ACTIONSCRIPT 3 Developer’s Guide en

ACTIONSCRIPT 3.0 DEVELOPER’S GUIDE
Working with geometry
The inflatePt() method works similarly, except that it takes a Point object as its parameter, rather than dx and dy
values.
Finding unions and intersections of Rectangle objects
Flash Player 9 and later, Adobe AIR 1.0 and later
You use the union() method to find the rectangular region formed by the boundaries of two rectangles:
import flash.display.*;
import flash.geom.Rectangle;
var rect1:Rectangle = new Rectangle(0, 0, 100, 100);
trace(rect1); // (x=0, y=0, w=100, h=100)
var rect2:Rectangle = new Rectangle(120, 60, 100, 100);
trace(rect2); // (x=120, y=60, w=100, h=100)
trace(rect1.union(rect2)); // (x=0, y=0, w=220, h=160)
You use the intersection() method to find the rectangular region formed by the overlapping region of two
rectangles:
import flash.display.*;
import flash.geom.Rectangle;
var rect1:Rectangle = new Rectangle(0, 0, 100, 100);
trace(rect1); // (x=0, y=0, w=100, h=100)
var rect2:Rectangle = new Rectangle(80, 60, 100, 100);
trace(rect2); // (x=120, y=60, w=100, h=100)
trace(rect1.intersection(rect2)); // (x=80, y=60, w=20, h=40)
You use the intersects() method to find out whether two rectangles intersect. You can also use the intersects()
method to find out whether a display object is in a certain region of the Stage. For the following code example, assume
the coordinate space of the display object container that contains the circle object is the same as that of the Stage.
The example shows how to use the intersects() method to determine if a display object, circle, intersects specified
regions of the Stage, defined by the target1 and target2 Rectangle objects:
import flash.display.*;
import flash.geom.Rectangle;
var circle:Shape = new Shape();
circle.graphics.lineStyle(2, 0xFF0000);
circle.graphics.drawCircle(250, 250, 100);
addChild(circle);
var circleBounds:Rectangle = circle.getBounds(stage);
var target1:Rectangle = new Rectangle(0, 0, 100, 100);
trace(circleBounds.intersects(target1)); // false
var target2:Rectangle = new Rectangle(0, 0, 300, 300);
trace(circleBounds.intersects(target2)); // true
Similarly, you can use the intersects() method to find out whether the bounding rectangles of two display objects
overlap. Use the getRect() method of the DisplayObject class to include any additional space that the strokes of a
display object add to a bounding region.
Other uses of Rectangle objects
Flash Player 9 and later, Adobe AIR 1.0 and later
Rectangle objects are used in the following methods and properties:
Last updated 6/6/2012
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