precision mediump float;

uniform float u_time;
uniform vec2 u_mouse;
uniform vec2 u_resolution;
varying vec2 v_uv;

float random(vec2 st) {
    return fract(sin(dot(st.xy, vec2(12.9898,78.233))) * 43758.5453123);
}

vec2 rotate2D(vec2 p, float angle) {
    float s = sin(angle);
    float c = cos(angle);
    return vec2(p.x * c - p.y * s, p.x * s + p.y * c);
}

float lines(vec2 pos, float b) {
    float scale = 10.0;
    pos *= scale;
    return smoothstep(0.0, 0.5 + b * 0.5, abs((sin(pos.x * 3.1415) + b * 2.0)));
}

void main() {
    vec2 st = v_uv;
    st.x *= u_resolution.x/u_resolution.y;
    
    vec2 mousePos = u_mouse - vec2(0.5);
    float dist = length(st - vec2(st.x * u_resolution.x/u_resolution.y, st.y) - mousePos);
    
    vec3 color = vec3(0.0);
    
    st = rotate2D(st, u_time * 0.2 + dist * 2.0);
    
    float pattern = lines(st, 0.5);
    
    vec3 color1 = vec3(0.9, 0.5, 0.9);
    vec3 color2 = vec3(0.3, 0, 0.4);
    
    color = mix(color1, color2, pattern + dist * 2.0);
    
    float noise = random(st + u_time * 0.1) * 0.02;
    color += noise;
    
    float vignette = 1.0 - length(v_uv - 0.5) * 1.2;
    color *= vignette;
    
    gl_FragColor = vec4(color, 1.0);
    
    #include <colorspace_fragment>
}