#version 410

uniform float eyePos;
uniform float time;

in vec3 colV;
in vec3 modelPosV;
in vec3 worldPosV;
in vec3 viewPosV;
in vec3 norV;
in vec2 uvV;

out vec4 fragColor;

vec3 mf(vec3 x)
{
    return x - floor(x);
}

void main (void)
{
    vec3 nNor = normalize(norV);
    vec3 colVL = colV;
    
    //    float k = sin(time) * 10.0 + 10.0;
    //    if(distance(worldPosV, vec3(0,0,0)) > k)
    //        discard;
    
    if(gl_FrontFacing)
    {
        // do the plaid-ing
        float sqF = .25;
        float w = 0.5;
        
        float plaidShade = 0.96;
        
        vec3 t = mf(modelPosV / sqF);
        if(t.x < w || t.y < w)
            colVL *= plaidShade;
        if(t.y < w || t.z < w)
            colVL *= plaidShade;
        if(t.z < w || t.x < w)
            colVL *= plaidShade;
    }
    
    fragColor = vec4(colVL,1);
    
    {
        // add a specular
        vec3 eyePos3 = vec3(0.0, 0.0, eyePos);
        float spec = dot(normalize(eyePos3 - viewPosV), normalize(nNor));
        spec = pow(spec,100.0);
        fragColor += vec4(spec, spec, spec, 1.0);
    }
}