index.js•2.05 kB
import { isNodePattern, throwError } from "@jimp/utils";
/**
* Scale the image so the given width and height keeping the aspect ratio. Some parts of the image may be clipped.
* @param {number} w the width to resize the image to
* @param {number} h the height to resize the image to
* @param {number} alignBits (optional) A bitmask for horizontal and vertical alignment
* @param {string} mode (optional) a scaling method (e.g. Jimp.RESIZE_BEZIER)
* @param {function(Error, Jimp)} cb (optional) a callback for when complete
* @returns {Jimp} this for chaining of methods
*/
export default () => ({
cover(w, h, alignBits, mode, cb) {
if (typeof w !== "number" || typeof h !== "number") {
return throwError.call(this, "w and h must be numbers", cb);
}
if (
alignBits &&
typeof alignBits === "function" &&
typeof cb === "undefined"
) {
cb = alignBits;
alignBits = null;
mode = null;
} else if (typeof mode === "function" && typeof cb === "undefined") {
cb = mode;
mode = null;
}
alignBits =
alignBits ||
this.constructor.HORIZONTAL_ALIGN_CENTER |
this.constructor.VERTICAL_ALIGN_MIDDLE;
const hbits = alignBits & ((1 << 3) - 1);
const vbits = alignBits >> 3;
// check if more flags than one is in the bit sets
if (
!(
(hbits !== 0 && !(hbits & (hbits - 1))) ||
(vbits !== 0 && !(vbits & (vbits - 1)))
)
)
return throwError.call(
this,
"only use one flag per alignment direction",
cb
);
const alignH = hbits >> 1; // 0, 1, 2
const alignV = vbits >> 1; // 0, 1, 2
const f =
w / h > this.bitmap.width / this.bitmap.height
? w / this.bitmap.width
: h / this.bitmap.height;
this.scale(f, mode);
this.crop(
((this.bitmap.width - w) / 2) * alignH,
((this.bitmap.height - h) / 2) * alignV,
w,
h
);
if (isNodePattern(cb)) {
cb.call(this, null, this);
}
return this;
},
});