// Update the texture with a portion of the given film.
public void UpdateTileFromFilm(Bounds2 <int> tileBounds, Film film)
{
foreach (var posFilm in tileBounds.IteratePoints())
{
if (posFilm.X >= 0 && posFilm.X < Program.Width && posFilm.Y >= 0 && posFilm.Y < Program.Height)
{
var pixel = film.GetPixel(posFilm);
var color = pixel.contribSum / pixel.filterWeightSum;
var offset = (posFilm.Y * Width + posFilm.X) * 4; // BGRA
bitmap[offset + 0] = (byte)Math.Min(255, color.B * 255);
bitmap[offset + 1] = (byte)Math.Min(255, color.G * 255);
bitmap[offset + 2] = (byte)Math.Min(255, color.R * 255);
}
}
}
public override void Render(Scene scene, Camera camera, IWindow window)
{
Preprocess(scene);
// Compute the number of tiles to use
var sampleBounds = camera.Film.GetSampleBounds();
var sampleExtent = sampleBounds.Diagonal();
var nTiles = new Vector2 <int>(
(sampleExtent.X + Program.TileSize - 1) / Program.TileSize,
(sampleExtent.Y + Program.TileSize - 1) / Program.TileSize);
// Render tiles in parallel
//Parallel.For(0, nTiles.X * nTiles.Y, tile =>
Parallel.For(0, nTiles.X * nTiles.Y, new ParallelOptions {
MaxDegreeOfParallelism = Program.ThreadCount
}, tile =>
{
var tileX = tile % nTiles.X;
var tileY = tile / nTiles.X;
// Get a sampler instance for the current tile
var seed = tileY * nTiles.X + tileX;
var tileSampler = Sampler.Clone(seed);
// Compute the extent of pixels to be sampled in this tile
var x0 = sampleBounds.Min.X + tileX * Program.TileSize;
var x1 = Math.Min(x0 + Program.TileSize, sampleBounds.Max.X);
var y0 = sampleBounds.Min.Y + tileY * Program.TileSize;
var y1 = Math.Min(y0 + Program.TileSize, sampleBounds.Max.Y);
var tileBounds = new Bounds2 <int>(new Point2 <int>(x0, y0), new Point2 <int>(x1, y1));
var filmTile = camera.Film.GetTile(tileBounds);
MarkTile(tileBounds);
// Loop over the pixels in the tile
foreach (var pixel in tileBounds.IteratePoints())
{
tileSampler.StartPixel(pixel);
do
{
var cameraSample = tileSampler.GetCameraSample(pixel);
if (pixel.X == 48 && pixel.Y == 209)
{
}
// Generate a camera ray for the current sample
var rayWeight = camera.GenerateRayDifferential(cameraSample, out RayDifferential ray);
ray.ScaleDifferentials((float)(1.0f / Math.Sqrt(tileSampler.SamplesPerPixel)));
// Evaluate radiance along the camera ray
var L = Spectrum.Zero;
if (rayWeight > 0)
{
L = Li(ray, scene, camera, tileSampler);
}
// TODO check invalid radiance
// Add the ray's contribution to the image
filmTile.AddSample(cameraSample.PosFilm, L, rayWeight);
} while (tileSampler.StartNextSample());
}
// Merge the tile into the film
camera.Film.MergeTile(filmTile);
//Thread.Sleep(100);
UnmarkTile(tileBounds);
UpdateTileFromFilm(tileBounds, camera.Film);
});
}