HTML5 Canvas画线技巧——实现绘制一个像素宽的细

ctx.lineWidth = 1;
ctx.beginPath();
ctx.moveTo(10, 100);
ctx.lineTo(300,100);
ctx.stroke();

/
<p> draw one pixel line </p>
@param fromX
@param formY
@param toX
@param toY
@param backgroundColor - default is white
@param vertical - boolean
/
CanvasRenderingContext2D.prototype.onePixelLineTo = function(fromX, fromY, toX, toY, backgroundColor, vertical) {
var currentStrokeStyle = this.strokeStyle;
this.beginPath();
this.moveTo(fromX, fromY);
this.lineTo(toX, toY);
this.closePath();
this.lineWidth=2;
this.stroke();
this.beginPath();
if(vertical) {
this.moveTo(fromX+1, fromY);
this.lineTo(toX+1, toY);
} else {
this.moveTo(fromX, fromY+1);
this.lineTo(toX, toY+1);
}
this.closePath();
this.lineWidth=2;
this.strokeStyle=backgroundColor;
this.stroke();
this.strokeStyle = currentStrokeStyle;
};

ctx.save();
ctx.translate(0.5,0.5);
ctx.lineWidth = 1;
ctx.beginPath();
ctx.moveTo(10, 100);
ctx.lineTo(300,100);
ctx.stroke();
ctx.restore();