Add m-esr52 at 52.6.0

1 files changed, 235 insertions, 0 deletions

diff --git a/image/decoders/nsBMPDecoder.h b/image/decoders/nsBMPDecoder.h
new file mode 100644
index 000000000..0cf2af689
--- /dev/null
+++ b/image/decoders/nsBMPDecoder.h
@@ -0,0 +1,235 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* 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"
+#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:
+    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;
+
+    /// 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;
+    uint8_t Get8(uint32_t aVal) const;
+  };
+
+public:
+  /// The individual color channels.
+  Value mRed;
+  Value mGreen;
+  Value mBlue;
+  Value mAlpha;
+
+  /// Set bitfields to the standard 5-5-5 16bpp values.
+  void SetR5G5B5();
+
+  /// 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;
+
+  /// 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();
+
+  /// 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.
+  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;
+
+  // 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;
+
+  // 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