#version 410

uniform float eyePos;

in vec3 colV;
out vec4 fragColor;

in vec3 viewPosV;


float mapRange(float x, float minIn, float maxIn, float minOut, float maxOut)
{
    x -= minIn;
    x = x * (maxOut - minOut) / (maxIn - minIn);
    x += minOut;
    if(minOut < maxOut)
        x = clamp(x, minOut, maxOut);
    else
        x = clamp(x, maxOut, minOut);
    return x;
}



void main (void)
{
    fragColor = vec4(colV, 1.0) / 3.0;
    float d = length(viewPosV);
    
    // fade out distance
    float viewDist1 = 10;
    float viewDist2 = 30;
    
    if(d > viewDist1)
    {
        fragColor.r *= mapRange(d, viewDist1, viewDist2, 1.0, 0.0);
        fragColor.g *= mapRange(d, viewDist1, viewDist2 * 2, 1.0, 0.0);
        float bb = mapRange(d, viewDist1, viewDist2 * 10, 1.0, 0.0);
        fragColor.b *= bb * bb;
    }
//    discard;
//    fragColor /= -viewPosV.z;
}