86Box/src/qt/sdl_joystick.cpp

// Lifted from wx-sdl2-joystick.c in PCem

#include <SDL2/SDL.h>

extern "C" {
#include <86box/device.h>
#include <86box/gameport.h>

int joysticks_present;
joystick_t joystick_state[MAX_JOYSTICKS];
plat_joystick_t plat_joystick_state[MAX_PLAT_JOYSTICKS];
static SDL_Joystick *sdl_joy[MAX_PLAT_JOYSTICKS];
}

void joystick_init() {
    if (SDL_InitSubSystem(SDL_INIT_JOYSTICK) != 0) {
        return;
    }
    joysticks_present = SDL_NumJoysticks();

    memset(sdl_joy, 0, sizeof(sdl_joy));
    for (int c = 0; c < joysticks_present; c++)
    {
        sdl_joy[c] = SDL_JoystickOpen(c);

        if (sdl_joy[c])
        {
            int d;

            strncpy(plat_joystick_state[c].name, SDL_JoystickNameForIndex(c), 64);
            plat_joystick_state[c].nr_axes = SDL_JoystickNumAxes(sdl_joy[c]);
            plat_joystick_state[c].nr_buttons = SDL_JoystickNumButtons(sdl_joy[c]);
            plat_joystick_state[c].nr_povs = SDL_JoystickNumHats(sdl_joy[c]);

            for (d = 0; d < std::min(plat_joystick_state[c].nr_axes, 8); d++)
            {
                sprintf(plat_joystick_state[c].axis[d].name, "Axis %i", d);
                plat_joystick_state[c].axis[d].id = d;
            }
            for (d = 0; d < std::min(plat_joystick_state[c].nr_buttons, 8); d++)
            {
                sprintf(plat_joystick_state[c].button[d].name, "Button %i", d);
                plat_joystick_state[c].button[d].id = d;
            }
            for (d = 0; d < std::min(plat_joystick_state[c].nr_povs, 4); d++)
            {
                sprintf(plat_joystick_state[c].pov[d].name, "POV %i", d);
                plat_joystick_state[c].pov[d].id = d;
            }
        }
    }
}

void joystick_close()
{
    int c;

    for (c = 0; c < joysticks_present; c++)
    {
        if (sdl_joy[c])
            SDL_JoystickClose(sdl_joy[c]);
    }
}

static int joystick_get_axis(int joystick_nr, int mapping)
{
    if (mapping & POV_X)
    {
        switch (plat_joystick_state[joystick_nr].p[mapping & 3])
        {
        case SDL_HAT_LEFTUP: case SDL_HAT_LEFT: case SDL_HAT_LEFTDOWN:
            return -32767;

        case SDL_HAT_RIGHTUP: case SDL_HAT_RIGHT: case SDL_HAT_RIGHTDOWN:
            return 32767;

        default:
            return 0;
        }
    }
    else if (mapping & POV_Y)
    {
        switch (plat_joystick_state[joystick_nr].p[mapping & 3])
        {
        case SDL_HAT_LEFTUP: case SDL_HAT_UP: case SDL_HAT_RIGHTUP:
            return -32767;

        case SDL_HAT_LEFTDOWN: case SDL_HAT_DOWN: case SDL_HAT_RIGHTDOWN:
            return 32767;

        default:
            return 0;
        }
    }
    else
        return plat_joystick_state[joystick_nr].a[plat_joystick_state[joystick_nr].axis[mapping].id];
}
void joystick_process()
{
    int c, d;

    SDL_JoystickUpdate();
    for (c = 0; c < joysticks_present; c++)
    {
        int b;

        plat_joystick_state[c].a[0] = SDL_JoystickGetAxis(sdl_joy[c], 0);
        plat_joystick_state[c].a[1] = SDL_JoystickGetAxis(sdl_joy[c], 1);
        plat_joystick_state[c].a[2] = SDL_JoystickGetAxis(sdl_joy[c], 2);
        plat_joystick_state[c].a[3] = SDL_JoystickGetAxis(sdl_joy[c], 3);
        plat_joystick_state[c].a[4] = SDL_JoystickGetAxis(sdl_joy[c], 4);
        plat_joystick_state[c].a[5] = SDL_JoystickGetAxis(sdl_joy[c], 5);

        for (b = 0; b < 16; b++)
            plat_joystick_state[c].b[b] = SDL_JoystickGetButton(sdl_joy[c], b);

        for (b = 0; b < 4; b++)
            plat_joystick_state[c].p[b] = SDL_JoystickGetHat(sdl_joy[c], b);
        //                pclog("joystick %i - x=%i y=%i b[0]=%i b[1]=%i  %i\n", c, joystick_state[c].x, joystick_state[c].y, joystick_state[c].b[0], joystick_state[c].b[1], joysticks_present);
    }

    for (c = 0; c < joystick_get_max_joysticks(joystick_type); c++)
    {
        if (joystick_state[c].plat_joystick_nr)
        {
            int joystick_nr = joystick_state[c].plat_joystick_nr - 1;

            for (d = 0; d < joystick_get_axis_count(joystick_type); d++)
                joystick_state[c].axis[d] = joystick_get_axis(joystick_nr, joystick_state[c].axis_mapping[d]);
            for (d = 0; d < joystick_get_button_count(joystick_type); d++)
                joystick_state[c].button[d] = plat_joystick_state[joystick_nr].b[joystick_state[c].button_mapping[d]];
            for (d = 0; d < joystick_get_pov_count(joystick_type); d++)
            {
                int x, y;
                double angle, magnitude;

                x = joystick_get_axis(joystick_nr, joystick_state[c].pov_mapping[d][0]);
                y = joystick_get_axis(joystick_nr, joystick_state[c].pov_mapping[d][1]);

                angle = (atan2((double)y, (double)x) * 360.0) / (2*M_PI);
                magnitude = sqrt((double)x*(double)x + (double)y*(double)y);

                if (magnitude < 16384)
                    joystick_state[c].pov[d] = -1;
                else
                    joystick_state[c].pov[d] = ((int)angle + 90 + 360) % 360;
            }
        }
        else
        {
            for (d = 0; d < joystick_get_axis_count(joystick_type); d++)
                joystick_state[c].axis[d] = 0;
            for (d = 0; d < joystick_get_button_count(joystick_type); d++)
                joystick_state[c].button[d] = 0;
            for (d = 0; d < joystick_get_pov_count(joystick_type); d++)
                joystick_state[c].pov[d] = -1;
        }
    }
}