javascript - 如何快速从源数组中读取子数组

Question

我目前使用以下内容:

const canvasOneBuffer = new Uint8Array(canvasOneImageData.data.buffer);
// within an x/y loop:
const newPixel1Data0 = canvasOneBuffer[4 * (x + y * canvasOne.width) + 0];
const newPixel1Data1 = canvasOneBuffer[4 * (x + y * canvasOne.width) + 1];
const newPixel1Data2 = canvasOneBuffer[4 * (x + y * canvasOne.width) + 2];
const newPixel1Data3 = canvasOneBuffer[4 * (x + y * canvasOne.width) + 3];
const pixel1Data = new Uint8ClampedArray(4);
pixel1Data[0] = newPixel1Data0;
pixel1Data[1] = newPixel1Data1;
pixel1Data[2] = newPixel1Data2;
pixel1Data[3] = newPixel1Data3;

但这似乎有点迟钝。有什么方法可以通过从缓冲区数组中读取一次来创建新的 Uint8ClampedArray(4); 吗？

Answer 1

你的意思是像

const pixel1Data = canvasOneBuffer.slice(0, 4)
.map(canvasItem => {
  // do what ever with canvasItem
});