javascript - 奇怪的使用圆形 lineJoin 和非整数比例进行线渲染

Question

某些线条lineJoin="round"奇怪地呈现在某些比例上，这是一个比例为 1.403619311470477 且没有它的示例：https ://jsfiddle.net/kxjcosgf/2/

<canvas id="canvas" width="2000" height="2000"> </canvas>

<script>
const points = "45.13869240187139,481.020616681278,45.13869240187139,480.72980663647314,44.84788235706651,479.5665664572536,44.70247733466407,477.9671112108268,44.84788235706651,477.53089614361943,44.84788235706651,477.385491121217,44.993287379468946,476.80387103160723,45.28409742427383,476.22225094199746,46.44733760349335,475.059010762778,47.319767737907995,474.9136057403755,47.90138782751775,475.34982080758283,48.19219787232263,475.7860358747902,48.483007917127516,476.5130609868024,48.62841293952995,476.94927605400966,48.33760289472507,477.67630116602186".split(",")

const ctx = canvas.getContext("2d")
ctx.strokeStyle = "black"
ctx.lineWidth = 2
ctx.lineCap = "round"
ctx.lineJoin = "round"

ctx.beginPath()
ctx.moveTo(points[0], points[1])
for (let i = 2; i < points.length; i += 2) {
  ctx.lineTo(points[i], points[i + 1])
}
ctx.stroke()

ctx.scale(1.403619311470477, 1.403619311470477)
ctx.beginPath()
ctx.moveTo(points[0], points[1])
for (let i = 2; i < points.length; i += 2) {
  ctx.lineTo(points[i], points[i + 1])
}
ctx.stroke()

window.scrollBy(0, 400)
</script>

我期望顶部笔划的缩放版本（标记为蓝色），但在 Chrome 94.0 上会出现奇怪的光线。

标签： javascriptgoogle-chromecanvashtml5-canvas