/// <summary>
/// Writes the bitmap header data to the binary stream.
/// </summary>
/// <param name="writer">
/// The <see cref="EndianBinaryWriter"/> containing the stream to write to.
/// </param>
/// <param name="fileHeader">
/// The <see cref="BmpFileHeader"/> containing the header data.
/// </param>
private static void WriteHeader(EndianBinaryWriter writer, BmpFileHeader fileHeader)
{
writer.Write(fileHeader.Type);
writer.Write(fileHeader.FileSize);
writer.Write(fileHeader.Reserved);
writer.Write(fileHeader.Offset);
}
/// <summary>
/// Reads the <see cref="BmpFileHeader"/> from the stream.
/// </summary>
private void ReadFileHeader()
{
byte[] data = new byte[BmpFileHeader.Size];
this.currentStream.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)
};
}
/// <summary>
/// Encodes the image to the specified stream from the <see cref="ImageBase{TColor, TPacked}"/>.
/// </summary>
/// <typeparam name="TColor">The pixel format.</typeparam>
/// <typeparam name="TPacked">The packed format. <example>long, float.</example></typeparam>
/// <param name="image">The <see cref="ImageBase{TColor, TPacked}"/> to encode from.</param>
/// <param name="stream">The <see cref="Stream"/> to encode the image data to.</param>
/// <param name="bitsPerPixel">The <see cref="BmpBitsPerPixel"/></param>
public void Encode <TColor, TPacked>(ImageBase <TColor, TPacked> image, Stream stream, BmpBitsPerPixel bitsPerPixel)
where TColor : struct, IPackedPixel <TPacked>
where TPacked : struct
{
Guard.NotNull(image, nameof(image));
Guard.NotNull(stream, nameof(stream));
this.bmpBitsPerPixel = bitsPerPixel;
// Cast to int will get the bytes per pixel
short bpp = (short)(8 * (int)bitsPerPixel);
int bytesPerLine = 4 * (((image.Width * bpp) + 31) / 32);
this.padding = bytesPerLine - (image.Width * (int)bitsPerPixel);
// Do not use IDisposable pattern here as we want to preserve the stream.
EndianBinaryWriter writer = new EndianBinaryWriter(EndianBitConverter.Little, stream);
BmpInfoHeader infoHeader = new BmpInfoHeader
{
HeaderSize = BmpInfoHeader.Size,
Height = image.Height,
Width = image.Width,
BitsPerPixel = bpp,
Planes = 1,
ImageSize = image.Height * bytesPerLine,
ClrUsed = 0,
ClrImportant = 0
};
BmpFileHeader fileHeader = new BmpFileHeader
{
Type = 19778, // BM
Offset = 54,
FileSize = 54 + infoHeader.ImageSize
};
WriteHeader(writer, fileHeader);
this.WriteInfo(writer, infoHeader);
this.WriteImage(writer, image);
writer.Flush();
}