public RawImage GetMip(TgvFile file, uint mip)
{
RawImage ret;
uint width = file.ImageWidth;
uint height = file.ImageHeight;
// Compute width and height.
for (uint m = 0; m < mip; m++)
{
width = Math.Max(1, width / 2);
height = Math.Max(1, height / 2);
}
ret = new RawImage(width, height);
using (var ms = new MemoryStream(file.MipMaps[(int)mip].Content))
{
if (DDS.DDS.IsCompressedFormat(file.Format))
{
ReadBlockFormat(ret, ms);
}
}
return ret;
}
private static void ReadBlockFormat(RawImage ret, Stream ms)
{
ret.ColFormat = RawImage.Format.Format_ARGB;
uint w = ret.Width;
uint h = ret.Height;
uint bw = (w + 3) / 4;
uint bh = (h + 3) / 4;
for (uint by = 0; by < bh; by++)
for (uint bx = 0; bx < bw; bx++)
{
var block = new ColorBlock();
// Read color block.
ReadBlock(block, ms);
// Write color block.
for (uint y = 0; y < Math.Min(4, h - 4 * by); y++)
for (uint x = 0; x < Math.Min(4, w - 4 * bx); x++)
ret.Data[(4 * by + y) * ret.Width + (4 * bx + x)] = block.Color(x, y);
}
}
/// Initialize this color block.
public ColorBlock(RawImage img, uint x, uint y)
: this()
{
init(img, x, y);
}
void init(RawImage img, uint x, uint y)
{
if (img == null)
throw new ArgumentNullException("img");
uint bw = Math.Min(img.Width - x, 4U);
uint bh = Math.Min(img.Height - y, 4U);
if (bw == 0 || bh == 0)
throw new InvalidOperationException("bw and bh have to be > 0)");
uint[] remainder = {
0, 0, 0, 0,
0, 1, 0, 1,
0, 1, 2, 0,
0, 1, 2, 3 };
// Blocks that are smaller than 4x4 are handled by repeating the pixels.
// @@ Thats only correct when block size is 1, 2 or 4, but not with 3. :(
for (uint i = 0; i < 4; i++)
{
//const int by = i % bh;
uint by = remainder[(bh - 1) * 4 + i];
for (uint e = 0; e < 4; e++)
{
//const int bx = e % bw;
uint bx = remainder[(bw - 1) * 4 + e];
Data[i * 4 + e] = img.Pixel(x + bx, y + by);
}
}
}
