From c25573db879c5e4050b1e07ff95ebbe954206108 Mon Sep 17 00:00:00 2001
From: numzero <numzer0@yandex.ru>
Date: Sat, 11 Jan 2025 16:00:37 +0300
Subject: [PATCH] Replace textureGathers with textureLoads

---
 src/main.rs   | 25 ++++---------------------
 src/step.wgsl | 26 +++++++++++++++++++-------
 2 files changed, 23 insertions(+), 28 deletions(-)

diff --git a/src/main.rs b/src/main.rs
index e14e0eb..8cf4458 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -122,17 +122,6 @@ fn main() {
 		cache: None,
 	});
 
-	let state_sampler = device.create_sampler(&wgpu::SamplerDescriptor {
-		label: None,
-		address_mode_u: wgpu::AddressMode::Repeat,
-		address_mode_v: wgpu::AddressMode::Repeat,
-		address_mode_w: wgpu::AddressMode::Repeat,
-		mag_filter: wgpu::FilterMode::Nearest,
-		min_filter: wgpu::FilterMode::Nearest,
-		mipmap_filter: wgpu::FilterMode::Nearest,
-		..Default::default()
-	});
-
 	let mut state = None;
 	#[allow(deprecated)]
 	event_loop
@@ -253,16 +242,10 @@ fn main() {
 						&device.create_bind_group(&wgpu::BindGroupDescriptor {
 							label: None,
 							layout: &step_pipeline.get_bind_group_layout(0),
-							entries: &[
-								wgpu::BindGroupEntry {
-									binding: 0,
-									resource: wgpu::BindingResource::TextureView(&state.last),
-								},
-								wgpu::BindGroupEntry {
-									binding: 1,
-									resource: wgpu::BindingResource::Sampler(&state_sampler),
-								},
-							],
+							entries: &[wgpu::BindGroupEntry {
+								binding: 0,
+								resource: wgpu::BindingResource::TextureView(&state.last),
+							}],
 						}),
 						&[],
 					);
diff --git a/src/step.wgsl b/src/step.wgsl
index 3f9906d..70ae300 100644
--- a/src/step.wgsl
+++ b/src/step.wgsl
@@ -12,16 +12,28 @@ fn on_vertex(@builtin(vertex_index) vi: u32) -> Varying {
 }
 
 @group(0) @binding(0) var field: texture_2d<u32>;
-@group(0) @binding(1) var smp: sampler;
 
 @fragment
 fn on_fragment(in: Varying) -> @location(0) u32 {
-	let a = textureGather(0, field, smp, in.uv, vec2(0, 0));
-	let b = textureGather(0, field, smp, in.uv, vec2(0, 1));
-	let c = textureGather(0, field, smp, in.uv, vec2(1, 0));
-	let d = textureGather(0, field, smp, in.uv, vec2(1, 1));
-	let state = a.y;
-	let n = a.x + a.z + a.w + b.x + b.y + c.y + c.z + d.y;
+	let dim = vec2i(textureDimensions(field));
+	let center = vec2i(in.screen.xy);
+	var nb: array<array<u32, 3>, 3>;
+	for (var j = 0; j < 3; j++) {
+		for (var i = 0; i < 3; i++) {
+			let off = vec2i(i, j);
+			let coords = (center + off + dim - 1) % dim;
+			let px = textureLoad(field, coords, 0);
+			nb[j][i] = px.x;
+		}
+	}
+	let state = nb[1][1];
+	var n = 0u;
+	for (var j = 0; j < 3; j++) {
+		for (var i = 0; i < 3; i++) {
+			n += nb[i][j];
+		}
+	}
+	n -= state;
 	switch (n) {
 	case 3u: { return 1u; }
 	case 4u: { return state; }