2012-03-27 171 views
0

我正在为canvascontext写一些额外的drawfunction。下面的代码应该允许用户用虚线或法线绘制圆角矩形。这几乎是完整的工作代码,但在绘制结束时,在圆角处绘制了一条额外的线条(我包含了该问题的图片)。请注意,只有在绘制矩形虚线时出现此问题,而其他版本则完美。圆角矩形虚线

if (window.CanvasRenderingContext2D && CanvasRenderingContext2D.prototype.lineTo){ 
     CanvasRenderingContext2D.prototype.dashedLine = function(pt1, pt2, dashLen) { 
       if (dashLen == undefined) dashLen = 6; 

       var dX = pt2.x - pt1.x; 
       var dY = pt2.y - pt1.y; 
       var dashes = Math.floor(Math.sqrt(dX * dX + dY * dY)/dashLen); 
       var dashX = dX/dashes; 
       var dashY = dY/dashes; 

       var q = 0; 
       while (q++ < dashes) { 
       pt1.x += dashX; 
       pt1.y += dashY; 
       this[q % 2 == 0 ? 'moveTo' : 'lineTo'](pt1.x, pt1.y); 
       } 
       this[q % 2 == 0 ? 'moveTo' : 'lineTo'](pt2.x, pt2.y); 
      }; 
     CanvasRenderingContext2D.prototype.roundRectangle = function(pt1, pt2, pt3, pt4, dashed, dashLen) { 
       function line(ctx, x1, y1, x2, y2, dashed) { 
       if (dashed) ctx.dashedLine({x:x1, y:y1}, {x:x2, y:y2}); 
       else { 
        ctx.lineTo(x2,y2);} 
       } 
       var radius = 8; 
       this.beginPath(); 
       line(this, pt1.x + radius, pt1.y, pt2.x - radius, pt2.y, dashed); 
       this.quadraticCurveTo(pt2.x, pt2.y, pt2.x, pt2.y + radius); 
       line(this, pt2.x, pt2.y + radius, pt3.x, pt3.y - radius, dashed); 
       this.quadraticCurveTo(pt3.x, pt3.y, pt3.x - radius, pt3.y); 
       line(this, pt3.x - radius, pt3.y, pt4.x + radius, pt4.y, dashed); 
       this.quadraticCurveTo(pt4.x, pt4.y, pt4.x, pt4.y - radius); 
       line(this, pt4.x, pt4.y - radius, pt1.x, pt1.y + radius, dashed); 
       this.quadraticCurveTo(pt1.x, pt1.y, pt1.x + radius, pt1.y); 

       this.closePath(); 
       this.stroke(); 
       this.fill(); 
     } 

}

enter image description here

有谁知道什么可以在这里是什么问题?

回答

1

this.closePath();行补充说,最后一段直线。只要删除它。

此外,为了获得更好的结果,除去this.beginPath();线和添加以下一个代替:

this.moveTo(pt1.x + radius, pt1.y); 

检查修改后的代码:http://jsfiddle.net/W8b3e/

+0

感谢您解决这个问题,但我想添加填充选项,以便背景可以着色。当我这样做时,只有二次曲线区域被着色,所以我需要这条路径。我在这里更改了代码:http://jsfiddle.net/W8b3e/2/ – Consec 2012-03-28 12:13:21