scripts/platforms/electron/icogen.js
"use strict";
//adapted from icon-gen code
if (window.haveElectron) {
let fs = require("fs");
let path = require("path");
let pngjsNozlib = require("pngjs-nozlib");
let png = require("pngjs");
const REQUIRED_IMAGE_SIZES = [16, 24, 32, 48, 64, 128, 256];
const DEFAULT_FILE_NAME = 'app';
const FILE_EXTENSION = '.ico';
const HEADER_SIZE = 6;
const DIRECTORY_SIZE = 16;
const BITMAPINFOHEADER_SIZE = 40;
const BI_RGB = 0;
/**
* Convert a PNG of the byte array to the DIB (Device Independent Bitmap) format.
* PNG in color RGBA (and more), the coordinate structure is the Top/Left to Bottom/Right.
* DIB in color BGRA, the coordinate structure is the Bottom/Left to Top/Right.
* @param {Buffer} src Target image.
* @param {Number} width The width of the image.
* @param {Number} height The height of the image.
* @param {Number} bpp The bit per pixel of the image.
* @return {Buffer} Converted image
* @see https://en.wikipedia.org/wiki/BMP_file_format
*/
const convertPNGtoDIB = (src, width, height, bpp) => {
const cols = width * bpp;
const rows = height * cols;
const rowEnd = rows - cols;
const dest = Buffer.alloc(src.length);
for (let row = 0; row < rows; row += cols) {
for (let col = 0; col < cols; col += bpp) {
// RGBA: Top/Left -> Bottom/Right
let pos = row + col;
const r = src.readUInt8(pos);
const g = src.readUInt8(pos + 1);
const b = src.readUInt8(pos + 2);
const a = src.readUInt8(pos + 3); // BGRA: Right/Left -> Top/Right
pos = rowEnd - row + col;
dest.writeUInt8(b, pos);
dest.writeUInt8(g, pos + 1);
dest.writeUInt8(r, pos + 2);
dest.writeUInt8(a, pos + 3);
}
}
return dest;
};
/**
* Create the BITMAPINFOHEADER.
* @param {Object} png PNG image.
* @param {Number} compression Compression mode
* @return {Buffer} BITMAPINFOHEADER data.
* @see https://msdn.microsoft.com/ja-jp/library/windows/desktop/dd183376%28v=vs.85%29.aspx
*/
const createBitmapInfoHeader = (png, compression) => {
const b = Buffer.alloc(BITMAPINFOHEADER_SIZE);
b.writeUInt32LE(BITMAPINFOHEADER_SIZE, 0); // 4 DWORD biSize
b.writeInt32LE(png.width, 4); // 4 LONG biWidth
b.writeInt32LE(png.height * 2, 8); // 4 LONG biHeight
b.writeUInt16LE(1, 12); // 2 WORD biPlanes
b.writeUInt16LE(png.bpp * 8, 14); // 2 WORD biBitCount
b.writeUInt32LE(compression, 16); // 4 DWORD biCompression
b.writeUInt32LE(png.data.length, 20); // 4 DWORD biSizeImage
b.writeInt32LE(0, 24); // 4 LONG biXPelsPerMeter
b.writeInt32LE(0, 28); // 4 LONG biYPelsPerMeter
b.writeUInt32LE(0, 32); // 4 DWORD biClrUsed
b.writeUInt32LE(0, 36); // 4 DWORD biClrImportant
return b;
};
/**
* Create the Icon entry.
*
* @param {Object} png PNG image.
* @param {Number} offset The offset of directory data from the beginning of the ICO/CUR file
*
* @return {Buffer} Directory data.
*
* @see https://msdn.microsoft.com/en-us/library/ms997538.aspx
*/
const createDirectory = (png, offset) => {
const b = Buffer.alloc(DIRECTORY_SIZE);
const size = png.data.length + BITMAPINFOHEADER_SIZE;
const width = 256 <= png.width ? 0 : png.width;
const height = 256 <= png.height ? 0 : png.height;
const bpp = png.bpp * 8;
b.writeUInt8(width, 0); // 1 BYTE Image width
b.writeUInt8(height, 1); // 1 BYTE Image height
b.writeUInt8(0, 2); // 1 BYTE Colors
b.writeUInt8(0, 3); // 1 BYTE Reserved
b.writeUInt16LE(1, 4); // 2 WORD Color planes
b.writeUInt16LE(bpp, 6); // 2 WORD Bit per pixel
b.writeUInt32LE(size, 8); // 4 DWORD Bitmap (DIB) size
b.writeUInt32LE(offset, 12); // 4 DWORD Offset
return b;
};
/**
* Create the ICO file header.
* @param {Number} count Specifies number of images in the file.
* @return {Buffer} Header data.
* @see https://msdn.microsoft.com/en-us/library/ms997538.aspx
*/
const createFileHeader = count => {
const b = Buffer.alloc(HEADER_SIZE);
b.writeUInt16LE(0, 0); // 2 WORD Reserved
b.writeUInt16LE(1, 2); // 2 WORD Type
b.writeUInt16LE(count, 4); // 2 WORD Image count
return b;
};
/**
* Check an option properties.
* @param {Object} options Output destination the path of directory.
* @param {String} options.name Name of an output file.
* @param {Number[]} options.sizes Structure of an image sizes.
* @returns {Object} Checked options.
*/
const checkOptions = options => {
if (options) {
return {
name: typeof options.name === 'string' && options.name !== '' ? options.name : DEFAULT_FILE_NAME,
sizes: Array.isArray(options.sizes) ? options.sizes : REQUIRED_IMAGE_SIZES
};
} else {
return {
name: DEFAULT_FILE_NAME,
sizes: REQUIRED_IMAGE_SIZES
};
}
};
/**
* Get the size of the required PNG.
* @return {Number[]} Sizes.
*/
const GetRequiredICOImageSizes = () => {
return REQUIRED_IMAGE_SIZES;
};
/**
* Generate the ICO file from a PNG images.
* @param {ImageInfo[]} images File informations..
* @param {String} dir Output destination the path of directory.
* @param {Object} options Options.
* @param {String} options.name Name of an output file.
* @param {Number} options.sizes Structure of an image sizes.
* @param {Logger} logger Logger.
* @return {Promise} Promise object.
*/
let stream = require("stream");
class WriteStream extends stream.Writable {
constructor() {
super();
this.data = [];
}
_write(chunk, encoding, cb) {
let buf = chunk;
if (!(buf instanceof Buffer)) {
Buffer.from(chunk, encoding);
}
for (let i = 0; i < buf.length; i++) {
this.data.push(buf[i]);
}
cb(null);
}
end() {
this.data = Buffer.from(this.data);
super.end();
}
}
exports.GetRequiredICOImageSizes = GetRequiredICOImageSizes;
const GenerateICO = (images, logger = console) => {
logger.log('ICO:');
const stream = new WriteStream();
stream.write(createFileHeader(images.length), 'binary');
let pngs = [];
for (let image of images) {
pngs.push(pngjsNozlib.PNG.sync.read(image));
}
let offset = HEADER_SIZE + DIRECTORY_SIZE * images.length;
pngs.forEach(png => {
const directory = createDirectory(png, offset);
stream.write(directory, 'binary');
offset += png.data.length + BITMAPINFOHEADER_SIZE;
});
pngs.forEach(png => {
const header = createBitmapInfoHeader(png, BI_RGB);
stream.write(header, 'binary');
const dib = convertPNGtoDIB(png.data, png.width, png.height, png.bpp);
stream.write(dib, 'binary');
});
stream.end();
return stream.data;
//logger.log(' Create: ' + dest);
//resolve(dest);
};
exports.GenerateICO = GenerateICO;
let _default = GenerateICO;
exports.default = _default;
}
