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CSharp · Console

/Program.cs

using System.Numerics;
using System.Linq;
using System;
using System.Diagnostics;

struct SampleBucket
{
	public int X;
	public int Y;
	public int W;
	public int H;
	public SampleLocation[] SampleLocations;
}

struct SampleLocation
{
	public uint PixelX;
	public uint PixelY;
	public int Index;
}
public class Test {


	public static void Main(string[] args) {

		const int NOOP = int.MinValue;
		

		const int PartitionSize = 32;


		int textureWidth = 416;
		int textureHeight = 452;
		int partitionsX = Math.Max((textureWidth / PartitionSize),1);
		int partitionsY = Math.Max((textureHeight / PartitionSize), 1);

		SampleLocation[] sampleLocations = new SampleLocation[1] {
			new SampleLocation() {
			PixelX = 51,
			PixelY = 448
			}
		};


		SampleBucket[] buckets = new SampleBucket[(partitionsX * partitionsY)];
		for(int x=0; x < partitionsX; ++x)
		{
			for(int y = 0;y < partitionsY; ++y)
			{
				int idx = x + (y * partitionsX);
				var bucketX = x * PartitionSize;
				var bucketY = y * PartitionSize;
				var bucketWidth = PartitionSize;
				var bucketHeight = PartitionSize;

				bucketWidth = Math.Min(bucketX + bucketWidth, (int)textureWidth) - bucketX;
				bucketHeight = Math.Min(bucketY + bucketHeight, (int)textureHeight) - bucketY;

				Debug.Assert(bucketWidth > 0);
				Debug.Assert(bucketHeight > 0);
				buckets[idx] = new SampleBucket()
				{
					X = bucketX,
					Y = bucketY,
					W = bucketWidth,
					H = bucketHeight,
					SampleLocations = Enumerable.Repeat(new SampleLocation() { Index = NOOP}, bucketWidth * bucketHeight).ToArray()
				};
			}
		}
		foreach(var l in sampleLocations)
		{
			int bucketX = (int)(l.PixelX / PartitionSize);
			int bucketY = (int)(l.PixelY / PartitionSize);
			int bucketIdx = bucketX + bucketY * partitionsX; 
			Debug.Assert(bucketIdx < buckets.Length);
			var bucket = buckets[bucketIdx];
			var locations = bucket.SampleLocations;
			var sampleX = l.PixelX - bucket.X;
			var sampleY = l.PixelY - bucket.Y;
			var sampleIdx = sampleX + sampleY * bucket.W;
			Debug.Assert(sampleIdx < locations.Length);
			locations[sampleIdx] = l;
		}
	}
}