@thi.ng/pixel/checks.js

Typedarray integer & float pixel buffers w/ customizable formats, blitting, drawing, convolution

import { assert } from "@thi.ng/errors/assert";
const ensureSize = (data, width, height, stride = 1) => assert(data.length >= width * height * stride, "pixel buffer too small");
const ensureImageData = (data, width, height) => data ? (ensureImageDataSize(data, width, height), data) : new ImageData(width, height);
const ensureImageDataSize = (data, width, height) => assert(
  data.width === width && data.height === height,
  "imagedata has wrong dimensions"
);
const ensureChannel = (fmt, id) => {
  const chan = fmt.channels[id];
  assert(chan != null, `invalid channel ID: ${id}`);
  return chan;
};
const ensureSingleChannel = (fmt) => assert(fmt.channels.length === 1, `require single channel buffer`);
const ensureAlpha = (fmt) => assert(!!fmt.alpha, "missing alpha channel");
export {
  ensureAlpha,
  ensureChannel,
  ensureImageData,
  ensureImageDataSize,
  ensureSingleChannel,
  ensureSize
};