bool Cube::Intersect(Ray& ray, float& t)
{
    int tNear = -2147000000;
    int tFar = 2147000000;
    //compute min and max
    //check x
    Min.x = min(Corner1.x, Corner2.x);
    Min.y = min(Corner1.y, Corner2.y);
    Min.z = min(Corner1.z, Corner2.z);
    Max.x = max(Corner1.x, Corner2.x);
    Max.y = max(Corner1.y, Corner2.y);
    Max.z = max(Corner1.z, Corner2.z);
    if((ray.dir.x == 0) && (ray.start.x < Min.x) && (ray.start.x > Max.x))
    {
        //parallel
        return false;
    }
    else
    {
        float t1 = (Min.x - ray.start.x) / ray.dir.x;
        float t2 = (Max.x - ray.start.x) / ray.dir.x;
        if(t1 > t2)
        {
            float temp1 = t1;
            t1 = t2;
            t2 = temp1;
        }
        if(t1 > tNear)
        {
            tNear = t1;
        }
        if(t2 > tFar)
        {
            tFar = t2;
        }
        if((tNear > tFar) || (tFar < 0))
            return false;
    }

    //check y
    if((ray.dir.y == 0) && (ray.start.y < Min.y) && (ray.start.y > Max.y))
    {
        //parallel
        return false;
    }
    else
    {
        float t1 = (Min.y - ray.start.y) / ray.dir.y;
        float t2 = (Max.y - ray.start.y) / ray.dir.y;
        if(t1 > t2)
        {
            float temp1 = t1;
            t1 = t2;
            t2 = temp1;
        }
        if(t1 > tNear)
        {
            tNear = t1;
        }
        if(t2 > tFar)
        {
            tFar = t2;
        }
        if((tNear > tFar) || (tFar < 0))
            return false;
    }

    //check z
    if((ray.dir.z == 0) && (ray.start.z < Min.z) && (ray.start.z > Max.z))
    {
        //parallel
        return false;
    }
    else
    {
        float t1 = (Min.z - ray.start.z) / ray.dir.z;
        float t2 = (Max.x - ray.start.z) / ray.dir.z;
        if(t1 > t2)
        {
            float temp1 = t1;
            t1 = t2;
            t2 = temp1;
        }
        if(t1 > tNear)
        {
            tNear = t1;
        }
        if(t2 > tFar)
        {
            tFar = t2;
        }
        if((tNear > tFar) || (tFar < 0))
            return false;
    }
    t = tNear;
    return true;
}