#version 330

in vec2 pass_textureCoords;

out vec4 out_color;

uniform vec3 color;
uniform sampler2D fontAtlas;

const float width = 0.5;
const float edge = 0.1;

const float borderWidth = 0.0;
const float borderEdge = 0.5;

const vec2 offset = vec2(0, 0.0);

const vec3 outlineColour = vec3(1.0,0.0,0.0);

void main(void){
	float distance = 1.0 - texture(fontAtlas, pass_textureCoords).a;
	float alpha = 1.0 - smoothstep(width, width + edge, distance);
	float distance2 = 1.0 - texture(fontAtlas, pass_textureCoords + offset).a;
	float outlineAlpha = 1.0 - smoothstep(borderWidth, borderWidth + borderEdge, distance2);
	float overallAlpha = alpha + (1.0 - alpha) * outlineAlpha;
	vec3 overallColor = mix(outlineColour, color, alpha / overallAlpha);
	out_color = vec4(overallColor, overallAlpha);
}