varying vec2 v_vTexcoord;
varying vec4 v_vColour;

uniform vec2 dimension;
uniform int  edge;

uniform vec2      width;
uniform int       widthUseSurf;
uniform sampler2D widthSurf;

uniform float blend;

void main() {
	float wid    = width.x;
	float widMax = max(width.x, width.y);
	if(widthUseSurf == 1) {
		vec4 _vMap = texture2D( widthSurf, v_vTexcoord );
		wid = mix(width.x, width.y, (_vMap.r + _vMap.g + _vMap.b) / 3.);
	}
	
	float bnd = 1. - blend;
	vec4  off;
	float m = 0.;
	vec2  v  = 1. - max(vec2(0.), abs(v_vTexcoord - 0.5) * 2. / wid - bnd) / (1. - bnd);
	vec2  vi = 1. - max(vec2(0.), (1. - abs(v_vTexcoord - 0.5) * 2.) / wid - bnd) / (1. - bnd);
	float mi = 1. - max(vi.x, vi.y);
	
	     if(edge == 0) m = min(max(v.x, v.y), max(v.x, v.y) + mi - 1.);
	else if(edge == 1) m = v.x;
	else if(edge == 2) m = v.y;
	
	m = clamp(m, 0., 1.);
	//m = smoothstep(0., 1., m);
	
	gl_FragColor = vec4(vec3(m), 1.);
}