refactor.rs

pub fn render_tiled(scene: Scene, settings: Settings) -> mpsc::Receiver<super::Tile> {
	let queue = Arc::new(MsQueue::new());
	let (sender, receiver) = mpsc::channel();

	// Split the backbuffer into tiles and push them into the queue
	{
		let mut x = 0;
		let mut y = 0;

		'gen_tiles: loop {
			let tile_min = (x, y);
			let tile_max = (
				(x + tile_size.0).min(self.width - 1),
				(y + tile_size.1).min(self.height - 1),
			);
			let width = tile_max.0 - tile_min.0;
			let height = tile_max.1 - tile_min.1;

			queue.push(super::Tile {
				sample_count: 0,
				left: tile_min.0,
				top: tile_min.1,
				width,
				height,
				data: vec![Vector3::new(0.0, 0.0, 0.0); width * height],
			});

			y += tile_size.1;
			if y >= self.height {
				y = 0;
				x += tile_size.0;
			}
			if x >= self.width {
				break 'gen_tiles;
			}
		}
	}

	for i in 0..settings.worker_count {
		let queue = queue.clone();
		let sender = sender.clone();
		
		// We clone both our scene and settings
		// This simplifies implementation
		let context = TraceContext {
			scene: scene.clone(),
			settings: settings.clone(),
		};

		thread::spawn(move || loop {
			let tile = queue.try_pop()?;

			for y in tile.top..(tile.top + tile.height) {
				for x in tile.left..(tile.left + tile.width) {
					let primary = generate_primary_ray(x, y, context.settings.camera_settings);
					let sample = trace(primary, &context);

					// Map the global pixel indices to the local tile buffer and store the sample
					tile.data[(x - tile.left) + (y - tile.top) * tile.width] += sample;
				}
			}

			tile.sample_count += 1;

			// Check if we are done
			if tile.sample_count == context.settings.sample_count {
				sender.send(tile);
				return Ok(());
			}

			// Check if we want to send our tile down the pipe
			if context.settings.samples_per_iteration != 0
				&& tile.sample_count % context.settings.samples_per_iteration == 0
			{
				sender.send(tile);
			}

			queue.push(tile);
		});
	}

	return receiver;
}

struct TraceContext {
	pub scene: Scene,
	pub settings: Settings,
}