| public setIndex ( uint index, uint value ) : void | ||
| index | uint | |
| value | uint | |
| return | void | |
static uint computeAlphaIndices(AlphaBlock4x4 src, AlphaBlockDXT5 block)
{
byte[] alphas = new byte[8];
block.evaluatePalette(alphas, false); // @@ Use target decoder.
uint totalError = 0;
for (uint i = 0; i < 16; i++)
{
byte alpha = src.alpha[i];
uint besterror = 256 * 256;
uint best = 8;
for (uint p = 0; p < 8; p++)
{
int d = alphas[p] - alpha;
uint error = (uint)(d * d);
if (error < besterror)
{
besterror = error;
best = p;
}
}
//nvDebugCheck(best < 8);
totalError += besterror;
block.setIndex(i, best);
}
return(totalError);
}
static void computeAlphaIndices_RGBM(ColorSet src, ColorBlock RGB, AlphaBlockDXT5 dst)
{
byte[] alphas = new byte[8];
dst.evaluatePalette(alphas, /*d3d9=*/ false); // @@ Use target decoder.
for (uint i = 0; i < 16; i++)
{
float R = src.color[i].x;
float G = src.color[i].y;
float B = src.color[i].z;
float r = (float)(RGB.color[i].r) / 255.0f;
float g = (float)(RGB.color[i].g) / 255.0f;
float b = (float)(RGB.color[i].b) / 255.0f;
float minDist = float.MaxValue;
uint bestIndex = 8;
for (uint p = 0; p < 8; p++)
{
// Compute M.
float M = (float)(alphas[p]) / 255.0f * (1 - threshold) + threshold;
// Decode color.
float fr = r * M;
float fg = g * M;
float fb = b * M;
// Measure error.
float error = Mathf.Pow(R - fr, 2) + Mathf.Pow(G - fg, 2) + Mathf.Pow(B - fb, 2);
if (error < minDist)
{
minDist = error;
bestIndex = p;
}
}
dst.setIndex(i, bestIndex);
}
}
static void computeAlphaIndices(AlphaBlock4x4 src, AlphaBlockDXT5 dst)
{
byte[] alphas = new byte[8];
dst.evaluatePalette(alphas, /*d3d9=*/ false); // @@ Use target decoder.
for (uint i = 0; i < 16; i++)
{
byte alpha = src.alpha[i];
uint minDist = int.MaxValue;
uint bestIndex = 8;
for (uint p = 0; p < 8; p++)
{
uint dist = alphaDistance(alpha, alphas[p]);
if (dist < minDist)
{
minDist = dist;
bestIndex = p;
}
}
dst.setIndex(i, bestIndex);
}
}
static void computeAlphaIndices_RGBM(ColorSet src, ColorBlock RGB, AlphaBlockDXT5 dst)
{
byte[] alphas = new byte[8];
dst.evaluatePalette(alphas, /*d3d9=*/false); // @@ Use target decoder.
for (uint i = 0; i < 16; i++)
{
float R = src.color[i].x;
float G = src.color[i].y;
float B = src.color[i].z;
float r = (float)(RGB.color[i].r) / 255.0f;
float g = (float)(RGB.color[i].g) / 255.0f;
float b = (float)(RGB.color[i].b) / 255.0f;
float minDist = float.MaxValue;
uint bestIndex = 8;
for (uint p = 0; p < 8; p++)
{
// Compute M.
float M = (float)(alphas[p]) / 255.0f * (1 - threshold) + threshold;
// Decode color.
float fr = r * M;
float fg = g * M;
float fb = b * M;
// Measure error.
float error = Mathf.Pow(R - fr, 2) + Mathf.Pow(G - fg, 2) + Mathf.Pow(B - fb, 2);
if (error < minDist)
{
minDist = error;
bestIndex = p;
}
}
dst.setIndex(i, bestIndex);
}
}
static void computeAlphaIndices(AlphaBlock4x4 src, AlphaBlockDXT5 dst)
{
byte[] alphas = new byte[8];
dst.evaluatePalette(alphas, /*d3d9=*/false); // @@ Use target decoder.
for (uint i = 0; i < 16; i++)
{
byte alpha = src.alpha[i];
uint minDist = int.MaxValue;
uint bestIndex = 8;
for (uint p = 0; p < 8; p++)
{
uint dist = alphaDistance(alpha, alphas[p]);
if (dist < minDist)
{
minDist = dist;
bestIndex = p;
}
}
dst.setIndex(i, bestIndex);
}
}
static void optimizeAlpha8(AlphaBlock4x4 src, AlphaBlockDXT5 block)
{
float alpha2_sum = 0;
float beta2_sum = 0;
float alphabeta_sum = 0;
float alphax_sum = 0;
float betax_sum = 0;
for (uint i = 0; i < 16; i++)
{
uint idx = block.index(i);
float alpha;
if (idx < 2)
{
alpha = 1.0f - idx;
}
else
{
alpha = (8.0f - idx) / 7.0f;
}
float beta = 1 - alpha;
alpha2_sum += alpha * alpha;
beta2_sum += beta * beta;
alphabeta_sum += alpha * beta;
alphax_sum += alpha * src.alpha[i];
betax_sum += beta * src.alpha[i];
}
float factor = 1.0f / (alpha2_sum * beta2_sum - alphabeta_sum * alphabeta_sum);
float a = (alphax_sum * beta2_sum - betax_sum * alphabeta_sum) * factor;
float b = (betax_sum * alpha2_sum - alphax_sum * alphabeta_sum) * factor;
byte alpha0 = (byte)(Math.Min(Math.Max(a, 0.0f), 255.0f));
byte alpha1 = (byte)(Math.Min(Math.Max(b, 0.0f), 255.0f));
if (alpha0 < alpha1)
{
swap(ref alpha0, ref alpha1);
// Flip indices:
for (uint i = 0; i < 16; i++)
{
uint idx = block.index(i);
if (idx < 2)
{
block.setIndex(i, 1 - idx);
}
else
{
block.setIndex(i, 9 - idx);
}
}
}
else if (alpha0 == alpha1)
{
for (uint i = 0; i < 16; i++)
{
block.setIndex(i, 0);
}
}
block.alpha0 = alpha0;
block.alpha1 = alpha1;
}