Function getNumRawDataModules

modules/data/qrcode/qrcodegen.c:249–259

Returns the number of data bits that can be stored in a QR Code of the given version number, after all function modules are excluded. This includes remainder bits, so it might not be a multiple of 8. The result is in the range [208, 29648]. This could be implemented as a 40-entry lookup table.

// all function modules are excluded. This includes remainder bits, so it might not be a multiple of 8.
// The result is in the range [208, 29648]. This could be implemented as a 40-entry lookup table.
testable int getNumRawDataModules(int version) {
	assert(qrcodegen_VERSION_MIN <= version && version <= qrcodegen_VERSION_MAX);
	int result = (16 * version + 128) * version + 64;
	if (version >= 2) {
		int numAlign = version / 7 + 2;
		result -= (25 * numAlign - 10) * numAlign - 55;
		if (version >= 7)
			result -= 18 * 2;  // Subtract version information
	}
	return result;
}