+/// @brief Handle sign of the signal according to several decoding methods
+///
+/// @param[in] signal - The signal
+/// @param[in] data_signal - The data of the signal
+/// @param[in] new_end_bit - The last bit of in the last byte of the data (data_signal[0])
+/// @param[in] can_data - The whole can data (needed for SIGN BIT EXTERN)
+///
+/// @return Returns the sign of the data
+///
+int decoder_t::handle_sign(const signal_t& signal, std::vector<uint8_t>& data_signal, uint8_t new_end_bit, const std::vector<uint8_t>& can_data)
+{
+ uint8_t data_byte = 0;
+ uint8_t mask = 0;
+ int end_bit = 0;
+
+ if(signal.get_sign() == sign_t::UNSIGNED)
+ return 1;
+ else if(signal.get_sign() == sign_t::SIGN_BIT_EXTERN) {
+ end_bit = signal.get_bit_sign_position()%8;
+ mask = static_cast<uint8_t>((1 << (end_bit + 1)) - 1);
+ data_byte = can_data[signal.get_bit_sign_position()/8] & mask;
+ }
+ else {
+ end_bit = new_end_bit;
+ mask = static_cast<uint8_t>((1 << (end_bit + 1)) - 1);
+ data_byte = data_signal[0] & mask;
+ }
+
+ //if negative: decode with right method
+ if(data_byte >> end_bit) {
+ switch(signal.get_sign())
+ {
+ //remove the sign bit to get the absolute value
+ case sign_t::SIGN_BIT:
+ data_signal[0] = static_cast<uint8_t>(data_signal[0] & (mask >> 1));
+ break;
+ //same method twos complement = ones complement + 1
+ case sign_t::ONES_COMPLEMENT:
+ case sign_t::TWOS_COMPLEMENT:
+ //complement only until end_bit
+ data_signal[0] = ((data_signal[0] ^ mask) & mask);
+ if(data_signal.size() > 1) {
+ for(int i=1; i < data_signal.size(); i++) {
+ data_signal[i] = data_signal[i] ^ 0xFF;
+ }
+ }
+ if(signal.get_sign() == sign_t::TWOS_COMPLEMENT)
+ data_signal[data_signal.size() - 1] = static_cast<uint8_t>(data_signal[data_signal.size() - 1] + 1);
+ break;
+ case sign_t::SIGN_BIT_EXTERN:
+ break;
+ default:
+ AFB_ERROR("Not a valid sign entry %d, considering the value as unsigned", signal.get_sign());
+ break;
+ }
+ return -1;
+ }
+ return 1;
+}
+