowBytes);
 
     /*
      *
      * Set an RLE pixel using the color table
      *
      */
-    void setRLEPixel(SkPMColor* dst, size_t dstRowBytes, int height,
-                     uint32_t x, uint32_t y, uint8_t index);
+    void setRLEPixel(SkPMColor* dst, size_t dstRowBytes,
+                     const SkImageInfo& dstInfo, uint32_t x, uint32_t y,
+                     uint8_t index);
+    /*
+     *
+     * Set an RLE24 pixel from R, G, B values
+     *
+     */
+    void setRLE24Pixel(SkPMColor* dst, size_t dstRowBytes,
+                       const SkImageInfo& dstInfo, uint32_t x, uint32_t y,
+                       uint8_t red, uint8_t green, uint8_t blue);
 
     /*
      *
      * Performs the bitmap decoding for RLE input format
      *
      */
     Result decodeRLE(const SkImageInfo& dstInfo, void* dst,
                      size_t dstRowBytes);
 
     /*
      *
      * Performs the bitmap decoding for standard input format
      *
      */
     Result decode(const SkImageInfo& dstInfo, void* dst, size_t dstRowBytes);
 
     /*
      *
      * Creates an instance of the decoder
      * Called only by NewFromStream
      *
      * @param srcInfo contains the source width and height
      * @param stream the stream of image data
      * @param bitsPerPixel the number of bits used to store each pixel
      * @param format the format of the bmp file
      * @param masks optional color masks for certain bmp formats, passes
                     ownership to SkBmpCodec
-     * @param colorTable array representing the color table for index-based bmp
-     *                   formats, colors are unpremultiplied, passes ownership
-     *                   to SkBmpCodec
+     * @param numColors the number of colors in the color table
+     * @param bytesPerColor the number of bytes in the stream used to represent
+                            each color in the color table
+     * @param offset the offset of the image pixel data from the end of the
+     *               color table
      * @param rowOrder indicates whether rows are ordered top-down or bottom-up
      * @param remainingBytes used only for RLE decodes, as we must decode all
      *                  of the data at once rather than row by row
      *                  it indicates the amount of data left in the stream
      *                  after decoding the headers
      *
      */
     SkBmpCodec(const SkImageInfo& srcInfo, SkStream* stream,
                uint16_t bitsPerPixel, BitmapInputFormat format,
-               SkMasks* masks, SkPMColor* colorTable,
-               RowOrder rowOrder, uint32_t remainingBytes);
+               SkMasks* masks, uint32_t numColors, uint32_t bytesPerColor,
+               uint32_t offset, RowOrder rowOrder, uint32_t remainingBytes);
 
     // Fields
     const uint16_t                      fBitsPerPixel;
     const BitmapInputFormat             fInputFormat;
     SkAutoTDelete<SkMasks>              fMasks;          // owned
-    const SkAutoTDeleteArray<SkPMColor> fColorTable;     // owned, unpremul
+    SkAutoTDeleteArray<SkPMColor>       fColorTable;     // owned, unpremul

[scroggo, 2015/03/17 13:27:22]

This is no longer necessarily unpremul.

[msarett, 2015/03/17 16:54:06]

Sorry, I missed that.

+    const uint32_t                      fNumColors;

[scroggo, 2015/03/17 13:27:22]

FWIW, you could use an SkColorTable which holds both the colors and a count. (It
only goes up to 256, but I imagine you don't have more than that?)

[msarett, 2015/03/17 16:54:06]

Unfortuntately, using SkColorTable does not allow me to get rid of this field. 
The only public constructor takes a const pointer, so I would not be able to
initialize the SkColorTable until I finish constructing the color table.

But I think it does make sense to use SkColorTable given that I have a color
table, so I will.

+    const uint32_t                      fBytesPerColor;
+    const uint32_t                      fOffset;
     const RowOrder                      fRowOrder;
     const uint32_t                      fRemainingBytes;

[scroggo, 2015/03/17 13:27:22]

It seems like the meaning of fRemainingBytes has changed. Maybe it should be
something like fRLEBytes?

[msarett, 2015/03/17 16:54:06]

Done.

 
     typedef SkCodec INHERITED;
 };