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Unified Diff: third_party/gif/GIFImageReader.h

Issue 2445653004: Rename GIFImageReader to SkGifImageReader (Closed)
Patch Set: Remove dependent patch set Created 4 years, 2 months ago
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Index: third_party/gif/GIFImageReader.h
diff --git a/third_party/gif/GIFImageReader.h b/third_party/gif/GIFImageReader.h
deleted file mode 100644
index 307b8c40921c76fd71221deba94efe58c210897e..0000000000000000000000000000000000000000
--- a/third_party/gif/GIFImageReader.h
+++ /dev/null
@@ -1,398 +0,0 @@
-/* -*- Mode: C; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
-/* ***** BEGIN LICENSE BLOCK *****
- * Version: MPL 1.1/GPL 2.0/LGPL 2.1
- *
- * The contents of this file are subject to the Mozilla Public License Version
- * 1.1 (the "License"); you may not use this file except in compliance with
- * the License. You may obtain a copy of the License at
- * http://www.mozilla.org/MPL/
- *
- * Software distributed under the License is distributed on an "AS IS" basis,
- * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
- * for the specific language governing rights and limitations under the
- * License.
- *
- * The Original Code is Mozilla Communicator client code.
- *
- * The Initial Developer of the Original Code is
- * Netscape Communications Corporation.
- * Portions created by the Initial Developer are Copyright (C) 1998
- * the Initial Developer. All Rights Reserved.
- *
- * Contributor(s):
- *
- * Alternatively, the contents of this file may be used under the terms of
- * either the GNU General Public License Version 2 or later (the "GPL"), or
- * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
- * in which case the provisions of the GPL or the LGPL are applicable instead
- * of those above. If you wish to allow use of your version of this file only
- * under the terms of either the GPL or the LGPL, and not to allow others to
- * use your version of this file under the terms of the MPL, indicate your
- * decision by deleting the provisions above and replace them with the notice
- * and other provisions required by the GPL or the LGPL. If you do not delete
- * the provisions above, a recipient may use your version of this file under
- * the terms of any one of the MPL, the GPL or the LGPL.
- *
- * ***** END LICENSE BLOCK ***** */
-
-#ifndef GIFImageReader_h
-#define GIFImageReader_h
-
-// Define ourselves as the clientPtr. Mozilla just hacked their C++ callback class into this old C decoder,
-// so we will too.
-class SkGifCodec;
-
-#include "SkCodec.h"
-#include "SkCodecPriv.h"
-#include "SkCodecAnimation.h"
-#include "SkColorTable.h"
-#include "SkData.h"
-#include "SkImageInfo.h"
-#include "SkStreamBuffer.h"
-#include "../private/SkTArray.h"
-#include <memory>
-#include <vector>
-
-typedef SkTArray<unsigned char, true> GIFRow;
-
-
-#define MAX_DICTIONARY_ENTRY_BITS 12
-#define MAX_DICTIONARY_ENTRIES 4096 // 2^MAX_DICTIONARY_ENTRY_BITS
-#define MAX_COLORS 256
-#define BYTES_PER_COLORMAP_ENTRY 3
-
-constexpr int cLoopCountNotSeen = -2;
-constexpr size_t kNotFound = static_cast<size_t>(-1);
-
-// List of possible parsing states.
-enum GIFState {
- GIFType,
- GIFGlobalHeader,
- GIFGlobalColormap,
- GIFImageStart,
- GIFImageHeader,
- GIFImageColormap,
- GIFImageBody,
- GIFLZWStart,
- GIFLZW,
- GIFSubBlock,
- GIFExtension,
- GIFControlExtension,
- GIFConsumeBlock,
- GIFSkipBlock,
- GIFDone,
- GIFCommentExtension,
- GIFApplicationExtension,
- GIFNetscapeExtensionBlock,
- GIFConsumeNetscapeExtension,
- GIFConsumeComment
-};
-
-struct GIFFrameContext;
-
-// LZW decoder state machine.
-class GIFLZWContext final : public SkNoncopyable {
-public:
- GIFLZWContext(SkGifCodec* client, const GIFFrameContext* frameContext)
- : codesize(0)
- , codemask(0)
- , clearCode(0)
- , avail(0)
- , oldcode(0)
- , firstchar(0)
- , bits(0)
- , datum(0)
- , ipass(0)
- , irow(0)
- , rowsRemaining(0)
- , rowIter(0)
- , m_client(client)
- , m_frameContext(frameContext)
- { }
-
- bool prepareToDecode();
- bool outputRow(const unsigned char* rowBegin);
- bool doLZW(const unsigned char* block, size_t bytesInBlock);
- bool hasRemainingRows() { return rowsRemaining; }
-
-private:
- // LZW decoding states and output states.
- int codesize;
- int codemask;
- int clearCode; // Codeword used to trigger dictionary reset.
- int avail; // Index of next available slot in dictionary.
- int oldcode;
- unsigned char firstchar;
- int bits; // Number of unread bits in "datum".
- int datum; // 32-bit input buffer.
- int ipass; // Interlace pass; Ranges 1-4 if interlaced.
- size_t irow; // Current output row, starting at zero.
- size_t rowsRemaining; // Rows remaining to be output.
-
- unsigned short prefix[MAX_DICTIONARY_ENTRIES];
- unsigned char suffix[MAX_DICTIONARY_ENTRIES];
- unsigned short suffixLength[MAX_DICTIONARY_ENTRIES];
- GIFRow rowBuffer; // Single scanline temporary buffer.
- unsigned char* rowIter;
-
- SkGifCodec* const m_client;
- const GIFFrameContext* m_frameContext;
-};
-
-class GIFColorMap final {
-public:
- GIFColorMap()
- : m_isDefined(false)
- , m_colors(0)
- , m_packColorProc(nullptr)
- {
- }
-
- void setNumColors(size_t colors) {
- m_colors = colors;
- }
-
- size_t numColors() const { return m_colors; }
-
- void setRawData(const char* data, size_t size)
- {
- // FIXME: Can we avoid this copy?
- m_rawData = SkData::MakeWithCopy(data, size);
- SkASSERT(m_colors * BYTES_PER_COLORMAP_ENTRY == size);
- m_isDefined = true;
- }
- bool isDefined() const { return m_isDefined; }
-
- // Build RGBA table using the data stream.
- sk_sp<SkColorTable> buildTable(SkColorType dstColorType, size_t transparentPixel) const;
-
-private:
- bool m_isDefined;
- size_t m_colors;
- sk_sp<SkData> m_rawData;
- mutable PackColorProc m_packColorProc;
- mutable sk_sp<SkColorTable> m_table;
-};
-
-// LocalFrame output state machine.
-struct GIFFrameContext : SkNoncopyable {
-public:
- GIFFrameContext(int id)
- : m_frameId(id)
- , m_xOffset(0)
- , m_yOffset(0)
- , m_width(0)
- , m_height(0)
- , m_transparentPixel(kNotFound)
- , m_disposalMethod(SkCodecAnimation::Keep_DisposalMethod)
- , m_requiredFrame(SkCodec::kNone)
- , m_dataSize(0)
- , m_progressiveDisplay(false)
- , m_interlaced(false)
- , m_delayTime(0)
- , m_currentLzwBlock(0)
- , m_isComplete(false)
- , m_isHeaderDefined(false)
- , m_isDataSizeDefined(false)
- {
- }
-
- ~GIFFrameContext()
- {
- }
-
- void addLzwBlock(const void* data, size_t size)
- {
- m_lzwBlocks.push_back(SkData::MakeWithCopy(data, size));
- }
-
- bool decode(SkGifCodec* client, bool* frameDecoded);
-
- int frameId() const { return m_frameId; }
- void setRect(unsigned x, unsigned y, unsigned width, unsigned height)
- {
- m_xOffset = x;
- m_yOffset = y;
- m_width = width;
- m_height = height;
- }
- SkIRect frameRect() const { return SkIRect::MakeXYWH(m_xOffset, m_yOffset, m_width, m_height); }
- unsigned xOffset() const { return m_xOffset; }
- unsigned yOffset() const { return m_yOffset; }
- unsigned width() const { return m_width; }
- unsigned height() const { return m_height; }
- size_t transparentPixel() const { return m_transparentPixel; }
- void setTransparentPixel(size_t pixel) { m_transparentPixel = pixel; }
- SkCodecAnimation::DisposalMethod getDisposalMethod() const { return m_disposalMethod; }
- void setDisposalMethod(SkCodecAnimation::DisposalMethod disposalMethod) { m_disposalMethod = disposalMethod; }
- size_t getRequiredFrame() const { return m_requiredFrame; }
- void setRequiredFrame(size_t req) { m_requiredFrame = req; }
- unsigned delayTime() const { return m_delayTime; }
- void setDelayTime(unsigned delay) { m_delayTime = delay; }
- bool isComplete() const { return m_isComplete; }
- void setComplete() { m_isComplete = true; }
- bool isHeaderDefined() const { return m_isHeaderDefined; }
- void setHeaderDefined() { m_isHeaderDefined = true; }
- bool isDataSizeDefined() const { return m_isDataSizeDefined; }
- int dataSize() const { return m_dataSize; }
- void setDataSize(int size)
- {
- m_dataSize = size;
- m_isDataSizeDefined = true;
- }
- bool progressiveDisplay() const { return m_progressiveDisplay; }
- void setProgressiveDisplay(bool progressiveDisplay) { m_progressiveDisplay = progressiveDisplay; }
- bool interlaced() const { return m_interlaced; }
- void setInterlaced(bool interlaced) { m_interlaced = interlaced; }
-
- void clearDecodeState() { m_lzwContext.reset(); }
- const GIFColorMap& localColorMap() const { return m_localColorMap; }
- GIFColorMap& localColorMap() { return m_localColorMap; }
-
-private:
- int m_frameId;
- unsigned m_xOffset;
- unsigned m_yOffset; // With respect to "screen" origin.
- unsigned m_width;
- unsigned m_height;
- size_t m_transparentPixel; // Index of transparent pixel. Value is kNotFound if there is no transparent pixel.
- SkCodecAnimation::DisposalMethod m_disposalMethod; // Restore to background, leave in place, etc.
- size_t m_requiredFrame;
- int m_dataSize;
-
- bool m_progressiveDisplay; // If true, do Haeberli interlace hack.
- bool m_interlaced; // True, if scanlines arrive interlaced order.
-
- unsigned m_delayTime; // Display time, in milliseconds, for this image in a multi-image GIF.
-
- std::unique_ptr<GIFLZWContext> m_lzwContext;
- std::vector<sk_sp<SkData>> m_lzwBlocks; // LZW blocks for this frame.
- GIFColorMap m_localColorMap;
-
- size_t m_currentLzwBlock;
- bool m_isComplete;
- bool m_isHeaderDefined;
- bool m_isDataSizeDefined;
-};
-
-class GIFImageReader final : public SkNoncopyable {
-public:
- // This takes ownership of stream.
- GIFImageReader(SkStream* stream)
- : m_client(nullptr)
- , m_state(GIFType)
- , m_bytesToConsume(6) // Number of bytes for GIF type, either "GIF87a" or "GIF89a".
- , m_version(0)
- , m_screenWidth(0)
- , m_screenHeight(0)
- , m_loopCount(cLoopCountNotSeen)
- , m_streamBuffer(stream)
- , m_parseCompleted(false)
- , m_firstFrameHasAlpha(false)
- , m_firstFrameSupportsIndex8(false)
- {
- }
-
- ~GIFImageReader()
- {
- }
-
- void setClient(SkGifCodec* client) { m_client = client; }
-
- unsigned screenWidth() const { return m_screenWidth; }
- unsigned screenHeight() const { return m_screenHeight; }
-
- // Option to pass to parse(). All enums are negative, because a non-negative value is used to
- // indicate that the Reader should parse up to and including the frame indicated.
- enum GIFParseQuery {
- // Parse enough to determine the size. Note that this parses the first frame's header,
- // since we may decide to expand based on the frame's dimensions.
- GIFSizeQuery = -1,
- // Parse to the end, so we know about all frames.
- GIFFrameCountQuery = -2,
- };
-
- // Parse incoming GIF data stream into internal data structures.
- // Non-negative values are used to indicate to parse through that frame.
- // Return true if parsing has progressed or there is not enough data.
- // Return false if a fatal error is encountered.
- bool parse(GIFParseQuery);
-
- // Decode the frame indicated by frameIndex.
- // frameComplete will be set to true if the frame is completely decoded.
- // The method returns false if there is an error.
- bool decode(size_t frameIndex, bool* frameComplete);
-
- size_t imagesCount() const
- {
- if (m_frames.empty())
- return 0;
-
- // This avoids counting an empty frame when the file is truncated right after
- // GIFControlExtension but before GIFImageHeader.
- // FIXME: This extra complexity is not necessary and we should just report m_frames.size().
- return m_frames.back()->isHeaderDefined() ? m_frames.size() : m_frames.size() - 1;
- }
- int loopCount() const { return m_loopCount; }
-
- const GIFColorMap& globalColorMap() const
- {
- return m_globalColorMap;
- }
-
- const GIFFrameContext* frameContext(size_t index) const
- {
- return index < m_frames.size() ? m_frames[index].get() : 0;
- }
-
- void clearDecodeState() {
- for (size_t index = 0; index < m_frames.size(); index++) {
- m_frames[index]->clearDecodeState();
- }
- }
-
- // Return the color table for frame index (which may be the global color table).
- sk_sp<SkColorTable> getColorTable(SkColorType dstColorType, size_t index) const;
-
- bool firstFrameHasAlpha() const { return m_firstFrameHasAlpha; }
-
- bool firstFrameSupportsIndex8() const { return m_firstFrameSupportsIndex8; }
-
-private:
- // Requires that one byte has been buffered into m_streamBuffer.
- unsigned char getOneByte() const {
- return reinterpret_cast<const unsigned char*>(m_streamBuffer.get())[0];
- }
-
- void addFrameIfNecessary();
- bool currentFrameIsFirstFrame() const
- {
- return m_frames.empty() || (m_frames.size() == 1u && !m_frames[0]->isComplete());
- }
-
- // Unowned pointer
- SkGifCodec* m_client;
-
- // Parsing state machine.
- GIFState m_state; // Current decoder master state.
- size_t m_bytesToConsume; // Number of bytes to consume for next stage of parsing.
-
- // Global (multi-image) state.
- int m_version; // Either 89 for GIF89 or 87 for GIF87.
- unsigned m_screenWidth; // Logical screen width & height.
- unsigned m_screenHeight;
- GIFColorMap m_globalColorMap;
- int m_loopCount; // Netscape specific extension block to control the number of animation loops a GIF renders.
-
- std::vector<std::unique_ptr<GIFFrameContext>> m_frames;
-
- SkStreamBuffer m_streamBuffer;
- bool m_parseCompleted;
-
- // These values can be computed before we create a GIFFrameContext, so we
- // store them here instead of on m_frames[0].
- bool m_firstFrameHasAlpha;
- bool m_firstFrameSupportsIndex8;
-};
-
-#endif

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