Finding the triangle containing a point

Main.hx

package ;

import flash.display.Sprite;
import flash.display.Stage;
import flash.display.StageAlign;
import flash.display.StageScaleMode;
import flash.events.Event;
import flash.Lib;

/**
 * ...
 * @author William Bundy
 */

class Main 
{
	static var stage:Stage;
	static function main() 
	{
		stage = Lib.current.stage;
		stage.scaleMode = StageScaleMode.NO_SCALE;
		stage.align = StageAlign.TOP_LEFT;
		// entry point
		
		createBox(16, 16, 256, 64);
		createBox(16, 96, 64, 256);
	}
	
	static function createBox(offsetX:Float, offsetY:Float, width:Int, height:Int):Void
	{
		var box:Sprite = new Sprite();
		var lineThickness:Float = 2.0;
		var lineDefaultColor:Int = 0;
		var lineClosestColor:Int = 0x00CC00;
		var boxwidth:Int = width;
		var boxheight:Int = height;
		var boxOffsetX:Float = offsetX;
		var boxOffsetY:Float = offsetY;
		stage.addChild(box);
		
		var closest:Int = 0; // top=0, right=1, bottom=2, left=3, for the sides
		
		stage.addEventListener(Event.ENTER_FRAME, function(e:Event):Void
		{
			var mx:Float = stage.mouseX;
			var my:Float = stage.mouseY;
			//See if the pointer is inside the box
			//        x1                           x2                     y1                      y2
			if (mx > boxOffsetX && mx < boxOffsetX + boxwidth && my > boxOffsetY && my < boxOffsetY + boxheight)
			{
				var ratio:Float = boxwidth / boxheight;
				//                            x1
				var distLeft:Float = mx - boxOffsetX;
				
				//                             x2
				var distRight:Float = (boxwidth + boxOffsetX) - mx;
				
				if (ratio > 1)
				{
					distLeft /= ratio;
					distRight /= ratio;
				}
				
				var minHorizDist:Float = Math.min(distLeft, distRight);
				//                           y1
				var distTop:Float = my - boxOffsetY;
				//                                 y2
				var distBottom:Float = (boxOffsetY + boxheight) - my;
				
				if (ratio < 1)
				{
					distTop *= ratio;
					distBottom *= ratio;
				}
				
				var minVertDist:Float = Math.min(distTop, distBottom);
				
				var minDist:Float = Math.min(minHorizDist, minVertDist);
				
				switch(minDist)
				{
					case distLeft:
						closest = 3;
					case distRight:
						closest = 1;
					case distTop:
						closest = 0;
					case distBottom:
						closest = 2;
				}
			}
			else
			{
				//if the pointer is outside the box
				closest = -1;
			}
			
			box.graphics.clear();
			//top
			if (closest == 0)
				box.graphics.lineStyle(lineThickness, lineClosestColor);
			else
				box.graphics.lineStyle(lineThickness, lineDefaultColor);
			box.graphics.moveTo(boxOffsetX, boxOffsetY);
			box.graphics.lineTo(boxOffsetX + boxwidth, boxOffsetY);
				
			//right
			if (closest == 1)
				box.graphics.lineStyle(lineThickness, lineClosestColor);
			else
				box.graphics.lineStyle(lineThickness, lineDefaultColor);
			box.graphics.lineTo(boxOffsetX + boxwidth, boxOffsetY + boxheight);	
			//bottom
			if (closest == 2)
				box.graphics.lineStyle(lineThickness, lineClosestColor);
			else
				box.graphics.lineStyle(lineThickness, lineDefaultColor);
			box.graphics.lineTo(boxOffsetX, boxOffsetY + boxheight);		
			//down
			if (closest == 3)
				box.graphics.lineStyle(lineThickness, lineClosestColor);
			else
				box.graphics.lineStyle(lineThickness, lineDefaultColor);
			box.graphics.lineTo(boxOffsetX, boxOffsetY);	
			
			box.graphics.lineStyle(lineThickness, lineDefaultColor);
			box.graphics.lineTo(boxOffsetX + boxwidth, boxOffsetY + boxheight);	
			box.graphics.moveTo(boxOffsetX + boxwidth, boxOffsetY);
			box.graphics.lineTo(boxOffsetX, boxOffsetY + boxheight);
			
		});
	}
	
}