uniform vec2 iResolution;
float pattern(vec2 uv) {
uv = uv * 2.0 - 1.0;
float t = pow(uv.x * uv.x, 0.3) + pow(uv.y * uv.y, 0.3) - 1.0;
return step(0.0, t) * t * 10.0 + step(0.2, t);
}
void main() {
// Normalized pixel coordinates (from 0 to 1)
vec2 uv = gl_FragCoord.xy / iResolution.xy;
gl_FragColor = vec4(pattern(uv), 0.0, 0.0, 1.0);
}
