清除canvas画布内容(点擦除+线擦除)(2)

var count = this.points.length(); var p: Core.Point = this.points.get(0); if (isDrawHit) { ctx.strokeStyle = this.colorKey; } else { ctx.strokeStyle = this.lineColor; } ctx.lineCap = "round"; ctx.lineJoin = 'round';//转折的时候不出现尖角 if (ctx.canvas.id == "hitCanvas") ctx.lineWidth = this.lineWidth + eraserRadius;//扩大hit上线条的范围，橡皮半径 else ctx.lineWidth = this.lineWidth; ctx.beginPath(); if (count >= 2) { ctx.moveTo(p.x, p.y); for (var i = 1; i < count - 2; i++) { // p = this.points.get(i); // ctx.lineTo(p.x, p.y); if (this.points.get(i).x == this.points.get(i + 1).x && this.points.get(i).y == this.points.get(i + 1).y) continue; var c = (this.points.get(i).x + this.points.get(i + 1).x) / 2; var d = (this.points.get(i).y + this.points.get(i + 1).y) / 2; ctx.quadraticCurveTo(this.points.get(i).x, this.points.get(i).y, c, d); //二次贝塞曲线函数 } // For the last 2 points if (count >= 3) { ctx.quadraticCurveTo( this.points.get(i).x, this.points.get(i).y, this.points.get(i + 1).x, this.points.get(i + 1).y ); } else if (count >= 2) { ctx.lineTo(this.points.get(1).x, this.points.get(1).y); } ctx.stroke(); } else { if (isDrawHit) { ctx.fillStyle = this.colorKey; } else { ctx.fillStyle = this.lineColor; } if (ctx.canvas.id == "hitCanvas") var radius = this.lineWidth + eraserRadius;//扩大hit上线条的范围，橡皮半径 else var radius = this.lineWidth; ctx.arc(this.points.get(0).x, this.points.get(0).y, radius, 0, 2 * Math.PI); ctx.fill(); }

（编辑：ASP站长网）