static void WriteBitmap(string path, uint[] palette, byte[] pixels, int width)
{
using var stream = File.Open(path, FileMode.Create, FileAccess.Write);
using var bw = new BinaryWriter(stream);
using var s = new GenericBinaryWriter(bw, Encoding.ASCII.GetBytes);
Bitmap8Bit.Serdes(new Bitmap8Bit((ushort)width, palette, pixels), s);
}
public static Bitmap8Bit Serdes(Bitmap8Bit b, ISerializer s)
{
if (s == null)
{
throw new ArgumentNullException(nameof(s));
}
var initialOffset = s.Offset;
b ??= new Bitmap8Bit();
//-------------\\
// File Header \\
//-------------\\
var magic = Encoding.ASCII.GetString(s.Bytes("Magic", Magic, 2)); // 0
if (magic != MagicString)
{
throw new FormatException($"Tried to read as bitmap, but incorrect signature \"{magic}\" found (expected BM)");
}
var sizeOffset = s.Offset;
uint size = s.UInt32("Size", 0); // 2 Will patch this at the end when writing
if (s.IsReading() && size > s.BytesRemaining + (s.Offset - initialOffset))
{
throw new FormatException($"Bitmap specified a size of {size}, but the stream only contains {s.BytesRemaining + (s.Offset - initialOffset)} bytes");
}
s.UInt16("Reserved1", 0); // 6
s.UInt16("Reserved2", 0); // 8
var pixelOffsetOffset = s.Offset;
uint pixelOffset = s.UInt32("PixelOffset", 0); // A Will patch later when writing
if (s.IsReading() && pixelOffset > s.BytesRemaining + (s.Offset - initialOffset))
{
throw new FormatException($"Bitmap specified a pixel offset of {pixelOffset}, but the stream only contains {s.BytesRemaining + (s.Offset - initialOffset)} bytes");
}
//------------\\
// DIB Header \\
//------------\\
const uint bitmapInfoHeaderSize = 40;
uint headerSize = s.UInt32("HeaderSize", bitmapInfoHeaderSize); // E
if (headerSize != bitmapInfoHeaderSize)
{
throw new FormatException($"Unsupported bitmap header size {headerSize}, expecting {bitmapInfoHeaderSize}.");
}
b.Width = s.UInt32("Width", b.Width); // 12
b.Height = s.UInt32("Width", b.Height); // 16
ushort planes = s.UInt16("Planes", 1); // 1A
if (planes != 1)
{
throw new FormatException($"Unsupported number of colour planes in bitmap: {planes}, expected 1");
}
ushort bpp = s.UInt16("BPP", 8); // 1C
if (bpp != 8)
{
throw new FormatException($"Unsupported colour depth: {bpp} bits per pixel, expected 8");
}
Compression compression = s.EnumU32("Compression", Compression.Rgb); // 1E
if (compression != Compression.Rgb)
{
throw new FormatException($"Unsupported compression method {compression}, expected RGB (0)");
}
s.UInt32("ImageSize", 0); // 22 Dummy value for RGB bitmaps
int widthPixelsPerMetre = s.Int32("HorizontalResolution", 3779); // 26
int heightPixelsPerMetre = s.Int32("VerticalResolution", 3779); // 2A
uint paletteSize = s.UInt32("PaletteSize", (uint)b.Palette.Count); // 2E
if (paletteSize != 256)
{
throw new FormatException($"Unsupported palette size {paletteSize}, expected 256");
}
s.UInt32("ImportantColours", 0); // 32 Ignored
//---------\\
// Palette \\ // 36
//---------\\
b.Palette = s.List("Palette", b.Palette, (int)paletteSize, (n, x, s2) =>
{
uint b1 = s2.UInt8(null, (byte)((x & 0x00ff0000) >> 16)); // B
uint b2 = s2.UInt8(null, (byte)((x & 0x0000ff00) >> 8)); // G
uint b3 = s2.UInt8(null, (byte)(x & 0x000000ff)); // R
uint b4 = s2.UInt8(null, 0); // A
return(0xff000000U | (b1 << 16) | (b2 << 8) | b3);
});
//------------\\
// Pixel Data \\
//------------\\
if (s.IsReading())
{
var tempOffset = s.Offset;
s.Seek(pixelOffsetOffset);
s.UInt32("PixelOffset", (uint)(tempOffset - initialOffset));
s.Seek(tempOffset);
}
b.Pixels ??= new byte[b.Width * b.Height];
uint stride = 4 * ((bpp * b.Width + 31) / 32);
for (int j = 0; j < b.Height; j++)
{
uint index = (uint)((b.Height - j - 1) * b.Width);
for (int i = 0; i < b.Width; i++)
{
b.Pixels[index] = s.UInt8(null, b.Pixels[index]);
index++;
}
if (stride - b.Width > 0) // Padding
{
s.RepeatU8(null, 0, (int)(stride - b.Width));
}
}
if (s.IsReading())
{
var tempOffset = s.Offset;
s.Seek(sizeOffset);
s.UInt32("Size", (uint)(tempOffset - initialOffset));
s.Seek(tempOffset);
}
return(b);
}
