precision mediump float;

#endif

​

uniform vec2 u_resolution;

uniform float u_time;

uniform vec2 u_mouse;

uniform sampler2D u_img;

​

void main() {

  vec2 coord = gl_FragCoord.xy / u_resolution;

  vec3 color = vec3(0.0);

  vec4 image = texture2D(u_img, coord);

  image.r += 0.3;

  image.b += sin(coord.x * 5.0) * abs(cos(u_time * 10.0));

  image.g -= 0.7;

  gl_FragColor = vec4(image);

}