Scanline decoding for bmp

src/codec/SkBmpRLECodec.cpp

Index: src/codec/SkBmpRLECodec.cpp
diff --git a/src/codec/SkBmpRLECodec.cpp b/src/codec/SkBmpRLECodec.cpp
index c71a5409d2c2c2ee5d2fa11261594c809f4c66d1..3ccecd243188b55f93ef78c579783db4e06e7504 100644
--- a/src/codec/SkBmpRLECodec.cpp
+++ b/src/codec/SkBmpRLECodec.cpp
@@ -45,10 +45,11 @@ static bool conversion_possible(const SkImageInfo& dst,
  * Called only by NewFromStream
  */
 SkBmpRLECodec::SkBmpRLECodec(const SkImageInfo& info, SkStream* stream,
+                             SkBmpCodec::BmpInputFormat inputFormat,
                              uint16_t bitsPerPixel, uint32_t numColors,
                              uint32_t bytesPerColor, uint32_t offset,
                              SkBmpCodec::RowOrder rowOrder, size_t RLEBytes)
-    : INHERITED(info, stream, bitsPerPixel, rowOrder)
+    : INHERITED(info, stream, inputFormat, bitsPerPixel, rowOrder)
     , fColorTable(NULL)
     , fNumColors(this->computeNumColors(numColors))
     , fBytesPerColor(bytesPerColor)
@@ -475,3 +476,57 @@ SkCodec::Result SkBmpRLECodec::decode(const SkImageInfo& dstInfo,
         }
     }
 }
+
+SkBmpRLEScanlineDecoder::SkBmpRLEScanlineDecoder(SkBmpRLECodec* codec)
+    : INHERITED(codec->getInfo())
+    , fCodec(codec)
+{}
+
+SkCodec::Result SkBmpRLEScanlineDecoder::onStart(const SkImageInfo& dstInfo,
+        const SkCodec::Options& options, SkPMColor inputColorPtr[], int* inputColorCount) {
+    if (!fCodec->rewindIfNeeded()) {
+        return SkCodec::kCouldNotRewind;
+    }
+    if (options.fSubset) {
+        // Subsets are not supported.
+        return SkCodec::kUnimplemented;
+    }
+    if (dstInfo.dimensions() != fCodec->getInfo().dimensions()) {
+        SkCodecPrintf("Error: scaling not supported.\n");
+        return SkCodec::kInvalidScale;
+    }
+    if (!conversion_possible(dstInfo, fCodec->getInfo())) {
+        SkCodecPrintf("Error: cannot convert input type to output type.\n");
+        return SkCodec::kInvalidConversion;
+    }
+
+    // Create the color table if necessary and prepare the stream for decode
+    // Note that if it is non-NULL, inputColorCount will be modified
+    if (!fCodec->createColorTable(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, fCodec->fColorTable, inputColorPtr, inputColorCount);
+
+    // Initialize a swizzler if necessary
+    if (!fCodec->initializeStreamBuffer()) {
+        SkCodecPrintf("Error: cannot initialize swizzler.\n");
+        return SkCodec::kInvalidConversion;
+    }
+
+    fDstInfo = dstInfo;
+    fOpts = options;
+
+    return SkCodec::kSuccess;
+}
+
+SkCodec::Result SkBmpRLEScanlineDecoder::onGetScanlines(void* dst,
+        int count, size_t rowBytes) {
+    // Create a new image info representing the portion of the image to decode
+    SkImageInfo rowInfo = fDstInfo.makeWH(dstInfo().width(), count);
+
+    // Decode the requested rows
+    SkCodec::Result r = fCodec->decode(rowInfo, dst, rowBytes, fOpts);
+}