public static void TraceTile(TileTraceParameters tile, float[] backbuffer, out long rayCount)
{
InitBatchArray(ref _rays);
InitBatchArray(ref _hits);
InitBatchArray(ref _localColor);
Ray[] rays = _rays;
HitInfo[] hits = _hits;
Vector3[] localColor = _localColor;
uint rndState = FastRandom.Seed();
rayCount = 0;
for (int x = tile.xStart; x < tile.xEnd; x++)
{
for (int y = tile.yStart; y < tile.yEnd; y++)
{
Vector3 color = new Vector3(0, 0, 0);
// Sample bouncing batches
for (int b = 0; b < tile.runtimeParams.sampleBatchCount; b++)
{
// Calculate batch info
int batchStart = b * tile.runtimeParams.batchSize, batchEnd = batchStart + tile.runtimeParams.batchSize;
int batchRayCount = Math.Min(batchEnd, tile.parameters.samplesPerPixel);
batchRayCount -= batchStart;
uint hitMask = 0;
uint bounces = uint.MaxValue;
float u = x * tile.runtimeParams.invWidth, v = y * tile.runtimeParams.invHeight;
// Get initial rays
tile.parameters.camera.GetRays(u, v, rays, batchRayCount, ref rndState);
// Reset local colors
for (int i = 0; i < batchRayCount; i++)
{
localColor[i] = tile.parameters.ambientLight;
}
Vector3 atten;
int bounceCount = 0;
while (bounceCount < tile.parameters.maxBounces && bounces != 0)
{
tile.parameters.scene.Raycast(rays, hits, 0.01f, tile.parameters.maxDepth, batchRayCount, bounces, ref hitMask, ref rayCount);
if (hitMask == 0)
{
break;
}
bounces = 0;
for (int i = 0; i < batchRayCount; i++)
{
if (BitHelper.GetBit(ref hitMask, i)) // Did ray hit?
{
if (hits[i].material.Scatter(ref hits[i], out atten, ref rays[i], tile.parameters.scene, ref rndState))
{
BitHelper.SetBit(ref bounces, i);
}
localColor[i] *= atten;
}
}
bounceCount++;
}
for (int i = 0; i < batchRayCount; i++)
{
color += localColor[i];
}
}
color *= tile.runtimeParams.invSamplesPerPixel;
// Write backbuffer
int idx = (y * (tile.parameters.width * 3)) + (x * 3);
backbuffer[idx] = color.X;
backbuffer[idx + 1] = color.Y;
backbuffer[idx + 2] = color.Z;
}
}
}