precision mediump float;

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

mat2 rotate2d(float angle) {
    float s = sin(angle);
    float c = cos(angle);
    return mat2(c, -s, s, c);
}

vec2 hash22(vec2 p) {
    vec3 p3 = fract(vec3(p.xyx) * vec3(.1031, .1030, .0973));
    p3 += dot(p3, p3.yzx+33.33);
    return fract((p3.xx+p3.yz)*p3.zy);
}

float gridPattern(vec2 p) {
    vec2 i = floor(p);
    vec2 f = fract(p);
    
    vec2 h = hash22(i);
    float mouseInfluence = length(u_mouse - v_uv) * 2.0;
    
    p = rotate2d(u_time * 0.2) * p;
    
    vec2 grid = abs(fract(p - 0.5) - 0.5) / fwidth(p);
    float line = min(grid.x, grid.y);
    
    return smoothstep(1.5 + mouseInfluence, 0.5, line);
}

void main() {
    vec2 uv = v_uv;
    vec2 aspect = vec2(u_resolution.x/u_resolution.y, 1.0);
    uv *= aspect;
    
    vec2 p = uv;
    p = (p - 0.5) * 10.0;
    
    p.x -= p.y * 0.577350269;
    p.y *= 1.15470053838;
    
    float pattern = gridPattern(p);
    
    vec3 color1 = vec3(0.1, 0.4, 0.6);
    vec3 color2 = vec3(0.2, 0.9, 1.0);
    vec3 bgColor = vec3(0., 0.12, 0.15);
    
    vec3 finalColor = mix(bgColor, mix(color1, color2, pattern), pattern);
    
    float vignette = 1.0 - length(v_uv - 0.5) * 1.2;
    finalColor *= vignette;
    
    gl_FragColor = vec4(finalColor, 1.0);
    
    #include <colorspace_fragment>
}