How does the (x,y) coordinates of an object relate to their left, top, right, and bottom coordinates?

When I’m drawing an object and providing the x and y coordinates, is that coordinate the center of the object or a different area of the object? I’m trying to acquire the left, top, right, and bottom pixel coordinates for my object to draw an interest area in an eye tracking system

The position is always the center of the object. You can use the total width and height to calculate the corners of any rectangular object (e.g., top left is x-width/2, y-height/2). For circles you take the radius and do some trigonometry.