1 files changed, 151 insertions, 0 deletions
diff --git a/gfx/skia/skia/src/codec/SkBmpCodec.h b/gfx/skia/skia/src/codec/SkBmpCodec.h
new file mode 100644
index 0000000000..97a15b6d23
--- /dev/null
+++ b/gfx/skia/skia/src/codec/SkBmpCodec.h
@@ -0,0 +1,151 @@
+/*
+ * Copyright 2015 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+#ifndef SkBmpCodec_DEFINED
+#define SkBmpCodec_DEFINED
+
+#include "include/codec/SkCodec.h"
+#include "include/core/SkColorSpace.h"
+#include "include/core/SkImageInfo.h"
+#include "include/core/SkStream.h"
+#include "include/core/SkTypes.h"
+#include "src/codec/SkColorTable.h"
+#include "src/codec/SkSwizzler.h"
+
+/*
+ * This class enables code sharing between its bmp codec subclasses.  The
+ * subclasses actually do the work.
+ */
+class SkBmpCodec : public SkCodec {
+public:
+    static bool IsBmp(const void*, size_t);
+
+    /*
+     * Assumes IsBmp was called and returned true
+     * Creates a bmp decoder
+     * Reads enough of the stream to determine the image format
+     */
+    static std::unique_ptr<SkCodec> MakeFromStream(std::unique_ptr<SkStream>, Result*);
+
+    /*
+     * Creates a bmp decoder for a bmp embedded in ico
+     * Reads enough of the stream to determine the image format
+     */
+    static std::unique_ptr<SkCodec> MakeFromIco(std::unique_ptr<SkStream>, Result*);
+
+protected:
+
+    SkBmpCodec(SkEncodedInfo&& info, std::unique_ptr<SkStream>,
+            uint16_t bitsPerPixel, SkCodec::SkScanlineOrder rowOrder);
+
+    SkEncodedImageFormat onGetEncodedFormat() const override { return SkEncodedImageFormat::kBMP; }
+
+    /*
+     * Read enough of the stream to initialize the SkBmpCodec.
+     * On kSuccess, if codecOut is not nullptr, it will be set to a new SkBmpCodec.
+     */
+    static Result ReadHeader(SkStream*, bool inIco, std::unique_ptr<SkCodec>* codecOut);
+
+    bool onRewind() override;
+
+    /*
+     * Returns whether this BMP is part of an ICO image.
+     */
+    bool inIco() const {
+        return this->onInIco();
+    }
+
+    virtual bool onInIco() const {
+        return false;
+    }
+
+    /*
+     * Get the destination row number corresponding to the encoded row number.
+     * For kTopDown, we simply return y, but for kBottomUp, the rows will be
+     * decoded in reverse order.
+     *
+     * @param y      Iterates from 0 to height, indicating the current row.
+     * @param height The height of the current subset of the image that we are
+     *               decoding.  This is generally equal to the full height
+     *               when we want to decode the full or one when we are
+     *               sampling.
+     */
+    int32_t getDstRow(int32_t y, int32_t height) const;
+
+    /*
+     * Accessors used by subclasses
+     */
+    uint16_t bitsPerPixel() const { return fBitsPerPixel; }
+    SkScanlineOrder onGetScanlineOrder() const override { return fRowOrder; }
+    size_t srcRowBytes() const { return fSrcRowBytes; }
+
+    /*
+     * To be overriden by bmp subclasses, which provide unique implementations.
+     * Performs subclass specific setup.
+     *
+     * @param dstInfo         Contains output information.  Height specifies
+     *                        the total number of rows that will be decoded.
+     * @param options         Additonal options to pass to the decoder.
+     */
+    virtual SkCodec::Result onPrepareToDecode(const SkImageInfo& dstInfo,
+            const SkCodec::Options& options) = 0;
+    SkCodec::Result prepareToDecode(const SkImageInfo& dstInfo,
+            const SkCodec::Options& options);
+
+    uint32_t* xformBuffer() const { return fXformBuffer.get(); }
+    void resetXformBuffer(int count) { fXformBuffer.reset(new uint32_t[count]); }
+
+    /*
+     * BMPs are typically encoded as BGRA/BGR so this is a more efficient choice
+     * than RGBA.
+     */
+    static constexpr SkColorType kXformSrcColorType = kBGRA_8888_SkColorType;
+    static constexpr auto kXformSrcColorFormat = skcms_PixelFormat_BGRA_8888;
+
+private:
+
+    /*
+     * Creates a bmp decoder
+     * Reads enough of the stream to determine the image format
+     */
+    static std::unique_ptr<SkCodec> MakeFromStream(std::unique_ptr<SkStream>, Result*, bool inIco);
+
+    /*
+     * Decodes the next dstInfo.height() lines.
+     *
+     * onGetPixels() uses this for full image decodes.
+     * SkScaledCodec::onGetPixels() uses the scanline decoder to call this with
+     * dstInfo.height() = 1, in order to implement sampling.
+     * A potential future use is to allow the caller to decode a subset of the
+     * lines in the image.
+     *
+     * @param dstInfo     Contains output information.  Height specifies the
+     *                    number of rows to decode at this time.
+     * @param dst         Memory location to store output pixels
+     * @param dstRowBytes Bytes in a row of the destination
+     * @return            Number of rows successfully decoded
+     */
+    virtual int decodeRows(const SkImageInfo& dstInfo, void* dst, size_t dstRowBytes,
+            const Options& opts) = 0;
+
+    virtual bool skipRows(int count);
+
+    Result onStartScanlineDecode(const SkImageInfo& dstInfo,
+            const SkCodec::Options&) override;
+
+    int onGetScanlines(void* dst, int count, size_t rowBytes) override;
+
+    bool onSkipScanlines(int count) override;
+
+    const uint16_t              fBitsPerPixel;
+    const SkScanlineOrder       fRowOrder;
+    const size_t                fSrcRowBytes;
+    std::unique_ptr<uint32_t[]> fXformBuffer;
+
+    typedef SkCodec INHERITED;
+};
+
+#endif