uniform sampler2D texture;
varying vec2 rcoords;
const float twopi = 6.28318530718;

void main() {
	float r = length(rcoords);
	if(r >= 1.0 || r < 0.0)
		discard;
	
	float a = atan(rcoords.y, rcoords.x) / twopi;
	vec4 col = gl_Color;
	col.a *= texture2D(texture, vec2(a,r)).r;
	if(col.a < 1.0 / 255.0)
		discard;
	
	gl_FragColor = col;
}