Home Page Forums MAME Non-Windows MAME Support Using a second keyboard as a joystick on linux

sudo evtest /dev/input/by-id/usb-VEC_VEC_USB_Footpedal-event-if00 --grab
Input driver version is 1.0.1
Input device ID: bus 0x3 vendor 0x5f3 product 0xff version 0x100
Input device name: "VEC  VEC USB Footpedal"
Supported events:
  Event type 0 (EV_SYN)
  Event type 1 (EV_KEY)
    Event code 256 (BTN_0)
    Event code 257 (BTN_1)
    Event code 258 (BTN_2)
  Event type 4 (EV_MSC)
    Event code 4 (MSC_SCAN)
Properties:
Testing ... (interrupt to exit)
Event: time 1617722876.764232, type 4 (EV_MSC), code 4 (MSC_SCAN), value 90001
Event: time 1617722876.764232, type 1 (EV_KEY), code 256 (BTN_0), value 1
Event: time 1617722876.764232, -------------- SYN_REPORT ------------
Event: time 1617722877.028207, type 4 (EV_MSC), code 4 (MSC_SCAN), value 90001
Event: time 1617722877.028207, type 1 (EV_KEY), code 256 (BTN_0), value 0
Event: time 1617722877.028207, -------------- SYN_REPORT ------------
Event: time 1617722877.796232, type 4 (EV_MSC), code 4 (MSC_SCAN), value 90002
Event: time 1617722877.796232, type 1 (EV_KEY), code 257 (BTN_1), value 1
Event: time 1617722877.796232, -------------- SYN_REPORT ------------
Event: time 1617722878.028207, type 4 (EV_MSC), code 4 (MSC_SCAN), value 90002
Event: time 1617722878.028207, type 1 (EV_KEY), code 257 (BTN_1), value 0
Event: time 1617722878.028207, -------------- SYN_REPORT ------------
Event: time 1617722879.588255, type 4 (EV_MSC), code 4 (MSC_SCAN), value 90003
Event: time 1617722879.588255, type 1 (EV_KEY), code 258 (BTN_2), value 1
Event: time 1617722879.588255, -------------- SYN_REPORT ------------
Event: time 1617722879.812259, type 4 (EV_MSC), code 4 (MSC_SCAN), value 90003
Event: time 1617722879.812259, type 1 (EV_KEY), code 258 (BTN_2), value 0
Event: time 1617722879.812259, -------------- SYN_REPORT ------------

        else if (buffer[0]==0xb0) // convert midi controller message into EV_REL events
      					{
      					button_event.type = EV_REL;
						button_event.code = (buffer[1]==25) ? REL_X : (buffer[1]==24) ? REL_Y : 0;  // turntable is 25 and 24
						button_event.value = (buffer[2] >= 64) ? buffer[2]-127 : buffer[2];   //  turntable moves are signed 7 bit, really never gets higher than +/- 30 with the fastest spin I could do
						
			
					  if(write(fd, &button_event, sizeof button_event) < 0)
							{
							  perror("write");
							  return 1;
							}
						
						// send SYNC event
						
						button_event.type = EV_SYN;
						button_event.code = 0;
						button_event.value = 0;

					  if(write(fd, &button_event, sizeof button_event) < 0)
							{
							  perror("write");
							  return 1;
							}

                        // loop over all (track)balls
                        for (int ball = 0; ball < SDL_JoystickNumBalls(joy); ball++)
                        {
                                int itemid;

                                if (ball * 2 < INPUT_MAX_ADD_RELATIVE)
                                        itemid = ITEM_ID_ADD_RELATIVE1 + ball * 2;
                                else
                                        itemid = ITEM_ID_OTHER_AXIS_RELATIVE;

                                snprintf(tempname, sizeof(tempname), "R%d %s", ball * 2, devinfo->name());
                                devinfo->device()->add_item(tempname, (input_item_id)itemid, generic_axis_get_state<std::int32_t>, &devinfo->joystick.
balls[ball * 2]);
                                snprintf(tempname, sizeof(tempname), "R%d %s", ball * 2 + 1, devinfo->name());
                                devinfo->device()->add_item(tempname, (input_item_id)(itemid + 1), generic_axis_get_state<std::int32_t>, &devinfo->joy
stick.balls[ball * 2 + 1]);
                        }
                }

                static int event_types[] = {
                        static_cast<int>(SDL_JOYAXISMOTION),
                        static_cast<int>(SDL_JOYBALLMOTION),
                        static_cast<int>(SDL_JOYHATMOTION),
                        static_cast<int>(SDL_JOYBUTTONDOWN),
                        static_cast<int>(SDL_JOYBUTTONUP)
                };

      // relative and positional controls all map directly with a 512x scale factor
        else
        {
                // The relative code is set up to allow specifing PORT_MINMAX and default values.
                // The validity checks are purposely set up to not allow you to use anything other
                // a default of 0 and PORT_MINMAX(0,mask).  This is in case the need arises to use
                // this feature in the future.  Keeping the code in does not hurt anything.
                if (m_adjmin > m_adjmax)
                        // adjust for signed
                        m_adjmin = -m_adjmin;

                if (m_wraps)
                        m_adjmax++;

                m_minimum = (m_adjmin - m_adjdefvalue) * INPUT_RELATIVE_PER_PIXEL;
                m_maximum = (m_adjmax - m_adjdefvalue) * INPUT_RELATIVE_PER_PIXEL;

                // make the scaling the same for easier coding when we need to scale
                m_scaleneg = m_scalepos = compute_scale(1, INPUT_RELATIVE_PER_PIXEL);

                if (m_field.analog_reset())
                        // delta values reverse from center
                        m_reverse_val = 0;
                else
                {
                        // positional controls reverse from their max range
                        m_reverse_val = m_maximum + m_minimum;

                        // relative controls reverse from 1 past their max range
                        if (m_wraps)
                        {
                                // FIXME: positional needs -1, using INPUT_RELATIVE_PER_PIXEL skips a position (and reads outside the table array)
                                if(field.type() == IPT_POSITIONAL || field.type() == IPT_POSITIONAL_V)
                                        m_reverse_val --;
                                else
                                        m_reverse_val -= INPUT_RELATIVE_PER_PIXEL;
                        }
                }
        }