package net.minecraft.network.protocol.game;

import net.minecraft.world.phys.Vec3;
import org.jetbrains.annotations.VisibleForTesting;

public class VecDeltaCodec {
	private static final double TRUNCATION_STEPS = 4096.0;
	private Vec3 base = Vec3.ZERO;

	@VisibleForTesting
	static long encode(double value) {
		return Math.round(value * 4096.0);
	}

	@VisibleForTesting
	static double decode(long value) {
		return value / 4096.0;
	}

	public Vec3 decode(long x, long y, long z) {
		if (x == 0L && y == 0L && z == 0L) {
			return this.base;
		} else {
			double d = x == 0L ? this.base.x : decode(encode(this.base.x) + x);
			double e = y == 0L ? this.base.y : decode(encode(this.base.y) + y);
			double f = z == 0L ? this.base.z : decode(encode(this.base.z) + z);
			return new Vec3(d, e, f);
		}
	}

	public long encodeX(Vec3 value) {
		return encode(value.x) - encode(this.base.x);
	}

	public long encodeY(Vec3 value) {
		return encode(value.y) - encode(this.base.y);
	}

	public long encodeZ(Vec3 value) {
		return encode(value.z) - encode(this.base.z);
	}

	public Vec3 delta(Vec3 value) {
		return value.subtract(this.base);
	}

	public void setBase(Vec3 base) {
		this.base = base;
	}

	public Vec3 getBase() {
		return this.base;
	}
}