How to determine which rectangle is intersecting more C# XNA

Question

Basically I have a grid of rectangles, 75x75 each, side by side. I'm placing an object into these rectangles and when I place the object I need to figure out which rectangle it is intersecting with the MOST.

It would most likely look something like this:

private Rectangle placeObject(Vector2 cursorPosition)
{
    Rectangle HolderRectangle;
    Rectangle r1 =  new Rectangle((int)cursorPosition.Position.X, (int)cursorPosition.Position.Y, 70, 70);    

    Foreach( Rectangle r in rectangles)
    {
        r2 = new Rectangle((int)r.Position.X, (int)r.Position.Y, 75,75)
        if( r1.Intersects(r2))
        {
            //Check how much it intersects
            //if it intersects more than the current holder Rectangle
            //set HolderRectangle = r2
        }
    }
    return HolderRectangle; 
}

Is what I'm asking even possible? If so how? All reply's are appreciated =)

Answer 1

如果所有矩形的大小均相同，则可以取其中心，您要检查其中心，测量两个点之间的长度，并与其他矩形相同。

Answer 2

If this is just for placement in a grid you certainly don't have to iterate over all of the "rectangles"

You know the dimensions of the grid components, in this case 75x75. If you divide your X and Y position by 75 you know which grid element it belongs to, you'll have to account for an offset if your camera can scroll.

Considering your example shows just a list of rectangles, I'm guessing your 2D map is actually just a one dimensional array. Which you can index into by [y * numRectsPerRow + x]

I don't know the background of your project, but I'm guessing you won't want to keep your grid represented by a bunch of rectangles for long.

Answer 3

I believe what you are looking for is the area of an overlapping rectangles.

See this thread:

What is an Efficient algorithm to find Area of Overlapping Rectangles