private void computeSubPixel(ImageSample sample, IntersectionState istate)
{
float x = sample.rx;
float y = sample.ry;
double q0 = QMC.halton(1, sample.i);
double q1 = QMC.halton(2, sample.i);
double q2 = QMC.halton(3, sample.i);
if (superSampling > 1)
{
// multiple sampling
sample.add(scene.getRadiance(istate, x, y, q1, q2, q0, sample.i));
for (int i = 1; i < superSampling; i++)
{
double time = QMC.mod1(q0 + i * invSuperSampling);
double lensU = QMC.mod1(q1 + QMC.halton(0, i));
double lensV = QMC.mod1(q2 + QMC.halton(1, i));
sample.add(scene.getRadiance(istate, x, y, lensU, lensV, time, sample.i + i));
}
sample.scale((float)invSuperSampling);
}
else
{
// single sample
sample.set(scene.getRadiance(istate, x, y, q1, q2, q0, sample.i));
}
}
private void renderBucket(IDisplay display, int bx, int by, int threadID, IntersectionState istate, ShadingCache cache)
{
// pixel sized extents
int x0 = bx * bucketSize;
int y0 = by * bucketSize;
int bw = Math.Min(bucketSize, imageWidth - x0);
int bh = Math.Min(bucketSize, imageHeight - y0);
// prepare bucket
display.imagePrepare(x0, y0, bw, bh, threadID);
Color[] bucketRGB = new Color[bw * bh];
float[] bucketAlpha = new float[bw * bh];
for (int y = 0, i = 0, cy = imageHeight - 1 - y0; y < bh; y++, cy--)
{
for (int x = 0, cx = x0; x < bw; x++, i++, cx++)
{
// sample pixel
Color c = Color.black();
float a = 0;
int instance = ((cx & ((1 << QMC.MAX_SIGMA_ORDER) - 1)) << QMC.MAX_SIGMA_ORDER) + QMC.sigma(cy & ((1 << QMC.MAX_SIGMA_ORDER) - 1), QMC.MAX_SIGMA_ORDER);
double jitterX = QMC.halton(0, instance);
double jitterY = QMC.halton(1, instance);
double jitterT = QMC.halton(2, instance);
double jitterU = QMC.halton(3, instance);
double jitterV = QMC.halton(4, instance);
for (int s = 0; s < numSamples; s++)
{
float rx = cx + 0.5f + (float)warpCubic(QMC.mod1(jitterX + s * invNumSamples));
float ry = cy + 0.5f + (float)warpCubic(QMC.mod1(jitterY + QMC.halton(0, s)));
double time = QMC.mod1(jitterT + QMC.halton(1, s));
double lensU = QMC.mod1(jitterU + QMC.halton(2, s));
double lensV = QMC.mod1(jitterV + QMC.halton(3, s));
ShadingState state = scene.getRadiance(istate, rx, ry, lensU, lensV, time, instance + s, 5, cache);
if (state != null)
{
c.add(state.getResult());
a++;
}
}
bucketRGB[i] = c.mul(invNumSamples);
bucketAlpha[i] = a * invNumSamples;
if (cache != null)
{
cache.reset();
}
}
}
// update pixels
display.imageUpdate(x0, y0, bw, bh, bucketRGB, bucketAlpha);
}
/**
* Get a QMC sample from a finite sequence of n elements. This provides
* better stratification than the infinite version, but does not allow for
* adaptive sampling.
*
* @param j sample number (starts from 0)
* @param dim dimension to sample
* @param n number of samples
* @return pseudo-random value in [0,1)
*/
public double getRandom(int j, int dim, int n)
{
switch (dim)
{
case 0:
return(QMC.mod1(qmcD0I + (double)j / (double)n));
case 1:
return(QMC.mod1(qmcD1I + QMC.halton(0, j)));
default:
return(QMC.mod1(QMC.halton(d + dim, i) + QMC.halton(dim - 1, j)));
}
}