Method getIntermediateWithZValue

src/main/java/net/minecraft/util/Vec3.java:182–197

Returns a new vector with z value equal to the second parameter, along the line between this vector and the passed in vector, or null if not possible.

(Vec3 vec, double z)

     * passed in vector, or null if not possible.
     */
    public Vec3 getIntermediateWithZValue(Vec3 vec, double z)
    {
        double d0 = vec.xCoord - this.xCoord;
        double d1 = vec.yCoord - this.yCoord;
        double d2 = vec.zCoord - this.zCoord;

        if (d2 * d2 < 1.0000000116860974E-7D)
        {
            return null;
        }
        else
        {
            double d3 = (z - this.zCoord) / d2;
            return d3 >= 0.0D && d3 <= 1.0D ? new Vec3(this.xCoord + d0 * d3, this.yCoord + d1 * d3, this.zCoord + d2 * d3) : null;
        }
    }

    public String toString()
    {