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 27cea4ead0e816a9d5f77e3abba484e0c633050f..f2e4af2ac4e3394d04c9451d7c3054f09279fbc9 100644
--- a/src/codec/SkBmpStandardCodec.cpp
+++ b/src/codec/SkBmpStandardCodec.cpp
@@ -170,7 +170,8 @@ SkCodec::Result SkBmpStandardCodec::onGetPixels(const SkImageInfo& dstInfo,
 bool SkBmpStandardCodec::initializeSwizzler(const SkImageInfo& dstInfo,
                                             const Options& opts) {
     // Allocate space for a row buffer
-    const size_t rowBytes = SkAlign4(compute_row_bytes(dstInfo.width(), this->bitsPerPixel()));
+    const size_t rowBytes = SkAlign4(compute_row_bytes(this->getInfo().width(),
+            this->bitsPerPixel()));
     fSrcBuffer.reset(SkNEW_ARRAY(uint8_t, rowBytes));
 
     // Get swizzler configuration
@@ -251,10 +252,10 @@ 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 width = this->getInfo().width();
     const int height = dstInfo.height();
     const size_t rowBytes = SkAlign4(compute_row_bytes(width, this->bitsPerPixel()));
 
@@ -335,3 +336,23 @@ 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;
+}