gecko-dev/image/decoders/nsBMPDecoder.h

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C
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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
2012-05-21 15:12:37 +04:00
/* 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_nsBMPDecoder_h
#define mozilla_image_decoders_nsBMPDecoder_h
#include "BMPHeaders.h"
#include "Decoder.h"
#include "gfxColor.h"
Bug 1204394 (part 1) - Using StreamingLexer in the BMP decoder. r=seth. This patch is a major overhaul of nsBMPDecoder. The patch improves the code in the following ways. - It converts nsBMPDecoder to use StreamingLexer, which makes it much easier to read. - It adds a detailed comment about the BMP format at the top of nsBMPDecoder.cpp. - It fixes lots of inconsistent indenting. - It moves |bihsize| from |mBFH| to |mBIH| to match the file format and common sense. The avoids the need for the confusing LENGTH/INTERNAL_LENGTH distinction. - It renames most of the types in BMPFileHeader.h, so they have better names, in StudlyCaps form, and within the new |bmp| namespace. - It removes the BMP_HEADER_LENGTH struct and inlines its values directly into the two places they were used. - It removes the MOZ_LOG logging done on some of the failure cases. (Most failure cases lacked logging so why bother with some?) - It removes over 200 lines of code, despite the addition of the big format comment. The patch changes the way BMPs are decoded as follows. - It adds stricter testing of the InfoHeader length, rejecting files with bad values. - It moves all header sanity checking that can lead to file rejection into the metadata decode phase. (Previously, bpp/compression consistency checking did not occur during a metadata decode.) - It removes BMPINFOHEADER::ALPHABITFIELDS, which was (a) a weird WinCE-only thing, and (b) we didn't actually allow it, and (c) we used the value 4 instead of 6(!). - It rejects the previously-accepted compression==RLE4 && bpp=1 combination because it doesn't make sense. - It removes a fudge in RLE absolute mode handling that permitted one pixel too many in a row but only if the row's width was odd(!) - It now rejects a file with a negative gap between the color table and the pixel data. The patch leaves the following problems unaddressed. - If bpp==32 we totally ignore compression==BITFIELDS and treat it like compression=RGB. - Transparency as specified in WinBMPv{4,5} isn't handled at all. These will be fixed in follow-ups. All these changes affect (for the better) the results of the following tests that will be added in part 2: - g/pal8v4.bmp - g/pal8v5.bmp - q/pal8os2sp.bmp - q/pal8os2v2.bmp - q/pal8os2v2-16.bmp - b/badheadersize.bmp - b/badpalettesize.bmp - b/badrle.bmp --HG-- extra : rebase_source : 8ddc2f5fccce6998348097ff9f0a1072d273cdf4
2015-10-09 08:47:56 +03:00
#include "StreamingLexer.h"
#include "mozilla/UniquePtr.h"
namespace mozilla {
namespace image {
namespace bmp {
/// This struct contains the fields from the file header and info header that
/// we use during decoding. (Excluding bitfields fields, which are kept in
/// BitFields.)
struct Header {
uint32_t mDataOffset; // Offset to raster data.
uint32_t mBIHSize; // Header size.
int32_t mWidth; // Image width.
int32_t mHeight; // Image height.
uint16_t mBpp; // Bits per pixel.
uint32_t mCompression; // See struct Compression for valid values.
uint32_t mImageSize; // (compressed) image size. Can be 0 if
// mCompression==0.
uint32_t mNumColors; // Used colors.
Header()
: mDataOffset(0)
, mBIHSize(0)
, mWidth(0)
, mHeight(0)
, mBpp(0)
, mCompression(0)
, mImageSize(0)
, mNumColors(0)
{}
};
/// An entry in the color table.
struct ColorTableEntry {
uint8_t mRed;
uint8_t mGreen;
uint8_t mBlue;
};
/// All the color-related bitfields for 16bpp and 32bpp images. We use this
/// even for older format BMPs that don't have explicit bitfields.
class BitFields {
class Value {
friend class BitFields;
uint32_t mMask; // The mask for the value.
uint8_t mRightShift; // The amount to right-shift after masking.
uint8_t mBitWidth; // The width (in bits) of the value.
/// Sets the mask (and thus the right-shift and bit-width as well).
void Set(uint32_t aMask);
public:
Bug 1214072 (part 2) - Implement transparency properly for BMP images. r=seth. Currently we don't implement transparency at all in BMP images except for an odd-duck case of BMPs within ICOs. This patch does the following. - It implements transparency properly for 16bpp and 32bpp images via bitfield masking. (For 32bpp images this also requires handling colors via bitfield masking.) The patch maintains the existing BMP-within-ICO transparency handling. - It also reworks BitFields::Value::Set(). * It now works correctly if the run of 1s goes all the way to bit 31 (the old code didn't set mBitWidth). * If the mask is 0, will give an mRightShift of 0 (old code gave 32, and right-shifting by 32 is dodgy). * It's now easier to read. - It renames transparent.bmp as transparent-if-within-ico.bmp. Ironically enough this file currently uses BITFIELDS compression and is WinBMPv5 format, which means it contains well-specified alpha data. In order to use it to test the hacky BMP-within-ICO transparency scheme the patch changes it to be WinBMPv3 format with RGB compression (i.e. no compression). I left the now-excess bytes (including the bitfields) in the info header in place because that's allowed -- thanks to the start of the pixel data being specified by the |dataoffset| field -- they'll just be ignored. - It tweaks the naming of the relevant gtests and some of their finer details to work with the new way of doing things. This fixes all four remaining failures in bmpsuite. --HG-- rename : image/test/gtest/transparent.bmp => image/test/gtest/transparent-if-within-ico.bmp extra : rebase_source : 2f4838d04bbae4fac00cc69e8d75469105a5de3b
2015-10-14 07:20:10 +03:00
Value()
{
mMask = 0;
mRightShift = 0;
mBitWidth = 0;
}
/// Returns true if this channel is used. Only used for alpha.
bool IsPresent() const { return mMask != 0x0; }
/// Extracts the single color value from the multi-color value.
uint8_t Get(uint32_t aVal) const;
Bug 1214072 (part 2) - Implement transparency properly for BMP images. r=seth. Currently we don't implement transparency at all in BMP images except for an odd-duck case of BMPs within ICOs. This patch does the following. - It implements transparency properly for 16bpp and 32bpp images via bitfield masking. (For 32bpp images this also requires handling colors via bitfield masking.) The patch maintains the existing BMP-within-ICO transparency handling. - It also reworks BitFields::Value::Set(). * It now works correctly if the run of 1s goes all the way to bit 31 (the old code didn't set mBitWidth). * If the mask is 0, will give an mRightShift of 0 (old code gave 32, and right-shifting by 32 is dodgy). * It's now easier to read. - It renames transparent.bmp as transparent-if-within-ico.bmp. Ironically enough this file currently uses BITFIELDS compression and is WinBMPv5 format, which means it contains well-specified alpha data. In order to use it to test the hacky BMP-within-ICO transparency scheme the patch changes it to be WinBMPv3 format with RGB compression (i.e. no compression). I left the now-excess bytes (including the bitfields) in the info header in place because that's allowed -- thanks to the start of the pixel data being specified by the |dataoffset| field -- they'll just be ignored. - It tweaks the naming of the relevant gtests and some of their finer details to work with the new way of doing things. This fixes all four remaining failures in bmpsuite. --HG-- rename : image/test/gtest/transparent.bmp => image/test/gtest/transparent-if-within-ico.bmp extra : rebase_source : 2f4838d04bbae4fac00cc69e8d75469105a5de3b
2015-10-14 07:20:10 +03:00
/// Like Get(), but specially for alpha.
uint8_t GetAlpha(uint32_t aVal, bool& aHasAlphaOut) const;
/// Specialized versions of Get() for when the bit-width is 5 or 8.
/// (They will assert if called and the bit-width is not 5 or 8.)
uint8_t Get5(uint32_t aVal) const;
Bug 1214072 (part 2) - Implement transparency properly for BMP images. r=seth. Currently we don't implement transparency at all in BMP images except for an odd-duck case of BMPs within ICOs. This patch does the following. - It implements transparency properly for 16bpp and 32bpp images via bitfield masking. (For 32bpp images this also requires handling colors via bitfield masking.) The patch maintains the existing BMP-within-ICO transparency handling. - It also reworks BitFields::Value::Set(). * It now works correctly if the run of 1s goes all the way to bit 31 (the old code didn't set mBitWidth). * If the mask is 0, will give an mRightShift of 0 (old code gave 32, and right-shifting by 32 is dodgy). * It's now easier to read. - It renames transparent.bmp as transparent-if-within-ico.bmp. Ironically enough this file currently uses BITFIELDS compression and is WinBMPv5 format, which means it contains well-specified alpha data. In order to use it to test the hacky BMP-within-ICO transparency scheme the patch changes it to be WinBMPv3 format with RGB compression (i.e. no compression). I left the now-excess bytes (including the bitfields) in the info header in place because that's allowed -- thanks to the start of the pixel data being specified by the |dataoffset| field -- they'll just be ignored. - It tweaks the naming of the relevant gtests and some of their finer details to work with the new way of doing things. This fixes all four remaining failures in bmpsuite. --HG-- rename : image/test/gtest/transparent.bmp => image/test/gtest/transparent-if-within-ico.bmp extra : rebase_source : 2f4838d04bbae4fac00cc69e8d75469105a5de3b
2015-10-14 07:20:10 +03:00
uint8_t Get8(uint32_t aVal) const;
};
public:
/// The individual color channels.
Value mRed;
Value mGreen;
Value mBlue;
Bug 1214072 (part 2) - Implement transparency properly for BMP images. r=seth. Currently we don't implement transparency at all in BMP images except for an odd-duck case of BMPs within ICOs. This patch does the following. - It implements transparency properly for 16bpp and 32bpp images via bitfield masking. (For 32bpp images this also requires handling colors via bitfield masking.) The patch maintains the existing BMP-within-ICO transparency handling. - It also reworks BitFields::Value::Set(). * It now works correctly if the run of 1s goes all the way to bit 31 (the old code didn't set mBitWidth). * If the mask is 0, will give an mRightShift of 0 (old code gave 32, and right-shifting by 32 is dodgy). * It's now easier to read. - It renames transparent.bmp as transparent-if-within-ico.bmp. Ironically enough this file currently uses BITFIELDS compression and is WinBMPv5 format, which means it contains well-specified alpha data. In order to use it to test the hacky BMP-within-ICO transparency scheme the patch changes it to be WinBMPv3 format with RGB compression (i.e. no compression). I left the now-excess bytes (including the bitfields) in the info header in place because that's allowed -- thanks to the start of the pixel data being specified by the |dataoffset| field -- they'll just be ignored. - It tweaks the naming of the relevant gtests and some of their finer details to work with the new way of doing things. This fixes all four remaining failures in bmpsuite. --HG-- rename : image/test/gtest/transparent.bmp => image/test/gtest/transparent-if-within-ico.bmp extra : rebase_source : 2f4838d04bbae4fac00cc69e8d75469105a5de3b
2015-10-14 07:20:10 +03:00
Value mAlpha;
/// Set bitfields to the standard 5-5-5 16bpp values.
void SetR5G5B5();
Bug 1214072 (part 2) - Implement transparency properly for BMP images. r=seth. Currently we don't implement transparency at all in BMP images except for an odd-duck case of BMPs within ICOs. This patch does the following. - It implements transparency properly for 16bpp and 32bpp images via bitfield masking. (For 32bpp images this also requires handling colors via bitfield masking.) The patch maintains the existing BMP-within-ICO transparency handling. - It also reworks BitFields::Value::Set(). * It now works correctly if the run of 1s goes all the way to bit 31 (the old code didn't set mBitWidth). * If the mask is 0, will give an mRightShift of 0 (old code gave 32, and right-shifting by 32 is dodgy). * It's now easier to read. - It renames transparent.bmp as transparent-if-within-ico.bmp. Ironically enough this file currently uses BITFIELDS compression and is WinBMPv5 format, which means it contains well-specified alpha data. In order to use it to test the hacky BMP-within-ICO transparency scheme the patch changes it to be WinBMPv3 format with RGB compression (i.e. no compression). I left the now-excess bytes (including the bitfields) in the info header in place because that's allowed -- thanks to the start of the pixel data being specified by the |dataoffset| field -- they'll just be ignored. - It tweaks the naming of the relevant gtests and some of their finer details to work with the new way of doing things. This fixes all four remaining failures in bmpsuite. --HG-- rename : image/test/gtest/transparent.bmp => image/test/gtest/transparent-if-within-ico.bmp extra : rebase_source : 2f4838d04bbae4fac00cc69e8d75469105a5de3b
2015-10-14 07:20:10 +03:00
/// Set bitfields to the standard 8-8-8 32bpp values.
void SetR8G8B8();
/// Test if bitfields have the standard 5-5-5 16bpp values.
bool IsR5G5B5() const;
Bug 1214072 (part 2) - Implement transparency properly for BMP images. r=seth. Currently we don't implement transparency at all in BMP images except for an odd-duck case of BMPs within ICOs. This patch does the following. - It implements transparency properly for 16bpp and 32bpp images via bitfield masking. (For 32bpp images this also requires handling colors via bitfield masking.) The patch maintains the existing BMP-within-ICO transparency handling. - It also reworks BitFields::Value::Set(). * It now works correctly if the run of 1s goes all the way to bit 31 (the old code didn't set mBitWidth). * If the mask is 0, will give an mRightShift of 0 (old code gave 32, and right-shifting by 32 is dodgy). * It's now easier to read. - It renames transparent.bmp as transparent-if-within-ico.bmp. Ironically enough this file currently uses BITFIELDS compression and is WinBMPv5 format, which means it contains well-specified alpha data. In order to use it to test the hacky BMP-within-ICO transparency scheme the patch changes it to be WinBMPv3 format with RGB compression (i.e. no compression). I left the now-excess bytes (including the bitfields) in the info header in place because that's allowed -- thanks to the start of the pixel data being specified by the |dataoffset| field -- they'll just be ignored. - It tweaks the naming of the relevant gtests and some of their finer details to work with the new way of doing things. This fixes all four remaining failures in bmpsuite. --HG-- rename : image/test/gtest/transparent.bmp => image/test/gtest/transparent-if-within-ico.bmp extra : rebase_source : 2f4838d04bbae4fac00cc69e8d75469105a5de3b
2015-10-14 07:20:10 +03:00
/// Test if bitfields have the standard 8-8-8 32bpp values.
bool IsR8G8B8() const;
/// Read the bitfields from a header. The reading of the alpha mask is
/// optional.
void ReadFromHeader(const char* aData, bool aReadAlpha);
/// Length of the bitfields structure in the BMP file.
static const size_t LENGTH = 12;
};
} // namespace bmp
class RasterImage;
/// Decoder for BMP-Files, as used by Windows and OS/2.
class nsBMPDecoder : public Decoder
{
public:
~nsBMPDecoder();
DecoderType GetType() const override { return DecoderType::BMP; }
/// @return true if this BMP is a valid ICO resource.
bool IsValidICOResource() const override { return true; }
/// Obtains the internal output image buffer.
uint32_t* GetImageData() { return reinterpret_cast<uint32_t*>(mImageData); }
/// Obtains the length of the internal output image buffer.
size_t GetImageDataLength() const { return mImageDataLength; }
/// Obtains the size of the compressed image resource.
int32_t GetCompressedImageSize() const;
/// Mark this BMP as being within an ICO file. Only used for testing purposes
/// because the ICO-specific constructor does this marking automatically.
Bug 1214072 (part 2) - Implement transparency properly for BMP images. r=seth. Currently we don't implement transparency at all in BMP images except for an odd-duck case of BMPs within ICOs. This patch does the following. - It implements transparency properly for 16bpp and 32bpp images via bitfield masking. (For 32bpp images this also requires handling colors via bitfield masking.) The patch maintains the existing BMP-within-ICO transparency handling. - It also reworks BitFields::Value::Set(). * It now works correctly if the run of 1s goes all the way to bit 31 (the old code didn't set mBitWidth). * If the mask is 0, will give an mRightShift of 0 (old code gave 32, and right-shifting by 32 is dodgy). * It's now easier to read. - It renames transparent.bmp as transparent-if-within-ico.bmp. Ironically enough this file currently uses BITFIELDS compression and is WinBMPv5 format, which means it contains well-specified alpha data. In order to use it to test the hacky BMP-within-ICO transparency scheme the patch changes it to be WinBMPv3 format with RGB compression (i.e. no compression). I left the now-excess bytes (including the bitfields) in the info header in place because that's allowed -- thanks to the start of the pixel data being specified by the |dataoffset| field -- they'll just be ignored. - It tweaks the naming of the relevant gtests and some of their finer details to work with the new way of doing things. This fixes all four remaining failures in bmpsuite. --HG-- rename : image/test/gtest/transparent.bmp => image/test/gtest/transparent-if-within-ico.bmp extra : rebase_source : 2f4838d04bbae4fac00cc69e8d75469105a5de3b
2015-10-14 07:20:10 +03:00
void SetIsWithinICO() { mIsWithinICO = true; }
/// Did the BMP file have alpha data of any kind? (Only use this after the
/// bitmap has been fully decoded.)
bool HasTransparency() const { return mDoesHaveTransparency; }
LexerResult DoDecode(SourceBufferIterator& aIterator,
IResumable* aOnResume) override;
nsresult BeforeFinishInternal() override;
nsresult FinishInternal() override;
private:
friend class DecoderFactory;
enum class State {
FILE_HEADER,
INFO_HEADER_SIZE,
INFO_HEADER_REST,
BITFIELDS,
COLOR_TABLE,
GAP,
AFTER_GAP,
PIXEL_ROW,
RLE_SEGMENT,
RLE_DELTA,
RLE_ABSOLUTE
};
// This is the constructor used for normal BMP images.
explicit nsBMPDecoder(RasterImage* aImage);
// This is the constructor used for BMP resources in ICO images.
nsBMPDecoder(RasterImage* aImage, uint32_t aDataOffset);
// Helper constructor called by the other two.
nsBMPDecoder(RasterImage* aImage, State aState, size_t aLength);
int32_t AbsoluteHeight() const { return abs(mH.mHeight); }
uint32_t* RowBuffer();
void FinishRow();
LexerTransition<State> ReadFileHeader(const char* aData, size_t aLength);
LexerTransition<State> ReadInfoHeaderSize(const char* aData, size_t aLength);
LexerTransition<State> ReadInfoHeaderRest(const char* aData, size_t aLength);
LexerTransition<State> ReadBitfields(const char* aData, size_t aLength);
LexerTransition<State> ReadColorTable(const char* aData, size_t aLength);
LexerTransition<State> SkipGap();
LexerTransition<State> AfterGap();
LexerTransition<State> ReadPixelRow(const char* aData);
LexerTransition<State> ReadRLESegment(const char* aData);
LexerTransition<State> ReadRLEDelta(const char* aData);
LexerTransition<State> ReadRLEAbsolute(const char* aData, size_t aLength);
StreamingLexer<State> mLexer;
bmp::Header mH;
Bug 1214072 (part 2) - Implement transparency properly for BMP images. r=seth. Currently we don't implement transparency at all in BMP images except for an odd-duck case of BMPs within ICOs. This patch does the following. - It implements transparency properly for 16bpp and 32bpp images via bitfield masking. (For 32bpp images this also requires handling colors via bitfield masking.) The patch maintains the existing BMP-within-ICO transparency handling. - It also reworks BitFields::Value::Set(). * It now works correctly if the run of 1s goes all the way to bit 31 (the old code didn't set mBitWidth). * If the mask is 0, will give an mRightShift of 0 (old code gave 32, and right-shifting by 32 is dodgy). * It's now easier to read. - It renames transparent.bmp as transparent-if-within-ico.bmp. Ironically enough this file currently uses BITFIELDS compression and is WinBMPv5 format, which means it contains well-specified alpha data. In order to use it to test the hacky BMP-within-ICO transparency scheme the patch changes it to be WinBMPv3 format with RGB compression (i.e. no compression). I left the now-excess bytes (including the bitfields) in the info header in place because that's allowed -- thanks to the start of the pixel data being specified by the |dataoffset| field -- they'll just be ignored. - It tweaks the naming of the relevant gtests and some of their finer details to work with the new way of doing things. This fixes all four remaining failures in bmpsuite. --HG-- rename : image/test/gtest/transparent.bmp => image/test/gtest/transparent-if-within-ico.bmp extra : rebase_source : 2f4838d04bbae4fac00cc69e8d75469105a5de3b
2015-10-14 07:20:10 +03:00
// If the BMP is within an ICO file our treatment of it differs slightly.
bool mIsWithinICO;
bmp::BitFields mBitFields;
// Might the image have transparency? Determined from the headers during
// metadata decode. (Does not guarantee the image actually has transparency.)
bool mMayHaveTransparency;
Bug 1214072 (part 2) - Implement transparency properly for BMP images. r=seth. Currently we don't implement transparency at all in BMP images except for an odd-duck case of BMPs within ICOs. This patch does the following. - It implements transparency properly for 16bpp and 32bpp images via bitfield masking. (For 32bpp images this also requires handling colors via bitfield masking.) The patch maintains the existing BMP-within-ICO transparency handling. - It also reworks BitFields::Value::Set(). * It now works correctly if the run of 1s goes all the way to bit 31 (the old code didn't set mBitWidth). * If the mask is 0, will give an mRightShift of 0 (old code gave 32, and right-shifting by 32 is dodgy). * It's now easier to read. - It renames transparent.bmp as transparent-if-within-ico.bmp. Ironically enough this file currently uses BITFIELDS compression and is WinBMPv5 format, which means it contains well-specified alpha data. In order to use it to test the hacky BMP-within-ICO transparency scheme the patch changes it to be WinBMPv3 format with RGB compression (i.e. no compression). I left the now-excess bytes (including the bitfields) in the info header in place because that's allowed -- thanks to the start of the pixel data being specified by the |dataoffset| field -- they'll just be ignored. - It tweaks the naming of the relevant gtests and some of their finer details to work with the new way of doing things. This fixes all four remaining failures in bmpsuite. --HG-- rename : image/test/gtest/transparent.bmp => image/test/gtest/transparent-if-within-ico.bmp extra : rebase_source : 2f4838d04bbae4fac00cc69e8d75469105a5de3b
2015-10-14 07:20:10 +03:00
// Does the image have transparency? Determined during full decoding, so only
// use this after that has been completed.
bool mDoesHaveTransparency;
uint32_t mNumColors; // The number of used colors, i.e. the number of
// entries in mColors, if it's present.
UniquePtr<bmp::ColorTableEntry[]> mColors; // The color table, if it's present.
uint32_t mBytesPerColor; // 3 or 4, depending on the format
// The number of bytes prior to the optional gap that have been read. This
// is used to find the start of the pixel data.
uint32_t mPreGapLength;
uint32_t mPixelRowSize; // The number of bytes per pixel row.
int32_t mCurrentRow; // Index of the row of the image that's currently
// being decoded: [height,1].
int32_t mCurrentPos; // Index into the current line. Used when
// doing RLE decoding and when filling in pixels
// for truncated files.
// Only used in RLE_ABSOLUTE state: the number of pixels to read.
uint32_t mAbsoluteModeNumPixels;
};
} // namespace image
} // namespace mozilla
#endif // mozilla_image_decoders_nsBMPDecoder_h