/// <summary>
/// Build iff chunk with id and data
/// </summary>
/// <param name="id"></param>
/// <param name="data"></param>
/// <returns></returns>
public static async Task <byte[]> BuildIffChunk(string id, byte[] data)
{
var chunk = new MemoryStream();
var chunkLength = data.Length;
var appendZero = false;
if ((chunkLength & 1) == 1)
{
chunkLength++;
appendZero = true;
}
await chunk.WriteBytes(Encoding.ASCII.GetBytes(id));
await chunk.WriteBytes(LittleEndianConverter.ConvertToBytes(chunkLength));
await chunk.WriteBytes(data);
if (appendZero)
{
await chunk.WriteBytes(new byte[1]);
}
return(chunk.ToArray());
}
/// <summary>
/// Build bitmap header chunk containing information defining the metrics of the image data
/// </summary>
/// <param name="image"></param>
/// <param name="depth"></param>
/// <param name="pack"></param>
/// <returns></returns>
public static async Task <byte[]> BuildBitMapHeaderChunk(Image image, int depth, bool pack)
{
var chunk = new MemoryStream();
await chunk.WriteBytes(LittleEndianConverter.ConvertToBytes((ushort)image.Width)); // width
await chunk.WriteBytes(LittleEndianConverter.ConvertToBytes((ushort)image.Height)); // height
await chunk.WriteBytes(LittleEndianConverter.ConvertToBytes((ushort)0)); // x
await chunk.WriteBytes(LittleEndianConverter.ConvertToBytes((ushort)0)); // y
chunk.WriteByte((byte)depth); // planes
chunk.WriteByte(0); // mask
chunk.WriteByte((byte)(pack ? 1 : 0)); // tcomp
chunk.WriteByte(0); // pad1
await chunk.WriteBytes(LittleEndianConverter.ConvertToBytes((ushort)0)); // transparent color
chunk.WriteByte(60); // xAspect
chunk.WriteByte(60); // yAspect
await chunk.WriteBytes(LittleEndianConverter.ConvertToBytes((ushort)image.Width)); // Lpage
await chunk.WriteBytes(LittleEndianConverter.ConvertToBytes((ushort)image.Height)); // Hpage
return(await BuildIffChunk(ChunkIdentifiers.BitmapHeader, chunk.ToArray()));
}
// create camg chunk
public static async Task <byte[]> CamgChunk(Image image, int depth)
{
var chunk = new MemoryStream();
await chunk.WriteBytes(LittleEndianConverter.ConvertToBytes((uint)depth)); // y
return(await BuildIffChunk(ChunkIdentifiers.Camg, chunk.ToArray()));
/*
* return ,$cmagStream.ToArray()
*
# if mode is not None:
# camg = iff_chunk("CAMG", struct.pack(">L", mode))
# else:
# camg = ""
# // uint viewmodes = input.ReadBEUInt32();
#
# // bytesloaded = size;
# // if ((viewmodes & 0x0800) > 0)
# // flagHAM = true;
# // if ((viewmodes & 0x0080) > 0)
# // flagEHB = true;
# //}
*/
}
public static async Task WriteLittleEndianUInt32(this Stream stream, uint value)
{
await stream.WriteBytes(LittleEndianConverter.ConvertToBytes(value));
}
