pigallery2/backend/middlewares/thumbnail/THRenderers.ts

import {Metadata, SharpInstance} from "@types/sharp";

export interface RendererInput {
    imagePath: string;
    size: number;
    makeSquare: boolean;
    thPath: string;
    __dirname: string;
}

export const softwareRenderer = (input: RendererInput, done) => {

    //generate thumbnail
    const Jimp = require("jimp");
    Jimp.read(input.imagePath).then((image) => {
        /**
         * newWidth * newHeight = size*size
         * newHeight/newWidth = height/width
         *
         * newHeight = (height/width)*newWidth
         * newWidth * newWidth = (size*size) / (height/width)
         *
         * @type {number}
         */
        const ratio = image.bitmap.height / image.bitmap.width;
        if (input.makeSquare == false) {
            let newWidth = Math.sqrt((input.size * input.size) / ratio);

            image.resize(newWidth, Jimp.AUTO, Jimp.RESIZE_BEZIER);
        } else {
            image.resize(input.size / Math.min(ratio, 1), Jimp.AUTO, Jimp.RESIZE_BEZIER);
            image.crop(0, 0, input.size, input.size);
        }
        image.quality(60);        // set JPEG quality
        image.write(input.thPath, () => { // save
            return done();
        });
    }).catch(function (err) {
        const Error = require(input.__dirname + "/../../../common/entities/Error").Error;
        const ErrorCodes = require(input.__dirname + "/../../../common/entities/Error").ErrorCodes;
        return done(new Error(ErrorCodes.GENERAL_ERROR, err));
    });
};

export const hardwareRenderer = (input: RendererInput, done) => {

    //generate thumbnail
    const sharp = require("sharp");

    const image: SharpInstance = sharp(input.imagePath);
    image
        .metadata()
        .then((metadata: Metadata) => {
            /**
             * newWidth * newHeight = size*size
             * newHeight/newWidth = height/width
             *
             * newHeight = (height/width)*newWidth
             * newWidth * newWidth = (size*size) / (height/width)
             *
             * @type {number}
             */
            try {
                const ratio = metadata.height / metadata.width;
                if (input.makeSquare == false) {
                    const newWidth = Math.round(Math.sqrt((input.size * input.size) / ratio));
                    image.resize(newWidth);

                } else {
                    image
                        .resize(input.size, input.size)
                        .crop(sharp.strategy.center);
                }
                image
                    .jpeg()
                    .toFile(input.thPath).then(() => {
                    return done();
                }).catch(function (err) {
                    const Error = require(input.__dirname + "/../../../common/entities/Error").Error;
                    const ErrorCodes = require(input.__dirname + "/../../../common/entities/Error").ErrorCodes;
                    return done(new Error(ErrorCodes.GENERAL_ERROR, err));
                });
            } catch (err) {
                const Error = require(input.__dirname + "/../../../common/entities/Error").Error;
                const ErrorCodes = require(input.__dirname + "/../../../common/entities/Error").ErrorCodes;
                return done(new Error(ErrorCodes.GENERAL_ERROR, err));
            }
        });

};