index.js•1.31 kB
import { isNodePattern } from "@jimp/utils";
/**
* Creates a circle out of an image.
* @param {object} options (optional) r: radius of effect
* @param {function(Error, Jimp)} cb (optional) a callback for when complete
* @returns {Jimp} this for chaining of methods
*/
export default () => ({
fisheye(options = { r: 2.5 }, cb) {
if (typeof options === "function") {
cb = options;
options = { r: 2.5 };
}
const source = this.cloneQuiet();
const { width, height } = source.bitmap;
source.scanQuiet(0, 0, width, height, (x, y) => {
const hx = x / width;
const hy = y / height;
const r = Math.sqrt(Math.pow(hx - 0.5, 2) + Math.pow(hy - 0.5, 2));
const rn = 2 * Math.pow(r, options.r);
const cosA = (hx - 0.5) / r;
const sinA = (hy - 0.5) / r;
const newX = Math.round((rn * cosA + 0.5) * width);
const newY = Math.round((rn * sinA + 0.5) * height);
const color = source.getPixelColor(newX, newY);
this.setPixelColor(color, x, y);
});
/* Set center pixel color, otherwise it will be transparent */
this.setPixelColor(
source.getPixelColor(width / 2, height / 2),
width / 2,
height / 2
);
if (isNodePattern(cb)) {
cb.call(this, null, this);
}
return this;
},
});