Method encodeSegments

src/third-party/qrcodegen/index.ts:71–129

(segs: Readonly<Array<QrSegment>>, ecl: QrCode.Ecc,
				minVersion: int = 1, maxVersion: int = 40,
				mask: int = -1, boostEcl: boolean = true)

		// between modes (such as alphanumeric and byte) to encode text in less space.
		// This is a mid-level API; the high-level API is encodeText() and encodeBinary().
		public static encodeSegments(segs: Readonly<Array<QrSegment>>, ecl: QrCode.Ecc,
				minVersion: int = 1, maxVersion: int = 40,
				mask: int = -1, boostEcl: boolean = true): QrCode {

			if (!(QrCode.MIN_VERSION <= minVersion && minVersion <= maxVersion && maxVersion <= QrCode.MAX_VERSION)
					|| mask < -1 || mask > 7)
				throw new RangeError("Invalid value");

			// Find the minimal version number to use
			let version: int;
			let dataUsedBits: int;
			for (version = minVersion; ; version++) {
				const dataCapacityBits: int = QrCode.getNumDataCodewords(version, ecl) * 8;  // Number of data bits available
				const usedBits: number = QrSegment.getTotalBits(segs, version);
				if (usedBits <= dataCapacityBits) {
					dataUsedBits = usedBits;
					break;  // This version number is found to be suitable
				}
				if (version >= maxVersion)  // All versions in the range could not fit the given data
					throw new RangeError("Data too long");
			}

			// Increase the error correction level while the data still fits in the current version number
			for (const newEcl of [QrCode.Ecc.MEDIUM, QrCode.Ecc.QUARTILE, QrCode.Ecc.HIGH]) {  // From low to high
				if (boostEcl && dataUsedBits <= QrCode.getNumDataCodewords(version, newEcl) * 8)
					ecl = newEcl;
			}

			// Concatenate all segments to create the data bit string
			let bb: Array<bit> = []
			for (const seg of segs) {
				appendBits(seg.mode.modeBits, 4, bb);
				appendBits(seg.numChars, seg.mode.numCharCountBits(version), bb);
				for (const b of seg.getData())
					bb.push(b);
			}
			assert(bb.length == dataUsedBits);

			// Add terminator and pad up to a byte if applicable
			const dataCapacityBits: int = QrCode.getNumDataCodewords(version, ecl) * 8;
			assert(bb.length <= dataCapacityBits);
			appendBits(0, Math.min(4, dataCapacityBits - bb.length), bb);
			appendBits(0, (8 - bb.length % 8) % 8, bb);
			assert(bb.length % 8 == 0);

			// Pad with alternating bytes until data capacity is reached
			for (let padByte = 0xEC; bb.length < dataCapacityBits; padByte ^= 0xEC ^ 0x11)
				appendBits(padByte, 8, bb);

			// Pack bits into bytes in big endian
			let dataCodewords: Array<byte> = [];
			while (dataCodewords.length * 8 < bb.length)
				dataCodewords.push(0);
			bb.forEach((b: bit, i: int) =>
				dataCodewords[i >>> 3] |= b << (7 - (i & 7)));

			// Create the QR Code object
			return new QrCode(version, ecl, dataCodewords, mask);