Add subsetting to SkScaledCodec

src/codec/SkBmpRLECodec.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 "SkBmpRLECodec.h"
 #include "SkCodecPriv.h"
 #include "SkColorPriv.h"
@@ skipping 182 matching lines @@
     fRLEBytes = remainingBytes + additionalBytes;
     return fRLEBytes;
 }
 
 /*
  * Set an RLE pixel using the color table
  */
 void SkBmpRLECodec::setPixel(void* dst, size_t dstRowBytes,
                              const SkImageInfo& dstInfo, uint32_t x, uint32_t y,
                              uint8_t index) {
-    if (is_coord_necessary(x, fSampleX, dstInfo.width())) {
+    if (is_coord_necessary(x, fSampleX, this->subsetWidth(), this->subsetLeft())) {
         // Set the row
         uint32_t row = this->getDstRow(y, dstInfo.height());
 
         // Set the pixel based on destination color type
         const int dstX = get_dst_coord(x, fSampleX);
         switch (dstInfo.colorType()) {
             case kN32_SkColorType: {
                 SkPMColor* dstRow = SkTAddOffset<SkPMColor>(dst, row * (int) dstRowBytes);
                 dstRow[dstX] = fColorTable->operator[](index);
                 break;
@@ skipping 12 matching lines @@
     }
 }
 
 /*
  * Set an RLE pixel from R, G, B values
  */
 void SkBmpRLECodec::setRGBPixel(void* dst, size_t dstRowBytes,
                                 const SkImageInfo& dstInfo, uint32_t x,
                                 uint32_t y, uint8_t red, uint8_t green,
                                 uint8_t blue) {
-    if (is_coord_necessary(x, fSampleX, dstInfo.width())) {
+    if (is_coord_necessary(x, fSampleX, this->subsetWidth(), this->subsetLeft())) {
         // Set the row
         uint32_t row = this->getDstRow(y, dstInfo.height());
 
         // Set the pixel based on destination color type
         const int dstX = get_dst_coord(x, fSampleX);
         switch (dstInfo.colorType()) {
             case kN32_SkColorType: {
                 SkPMColor* dstRow = SkTAddOffset<SkPMColor>(dst, row * (int) dstRowBytes);
                 dstRow[dstX] = SkPackARGB32NoCheck(0xFF, red, green, blue);
                 break;
@@ skipping 23 matching lines @@
 
     // Copy the color table to the client if necessary
     copy_color_table(dstInfo, this->fColorTable, inputColorPtr, inputColorCount);
 
     // Initialize a buffer for encoded RLE data
     if (!this->initializeStreamBuffer()) {
         SkCodecPrintf("Error: cannot initialize stream buffer.\n");
         return SkCodec::kInvalidConversion;
     }
 
-    SkScaledCodec::ComputeSampleSize(dstInfo, this->getInfo(), &fSampleX, NULL);
+    SkScaledCodec::ComputeSampleSize(dstInfo.dimensions(), this->getInfo().dimensions(), &fSampleX,
+            nullptr);
 
     return SkCodec::kSuccess;
 }
 
 /*
  * Performs the bitmap decoding for RLE input format
  * RLE decoding is performed all at once, rather than a one row at a time
  */
 int SkBmpRLECodec::decodeRows(const SkImageInfo& dstInfo, void* dst, size_t dstRowBytes,
         const Options& opts) {
     // Set RLE flags
     static const uint8_t RLE_ESCAPE = 0;
     static const uint8_t RLE_EOL = 0;
     static const uint8_t RLE_EOF = 1;
     static const uint8_t RLE_DELTA = 2;
 
     // Set constant values
     const int width = this->getInfo().width();
     const int height = dstInfo.height();
 
     // Destination parameters
     int x = 0;
     int y = 0;
 
     // Set the background as transparent.  Then, if the RLE code skips pixels,
     // the skipped pixels will be transparent.
     // Because of the need for transparent pixels, kN32 is the only color
     // type that makes sense for the destination format.
     SkASSERT(kN32_SkColorType == dstInfo.colorType());
-    SkSwizzler::Fill(dst, dstInfo, dstRowBytes, SK_ColorTRANSPARENT, opts.fZeroInitialized);
+    SkSwizzler::Fill(dst, dstInfo.makeWH(this->subsetWidth(), height), dstRowBytes,
+            SK_ColorTRANSPARENT, opts.fZeroInitialized);
 
     while (true) {
         // If we have reached a row that is beyond the requested height, we have
         // succeeded.
         if (y >= height) {
             // It would be better to check for the EOF marker before indicating
             // success, but we may be performing a scanline decode, which
             // would require us to stop before decoding the full height.
             return height;
         }
@@ skipping 144 matching lines @@
 
                 // Set the indicated number of pixels
                 for (int which = 0; x < endX; x++) {
                     setPixel(dst, dstRowBytes, dstInfo, x, y, indices[which]);
                     which = !which;
                 }
             }
         }
     }
 }