grid collsions 3

void TestSquareCollision(ref Vector2 positionOffset, Vector2 topLeftOld, Vector2 bottomRightOld, Vector2 topLeftB, Vector2 bottomRightB)
{
    Vector2 topLeftNew = topLeftOld + positionOffset;
    Vector2 bottomRightNew = bottomRightOld + positionOffset;

    if (topLeftB.X < bottomRightNew.X &&
            topLeftNew.X < bottomRightB.X &&
            topLeftB.Y < bottomRightNew.Y &&
            topLeftNew.Y < bottomRightB.Y)
    {
        if (positionOffset.X == 0 || (topLeftB.X < bottomRightOld.X && topLeftOld.X < bottomRightB.X))
        {
            if (positionOffset.Y < 0)
            {
                positionOffset.Y += bottomRightB.Y - topLeftNew.Y;
                if (positionOffset.Y > 0)
                    positionOffset.Y = 0;
            }
            else if (positionOffset.Y > 0)
            {
                positionOffset.Y -= bottomRightNew.Y - topLeftB.Y;
                if (positionOffset.Y < 0)
                    positionOffset.Y = 0;
            }
        }
        else if (positionOffset.Y == 0 || (topLeftB.Y < bottomRightOld.Y && topLeftOld.Y < bottomRightB.Y))
        {
            if (positionOffset.X < 0)
            {
                positionOffset.X += bottomRightB.X - topLeftNew.X;
                if (positionOffset.X > 0)
                    positionOffset.X = 0;
            }
            else if (positionOffset.X > 0)
            {
                positionOffset.X -= bottomRightNew.X - topLeftB.X;
                if (positionOffset.X < 0)
                    positionOffset.X = 0;
            }
        } // TODO: Replace this with a log error
        else throw new NotImplementedException("Encountered a corner case in square collision detection.");
    }
}