From d5829527c18208a290b2f48e2cdbd8265879cc83 Mon Sep 17 00:00:00 2001
From: Rakarake <raka@rakarake.xyz>
Date: Sat, 27 Dec 2025 14:34:02 +0100
Subject: [PATCH] perlin noise function

---
 fragment.glsl | 20 +++++++++++---------
 1 file changed, 11 insertions(+), 9 deletions(-)

diff --git a/fragment.glsl b/fragment.glsl
index c6cbb79..363f959 100644
--- a/fragment.glsl
+++ b/fragment.glsl
@@ -48,14 +48,7 @@ float fade(float t) {
 	return ((6.0*t - 15.0)*t + 10.0)*t*t*t;
 }
 
-
-void main() {
-    vec2 uv = gl_FragCoord.xy / WindowSize;
-    // We'll make origin in the top-left.
-    uv.y = 1.0 - uv.y;
-    float frac = WindowSize.x / WindowSize.y;
-    uv.x *= frac;
-
+float perlin_noise(vec2 uv) {
     vec2 grid_edge_offset = mod(uv, cell_size);
     // c: corner
     vec2 c_tl = uv - grid_edge_offset;
@@ -74,6 +67,15 @@ void main() {
     float u = fade(tile_uv.x);
     float v = fade(tile_uv.y);
     float val = lerp(lerp(c_tl_dot, c_bl_dot, v), lerp(c_tr_dot, c_br_dot, v), u);
-    float out_val = val /2.0 + 0.5;
+    return val /2.0 + 0.5;
+}
+
+
+void main() {
+    vec2 uv = gl_FragCoord.xy / WindowSize;
+    // We'll make origin in the top-left.
+    uv.y = 1.0 - uv.y;
+    uv.x *= WindowSize.x / WindowSize.y;
+    float out_val = perlin_noise(uv);
     color = vec4(out_val, out_val, out_val, 1.0);
 }