Make SkSwizzler::Fill() support 565

src/codec/SkJpegCodec.cpp

 /*
  * 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 "SkJpegCodec.h"
 #include "SkJpegDecoderMgr.h"
@@ skipping 336 matching lines @@
         // Read rows of the image
         uint32_t rowsDecoded = turbo_jpeg_read_scanlines(dinfo, &dstRow, 1);
 
         // If we cannot read enough rows, assume the input is incomplete
         if (rowsDecoded != 1) {
             // Fill the remainder of the image with black. This error handling
             // behavior is unspecified but SkCodec consistently uses black as
             // the fill color for opaque images.  If the destination is kGray,
             // the low 8 bits of SK_ColorBLACK will be used.  Conveniently,
             // these are zeros, which is the representation for black in kGray.
+            // If the destination is kRGB_565, the low 16 bits of SK_ColorBLACK
+            // will be used.  Conveniently, these are zeros, which is the

[scroggo, 2015/07/29 17:15:14]

nit: if kYes_ZeroInitialized, we could skip this.

[msarett, 2015/07/29 17:29:39]

Done.

+            // representation for black in kRGB_565.
             SkSwizzler::Fill(dstRow, dstInfo, dstRowBytes, dstHeight - y, SK_ColorBLACK, NULL);
 
             // Prevent libjpeg from failing on incomplete decode
             dinfo->output_scanline = dstHeight;
 
             // Finish the decode and indicate that the input was incomplete.
             turbo_jpeg_finish_decompress(dinfo);
             return fDecoderMgr->returnFailure("Incomplete image data", kIncompleteInput);
         }
 
@@ skipping 127 matching lines @@
 
     // Now, given valid output dimensions, we can start the decompress
     if (!turbo_jpeg_start_decompress(codec->fDecoderMgr->dinfo())) {
         SkCodecPrintf("start decompress failed\n");
         return NULL;
     }
 
     // Return the new scanline decoder
     return SkNEW_ARGS(SkJpegScanlineDecoder, (dstInfo, codec.detach()));
 }