gecko-dev/image/decoders/nsICODecoder.h
Andrew Osmond 09266efcbc Bug 1732115 - Part 3. Refactor decoder pipeline to partially use Unoriented/OrientedPixel. r=tnikkel
Rather than change every use of IntSize/Rect/Point in image/, this patch
attempts to draw the line at the relevant parts of the decoding pipeline
to prevent confusion about which size and orientation we are working
with.

Differential Revision: https://phabricator.services.mozilla.com/D126381
2021-10-06 14:41:17 +00:00

107 lines
3.7 KiB
C++

/* vim:set tw=80 expandtab softtabstop=4 ts=4 sw=2: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#ifndef mozilla_image_decoders_nsICODecoder_h
#define mozilla_image_decoders_nsICODecoder_h
#include "StreamingLexer.h"
#include "Decoder.h"
#include "Downscaler.h"
#include "imgFrame.h"
#include "mozilla/gfx/2D.h"
#include "nsBMPDecoder.h"
#include "nsPNGDecoder.h"
#include "ICOFileHeaders.h"
namespace mozilla {
namespace image {
class RasterImage;
enum class ICOState {
HEADER,
DIR_ENTRY,
FINISHED_DIR_ENTRY,
ITERATE_UNSIZED_DIR_ENTRY,
SKIP_TO_RESOURCE,
FOUND_RESOURCE,
SNIFF_RESOURCE,
READ_RESOURCE,
PREPARE_FOR_MASK,
READ_MASK_ROW,
FINISH_MASK,
SKIP_MASK,
FINISHED_RESOURCE
};
class nsICODecoder : public Decoder {
public:
virtual ~nsICODecoder() {}
/// @return The offset from the beginning of the ICO to the first resource.
size_t FirstResourceOffset() const;
DecoderType GetType() const override { return DecoderType::ICO; }
LexerResult DoDecode(SourceBufferIterator& aIterator,
IResumable* aOnResume) override;
nsresult FinishInternal() override;
nsresult FinishWithErrorInternal() override;
private:
friend class DecoderFactory;
// Decoders should only be instantiated via DecoderFactory.
explicit nsICODecoder(RasterImage* aImage);
// Flushes the contained decoder to read all available data and sets the
// appropriate errors. Returns true if there are no errors.
bool FlushContainedDecoder();
// Gets decoder state from the contained decoder so it's visible externally.
nsresult GetFinalStateFromContainedDecoder();
// Obtains the number of colors from the BPP, mBPP must be filled in
uint16_t GetNumColors();
LexerTransition<ICOState> ReadHeader(const char* aData);
LexerTransition<ICOState> ReadDirEntry(const char* aData);
LexerTransition<ICOState> IterateUnsizedDirEntry();
LexerTransition<ICOState> FinishDirEntry();
LexerTransition<ICOState> SniffResource(const char* aData);
LexerTransition<ICOState> ReadResource();
LexerTransition<ICOState> ReadBIH(const char* aData);
LexerTransition<ICOState> PrepareForMask();
LexerTransition<ICOState> ReadMaskRow(const char* aData);
LexerTransition<ICOState> FinishMask();
LexerTransition<ICOState> FinishResource();
struct IconDirEntryEx : public IconDirEntry {
OrientedIntSize mSize;
};
StreamingLexer<ICOState, 32> mLexer; // The lexer.
Maybe<Downscaler> mDownscaler; // The downscaler used for the mask.
RefPtr<Decoder> mContainedDecoder; // Either a BMP or PNG decoder.
Maybe<SourceBufferIterator>
mReturnIterator; // Iterator to save return point.
UniquePtr<uint8_t[]> mMaskBuffer; // A temporary buffer for the alpha mask.
nsTArray<IconDirEntryEx> mDirEntries; // Valid dir entries with a size.
nsTArray<IconDirEntryEx> mUnsizedDirEntries; // Dir entries without a size.
IconDirEntryEx* mDirEntry; // The dir entry for the selected resource.
uint16_t mNumIcons; // Stores the number of icons in the ICO file.
uint16_t mCurrIcon; // Stores the current dir entry index we are processing.
uint16_t mBPP; // The BPP of the resource we're decoding.
uint32_t
mMaskRowSize; // The size in bytes of each row in the BMP alpha mask.
uint32_t mCurrMaskLine; // The line of the BMP alpha mask we're processing.
bool mIsCursor; // Is this ICO a cursor?
bool mHasMaskAlpha; // Did the BMP alpha mask have any transparency?
};
} // namespace image
} // namespace mozilla
#endif // mozilla_image_decoders_nsICODecoder_h