Moasic

#ifdef GL_ES
precision mediump float;
#define GLSLIFY 1
#endif

uniform vec2 u_resolution;
uniform float u_time;
uniform vec2 u_mouse;

#define GLSLIFY 1
float random (vec2 st_0) {
    return fract(sin(dot(st_0.xy, vec2(12.9898,78.233)))*43758.5453123);
}

void main() {
    vec2 st = gl_FragCoord.xy/u_resolution.xy;
    st *= 10.0; // Scale the coordinate system by 10
    vec2 ipos = floor(st);  // get the integer coords
    vec2 fpos = fract(st);  // get the fractional coords

    // Assign a random value based on the integer coord
    vec3 color = vec3(random( ipos ));
    // Uncomment to see the subdivided grid
    // color = vec3(fpos,0.0);

    gl_FragColor = vec4(color, 1.0);
}