// Cartoon shader II
// by guest(r)
// license: GNU-GPL

#ifdef GL_ES
precision mediump float;
#endif

const float th = 0.15;      // outlines sensitivity, recommended from 0.00...0.50
const float bb = 1.50;      // outlines strength,    recommended from 0.50...4.00
const float pp = 1.55;      // outlines blackening,  recommended from 0.25...2.00
const float cl = 7.00;      // color levels,         recommended form 2.00...10.0 

uniform sampler2D Sample;
varying vec4 TexCoord[8];

void main()

{

 vec3 uy = texture2D(Sample, TexCoord[1].xy).xyz; 
 vec3 lx = texture2D(Sample, TexCoord[4].xy).xyz; 
 vec3 rx = texture2D(Sample, TexCoord[5].xy).xyz; 
 vec3 dy = texture2D(Sample, TexCoord[2].xy).xyz; 
 vec3 ct = texture2D(Sample, TexCoord[0].xy).xyz; 
 vec3 dt = vec3(1.0,1.0,1.0);

 float d1 = 2.5*dot(abs(lx-rx),dt)/(dot(lx+rx,dt)+0.50);
 float d2 = 2.5*dot(abs(uy-dy),dt)/(dot(uy+dy,dt)+0.50);
 float d  = d1 + d2;

 float l = cl*length(ct)/1.73;
 float p = floor(l); 
 float v = fract(l); 

 float t = 0.33;
 if (p==0.0) t = 0.6;

 v = 0.6*(max(v-1.0+t,0.0))/t; 
 v = 1.73*(p+v)/cl + 0.05;
 
 gl_FragColor.xyz =(1.12-bb*pow(max(d-th,0.0),pp))*v*normalize(ct);
}