Lenia: remove texture sampler, reduce gpu usage by ~45%

lenia-kernel/src/main.rs

@@ -10,18 +10,23 @@ fn main() {
 	let radius = args[0].parse().unwrap();
 	let k_offset = 0.435;
 	let k_sharpness = 28.0;
+	let precision = 50.0; // for rounding
 
 	let mut img = image::RgbImage::new(radius * 2 + 1, radius * 2 + 1);
 
 	let mut total_max = 0.0;
+	let mut total_lookups = 0;
 	println!("// generated by the rust program");
 	println!("#define RADIUS {}", radius);
 	println!("const half Kernel[{}][{}] = {{", radius + 1, radius);
 	for y in 0..=radius {
 		print!("	{{");
 		for x in 1..=radius {
-			let k = (k(x, y, radius, k_offset, k_sharpness) * 50.0).floor() / 50.0;
+			let k = (k(x, y, radius, k_offset, k_sharpness) * precision).floor() / precision;
 			total_max += k * 4.0;
+			if k > 0.0 {
+				total_lookups += 1;
+			}
 			print!("{:.2}, ", k);
 			{
 				let pixel = image::Rgb([0, (k * 255.0) as u8, 0]);
@@ -36,6 +41,12 @@ fn main() {
 	}
 	println!("}};");
 	println!("const float total_max = {};", total_max);
+	println!(
+		"// Total texture lookups: {} * 4 + 1 = {}",
+		total_lookups,
+		total_lookups * 4 + 1
+	);
+	println!("// (lookups multiplied by 0.0 get optimised away by the shader compiler, and this giant table generally only exists at compile time)");
 	img.save("kernel.png").unwrap();
 }