Fix evdev axis reversal

[refi64]

@toccata10 See if this works now.

[mention-bot]

@kirbyfan64, thanks for your PR! By analyzing the history of the files in this pull request, we identified @hcorion to be a potential reviewer.

[hcorion]

Please merge after #3283

[hcorion]

From what I can tell, this won't work if joystick squircling is on (and it's on by default).

[toccata10]

It's working with
Squircle Joysticks: false
in the config file

[toccata10]

Strangely, on Tekken 6, when I press down, it registers up (and up registers up). Seems to be the only game with this pb (with keyboard, it is ok).
RPCS3-Tekken6.zip
Edit: with
Reverse left stick X axis: false
the behaviour is correct: I can go up and down (although my stick is reversed).
Always wondered why
value = 256 - value;
and not:
value = 255 - value;
(no time now to test it, but I will)

[toccata10]

A new test with (line 474):
value = 255 - value;
It fixes tekken 6 and it's ok with the other games I tested.

[toccata10]

Fixes Tekken 6 input

[toccata10]

value = 255 - value; //fixes Tekken 6 input

[toccata10]

For Squircle:
With Reverse left stick X axis: true, line 451 should be
pad.m_sticks[Xaxis].m_value = scale_axis(ABS_X, 255-joy_axis[i][Xaxis]);

[toccata10]

Now that #3283 is merged, this fixes the missing reversal (without squircle), Line 103:

                     {
                        int value = scale_axis(evt.code, evt.value);

                        if (revaxis[axis])
                        {
                            value = 255 - value;
                        }

                        pad->m_sticks[axis].m_value = value;
                    }

[toccata10]

@kirbyfan64 any chance to see this corrected so that it can be merged ? Thks

[toccata10]

For the squircle pb with axis reversal, this is working:

                if (g_evdev_joystick_config.squirclejoysticks)
                {
                        if (revaxis[axis])
						{
							joy_axis[i][axis] = 255-evt.value;
                        }
						else
						{
							joy_axis[i][axis] = evt.value;
						}

@kirbyfan64: do you want me to create a pull request ? I don't know if you're still interested (or simply have time) in this. That's my corrected file:
evdev_joystick_handler-correct.zip

[refi64]

@toccata10 Sorry! I totally forgot about this. I pushed a new version that should work with both squircle and normal modes.

[toccata10]

Works fine now on my system. Thanks.