graphicsutils.as

QS我也没用过

package qs.utils
{
	import mx.graphics.IStroke;
	import flash.display.Graphics;
	
	public class GraphicsUtils
	{
		public static function _drawDashedLine(target:Graphics,stroke:IStroke,pattern:Array,
												drawingState:DashStruct,
												x0:Number,y0:Number,x1:Number,y1:Number):void
		{			
			var dX:Number = x1 - x0;
			var dY:Number = y1 - y0;
			var len:Number = Math.sqrt(dX*dX + dY*dY);
			dX /= len;
			dY /= len;
			var tMax:Number = len;
			
			
			var t:Number = -drawingState.offset;
			var bDrawing:Boolean = drawingState.drawing;
			var patternIndex:int = drawingState.patternIndex;
			var styleInited:Boolean = drawingState.styleInited;
			while(t < tMax)
			{
				t += pattern[patternIndex];
				if(t < 0)
				{
					var x:int = 5;
				}
				if(t >= tMax)
				{
					drawingState.offset = pattern[patternIndex] - (t - tMax);
					drawingState.patternIndex = patternIndex;
					drawingState.drawing = bDrawing;
					drawingState.styleInited = true;
					t = tMax;
				}
				
				if(styleInited == false)
				{
					if(bDrawing)
						stroke.apply(target);
					else
						target.lineStyle(0,0,0);
				}
				else
				{
					styleInited = false;
				}
					
				target.lineTo(x0 + t*dX,y0 + t*dY);

				bDrawing = !bDrawing;
				patternIndex = (patternIndex + 1) % pattern.length;
			}
		}

				
		public static function drawDashedPolyLine(target:Graphics,stroke:IStroke,pattern:Array,points:Array):void
		{
			if(points.length == 0)
				return;
				
			var prev:Object = points[0];

			var struct:DashStruct = new DashStruct();							
			target.moveTo(prev.x,prev.y);
			for(var i:int = 1;i<points.length;i++)
			{
				var current:Object = points[i];
				_drawDashedLine(target,stroke,pattern,struct,prev.x,prev.y,current.x,current.y);
				prev = current;
			}
		}
	}
}

class DashStruct
{
	public function init():void
	{
		drawing = true;
		patternIndex = 0;
		offset = 0;
	}
	public var drawing:Boolean = true;
	public var patternIndex:int = 0;
	public var offset:Number = 0;	
	public var styleInited:Boolean = false;
}