shader_type canvas_item;

uniform float textureSize = 400.0;
uniform vec3 fillColor:source_color = vec3(1.0,0.0,0.0);
uniform vec3 borderColor:source_color = vec3(1.0,1.0,1.0);
uniform float borderWidth = 0.1;
uniform vec2 angles = vec2(0.2,0.4);
uniform float smoothWidth:hint_range(0.0001, 0.1, 0.0001) = 0.01;

void vertex() {

}

//vec2 polar_coordinates(vec2 uv, vec2 center, vec2 tps) {
//	vec2 dir = uv - center*textureSize*tps.x;
//	dir = vec2(dir.y,-dir.x);
//	float radius = length(dir) * 2.0;
//	float angle = atan(dir.y, dir.x) * 1.0/(3.1416 * 2.0);
//	return vec2(radius/(textureSize*tps.x), angle + 0.5);
//}

float sd_circle(vec2 norm_uv,float radius){
	float d = distance(norm_uv,vec2(0.0));
	return d - radius;
}

float sd_line(vec2 norm_uv){
	return norm_uv.x;
}

vec2 rotate_uv(vec2 norm_uv, float angle_normal){
	float angle_rad = angle_normal * 2.0 * PI;
	mat2 rotation = mat2(vec2( cos(angle_rad), sin(angle_rad)),
						 vec2(-sin(angle_rad), cos(angle_rad)));
	return norm_uv * rotation;
}

vec2 normalize_uv(vec2 uv,vec2 tps){
	vec2 zeroToOne = uv / (textureSize*tps);
	return zeroToOne*2.0-1.0;
}

void fragment() {
	//vec2 pc = polar_coordinates(UV,vec2(0.5,0.5),TEXTURE_PIXEL_SIZE);
	//bool isIn = pc.x<1.0 && pc.y > 0.2 && pc.y < 0.9;
	////bool isIn = TEXTURE_PIXEL_SIZE.x < 1.0/3.99;
	////COLOR = vec4(pc.x,pc.y,0,1);
	//COLOR.a = isIn?1.0f:0.0f;
	//COLOR.rgb = (pc.x > 1.0-borderWidth)?borderColor:fillColor;
	vec2 normal_uv = normalize_uv(UV,TEXTURE_PIXEL_SIZE);
	//vec2 normal_uv = VERTEX;
	bool isBigAngle = angles.y - angles.x >0.5;
	float line1 = sd_line(rotate_uv(normal_uv,angles.x));
	float line2 = sd_line(rotate_uv(normal_uv,angles.y));
	float linesCombined = isBigAngle ? min(-line1,line2):max(-line1,line2);
	float circle = sd_circle(normal_uv,0.95);
	float final_distance = max(linesCombined,circle);
	//float final_distance = sd_line(normal_uv);
	COLOR.a = 1.0-smoothstep(0.0,1.0, final_distance/smoothWidth);
	//COLOR.r = 0.0;
	//COLOR.g = 0.0;
	//COLOR.b = 0.0;
	//COLOR.rg = VERTEX*SCREEN_PIXEL_SIZE;
	//COLOR.rg = UV*TEXTURE_PIXEL_SIZE;
	//COLOR.rg = center;
	COLOR.rgb = fillColor;
}

//void light() {
//	// Called for every pixel for every light affecting the CanvasItem.
//	// Uncomment to replace the default light processing function with this one.
//}