Canvas曲线绘制

arc()

arc(

​ centerx, centery, radius,

​ startingAngle, endingAngle,

​ anticlockwise = false

)

arcTo()

arcTo(

​ x1, y1,

​ x2, y2,

​ radius );

二次贝塞尔(Bezier) 曲线 quadraticCurveTo()

quadraticCurveTo(

​ x1, y1,

​ x2, y2 );

三次贝塞尔(Bezier) 曲线 bezierCurveTo()

bezierCurveTo(

​ x1, y1,

​ x2, y2，

​ x3, y3 );