uniform float time;
    uniform vec2 resolution;

    float shape(vec2 st, float radius) {
        st = vec2(0.5)-st;
        float r = length(st)*2.0;
        float a = atan(st.y,st.x);
        float m = abs(mod(a+time*2.,3.14*2.)-3.14)/3.6;
        float f = radius;
        f += (sin(a*10.)*.1*pow(m,2.));
        return 1.-step(f,r);
    }

    void main( void ) {

        vec3 yellow = vec3(1.0,1.0,.0);
        vec3 red = vec3(1.0,0.0,.0);
        vec3 blue = vec3(0.0,0.0,1.0);
        vec3 pink = vec3(1.0,0.0,1.0);

        vec2 st = gl_FragCoord.xy/resolution.xy;
        vec3 color = vec3(shape(st,0.8)) * blue;
        color += vec3(shape(st - vec2(0.2),0.8)) * yellow;
        color += vec3(shape(st - vec2(0.1, 0.0),0.8)) * pink;

        gl_FragColor = vec4( color, 1.0 );
        gl_FragColor.rgb *= gl_FragColor.a;

    }