CS 0007 Assignment 2 – Overlapping Rectangles

Objective:

Write a program that asks the user for the coordinates of the upper-left and lower-right corners of two rectangles and then computes the coordinates of the upper-left and lower-right corners of the rectangle that’s formed when the two overlap (if any).

Requirements:

Rectangles that share a side do not overlap.

You must call a procedure from the main program block to "gather" the coordinates from the user. Here’s an example of the header of such a procedure:

procedure gatherpoints (var x1a,y1a,x2a,y2a,x1b,y1b,x2b,y2b:integer);

(x1a,y1a) are the coordinates of the upper-left point of the first rectangle.

(x2a,y2a) are the coordinates of the lower-right point of the first rectangle.

(x1b,y1b) are the coordinates of the upper-left point of the second rectangle.

(x2b,y2b) are the coordinates of the lower-right point of the second rectangle.

You must use a function to compute the overlap space. If there is an overlap space, the function returns true. It there is not an overlap space, the function returns false. Here’s an example of a function header that would do this:

function overlap (x1a,y1a,x2a,y2a,x1b,y1b,x2b,y2b:integer;var x1,y1,x2,y2:integer):boolean;

(The function takes the coordinates through pass by value, sends the overlap coordinates out through pass by variable, and returns a boolean value.)

You do not have to check for illegal inputs on this program. You may assume the points that are entered from the user are positive integers and the relationship between the upper-left and lower-right points are valid.

The program must continuously run until the user wishes to stop (you need a loop).

Example I/O:

Enter x and y coordinate for upper-left of rectangle 1: 0 0

Enter x and y coordinate for lower-right of rectangle 1: 100 100

Enter x and y coordinate for upper-left of rectangle 2: 40 40

Enter x and y coordinate for lower-right of rectangle 2: 120 60

Overlap is (40,40) (100,60)

Run again? (Y/N) y

Enter x and y coordinate for upper-left of rectangle 1: 0 40

Enter x and y coordinate for lower-right of rectangle 1: 100 60

Enter x and y coordinate for upper-left of rectangle 2: 40 0

Enter x and y coordinate for lower-right of rectangle 2: 200 60

Overlap is (40,40) (100,60)

Run again? (Y/N) y

Enter x and y coordinate for upper-left of rectangle 1: 0 0

Enter x and y coordinate for lower-right of rectangle 1: 100 100

Enter x and y coordinate for upper-left of rectangle 2: 20 20

Enter x and y coordinate for lower-right of rectangle 2: 40 40

Overlap is (20,20) (40,40)

Run again? (Y/N) n

Visualization:

Due Date:

Wednesday, October 20, 1999.

What To Turn In:

Turn in a 3.5" floppy disk and a printout containing your source code (in lecture).