struct appdata_full {
    vec4 vertex;
    vec3 normal;
};
struct v2f {
    vec4 pos;
    vec3 backContrib;
    vec3 nl;
};
uniform vec3 _TerrainTreeLightDirections[4];
uniform float _TranslucencyViewDependency;

v2f vert(in appdata_full v)
{
    v2f o;
    vec3 viewDir;
    o.pos = v.vertex;
    viewDir = v.vertex.xyz;

    // Do we unroll this loop?
    // At some point we didn't since the loop body was deemed "too large"
    for (int j = 0; j < 3; j++)
    {
        vec3 lightDir = _TerrainTreeLightDirections[j];
        float nl = dot(v.normal, lightDir);
        float backContrib = dot(viewDir, -lightDir);
        o.backContrib[ j ] = mix(-nl, backContrib, _TranslucencyViewDependency);
        o.nl[ j ] = max(0.0, (nl * 0.6) + 0.4);
    }
    return o;
}

void main() {
    v2f xl_retval;
    appdata_full xlt_v;
    xlt_v.vertex = gl_Vertex;
    xlt_v.normal = gl_Normal;
    xl_retval = vert(xlt_v);
    gl_Position = xl_retval.pos;
    gl_TexCoord[2] = vec4(xl_retval.backContrib, 0.0);
    gl_TexCoord[3] = vec4(xl_retval.nl, 0.0);
}