From 1e0c44cc3d2fe4511ba2cec10b8b07c532f69c94 Mon Sep 17 00:00:00 2001
From: Rakarake <raka@rakarake.xyz>
Date: Sat, 27 Dec 2025 16:46:33 +0100
Subject: [PATCH] nice wavey pattern

---
 fragment.glsl | 33 ++++++++++++++++++++++-----------
 1 file changed, 22 insertions(+), 11 deletions(-)

diff --git a/fragment.glsl b/fragment.glsl
index 363f959..9018877 100644
--- a/fragment.glsl
+++ b/fragment.glsl
@@ -29,14 +29,15 @@ float rand(vec2 v, vec2 offset) {
     return float(hash) * (1.0/float(0xffffffffu));
 }
 
-float cell_size = 0.01;
+float cell_size = 0.04;
 #define PI 3.1415926538
 
 // whatever that corner contributes
-float c_dot(vec2 point, vec2 corner) {
+// vector_offset and angle_offset are optional variation variables
+float c_dot(vec2 point, vec2 corner, vec2 vector_offset, float angle_offset) {
     vec2 c = vec2(ivec2(round(corner * 100.0)));
-    float angle = rand(c, vec2(0.0, 0.0)) * 2.0*PI;
-    vec2 random_corner_vec = vec2(cos(angle), sin(angle));
+    float angle = rand(c, vec2(0.0, 0.0)) * 2.0*PI + angle_offset;
+    vec2 random_corner_vec = vec2(cos(angle), sin(angle)) + vector_offset;
     vec2 offset = (point - corner) / cell_size;
     float dot_product = dot(random_corner_vec, offset);
     // for now just return something
@@ -48,17 +49,17 @@ float fade(float t) {
 	return ((6.0*t - 15.0)*t + 10.0)*t*t*t;
 }
 
-float perlin_noise(vec2 uv) {
+float perlin_noise(vec2 uv, vec2 vector_offset, float angle_offset) {
     vec2 grid_edge_offset = mod(uv, cell_size);
     // c: corner
     vec2 c_tl = uv - grid_edge_offset;
     vec2 c_tr = uv - grid_edge_offset + vec2(cell_size, 0);
     vec2 c_bl = uv - grid_edge_offset + vec2(0,         cell_size);
     vec2 c_br = uv - grid_edge_offset + vec2(cell_size, cell_size);
-    float c_tl_dot = c_dot(uv, c_tl);
-    float c_tr_dot = c_dot(uv, c_tr);
-    float c_bl_dot = c_dot(uv, c_bl);
-    float c_br_dot = c_dot(uv, c_br);
+    float c_tl_dot = c_dot(uv, c_tl, vector_offset, angle_offset);
+    float c_tr_dot = c_dot(uv, c_tr, vector_offset, angle_offset);
+    float c_bl_dot = c_dot(uv, c_bl, vector_offset, angle_offset);
+    float c_br_dot = c_dot(uv, c_br, vector_offset, angle_offset);
 
     // the uv within the tile (0 to 1)
     vec2 tile_uv = (uv - c_tl) / cell_size;
@@ -76,6 +77,16 @@ void main() {
     // 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);
+    uv.y += sin(uv.x * 2.0 + time * 0.2) * 0.47;
+    uv.y += sin(uv.x * 4.3 + time * 1.34) * 0.09;
+    uv += 100.0;
+    //uv.x += time / 20.0;
+    float out_val = perlin_noise(uv, vec2(0.0, 0.0), time / 1.0);
+    float min = 0.42;
+    float max = 0.58;
+    out_val = out_val + sin(uv.y + time) / 15.2;
+    out_val = clamp(out_val, min, max);
+    out_val -= min;
+    out_val *= (1.0 - (max - min)) / (max - min);
+    color = vec4(out_val, 0.4, 0.8, 1.0);
 }