From f9830e363667d02fc34ad28602d56a0f9cb31c88 Mon Sep 17 00:00:00 2001 From: Jason Nelson Date: Mon, 16 Apr 2018 12:39:09 -0700 Subject: [PATCH] Move & simplify BmpHeader & BmpInfoHeader parsing logic --- src/ImageSharp/Formats/Bmp/BmpDecoderCore.cs | 135 +++++------------- src/ImageSharp/Formats/Bmp/BmpEncoderCore.cs | 23 ++- src/ImageSharp/Formats/Bmp/BmpFileHeader.cs | 8 +- src/ImageSharp/Formats/Bmp/BmpInfoHeader.cs | 65 ++++++++- .../Formats/Bmp/IBmpDecoderOptions.cs | 7 +- .../Formats/Bmp/IBmpEncoderOptions.cs | 5 - src/ImageSharp/Formats/Bmp/ImageExtensions.cs | 2 - 7 files changed, 111 insertions(+), 134 deletions(-) diff --git a/src/ImageSharp/Formats/Bmp/BmpDecoderCore.cs b/src/ImageSharp/Formats/Bmp/BmpDecoderCore.cs index dfbd44c046..f4a009dd28 100644 --- a/src/ImageSharp/Formats/Bmp/BmpDecoderCore.cs +++ b/src/ImageSharp/Formats/Bmp/BmpDecoderCore.cs @@ -34,29 +34,29 @@ namespace SixLabors.ImageSharp.Formats.Bmp private const int Rgb16BMask = 0x1F; /// - /// RLE8 flag value that indicates following byte has special meaning + /// RLE8 flag value that indicates following byte has special meaning. /// private const int RleCommand = 0x00; /// - /// RLE8 flag value marking end of a scan line + /// RLE8 flag value marking end of a scan line. /// private const int RleEndOfLine = 0x00; /// - /// RLE8 flag value marking end of bitmap data + /// RLE8 flag value marking end of bitmap data. /// private const int RleEndOfBitmap = 0x01; /// - /// RLE8 flag value marking the start of [x,y] offset instruction + /// RLE8 flag value marking the start of [x,y] offset instruction. /// private const int RleDelta = 0x02; /// /// The stream to decode from. /// - private Stream currentStream; + private Stream stream; /// /// The file header containing general information. @@ -261,7 +261,7 @@ namespace SixLabors.ImageSharp.Formats.Bmp while (count < buffer.Length) { - if (this.currentStream.Read(cmd, 0, cmd.Length) != 2) + if (this.stream.Read(cmd, 0, cmd.Length) != 2) { throw new Exception("Failed to read 2 bytes from stream"); } @@ -283,8 +283,8 @@ namespace SixLabors.ImageSharp.Formats.Bmp break; case RleDelta: - int dx = this.currentStream.ReadByte(); - int dy = this.currentStream.ReadByte(); + int dx = this.stream.ReadByte(); + int dy = this.stream.ReadByte(); count += (w * dy) + dx; break; @@ -299,7 +299,7 @@ namespace SixLabors.ImageSharp.Formats.Bmp length += length & 1; byte[] run = new byte[length]; - this.currentStream.Read(run, 0, run.Length); + this.stream.Read(run, 0, run.Length); for (int i = 0; i < copyLength; i++) { buffer[count++] = run[i]; @@ -356,7 +356,7 @@ namespace SixLabors.ImageSharp.Formats.Bmp for (int y = 0; y < height; y++) { int newY = Invert(y, height, inverted); - this.currentStream.Read(row.Array, 0, row.Length()); + this.stream.Read(row.Array, 0, row.Length()); int offset = 0; Span pixelRow = pixels.GetRowSpan(newY); @@ -402,7 +402,7 @@ namespace SixLabors.ImageSharp.Formats.Bmp { for (int y = 0; y < height; y++) { - this.currentStream.Read(buffer.Array, 0, stride); + this.stream.Read(buffer.Array, 0, stride); int newY = Invert(y, height, inverted); Span pixelRow = pixels.GetRowSpan(newY); @@ -440,7 +440,7 @@ namespace SixLabors.ImageSharp.Formats.Bmp { for (int y = 0; y < height; y++) { - this.currentStream.Read(row); + this.stream.Read(row); int newY = Invert(y, height, inverted); Span pixelSpan = pixels.GetRowSpan(newY); PixelOperations.Instance.PackFromBgr24Bytes(row.Span, pixelSpan, width); @@ -465,7 +465,7 @@ namespace SixLabors.ImageSharp.Formats.Bmp { for (int y = 0; y < height; y++) { - this.currentStream.Read(row); + this.stream.Read(row); int newY = Invert(y, height, inverted); Span pixelSpan = pixels.GetRowSpan(newY); PixelOperations.Instance.PackFromBgra32Bytes(row.Span, pixelSpan, width); @@ -478,98 +478,43 @@ namespace SixLabors.ImageSharp.Formats.Bmp /// private void ReadInfoHeader() { - byte[] data = new byte[BmpInfoHeader.MaxHeaderSize]; + byte[] buffer = new byte[BmpInfoHeader.MaxHeaderSize]; // TODO: Stackalloc // read header size - this.currentStream.Read(data, 0, BmpInfoHeader.HeaderSizeSize); - int headerSize = BitConverter.ToInt32(data, 0); - if (headerSize < BmpInfoHeader.BitmapCoreHeaderSize) + this.stream.Read(buffer, 0, BmpInfoHeader.HeaderSizeSize); + int headerSize = BitConverter.ToInt32(buffer, 0); + if (headerSize < BmpInfoHeader.CoreSize) { throw new NotSupportedException($"This kind of bitmap files (header size $headerSize) is not supported."); } - int skipAmmount = 0; + int skipAmount = 0; if (headerSize > BmpInfoHeader.MaxHeaderSize) { - skipAmmount = headerSize - BmpInfoHeader.MaxHeaderSize; + skipAmount = headerSize - BmpInfoHeader.MaxHeaderSize; headerSize = BmpInfoHeader.MaxHeaderSize; } // read the rest of the header - this.currentStream.Read(data, BmpInfoHeader.HeaderSizeSize, headerSize - BmpInfoHeader.HeaderSizeSize); + this.stream.Read(buffer, BmpInfoHeader.HeaderSizeSize, headerSize - BmpInfoHeader.HeaderSizeSize); - switch (headerSize) + if (headerSize == BmpInfoHeader.CoreSize) { - case BmpInfoHeader.BitmapCoreHeaderSize: - this.infoHeader = this.ParseBitmapCoreHeader(data); - break; - case BmpInfoHeader.BitmapInfoHeaderSize: - this.infoHeader = this.ParseBitmapInfoHeader(data); - break; - default: - if (headerSize > BmpInfoHeader.BitmapInfoHeaderSize) - { - this.infoHeader = this.ParseBitmapInfoHeader(data); - break; - } - else - { - throw new NotSupportedException($"This kind of bitmap files (header size $headerSize) is not supported."); - } + // 12 bytes + this.infoHeader = BmpInfoHeader.ParseCore(buffer); } - - // skip the remaining header because we can't read those parts - this.currentStream.Skip(skipAmmount); - } - - /// - /// Parses the from the stream, assuming it uses the BITMAPCOREHEADER format. - /// - /// Header bytes read from the stream - /// Parsed header - /// - private BmpInfoHeader ParseBitmapCoreHeader(byte[] data) - { - return new BmpInfoHeader + else if (headerSize >= BmpInfoHeader.Size) { - HeaderSize = BitConverter.ToInt32(data, 0), - Width = BitConverter.ToUInt16(data, 4), - Height = BitConverter.ToUInt16(data, 6), - Planes = BitConverter.ToInt16(data, 8), - BitsPerPixel = BitConverter.ToInt16(data, 10), - - // the rest is not present in the core header - ImageSize = 0, - XPelsPerMeter = 0, - YPelsPerMeter = 0, - ClrUsed = 0, - ClrImportant = 0, - Compression = BmpCompression.RGB - }; - } - - /// - /// Parses the from the stream, assuming it uses the BITMAPINFOHEADER format. - /// - /// Header bytes read from the stream - /// Parsed header - /// - private BmpInfoHeader ParseBitmapInfoHeader(byte[] data) - { - return new BmpInfoHeader + // >= 40 bytes + this.infoHeader = BmpInfoHeader.Parse(buffer); + } + else { - HeaderSize = BitConverter.ToInt32(data, 0), - Width = BitConverter.ToInt32(data, 4), - Height = BitConverter.ToInt32(data, 8), - Planes = BitConverter.ToInt16(data, 12), - BitsPerPixel = BitConverter.ToInt16(data, 14), - ImageSize = BitConverter.ToInt32(data, 20), - XPelsPerMeter = BitConverter.ToInt32(data, 24), - YPelsPerMeter = BitConverter.ToInt32(data, 28), - ClrUsed = BitConverter.ToInt32(data, 32), - ClrImportant = BitConverter.ToInt32(data, 36), - Compression = (BmpCompression)BitConverter.ToInt32(data, 16) - }; + throw new NotSupportedException($"ImageSharp does not support this BMP file. HeaderSize: {headerSize}."); + } + + // skip the remaining header because we can't read those parts + this.stream.Skip(skipAmount); } /// @@ -577,15 +522,11 @@ namespace SixLabors.ImageSharp.Formats.Bmp /// private void ReadFileHeader() { - byte[] data = new byte[BmpFileHeader.Size]; + byte[] data = new byte[BmpFileHeader.Size]; // TODO: Stackalloc - this.currentStream.Read(data, 0, BmpFileHeader.Size); + this.stream.Read(data, 0, BmpFileHeader.Size); - this.fileHeader = new BmpFileHeader( - type: BitConverter.ToInt16(data, 0), - fileSize: BitConverter.ToInt32(data, 2), - reserved: BitConverter.ToInt32(data, 6), - offset: BitConverter.ToInt32(data, 10)); + this.fileHeader = BmpFileHeader.Parse(data); } /// @@ -593,7 +534,7 @@ namespace SixLabors.ImageSharp.Formats.Bmp /// private void ReadImageHeaders(Stream stream, out bool inverted, out byte[] palette) { - this.currentStream = stream; + this.stream = stream; try { @@ -640,7 +581,7 @@ namespace SixLabors.ImageSharp.Formats.Bmp palette = new byte[colorMapSize]; - this.currentStream.Read(palette, 0, colorMapSize); + this.stream.Read(palette, 0, colorMapSize); } if (this.infoHeader.Width > int.MaxValue || this.infoHeader.Height > int.MaxValue) diff --git a/src/ImageSharp/Formats/Bmp/BmpEncoderCore.cs b/src/ImageSharp/Formats/Bmp/BmpEncoderCore.cs index 1e0ecd3b14..2b0c907338 100644 --- a/src/ImageSharp/Formats/Bmp/BmpEncoderCore.cs +++ b/src/ImageSharp/Formats/Bmp/BmpEncoderCore.cs @@ -18,9 +18,6 @@ namespace SixLabors.ImageSharp.Formats.Bmp /// private int padding; - /// - /// Gets or sets the number of bits per pixel. - /// private readonly BmpBitsPerPixel bitsPerPixel; private readonly MemoryManager memoryManager; @@ -53,17 +50,15 @@ namespace SixLabors.ImageSharp.Formats.Bmp int bytesPerLine = 4 * (((image.Width * bpp) + 31) / 32); this.padding = bytesPerLine - (image.Width * (int)this.bitsPerPixel); - var infoHeader = new BmpInfoHeader - { - HeaderSize = BmpInfoHeader.BitmapInfoHeaderSize, - Height = image.Height, - Width = image.Width, - BitsPerPixel = bpp, - Planes = 1, - ImageSize = image.Height * bytesPerLine, - ClrUsed = 0, - ClrImportant = 0 - }; + var infoHeader = new BmpInfoHeader( + headerSize: BmpInfoHeader.Size, + height: image.Height, + width: image.Width, + bitsPerPixel: bpp, + planes: 1, + imageSize: image.Height * bytesPerLine, + clrUsed: 0, + clrImportant: 0); var fileHeader = new BmpFileHeader( type: 19778, // BM diff --git a/src/ImageSharp/Formats/Bmp/BmpFileHeader.cs b/src/ImageSharp/Formats/Bmp/BmpFileHeader.cs index 64474ad909..d94fefa057 100644 --- a/src/ImageSharp/Formats/Bmp/BmpFileHeader.cs +++ b/src/ImageSharp/Formats/Bmp/BmpFileHeader.cs @@ -2,7 +2,6 @@ // Licensed under the Apache License, Version 2.0. using System; -using System.Buffers.Binary; using System.Runtime.InteropServices; namespace SixLabors.ImageSharp.Formats.Bmp @@ -57,14 +56,17 @@ namespace SixLabors.ImageSharp.Formats.Bmp /// public int Offset { get; } + public static BmpFileHeader Parse(Span data) + { + return MemoryMarshal.Cast(data)[0]; + } + public unsafe void WriteTo(Span buffer) { fixed (BmpFileHeader* pointer = &this) { MemoryMarshal.AsBytes(new ReadOnlySpan(pointer, 1)).CopyTo(buffer); } - - // TODO: Big Endian Platforms } } } \ No newline at end of file diff --git a/src/ImageSharp/Formats/Bmp/BmpInfoHeader.cs b/src/ImageSharp/Formats/Bmp/BmpInfoHeader.cs index b38cfd450f..d7fb2f844e 100644 --- a/src/ImageSharp/Formats/Bmp/BmpInfoHeader.cs +++ b/src/ImageSharp/Formats/Bmp/BmpInfoHeader.cs @@ -1,6 +1,7 @@ // Copyright (c) Six Labors and contributors. // Licensed under the Apache License, Version 2.0. using System; +using System.Buffers.Binary; using System.Runtime.InteropServices; namespace SixLabors.ImageSharp.Formats.Bmp @@ -14,28 +15,52 @@ namespace SixLabors.ImageSharp.Formats.Bmp [StructLayout(LayoutKind.Sequential, Pack = 1)] internal struct BmpInfoHeader { - // TODO: Make readonly - /// /// Defines the size of the BITMAPINFOHEADER data structure in the bitmap file. /// - public const int BitmapInfoHeaderSize = 40; + public const int Size = 40; /// /// Defines the size of the BITMAPCOREHEADER data structure in the bitmap file. /// - public const int BitmapCoreHeaderSize = 12; + public const int CoreSize = 12; /// /// Defines the size of the biggest supported header data structure in the bitmap file. /// - public const int MaxHeaderSize = BitmapInfoHeaderSize; + public const int MaxHeaderSize = Size; /// /// Defines the size of the field. /// public const int HeaderSizeSize = 4; + public BmpInfoHeader( + int headerSize, + int width, + int height, + short planes, + short bitsPerPixel, + BmpCompression compression = default, + int imageSize = 0, + int xPelsPerMeter = 0, + int yPelsPerMeter = 0, + int clrUsed = 0, + int clrImportant = 0) + { + this.HeaderSize = headerSize; + this.Width = width; + this.Height = height; + this.Planes = planes; + this.BitsPerPixel = bitsPerPixel; + this.Compression = compression; + this.ImageSize = imageSize; + this.XPelsPerMeter = xPelsPerMeter; + this.YPelsPerMeter = yPelsPerMeter; + this.ClrUsed = clrUsed; + this.ClrImportant = clrImportant; + } + /// /// Gets or sets the size of this header /// @@ -98,14 +123,40 @@ namespace SixLabors.ImageSharp.Formats.Bmp /// public int ClrImportant { get; set; } + + /// + /// Parses the full BITMAPINFOHEADER header (40 bytes). + /// + /// The data to parse. + /// Parsed header + /// + public static BmpInfoHeader Parse(ReadOnlySpan data) + { + return MemoryMarshal.Cast(data)[0]; + } + + /// + /// Parses the BITMAPCOREHEADER consisting of the headerSize, width, height, planes, and bitsPerPixel fields (12 bytes). + /// + /// The data to parse, + /// Parsed header + /// + public static BmpInfoHeader ParseCore(ReadOnlySpan data) + { + return new BmpInfoHeader( + headerSize: BinaryPrimitives.ReadInt32LittleEndian(data.Slice(0, 4)), + width: BinaryPrimitives.ReadUInt16LittleEndian(data.Slice(4, 2)), + height: BinaryPrimitives.ReadUInt16LittleEndian(data.Slice(6, 2)), + planes: BinaryPrimitives.ReadInt16LittleEndian(data.Slice(8, 2)), + bitsPerPixel: BinaryPrimitives.ReadInt16LittleEndian(data.Slice(10, 2))); + } + public unsafe void WriteTo(Span buffer) { fixed (BmpInfoHeader* pointer = &this) { MemoryMarshal.AsBytes(new ReadOnlySpan(pointer, 1)).CopyTo(buffer); } - - // TODO: Big Endian Platforms } } } \ No newline at end of file diff --git a/src/ImageSharp/Formats/Bmp/IBmpDecoderOptions.cs b/src/ImageSharp/Formats/Bmp/IBmpDecoderOptions.cs index 920c9ce028..c44ca73f2e 100644 --- a/src/ImageSharp/Formats/Bmp/IBmpDecoderOptions.cs +++ b/src/ImageSharp/Formats/Bmp/IBmpDecoderOptions.cs @@ -1,11 +1,6 @@ // Copyright (c) Six Labors and contributors. // Licensed under the Apache License, Version 2.0. -using System; -using System.Collections.Generic; -using System.IO; -using SixLabors.ImageSharp.PixelFormats; - namespace SixLabors.ImageSharp.Formats.Bmp { /// @@ -15,4 +10,4 @@ namespace SixLabors.ImageSharp.Formats.Bmp { // added this for consistancy so we can add stuff as required, no options currently availible } -} +} \ No newline at end of file diff --git a/src/ImageSharp/Formats/Bmp/IBmpEncoderOptions.cs b/src/ImageSharp/Formats/Bmp/IBmpEncoderOptions.cs index c4e219889d..0bfd6980bf 100644 --- a/src/ImageSharp/Formats/Bmp/IBmpEncoderOptions.cs +++ b/src/ImageSharp/Formats/Bmp/IBmpEncoderOptions.cs @@ -1,11 +1,6 @@ // Copyright (c) Six Labors and contributors. // Licensed under the Apache License, Version 2.0. -using System; -using System.Collections.Generic; -using System.IO; -using SixLabors.ImageSharp.PixelFormats; - namespace SixLabors.ImageSharp.Formats.Bmp { /// diff --git a/src/ImageSharp/Formats/Bmp/ImageExtensions.cs b/src/ImageSharp/Formats/Bmp/ImageExtensions.cs index 35e168e278..57e4615bad 100644 --- a/src/ImageSharp/Formats/Bmp/ImageExtensions.cs +++ b/src/ImageSharp/Formats/Bmp/ImageExtensions.cs @@ -1,10 +1,8 @@ // Copyright (c) Six Labors and contributors. // Licensed under the Apache License, Version 2.0. -using System; using System.IO; using SixLabors.ImageSharp.Advanced; -using SixLabors.ImageSharp.Formats; using SixLabors.ImageSharp.Formats.Bmp; using SixLabors.ImageSharp.PixelFormats;