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我不知道水平调整正弦波大小并在调整窗口大小时缩小比例的正确方法。它仍然需要垂直位于同一位置，我现在只需要水平和按比例调整大小。正弦波显示在这个 js-fiddle 中： https ://jsfiddle.net/x2audoqk/7/

正弦波的js代码：

const canvas = document.querySelector("canvas")
const c = canvas.getContext("2d")

canvas.width = innerWidth
canvas.height = innerHeight

// Resize wave vertically
window.addEventListener("resize", () => {
    canvas.width = innerWidth
    canvas.height = innerHeight
    wave.y = canvas.height / 1.5
})

const wave = {
    y: canvas.height / 1.5,
    length: -0.0045,
    amplitude: 47.5,
    frequency: 0.0045
}

let increment = wave.frequency

const animate = () => {
    requestAnimationFrame(animate)

    // Deletes previous waves
    c.clearRect(0, 0, canvas.width, canvas.height)

    c.beginPath()

    // Get all the points on the line so you can modify it with sin
    for (let i = 0; i <= canvas.width; i++) {
        c.moveTo(i, wave.y + Math.sin(i * wave.length + increment) * wave.amplitude * Math.sin(increment))
        c.lineTo(i, canvas.height)
    }

    // Style
    c.strokeStyle = 'rgba(1, 88, 206, .25)'
    c.stroke()
    increment += wave.frequency
    c.closePath()
}
animate()

我如何实现这一目标？如果您需要更多信息或澄清，请随时询问。

4

1 回答 1

1

不知道是不是你想要的

但是通过添加这条线，波浪的长度适合画布的宽度

window.addEventListener("resize", function () {
    canvas.width = innerWidth
    canvas.height = innerHeight
    wave.y = canvas.height / 1.5
    wave.length = -2/canvas.width // <---- add this line
})

https://jsfiddle.net/gui3_/mwzun5dr/1/

编辑

为了使它干净，还应该更改以下内容，以便在调整大小之前波浪的长度是相同的计算


const wave = {
    y: canvas.height / 1.5,
    length: -2/canvas.width, //-0.0045,
    amplitude: 47.5,
    frequency: 0.0045
}
于 2019-11-23T12:35:00.473 回答