Create a three-square Bezier curve path in the WeChat small program API drawing
May 19, 2021 WeChat Mini Program Development Document
Table of contents
Drawing interfaces and methods
canvasContext.bezierCurveTo
Defined
Create a three-square Bezier curve path.
Tip : The starting point of the curve is the previous point in the path.
Parameters
| Parameters | Type | Description |
|---|---|---|
| cp1x | Number | The x coordinates of the first Bezier control point |
| cp1y | Number | The y coordinate of the first Bezier control point |
| cp2x | Number | The x coordinates of the second Bezier control point |
| cp2y | Number | The y coordinates of the second Bezier control point |
| Ⅹ | Number | The x coordinates of the end point |
| Y | Number | The y coordinates of the end point |
Example
const ctx = wx.createCanvasContext('myCanvas')
// Draw points
ctx.beginPath()
ctx.arc(20, 20, 2, 0, 2 * Math.PI)
ctx.setFillStyle('red')
ctx.fill()
ctx.beginPath()
ctx.arc(200, 20, 2, 0, 2 * Math.PI)
ctx.setFillStyle('lightgreen')
ctx.fill()
ctx.beginPath()
ctx.arc(20, 100, 2, 0, 2 * Math.PI)
ctx.arc(200, 100, 2, 0, 2 * Math.PI)
ctx.setFillStyle('blue')
ctx.fill()
ctx.setFillStyle('black')
ctx.setFontSize(12)
// Draw guides
ctx.beginPath()
ctx.moveTo(20, 20)
ctx.lineTo(20, 100)
ctx.lineTo(150, 75)
ctx.moveTo(200, 20)
ctx.lineTo(200, 100)
ctx.lineTo(70, 75)
ctx.setStrokeStyle('#AAAAAA')
ctx.stroke()
// Draw quadratic curve
ctx.beginPath()
ctx.moveTo(20, 20)
ctx.bezierCurveTo(20, 100, 200, 100, 200, 20)
ctx.setStrokeStyle('black')
ctx.stroke()
ctx.draw()
The
moveTo(20, 20)
bezierCurveTo(20, 100, 200, 100, 200, 20)
are as follows:
- Red: Start point (20, 20)
- Blue: Two control points (20, 100) (200, 100)
- Green: End point (200, 20)