cga shader

precision highp float;

varying vec3 n;
varying vec2 uv;

uniform sampler2D tex;
uniform vec2 resolution;


//#pragma include "noise2D.glsl // for snoise(vec2 v)
//#pragma include "noise3D.glsl" //  for snoise(vec3 v)
//#pragma include "noise4D.glsl" //  for snoise(vec4 v)
//#pragma include "cellular2D.glsl" //  for cellular(vec2 P)
//#pragma include "cellular2x2.glsl" //  for cellular2x2(vec2 P)
//#pragma include "cellular2x2x2.glsl" //  for cellular2x2x2(vec3 P)
//#pragma include "cellular3D.glsl" //  cellular(vec3 P)

void main(void)
{
	// constants & options
	vec2 pos = ( gl_FragCoord.xy / vec2(300.0) );
	const float grads = 3.0; // oolor levels
	vec3 clr[3];
	clr[0] = vec3(0.0,0.0,0.0);
	clr[1] = vec3(0.0,0.0,0.0);
	clr[2] = vec3(1.0,1.0,1.0);

	// clr[0] = vec3(1.0,0.0,0.0);
	// clr[1] = vec3(0.0,1.0,0.0);
	// clr[2] = vec3(0.0,0.0,1.0);
	
	
    // vec3 eyeSpaceLigthDirection = vec3(0.0,0.0,1.0);
    // float diffuse = max(0.0,dot(normalize(n),eyeSpaceLigthDirection));
    // texture2D(tex,uv).xyz*diffuse
    float gray = (texture2D(tex,uv).x + texture2D(tex,uv).y + texture2D(tex,uv).z) / 3.0;
    
    
    gray = floor(gray*grads) / grads;
    vec3 color = vec3(gray);
	for(int i=0;i<3;i++) {
		if(gray < 0.34*float(i+1) && gray >= 0.29*float(i)) {
			color = clr[i];
			if(i==1) {
				if(mod(gl_FragCoord.x,2.0) == mod(gl_FragCoord.y,2.0)) {
					color = clr[2];
				}
			}
		}
	}
	


	
	// vec3(gl_FragCoord.x/300.0)
	gl_FragColor = vec4( color, 1.0);
}