private void AntiAliasXSpan(RectangleInt viewport, Scene scene, ColorF[][] imageBufferAsDoubles, int maxSamples, int y)
{
for (int x = 1; x < viewport.Width - 1; x++)
{
ColorF avg = (imageBufferAsDoubles[x - 1][y - 1] + imageBufferAsDoubles[x][y - 1] + imageBufferAsDoubles[x + 1][y - 1] +
imageBufferAsDoubles[x - 1][y] + imageBufferAsDoubles[x][y] + imageBufferAsDoubles[x + 1][y] +
imageBufferAsDoubles[x - 1][y + 1] + imageBufferAsDoubles[x][y + 1] + imageBufferAsDoubles[x + 1][y + 1]) / 9;
// use a more accurate anti-aliasing method (MonteCarlo implementation)
// this will fire multiple rays per pixel
double sumOfDifferencesThreshold = .05; // TODO: figure out a good way to determine this.
if (avg.SumOfDistances(imageBufferAsDoubles[x][y]) > sumOfDifferencesThreshold)
{
ColorF accumulatedColor = imageBufferAsDoubles[x][y];
for (int i = 0; i < maxSamples; i++)
{
// get some 'random' samples
double rx = Math.Sign(i % 4 - 1.5) * (IntNoise(x + y * viewport.Width * maxSamples * 2 + i) + 1) / 4;
double ry = Math.Sign(i % 2 - 0.5) * (IntNoise(x + y * viewport.Width * maxSamples * 2 + 1 + i) + 1) / 4;
double xp = x + rx;
double yp = y + ry;
Ray ray = scene.camera.GetRay(xp, yp);
accumulatedColor += FullyTraceRay(ray, scene, out _);
}
imageBufferAsDoubles[x][y] = accumulatedColor / (maxSamples + 1);
}
}
}
