private static void writeData(Bitmap png, BinaryWriterWrapper bw, bool premultiply)
{
bw.Write7BitEncodedInt(1); // type-reader-count
bw.WriteString(TEXTURE_2D_TYPE); // type-reader-name
bw.WriteInt(0); // reader version number
bw.Write7BitEncodedInt(0); // shared-resource-count
// writing the image pixel data
bw.WriteByte(1); // type id + 1 (referencing the TEXTURE_2D_TYPE)
bw.WriteInt(0); // surface format; 0=color
bw.WriteInt(png.Width);
bw.WriteInt(png.Height);
bw.WriteInt(1); // mip count
bw.WriteInt(imageSize(png)); // number of bytes in the image pixel data
BitmapData bitmapData = png.LockBits(new Rectangle(0, 0, png.Width, png.Height), System.Drawing.Imaging.ImageLockMode.ReadWrite, System.Drawing.Imaging.PixelFormat.Format32bppArgb);
try {
var length = bitmapData.Stride * bitmapData.Height;
byte[] bytes = new byte[length];
Marshal.Copy(bitmapData.Scan0, bytes, 0, length);
for (int i = 0; i < bytes.Length; i += 4)
{
// always swap red and blue channels
// premultiply alpha if requested
int a = bytes[i + 3];
if (!premultiply || a == 255)
{
// No premultiply necessary
byte b = bytes[i];
bytes[i] = bytes[i + 2];
bytes[i + 2] = b;
}
else if (a != 0)
{
byte b = bytes[i];
bytes[i] = (byte)(bytes[i + 2] * a / 255);
bytes[i + 1] = (byte)(bytes[i + 1] * a / 255);
bytes[i + 2] = (byte)(b * a / 255);
}
else
{
// alpha is zero, so just zero everything
bytes[i] = 0;
bytes[i + 1] = 0;
bytes[i + 2] = 0;
}
}
bw.WriteByteArray(bytes);
} finally {
png.UnlockBits(bitmapData);
}
}
private static void writeCompressedData(BinaryWriterWrapper bw, Bitmap png, bool premultiply)
{
using (MemoryStream stream = new MemoryStream()) {
byte[] uncompressedData;
using (BinaryWriterWrapper mw = new BinaryWriterWrapper(new BinaryWriter(stream))) {
writeData(png, mw, premultiply);
uncompressedData = stream.ToArray();
}
byte[] compressedData = XCompress.Compress(uncompressedData);
bw.WriteInt(6 + 4 + 4 + compressedData.Length); // compressed file size including headers
bw.WriteInt(uncompressedData.Length); // uncompressed data size (exluding headers! only the data)
bw.WriteByteArray(compressedData);
}
}
private static void writeData(Bitmap png, BinaryWriterWrapper bw) {
bw.Write7BitEncodedInt(1); // type-reader-count
bw.WriteString(TEXTURE_2D_TYPE); // type-reader-name
bw.WriteInt(0); // reader version number
bw.Write7BitEncodedInt(0); // shared-resource-count
// writing the image pixel data
bw.WriteByte(1); // type id + 1 (referencing the TEXTURE_2D_TYPE)
bw.WriteInt(0); // surface format; 0=color
bw.WriteInt(png.Width);
bw.WriteInt(png.Height);
bw.WriteInt(1); // mip count
bw.WriteInt(imageSize(png)); // number of bytes in the image pixel data
BitmapData bitmapData = png.LockBits(new Rectangle(0, 0, png.Width, png.Height), System.Drawing.Imaging.ImageLockMode.ReadWrite, System.Drawing.Imaging.PixelFormat.Format32bppArgb);
try {
var length = bitmapData.Stride * bitmapData.Height;
byte[] bytes = new byte[length];
Marshal.Copy(bitmapData.Scan0, bytes, 0, length);
for (int i = 0; i < bytes.Length; i += 4) {
byte b = bytes[i];
bytes[i] = bytes[i + 2];
bytes[i + 2] = b;
}
bw.WriteByteArray(bytes);
} finally {
png.UnlockBits(bitmapData);
}
}
private static void writeCompressedData(BinaryWriterWrapper bw, Bitmap png) {
using (MemoryStream stream = new MemoryStream()) {
byte[] uncompressedData;
using (BinaryWriterWrapper mw = new BinaryWriterWrapper(new BinaryWriter(stream))) {
writeData(png, mw);
uncompressedData = stream.ToArray();
}
byte[] compressedData = XCompress.Compress(uncompressedData);
bw.WriteInt(6 + 4 + 4 + compressedData.Length); // compressed file size including headers
bw.WriteInt(uncompressedData.Length); // uncompressed data size (exluding headers! only the data)
bw.WriteByteArray(compressedData);
}
}