CodeChickenCore/codechicken/lib/lighting/LC.java

package codechicken.lib.lighting;

import codechicken.lib.render.CCModel;
import codechicken.lib.util.Copyable;
import codechicken.lib.vec.Rotation;
import codechicken.lib.vec.Vector3;

public class LC implements Copyable<LC>
{
    public int side;
    public float fa;
    public float fb;
    public float fc;
    public float fd;

    public LC() {
        this(0, 0, 0, 0, 0);
    }

    public LC(int s, float a, float b, float c, float d) {
        side = s;
        fa = a;
        fb = b;
        fc = c;
        fd = d;
    }

    public LC set(int s, float a, float b, float c, float d) {
        side = s;
        fa = a;
        fb = b;
        fc = c;
        fd = d;
        return this;
    }

    public LC set(LC lc) {
        return set(lc.side, lc.fa, lc.fb, lc.fc, lc.fd);
    }

    public LC compute(Vector3 vec, Vector3 normal) {
        int side = CCModel.findSide(normal);
        if (side < 0)
            return set(12, 1, 0, 0, 0);
        return compute(vec, side);
    }

    public LC compute(Vector3 vec, int side) {
        boolean offset = false;
        switch (side) {
            case 0:
                offset = vec.y <= 0;
                break;
            case 1:
                offset = vec.y >= 1;
                break;
            case 2:
                offset = vec.z <= 0;
                break;
            case 3:
                offset = vec.z >= 1;
                break;
            case 4:
                offset = vec.x <= 0;
                break;
            case 5:
                offset = vec.x >= 1;
                break;
        }
        if (!offset)
            side += 6;
        return computeO(vec, side);
    }

    public LC computeO(Vector3 vec, int side) {
        Vector3 v1 = Rotation.axes[((side & 0xE) + 3) % 6];
        Vector3 v2 = Rotation.axes[((side & 0xE) + 5) % 6];
        float d1 = (float) vec.scalarProject(v1);
        float d2 = 1 - d1;
        float d3 = (float) vec.scalarProject(v2);
        float d4 = 1 - d3;
        return set(side, d2 * d4, d2 * d3, d1 * d4, d1 * d3);
    }

    @Override
    public LC copy() {
        return new LC(side, fa, fb, fc, fd);
    }
}