Pixel-Composer/shaders/sh_sdf_dist/sh_sdf_dist.fsh

varying vec2 v_vTexcoord;
varying vec4 v_vColour;

uniform sampler2D original;

uniform int side;
uniform int alpha;
uniform int invert;
uniform float max_distance;

void main() {
	vec4 col = texture2D( gm_BaseTexture, v_vTexcoord );
	float aa = alpha == 1? texture2D( original, v_vTexcoord ).a : 1.;
	
	if(col.xy == vec2(0.)) {
		gl_FragColor = vec4(vec3(0.), aa);
		return;
	}
	
	float dist = (max_distance - distance(col.xy, v_vTexcoord)) / max_distance;
	if(invert == 1) dist = 1. - dist;
	
	if((side == 0 && col.z == 0.) || (side == 1 && col.z == 1.)) {
		gl_FragColor = vec4(vec3(col.z), aa);
		return;
	}
	
    gl_FragColor = vec4(vec3(dist), aa);
}