protected void CompressMip(DXT1Mip mip, byte[] buffer)
{
Debug.Assert(buffer.Length == (mip.Width * mip.Height * srcPixelSize));
byte[] block = new byte[64];
int blocksWidth = mip.Width / 4;
int blocksHeight = mip.Height / 4;
int stride = mip.Width * srcPixelSize;
int copyLen = 4 * srcPixelSize;
int dxtOffset = 0;
for (int y = 0; y < mip.Height; y += 4)
{
int lineOffset = y * stride;
for (int x = 0; x < mip.Width; x += 4)
{
int offset = lineOffset + x * srcPixelSize;
int destOffset = 0;
// fill the block with data from the source image
for (int line = 0; line < 4; line++)
{
Buffer.BlockCopy(buffer, offset, block, destOffset, copyLen);
offset += stride;
destOffset += copyLen;
}
CompressBlockDXT1Opaque(block, mip.Buffer, dxtOffset);
dxtOffset += 8;
}
}
}
public DXT1Image(Image source)
{
// make sure width and height are divisible by 4
Debug.Assert((source.Width & 0x3) == 0);
Debug.Assert((source.Height & 0x3) == 0);
// width and height are powers of 2
Debug.Assert(isPowerOf2(source.Width));
Debug.Assert(isPowerOf2(source.Height));
// only support RGB 24-bit images for now
//Debug.Assert(source.Format == PixelFormat.R8G8B8);
// only normal textures
Debug.Assert(source.NumFaces == 1);
Debug.Assert(source.NumMipMaps == 1);
width = source.Width;
height = source.Height;
int mipWidth = width;
int mipHeight = height;
int mipLevels;
if (width > height)
{
mipLevels = log2(width) - 1;
}
else
{
mipLevels = log2(height) - 1;
}
compressedMips = new DXT1Mip[mipLevels];
// start by using the source image data for the first iterations.
// later iterations will use new allocated buffers containing scaled pixels
byte[] rawBuffer = source.Data;
for( int mipLevel = 0; mipLevel < mipLevels; mipLevel++)
{
compressedMips[mipLevel] = new DXT1Mip(mipWidth, mipHeight);
//CompressMip(compressedMips[mipLevel], rawBuffer);
unsafe
{
byte [] outBuffer = compressedMips[mipLevel].Buffer;
GCHandle inHandle = GCHandle.Alloc(rawBuffer, GCHandleType.Pinned);
GCHandle outHandle = GCHandle.Alloc(outBuffer, GCHandleType.Pinned);
IntPtr pIn = inHandle.AddrOfPinnedObject();
IntPtr pOut = outHandle.AddrOfPinnedObject();
CompressImageDXT1(pIn, pOut, mipWidth, mipHeight);
inHandle.Free();
outHandle.Free();
}
mipWidth = mipWidth / 2;
mipHeight = mipHeight / 2;
// create a new uncompressed buffer by scaling the last buffer
// to the new mip size
rawBuffer = scaleRawHalfBox(mipWidth, mipHeight, rawBuffer);
}
}
protected void CompressMip(DXT1Mip mip, byte[] buffer)
{
Debug.Assert(buffer.Length == (mip.Width * mip.Height * srcPixelSize));
byte[] block = new byte[64];
int blocksWidth = mip.Width / 4;
int blocksHeight = mip.Height / 4;
int stride = mip.Width * srcPixelSize;
int copyLen = 4 * srcPixelSize;
int dxtOffset = 0;
for (int y = 0; y < mip.Height; y += 4)
{
int lineOffset = y * stride;
for (int x = 0; x < mip.Width; x += 4)
{
int offset = lineOffset + x * srcPixelSize;
int destOffset = 0;
// fill the block with data from the source image
for (int line = 0; line < 4; line++)
{
Buffer.BlockCopy(buffer, offset, block, destOffset, copyLen);
offset += stride;
destOffset += copyLen;
}
CompressBlockDXT1Opaque(block, mip.Buffer, dxtOffset);
dxtOffset += 8;
}
}
}
public DXT1Image(Image source)
{
// make sure width and height are divisible by 4
Debug.Assert((source.Width & 0x3) == 0);
Debug.Assert((source.Height & 0x3) == 0);
// width and height are powers of 2
Debug.Assert(isPowerOf2(source.Width));
Debug.Assert(isPowerOf2(source.Height));
// only support RGB 24-bit images for now
//Debug.Assert(source.Format == PixelFormat.R8G8B8);
// only normal textures
Debug.Assert(source.NumFaces == 1);
Debug.Assert(source.NumMipMaps == 1);
width = source.Width;
height = source.Height;
int mipWidth = width;
int mipHeight = height;
int mipLevels;
if (width > height)
{
mipLevels = log2(width) - 1;
}
else
{
mipLevels = log2(height) - 1;
}
compressedMips = new DXT1Mip[mipLevels];
// start by using the source image data for the first iterations.
// later iterations will use new allocated buffers containing scaled pixels
byte[] rawBuffer = source.Data;
for (int mipLevel = 0; mipLevel < mipLevels; mipLevel++)
{
compressedMips[mipLevel] = new DXT1Mip(mipWidth, mipHeight);
//CompressMip(compressedMips[mipLevel], rawBuffer);
unsafe
{
byte [] outBuffer = compressedMips[mipLevel].Buffer;
GCHandle inHandle = GCHandle.Alloc(rawBuffer, GCHandleType.Pinned);
GCHandle outHandle = GCHandle.Alloc(outBuffer, GCHandleType.Pinned);
IntPtr pIn = inHandle.AddrOfPinnedObject();
IntPtr pOut = outHandle.AddrOfPinnedObject();
CompressImageDXT1(pIn, pOut, mipWidth, mipHeight);
inHandle.Free();
outHandle.Free();
}
mipWidth = mipWidth / 2;
mipHeight = mipHeight / 2;
// create a new uncompressed buffer by scaling the last buffer
// to the new mip size
rawBuffer = scaleRawHalfBox(mipWidth, mipHeight, rawBuffer);
}
}
