Scanline decoding for bmp

src/codec/SkBmpStandardCodec.cpp

Index: src/codec/SkBmpStandardCodec.cpp
diff --git a/src/codec/SkBmpStandardCodec.cpp b/src/codec/SkBmpStandardCodec.cpp
index 08146fc3e48f9a75f528044ade27e7fb497df13b..a4d296b8f560e18715dac67a7244a29acd66e75f 100644
--- a/src/codec/SkBmpStandardCodec.cpp
+++ b/src/codec/SkBmpStandardCodec.cpp
@@ -45,10 +45,11 @@ static bool conversion_possible(const SkImageInfo& dst,
  * Called only by NewFromStream
  */
 SkBmpStandardCodec::SkBmpStandardCodec(const SkImageInfo& info, SkStream* stream,
+                                       SkBmpCodec::BmpInputFormat inputFormat,
                                        uint16_t bitsPerPixel, uint32_t numColors,
                                        uint32_t bytesPerColor, uint32_t offset,
                                        SkBmpCodec::RowOrder rowOrder, bool inIco)
-    : INHERITED(info, stream, bitsPerPixel, rowOrder)
+    : INHERITED(info, stream, inputFormat, bitsPerPixel, rowOrder)
     , fColorTable(NULL)
     , fNumColors(this->computeNumColors(numColors))
     , fBytesPerColor(bytesPerColor)
@@ -280,8 +281,8 @@ static uint32_t get_fill_color_or_index(uint16_t bitsPerPixels, SkAlphaType alph
  * Performs the bitmap decoding for standard input format
  */
 SkCodec::Result SkBmpStandardCodec::decode(const SkImageInfo& dstInfo,
-                                   void* dst, size_t dstRowBytes,
-                                   const Options& opts) {
+                                           void* dst, size_t dstRowBytes,
+                                           const Options& opts) {
     // Set constant values
     const int width = dstInfo.width();
     const int height = dstInfo.height();
@@ -359,3 +360,24 @@ SkCodec::Result SkBmpStandardCodec::decode(const SkImageInfo& dstInfo,
     // Finished decoding the entire image
     return kSuccess;
 }
+
+SkCodec::Result SkBmpStandardCodec::onStart(const SkImageInfo& dstInfo,
+        const SkCodec::Options& options, SkPMColor inputColorPtr[], int* inputColorCount) {
+    // Create the color table if necessary and prepare the stream for decode
+    // Note that if it is non-NULL, inputColorCount will be modified
+    if (!this->createColorTable(dstInfo.alphaType(), inputColorCount)) {
+        SkCodecPrintf("Error: could not create color table.\n");
+        return SkCodec::kInvalidInput;
+    }
+
+    // Copy the color table to the client if necessary
+    copy_color_table(dstInfo, this->fColorTable, inputColorPtr, inputColorCount);
+
+    // Initialize a swizzler if necessary
+    if (!this->initializeSwizzler(dstInfo, options)) {
+        SkCodecPrintf("Error: cannot initialize swizzler.\n");
+        return SkCodec::kInvalidConversion;
+    }
+
+    return SkCodec::kSuccess;
+}