public static Color[] DecodeETC1(ulong Data, ulong Alpha = ~0ul)
{
Color[] Result = new Color[4 * 4];
bool diffbit = ((Data >> 33) & 1) == 1;
bool flipbit = ((Data >> 32) & 1) == 1; //0: |||, 1: |-|
int r1, r2, g1, g2, b1, b2;
if (diffbit) //'differential' mode
{
int r = (int)((Data >> 59) & 0x1F);
int g = (int)((Data >> 51) & 0x1F);
int b = (int)((Data >> 43) & 0x1F);
r1 = (r << 3) | ((r & 0x1C) >> 2);
g1 = (g << 3) | ((g & 0x1C) >> 2);
b1 = (b << 3) | ((b & 0x1C) >> 2);
r += (int)((Data >> 56) & 0x7) << 29 >> 29;
g += (int)((Data >> 48) & 0x7) << 29 >> 29;
b += (int)((Data >> 40) & 0x7) << 29 >> 29;
r2 = (r << 3) | ((r & 0x1C) >> 2);
g2 = (g << 3) | ((g & 0x1C) >> 2);
b2 = (b << 3) | ((b & 0x1C) >> 2);
}
else //'individual' mode
{
r1 = (int)((Data >> 60) & 0xF) * 0x11;
g1 = (int)((Data >> 52) & 0xF) * 0x11;
b1 = (int)((Data >> 44) & 0xF) * 0x11;
r2 = (int)((Data >> 56) & 0xF) * 0x11;
g2 = (int)((Data >> 48) & 0xF) * 0x11;
b2 = (int)((Data >> 40) & 0xF) * 0x11;
}
int Table1 = (int)((Data >> 37) & 0x7);
int Table2 = (int)((Data >> 34) & 0x7);
for (int y3 = 0; y3 < 4; y3++)
{
for (int x3 = 0; x3 < 4; x3++)
{
//if (x + j + x3 >= physicalwidth) continue;
//if (y + i + y3 >= physicalheight) continue;
int val = (int)((Data >> (x3 * 4 + y3)) & 0x1);
bool neg = ((Data >> (x3 * 4 + y3 + 16)) & 0x1) == 1;
uint c;
if ((flipbit && y3 < 2) || (!flipbit && x3 < 2))
{
int add = ETC1Modifiers[Table1, val] * (neg ? -1 : 1);
c = GFXUtil.ToArgb((byte)(((Alpha >> ((x3 * 4 + y3) * 4)) & 0xF) * 0x11), (byte)ColorClamp(r1 + add), (byte)ColorClamp(g1 + add), (byte)ColorClamp(b1 + add));
}
else
{
int add = ETC1Modifiers[Table2, val] * (neg ? -1 : 1);
c = GFXUtil.ToArgb((byte)(((Alpha >> ((x3 * 4 + y3) * 4)) & 0xF) * 0x11), (byte)ColorClamp(r2 + add), (byte)ColorClamp(g2 + add), (byte)ColorClamp(b2 + add));
}
Result[y3 * 4 + x3] = Color.FromArgb((int)c);
//res[(i + y3) * stride + x + j + x3] = c;
}
}
return(Result);
}
public static uint[] DecodeDTX1(ushort Color0, ushort Color1, uint Data)
{
uint[] Palette = new uint[4];
Palette[0] = GFXUtil.ConvertColorFormat(Color0, ColorFormat.RGB565, ColorFormat.ARGB8888);
Palette[1] = GFXUtil.ConvertColorFormat(Color1, ColorFormat.RGB565, ColorFormat.ARGB8888);
Color a = Color.FromArgb((int)Palette[0]);
Color b = Color.FromArgb((int)Palette[1]);
if (Color0 > Color1) //1/3 and 2/3
{
Palette[2] = GFXUtil.ToColorFormat((a.R * 2 + b.R * 1) / 3, (a.G * 2 + b.G * 1) / 3, (a.B * 2 + b.B * 1) / 3, ColorFormat.ARGB8888);
Palette[3] = GFXUtil.ToColorFormat((a.R * 1 + b.R * 2) / 3, (a.G * 1 + b.G * 2) / 3, (a.B * 1 + b.B * 2) / 3, ColorFormat.ARGB8888);
}
else //1/2 and transparent
{
Palette[2] = GFXUtil.ToColorFormat((a.R + b.R) / 2, (a.G + b.G) / 2, (a.B + b.B) / 2, ColorFormat.ARGB8888);
Palette[3] = 0;
}
uint[] Result = new uint[4 * 4];
int q = 30;
for (int y = 0; y < 4; y++)
{
for (int x = 0; x < 4; x++)
{
Result[y * 4 + x] = Palette[(Data >> q) & 3];
q -= 2;
}
}
return(Result);
}
