erm

fragment.glsl

@@ -7,7 +7,27 @@ float rand(vec2 co){
     return fract(sin(dot(co, vec2(12.9898, 78.233))) * 43758.5453);
 }
 
-float cell_size = 0.1;
+float cell_size = 0.05;
+
+#define PI 3.1415926538
+
+// whatever that corner contributes
+float c_dot(vec2 point, vec2 corner) {
+    float angle = rand(corner) * 2*PI;
+    vec2 random_corner_vec = vec2(cos(angle), sin(angle));
+    vec2 offset = point - corner;
+    float dot_product = dot(random_corner_vec, offset);
+    // for now just return something
+    return dot_product;
+}
+
+float lerp(float a, float b, float x) {
+    return a + x*(b-a);
+}
+
+float fade(float t) {
+	return ((6*t - 15)*t + 10)*t*t*t;
+}
 
 void main() {
     // We'll make origin in the top-left.
@@ -19,16 +39,22 @@ void main() {
     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);
-    // random vectors
-    vec2 c_tl_ran = rand(c_tl);
-    vec2 c_tr_ran = rand(c_tr);
-    vec2 c_bl_ran = rand(c_bl);
-    vec2 c_br_ran = rand(c_br);
-    // offset vectors
-    vec2 c_tl_off = c_tl - uv;
-    vec2 c_tr_off = c_tr - uv;
-    vec2 c_bl_off = c_bl - uv;
-    vec2 c_br_off = c_br - uv;
+    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);
 
-    FragColor = 
+    // lerp index
+    vec2 tile_uv = (uv - c_tl) / cell_size;
+    float u = fade(tile_uv.x);
+    float v = fade(tile_uv.y);
+    //float val = smoothstep(tile_uv.x, smoothstep(tile_uv.y, c_bl_dot, c_tl_dot), smoothstep(tile_uv.y, c_br_dot, c_tr_dot));
+    float val = lerp(lerp(c_tl_dot, c_bl_dot, v), lerp(c_tr_dot, c_br_dot, v), u);
+    //float val = tile_uv.y;
+    //float val = c_bl_dot*2 + 0.5;
+    val = val * 20;
+    FragColor = vec4(val, val, val, 1);
+
+    //float yes = 0.5 + (c_dot(uv, c_tl) + c_dot(uv, c_tr) + c_dot(uv, c_bl) + c_dot(uv, c_br)) / 2;
+    //FragColor = vec4(yes, yes, yes, 1);
 }