本篇文章给大家带来的内容是关于canvas波浪效果的实现代码，有一定的参考价值，有需要的朋友可以参考一下，希望对你有所帮助。

基于canvas的三次贝塞尔曲线(bezierCurveTo)

var WAVE_HEIGHT = 200 //波浪变化高度

var SCALE = 0.5 // 绘制速率

var CYCLE = 360 / SCALE

var TIME = 0

function initCanvas() {

var c = document.getElementById("myCanvas")

var width = window.screen.width

var height = window.screen.height

var ctx = c.getContext("2d")

c.width = width

c.height = height

// start

window.requestAnimationFrame(function() {

draw(ctx, width, height)

})

}

function draw(ctx, width, height) {

ctx.clearRect(0, 0, width, height)

TIME = (TIME + 1) % CYCLE

var angle = SCALE * TIME // 当前正弦角度

var dAngle = 60 // 两个波峰相差的角度

ctx.beginPath()

ctx.moveTo(0, height * 0.5 + distance(WAVE_HEIGHT, angle, 0))

ctx.bezierCurveTo(

width * 0.4,

height * 0.5 + distance(WAVE_HEIGHT, angle, dAngle),

width * 0.6,

height * 0.5 + distance(WAVE_HEIGHT, angle, 2 * dAngle),

width,

height * 0.5 + distance(WAVE_HEIGHT, angle, 3 * dAngle)

)

ctx.strokeStyle = "#ff0000"

ctx.stroke()

ctx.beginPath()

ctx.moveTo(0, height * 0.5 + distance(WAVE_HEIGHT, angle, -30))

ctx.bezierCurveTo(

width * 0.3,

height * 0.5 + distance(WAVE_HEIGHT, angle, dAngle - 30),

width * 0.7,

height * 0.5 + distance(WAVE_HEIGHT, angle, 2 * dAngle - 30),

width,

height * 0.5 + distance(WAVE_HEIGHT, angle, 3 * dAngle - 30)

)

ctx.strokeStyle = "#0000ff"

ctx.stroke()

function distance(height, currAngle, diffAngle) {

return height * Math.cos((((currAngle - diffAngle) % 360) * Math.PI) / 180)

}

// animate

window.requestAnimationFrame(function() {

draw(ctx, width, height)

})

}

initCanvas()