gamecontroller_powerlevel.c

#include <SDL2/SDL.h>

int main(void) { 
    SDL_Init(SDL_INIT_EVERYTHING);
    SDL_GameControllerAddMappingsFromFile("gamecontrollerdb.txt");
    SDL_Window *window = SDL_CreateWindow("Controllers", SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED, 800, 600, SDL_WINDOW_SHOWN);
    SDL_Renderer *renderer = SDL_CreateRenderer(window, -1, SDL_RENDERER_ACCELERATED | SDL_RENDERER_PRESENTVSYNC);

    SDL_bool is_running = SDL_TRUE;
    SDL_GameController *ctrl;
    SDL_Joystick *joystick;
    SDL_JoystickPowerLevel plevel;
    SDL_Event event;
    const char *name;
    while(is_running == SDL_TRUE)
    {
        while(SDL_PollEvent(&event)) 
        {
            switch(event.type)
            {
                case SDL_QUIT:
                    is_running = SDL_FALSE;
                    break;
                case SDL_KEYDOWN:
                    if (event.key.keysym.sym == SDLK_ESCAPE) {
                        is_running = SDL_FALSE;
                    }
                    break;

                case SDL_CONTROLLERDEVICEADDED:
                    name = SDL_JoystickNameForIndex(event.cdevice.which);
                    if (name && SDL_strstr(name, "Motion Sensors")) { break; }

                    ctrl = SDL_GameControllerOpen(event.cdevice.which);
                    if(ctrl)
                    {
                        joystick = SDL_GameControllerGetJoystick (ctrl);
                        plevel = SDL_JoystickCurrentPowerLevel(joystick);
                        if (plevel == SDL_JOYSTICK_POWER_UNKNOWN)
                        {
                            SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
                                        "%s: SDL_JoystickCurrentPowerLevel(): %s\n",
                                        __func__, SDL_GetError());
                        }
                        SDL_Log("Controller %d opened - PowerLevel %d\n", event.cdevice.which, plevel);
                    } else {
                        SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
                                     "%s: SDL_GameControllerOpen(%d): %s\n",
                                     __func__, event.cdevice.which, SDL_GetError());
                    }
                    break;
                case SDL_CONTROLLERDEVICEREMOVED:
                    SDL_Log("Controller %d detached.\n", (int) event.cdevice.which);
                    ctrl = SDL_GameControllerFromInstanceID(event.cdevice.which);
                    if(ctrl)
                    {
                        SDL_GameControllerClose(ctrl);
                        SDL_Log("Controller %d closed.\n", (int) event.cdevice.which);
                    } else {
                            SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
                                        "%s: SDL_GameControllerFromInstanceID(%d): %s\n",
                                        __func__, event.cdevice.which, SDL_GetError());
                    }
                    break;
                case SDL_CONTROLLERBUTTONDOWN:
                case SDL_CONTROLLERBUTTONUP:
                    SDL_Log("Controller %d button '%s' %s\n",
                            event.cdevice.which,
                            SDL_GameControllerGetStringForButton((SDL_GameControllerButton)event.cbutton.button), 
                            event.cbutton.state ? "pressed" : "released");
                    break;

                /* 
                 * JOYSTICK
                 */
                case SDL_JOYDEVICEADDED:
                    /* This device is a Game Controller we will handle elsewhere */
                    if (SDL_IsGameController(event.jdevice.which)) {
                        SDL_Log("JOYDEVADD: Guard triggered\n");
                        break; }

                    SDL_Log("Joystick   %d found.\n", event.jdevice.which );
                    joystick = SDL_JoystickOpen(event.jdevice.which);
                    if(joystick) {
                        plevel = SDL_JoystickCurrentPowerLevel(joystick);
                        if (plevel == SDL_JOYSTICK_POWER_UNKNOWN)
                        {
                            SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
                                        "%s: SDL_JoystickCurrentPowerLevel(): %s\n",
                                        __func__, SDL_GetError());
                        }
                        SDL_Log("Joystick   %d opened - PowerLevel %d\n", event.jdevice.which, plevel);
                    } else {
                        SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
                                    "%s: SDL_JoystickOpen(%d): %s\n",
                                    __func__, event.jdevice.which, SDL_GetError());
                    }
                    break;
                case SDL_JOYDEVICEREMOVED:
                    /*
                     * This guard is necessary for two reasons:
                     * 1. If a joystick event was received but we will handle
                     *    as a GameController;
                     * 2. If it was ALREADY handled as game controller, hence
                     *    we will not be able to fetch the controller or the
                     *    joystick id
                     */
                    joystick = SDL_JoystickFromInstanceID(event.jdevice.which);
                    if (SDL_GameControllerFromInstanceID(event.jdevice.which) || !joystick) {
                        SDL_Log("JOYDEVREM: Guard triggered\n");
                        break; }

                    SDL_Log("Joystick   %d dettached.\n", event.jdevice.which);
                    if(joystick)
                    {
                        SDL_JoystickClose(joystick);
                        SDL_Log("Joystick   %d closed.\n", (int) event.jdevice.which);
                    } else {
                        SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
                                    "%s: SDL_JoystickFromInstanceID(%d): %s\n",
                                    __func__, event.jdevice.which, SDL_GetError());
                    }
                    break;
                case SDL_JOYBUTTONDOWN:
                case SDL_JOYBUTTONUP:
                    /* This device is a Game Controller we will handle elsewhere */
                    if (SDL_GameControllerFromInstanceID(event.jdevice.which)) {
                        SDL_Log("JOYDEVBUT: Guard triggered\n");
                        break; }

                    SDL_Log("Joystick   %d - Button: %d %s\n", 
                            event.jdevice.which,
                            event.jbutton.button,
                            event.jbutton.state ? "pressed" : "released");
                    break;
                default:
                    break;
            }
        }

        SDL_RenderClear(renderer);
        SDL_RenderPresent(renderer);
        SDL_Delay(10);       /* Keep CPU cool */
    }

    if (renderer)           SDL_DestroyRenderer(renderer);
    if (window)             SDL_DestroyWindow(window);
    SDL_Quit();
    return 0;
}