#ifdef GL_ES
precision mediump float;
#endif

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

void main() {
    vec3 color = vec3(0);
		vec2 st = (gl_FragCoord.xy-.5*u_resolution.xy)/u_resolution.y;
		st *= u_time;

    float m = .5 - abs(sin(st.x));
		color += m;

		gl_FragColor = vec4(color,1.0);
}