#define pi 3.141592653589793238462643383279
#define twopi (pi * 2.0)
uniform float dist;
uniform float scale;
uniform float minRad;
uniform float maxRad;
varying vec2 rcoords;

void main() {
	float modDist = dist / scale;
	float width = 0.02 * max(min(modDist / 10.0, 5.0), 1.0);
	float r = length(rcoords);
	if(r >= 1.0 || r < 1.0 - width)
		discard;

	float ang = atan(rcoords.y, rcoords.x);
	if(ang < minRad && ang > maxRad - twopi)
		discard;
	if(ang > maxRad && ang < minRad + twopi)
		discard;
	
	float bdist = r - (1.0 - width);

	vec4 col = gl_Color;
	col.a = 0.5;
	col.a *= min(bdist / (width * 0.5), (width - bdist) / (width * 0.5));
	col.a *= 1.0 - smoothstep(30.0, 70.0, modDist);
	gl_FragColor = col;
}