Rename SkCodec_libbmp to SkBmpCodec

BUG=skia:

Review URL: https://codereview.chromium.org/1254963006

1 files changed, 193 insertions, 0 deletions

diff --git a/src/codec/SkBmpCodec.h b/src/codec/SkBmpCodec.h
new file mode 100644
index 0000000000..9909945c51
--- /dev/null
+++ b/src/codec/SkBmpCodec.h
@@ -0,0 +1,193 @@
+/*
+ * 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 "SkCodec.h"
+#include "SkColorTable.h"
+#include "SkImageInfo.h"
+#include "SkMaskSwizzler.h"
+#include "SkStream.h"
+#include "SkSwizzler.h"
+#include "SkTypes.h"
+
+// TODO: rename SkCodec_libbmp files to SkBmpCodec
+/*
+ *
+ * This class implements the decoding for bmp images
+ *
+ */
+class SkBmpCodec : public SkCodec {
+public:
+
+    /*
+     *
+     * Describes if rows of the input start at the top or bottom of the image
+     *
+     */
+    enum RowOrder {
+        kTopDown_RowOrder,
+        kBottomUp_RowOrder
+    };
+
+    /*
+     *
+     * Checks the start of the stream to see if the image is a bmp
+     *
+     */
+    static bool IsBmp(SkStream*);
+
+    /*
+     *
+     * Assumes IsBmp was called and returned true
+     * Creates a bmp decoder
+     * Reads enough of the stream to determine the image format
+     *
+     */
+    static SkCodec* NewFromStream(SkStream*);
+
+    /*
+     *
+     * Creates a bmp decoder for a bmp embedded in ico
+     * Reads enough of the stream to determine the image format
+     *
+     */
+    static SkCodec* NewFromIco(SkStream*);
+
+protected:
+
+    /*
+     *
+     * Initiates the bmp decode
+     *
+     */
+    Result onGetPixels(const SkImageInfo& dstInfo, void* dst,
+                       size_t dstRowBytes, const Options&, SkPMColor*,
+                       int*) override;
+
+    SkEncodedFormat onGetEncodedFormat() const override { return kBMP_SkEncodedFormat; }
+
+private:
+
+    /*
+     *
+     * Used to define the input format of the bmp
+     *
+     */
+    enum BitmapInputFormat {
+        kStandard_BitmapInputFormat,
+        kRLE_BitmapInputFormat,
+        kBitMask_BitmapInputFormat,
+        kUnknown_BitmapInputFormat
+    };
+
+    /*
+     *
+     * Creates the color table
+     * Sets colorCount to the new color count if it is non-NULL
+     */
+     bool createColorTable(SkAlphaType alphaType, int* colorCount);
+
+    /*
+     *
+     * Creates a bmp decoder
+     * Reads enough of the stream to determine the image format
+     *
+     */
+    static SkCodec* NewFromStream(SkStream*, bool isIco);
+
+    /*
+     *
+     * Read enough of the stream to initialize the SkBmpCodec. Returns a bool
+     * representing success or failure. If it returned true, and codecOut was
+     * not NULL, it will be set to a new SkBmpCodec.
+     * Does *not* take ownership of the passed in SkStream.
+     *
+     */
+    static bool ReadHeader(SkStream*, bool isIco, SkCodec** codecOut);
+
+    /*
+     *
+     * Performs the bitmap decoding for bit masks input format
+     *
+     */
+    Result decodeMask(const SkImageInfo& dstInfo, void* dst,
+                      size_t dstRowBytes, const Options& opts);
+
+    /*
+     *
+     * Set an RLE pixel using the color table
+     *
+     */
+    void setRLEPixel(void* dst, size_t dstRowBytes,
+                     const SkImageInfo& dstInfo, uint32_t x, uint32_t y,
+                     uint8_t index);
+    /*
+     *
+     * Set an RLE24 pixel from R, G, B values
+     *
+     */
+    void setRLE24Pixel(void* dst, size_t dstRowBytes,
+                       const SkImageInfo& dstInfo, uint32_t x, uint32_t y,
+                       uint8_t red, uint8_t green, uint8_t blue);
+
+    /*
+     *
+     * Performs the bitmap decoding for RLE input format
+     *
+     */
+    Result decodeRLE(const SkImageInfo& dstInfo, void* dst,
+                     size_t dstRowBytes, const Options& opts);
+
+    /*
+     *
+     * Performs the bitmap decoding for standard input format
+     *
+     */
+    Result decode(const SkImageInfo& dstInfo, void* dst, size_t dstRowBytes, const Options& opts);
+
+    /*
+     *
+     * Creates an instance of the decoder
+     * Called only by NewFromStream
+     *
+     * @param srcInfo contains the source width and height
+     * @param stream the stream of image data
+     * @param bitsPerPixel the number of bits used to store each pixel
+     * @param format the format of the bmp file
+     * @param masks optional color masks for certain bmp formats, passes
+                    ownership to SkBmpCodec
+     * @param numColors the number of colors in the color table
+     * @param bytesPerColor the number of bytes in the stream used to represent
+                            each color in the color table
+     * @param offset the offset of the image pixel data from the end of the
+     *               headers
+     * @param rowOrder indicates whether rows are ordered top-down or bottom-up
+     * @param RLEBytes used only for RLE decodes, as we must decode all
+     *                  of the data at once rather than row by row
+     *                  it indicates the amount of data left in the stream
+     *                  after decoding the headers
+     *
+     */
+    SkBmpCodec(const SkImageInfo& srcInfo, SkStream* stream,
+               uint16_t bitsPerPixel, BitmapInputFormat format,
+               SkMasks* masks, uint32_t numColors, uint32_t bytesPerColor,
+               uint32_t offset, RowOrder rowOrder, size_t RLEBytes,
+               bool isIco);
+
+    // Fields
+    const uint16_t                      fBitsPerPixel;
+    const BitmapInputFormat             fInputFormat;
+    SkAutoTDelete<SkMasks>              fMasks;          // owned
+    SkAutoTUnref<SkColorTable>          fColorTable;     // owned
+    uint32_t                            fNumColors;
+    const uint32_t                      fBytesPerColor;
+    const uint32_t                      fOffset;
+    const RowOrder                      fRowOrder;
+    const size_t                        fRLEBytes;
+    const bool                          fIsIco;
+
+    typedef SkCodec INHERITED;
+};