Question

I’m stuck on some trivial question and, well, I guess I need help here.

I have two rectangles and it’s guaranteed that they have one common point from their 4 base points (upper part of the picture). It’s also guaranteed that they are axis-aligned.

I know this common point (which also can be easily deduced), dimensions and the coordinates of these rectangles.

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Now, I need to retrieve the coordinates of the rectangles named 1 and 2 and I’m seeking for an easy way to do that (lower part of the picture).

My current implementation relies on many if statements and I suspect I’m too stupid to find a better way.

Thank you.

Update: My current implementation.

Point commonPoint = getCommonPoint(bigRectangle, smallRectangle);

rectangle2 = new Rectangle(smallRectangle.getAdjacentVerticalPoint(commonPoint),
                           bigRectangle.getOppositePoint(commonPoint));

rectangle1 = new Rectangle(smallRectangle.getAdjacentHorizontalPoint(commonPoint)
                           bigRectangle.getOppositePoint(commonPoint));

// Now simply adjust one of these rectangles to remove the overlap,
// it's trivial - we take the 'opposite' points for 'small' and 'big'
// rectangles and then use their absolute coordinate difference as
// a fix for either width of 'rectangle2' or height of 'rectangle1'
// (in this situation it's going to be width).

adjustRectangle(rectangle2);

This is refactored, but still methods getCommonPoint and getAdjacent... and getOpposite have many if statements and I thought if this can be done better.

Answer 1

The top and bottom values of Rectangle 1 are the same as the big rectangle. The left and right values of rectangle 2 are the same as the small rectangle. We only need to obtain the left and right values of rectangle 1, and the top and bottom values for rectangle 2. So we only have 2 simple if-statements:

if (bigRectangle.Left == smallRectangle.Left) 
    left = smallRectangle.Right
    right = bigRectangle.Right
else
    left = bigRectangle.Left
    right = smallRectangle.Left
rectangle1 = new Rectangle(left, bigRectangle.Top, right - left, bigRectangle.Height)

if (bigRectangle.Top == smallRectangle.Top)
    top = smallRectangle.Bottom
    bottom = bigRectangle.Bottom
else
    top = bigRectangle.Top
    bottom = smallRectangle.Top
rectangle2 = new Rectangle(smallRectangle.Left, top, smallRectangle.Width, bottom - top)

In the above, the Rectangle constructors takes as inputs: left, top, width, height.