uniform float time;
uniform vec2 resolution;
uniform vec2 mouse;
uniform sampler2D backBuffer;

void main(void)
{

    vec2 uv = gl_FragCoord.xy/resolution.xy;
	vec3 col = texture2D(backBuffer,uv).xyz* (1.0 - ((length(gl_FragCoord.xy - vec2(mouse.x,resolution.y * (1.0 - mouse.y)) ) / 200.0) ) * 
	(( (length(gl_FragCoord.xy - vec2(600.0,300.0) ) / 200.0) )));

    gl_FragColor = vec4(col,1.0);
}