testjoystick.c File Reference

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "SDL.h"

Include dependency graph for testjoystick.c:

Go to the source code of this file.

Macros
#define	SCREEN_WIDTH   640
#define	SCREEN_HEIGHT   480

Functions
static void	PrintJoystick (SDL_Joystick *joystick)
static void	DrawRect (SDL_Renderer *r, const int x, const int y, const int w, const int h)
void	loop (void *arg)
int	main (int argc, char *argv[])

Variables
static SDL_Window *	window = NULL
static SDL_Renderer *	screen = NULL
static SDL_Joystick *	joystick = NULL
static SDL_bool	done = SDL_FALSE

Macro Definition Documentation

SCREEN_HEIGHT

#define SCREEN_HEIGHT   480

Definition at line 32 of file testjoystick.c.

SCREEN_WIDTH

#define SCREEN_WIDTH   640

Definition at line 31 of file testjoystick.c.

Function Documentation

DrawRect()

static void DrawRect ( SDL_Renderer *  r, const int  x, const int  y, const int  w, const int  h  )

static

Definition at line 93 of file testjoystick.c.

{
    const SDL_Rect area = { x, y, w, h };
    SDL_RenderFillRect(r, &area);
}

References SDL_RenderFillRect.

Referenced by loop().

loop()

void loop

(

void *

arg

)

Definition at line 100 of file testjoystick.c.

{
    SDL_Event event;
    int i;
 
    /* blank screen, set up for drawing this frame. */
    SDL_SetRenderDrawColor(screen, 0x0, 0x0, 0x0, SDL_ALPHA_OPAQUE);
    SDL_RenderClear(screen);
 
    while (SDL_PollEvent(&event)) {
        switch (event.type) {
 
        case SDL_JOYDEVICEADDED:
            SDL_Log("Joystick device %d added.\n", (int) event.jdevice.which);
            if (!joystick) {
                joystick = SDL_JoystickOpen(event.jdevice.which);
                if (joystick) {
                    PrintJoystick(joystick);
                } else {
                    SDL_Log("Couldn't open joystick: %s\n", SDL_GetError());
                }
            }
            break;
 
        case SDL_JOYDEVICEREMOVED:
            SDL_Log("Joystick device %d removed.\n", (int) event.jdevice.which);
            if (event.jdevice.which == SDL_JoystickInstanceID(joystick)) {
                SDL_JoystickClose(joystick);
                joystick = SDL_JoystickOpen(0);
            }
            break;
 
        case SDL_JOYAXISMOTION:
            SDL_Log("Joystick %d axis %d value: %d\n",
                   event.jaxis.which,
                   event.jaxis.axis, event.jaxis.value);
            break;
        case SDL_JOYHATMOTION:
            SDL_Log("Joystick %d hat %d value:",
                   event.jhat.which, event.jhat.hat);
            if (event.jhat.value == SDL_HAT_CENTERED)
                SDL_Log(" centered");
            if (event.jhat.value & SDL_HAT_UP)
                SDL_Log(" up");
            if (event.jhat.value & SDL_HAT_RIGHT)
                SDL_Log(" right");
            if (event.jhat.value & SDL_HAT_DOWN)
                SDL_Log(" down");
            if (event.jhat.value & SDL_HAT_LEFT)
                SDL_Log(" left");
            SDL_Log("\n");
            break;
        case SDL_JOYBALLMOTION:
            SDL_Log("Joystick %d ball %d delta: (%d,%d)\n",
                   event.jball.which,
                   event.jball.ball, event.jball.xrel, event.jball.yrel);
            break;
        case SDL_JOYBUTTONDOWN:
            SDL_Log("Joystick %d button %d down\n",
                   event.jbutton.which, event.jbutton.button);
            /* First button triggers a 0.5 second full strength rumble */
            if (event.jbutton.button == 0) {
                SDL_JoystickRumble(joystick, 0xFFFF, 0xFFFF, 500);
            }
            break;
        case SDL_JOYBUTTONUP:
            SDL_Log("Joystick %d button %d up\n",
                   event.jbutton.which, event.jbutton.button);
            break;
        case SDL_KEYDOWN:
            /* Press the L key to lag for 3 seconds, to see what happens
                when SDL doesn't service the event loop quickly. */
            if (event.key.keysym.sym == SDLK_l) {
                SDL_Log("Lagging for 3 seconds...\n");
                SDL_Delay(3000);
                break;
            }
 
            if ((event.key.keysym.sym != SDLK_ESCAPE) &&
                (event.key.keysym.sym != SDLK_AC_BACK)) {
                break;
            }
            /* Fall through to signal quit */
        case SDL_FINGERDOWN:
        case SDL_MOUSEBUTTONDOWN:
        case SDL_QUIT:
            done = SDL_TRUE;
            break;
        default:
            break;
        }
    }
 
    if (joystick) {
 
        /* Update visual joystick state */
        SDL_SetRenderDrawColor(screen, 0x00, 0xFF, 0x00, SDL_ALPHA_OPAQUE);
        for (i = 0; i < SDL_JoystickNumButtons(joystick); ++i) {
            if (SDL_JoystickGetButton(joystick, i) == SDL_PRESSED) {
                DrawRect(screen, (i%20) * 34, SCREEN_HEIGHT - 68 + (i/20) * 34, 32, 32);
            }
        }
 
        SDL_SetRenderDrawColor(screen, 0xFF, 0x00, 0x00, SDL_ALPHA_OPAQUE);
        for (i = 0; i < SDL_JoystickNumAxes(joystick); ++i) {
            /* Draw the X/Y axis */
            int x, y;
            x = (((int) SDL_JoystickGetAxis(joystick, i)) + 32768);
            x *= SCREEN_WIDTH;
            x /= 65535;
            if (x < 0) {
                x = 0;
            } else if (x > (SCREEN_WIDTH - 16)) {
                x = SCREEN_WIDTH - 16;
            }
            ++i;
            if (i < SDL_JoystickNumAxes(joystick)) {
                y = (((int) SDL_JoystickGetAxis(joystick, i)) + 32768);
            } else {
                y = 32768;
            }
            y *= SCREEN_HEIGHT;
            y /= 65535;
            if (y < 0) {
                y = 0;
            } else if (y > (SCREEN_HEIGHT - 16)) {
                y = SCREEN_HEIGHT - 16;
            }
 
            DrawRect(screen, x, y, 16, 16);
        }
 
        SDL_SetRenderDrawColor(screen, 0x00, 0x00, 0xFF, SDL_ALPHA_OPAQUE);
        for (i = 0; i < SDL_JoystickNumHats(joystick); ++i) {
            /* Derive the new position */
            int x = SCREEN_WIDTH/2;
            int y = SCREEN_HEIGHT/2;
            const Uint8 hat_pos = SDL_JoystickGetHat(joystick, i);
 
            if (hat_pos & SDL_HAT_UP) {
                y = 0;
            } else if (hat_pos & SDL_HAT_DOWN) {
                y = SCREEN_HEIGHT-8;
            }
 
            if (hat_pos & SDL_HAT_LEFT) {
                x = 0;
            } else if (hat_pos & SDL_HAT_RIGHT) {
                x = SCREEN_WIDTH-8;
            }
 
            DrawRect(screen, x, y, 8, 8);
        }
    }
 
    SDL_RenderPresent(screen);
 
#ifdef __EMSCRIPTEN__
    if (done) {
        emscripten_cancel_main_loop();
    }
#endif
}

References done, DrawRect(), i, int(), joystick, PrintJoystick(), screen, SCREEN_HEIGHT, SCREEN_WIDTH, SDL_ALPHA_OPAQUE, SDL_Delay, SDL_FINGERDOWN, SDL_GetError, SDL_HAT_CENTERED, SDL_HAT_DOWN, SDL_HAT_LEFT, SDL_HAT_RIGHT, SDL_HAT_UP, SDL_JOYAXISMOTION, SDL_JOYBALLMOTION, SDL_JOYBUTTONDOWN, SDL_JOYBUTTONUP, SDL_JOYDEVICEADDED, SDL_JOYDEVICEREMOVED, SDL_JOYHATMOTION, SDL_JoystickClose, SDL_JoystickGetAxis, SDL_JoystickGetButton, SDL_JoystickGetHat, SDL_JoystickInstanceID, SDL_JoystickNumAxes, SDL_JoystickNumButtons, SDL_JoystickNumHats, SDL_JoystickOpen, SDL_JoystickRumble, SDL_KEYDOWN, SDL_Log, SDL_MOUSEBUTTONDOWN, SDL_PollEvent, SDL_PRESSED, SDL_QUIT, SDL_RenderClear, SDL_RenderPresent, SDL_SetRenderDrawColor, SDL_TRUE, SDLK_AC_BACK, SDLK_ESCAPE, and SDLK_l.

Referenced by main().

main()

int main	(	int	argc,
		char *	argv[]
	)

Definition at line 265 of file testjoystick.c.

{
    SDL_SetHint(SDL_HINT_ACCELEROMETER_AS_JOYSTICK, "0");
 
    /* Enable standard application logging */
    SDL_LogSetPriority(SDL_LOG_CATEGORY_APPLICATION, SDL_LOG_PRIORITY_INFO);
 
    /* Initialize SDL (Note: video is required to start event loop) */
    if (SDL_Init(SDL_INIT_VIDEO | SDL_INIT_JOYSTICK) < 0) {
        SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Couldn't initialize SDL: %s\n", SDL_GetError());
        exit(1);
    }
 
    /* Create a window to display joystick axis position */
    window = SDL_CreateWindow("Joystick Test", SDL_WINDOWPOS_CENTERED,
                              SDL_WINDOWPOS_CENTERED, SCREEN_WIDTH,
                              SCREEN_HEIGHT, 0);
    if (window == NULL) {
        SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Couldn't create window: %s\n", SDL_GetError());
        return SDL_FALSE;
    }
 
    screen = SDL_CreateRenderer(window, -1, 0);
    if (screen == NULL) {
        SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Couldn't create renderer: %s\n", SDL_GetError());
        SDL_DestroyWindow(window);
        return SDL_FALSE;
    }
 
    SDL_SetRenderDrawColor(screen, 0x00, 0x00, 0x00, SDL_ALPHA_OPAQUE);
    SDL_RenderClear(screen);
    SDL_RenderPresent(screen);
 
    /* Loop, getting joystick events! */
#ifdef __EMSCRIPTEN__
    emscripten_set_main_loop_arg(loop, NULL, 0, 1);
#else
    while (!done) {
        loop(NULL);
    }
#endif
 
    SDL_DestroyRenderer(screen);
    SDL_DestroyWindow(window);
 
    SDL_QuitSubSystem(SDL_INIT_VIDEO | SDL_INIT_JOYSTICK);
 
    return 0;
}

References done, loop(), NULL, screen, SCREEN_HEIGHT, SCREEN_WIDTH, SDL_ALPHA_OPAQUE, SDL_CreateRenderer, SDL_CreateWindow, SDL_DestroyRenderer, SDL_DestroyWindow, SDL_FALSE, SDL_GetError, SDL_HINT_ACCELEROMETER_AS_JOYSTICK, SDL_Init, SDL_INIT_JOYSTICK, SDL_INIT_VIDEO, SDL_LOG_CATEGORY_APPLICATION, SDL_LOG_PRIORITY_INFO, SDL_LogError, SDL_LogSetPriority, SDL_QuitSubSystem, SDL_RenderClear, SDL_RenderPresent, SDL_SetHint, SDL_SetRenderDrawColor, and SDL_WINDOWPOS_CENTERED.

PrintJoystick()

static void PrintJoystick ( SDL_Joystick *  joystick )

static

Definition at line 41 of file testjoystick.c.

{
    const char *type;
    char guid[64];
 
    SDL_assert(SDL_JoystickFromInstanceID(SDL_JoystickInstanceID(joystick)) == joystick);
    SDL_JoystickGetGUIDString(SDL_JoystickGetGUID(joystick), guid, sizeof (guid));
    switch (SDL_JoystickGetType(joystick)) {
    case SDL_JOYSTICK_TYPE_GAMECONTROLLER:
        type = "Game Controller";
        break;
    case SDL_JOYSTICK_TYPE_WHEEL:
        type = "Wheel";
        break;
    case SDL_JOYSTICK_TYPE_ARCADE_STICK:
        type = "Arcade Stick";
        break;
    case SDL_JOYSTICK_TYPE_FLIGHT_STICK:
        type = "Flight Stick";
        break;
    case SDL_JOYSTICK_TYPE_DANCE_PAD:
        type = "Dance Pad";
        break;
    case SDL_JOYSTICK_TYPE_GUITAR:
        type = "Guitar";
        break;
    case SDL_JOYSTICK_TYPE_DRUM_KIT:
        type = "Drum Kit";
        break;
    case SDL_JOYSTICK_TYPE_ARCADE_PAD:
        type = "Arcade Pad";
        break;
    case SDL_JOYSTICK_TYPE_THROTTLE:
        type = "Throttle";
        break;
    default:
        type = "Unknown";
        break;
    }
    SDL_Log("Joystick\n");
    SDL_Log("       name: %s\n", SDL_JoystickName(joystick));
    SDL_Log("       type: %s\n", type);
    SDL_Log("       axes: %d\n", SDL_JoystickNumAxes(joystick));
    SDL_Log("      balls: %d\n", SDL_JoystickNumBalls(joystick));
    SDL_Log("       hats: %d\n", SDL_JoystickNumHats(joystick));
    SDL_Log("    buttons: %d\n", SDL_JoystickNumButtons(joystick));
    SDL_Log("instance id: %d\n", SDL_JoystickInstanceID(joystick));
    SDL_Log("       guid: %s\n", guid);
    SDL_Log("    VID/PID: 0x%.4x/0x%.4x\n", SDL_JoystickGetVendor(joystick), SDL_JoystickGetProduct(joystick));
}

References joystick, SDL_assert, SDL_JOYSTICK_TYPE_ARCADE_PAD, SDL_JOYSTICK_TYPE_ARCADE_STICK, SDL_JOYSTICK_TYPE_DANCE_PAD, SDL_JOYSTICK_TYPE_DRUM_KIT, SDL_JOYSTICK_TYPE_FLIGHT_STICK, SDL_JOYSTICK_TYPE_GAMECONTROLLER, SDL_JOYSTICK_TYPE_GUITAR, SDL_JOYSTICK_TYPE_THROTTLE, SDL_JOYSTICK_TYPE_WHEEL, SDL_JoystickFromInstanceID, SDL_JoystickGetGUID, SDL_JoystickGetGUIDString, SDL_JoystickGetProduct, SDL_JoystickGetType, SDL_JoystickGetVendor, SDL_JoystickInstanceID, SDL_JoystickName, SDL_JoystickNumAxes, SDL_JoystickNumBalls, SDL_JoystickNumButtons, SDL_JoystickNumHats, and SDL_Log.

Referenced by loop().

Variable Documentation

done

SDL_bool done = SDL_FALSE

static

Definition at line 38 of file testjoystick.c.

Referenced by loop(), and main().

joystick

SDL_Joystick* joystick = NULL

static

Definition at line 37 of file testjoystick.c.

Referenced by IOS_AccelerometerUpdate(), IOS_JoystickClose(), IOS_JoystickHasLED(), IOS_JoystickOpen(), IOS_JoystickRumble(), IOS_JoystickRumbleTriggers(), IOS_JoystickSetLED(), IOS_JoystickSetSensorsEnabled(), IOS_JoystickUpdate(), IOS_MFIJoystickUpdate(), loop(), main(), PrintJoystick(), SDL_GameControllerFromPlayerIndex(), SDL_GameControllerGetNumTouchpadFingers(), SDL_GameControllerGetNumTouchpads(), SDL_GameControllerGetSensorData(), SDL_GameControllerGetTouchpadFinger(), SDL_GameControllerHandleDelayedGuideButton(), SDL_GameControllerHasSensor(), SDL_GameControllerIsSensorEnabled(), SDL_GameControllerSetSensorEnabled(), SDL_HapticOpenFromJoystick(), SDL_JoystickAxesCenteredAtZero(), SDL_JoystickClose(), SDL_JoystickCurrentPowerLevel(), SDL_JoystickFromInstanceID(), SDL_JoystickFromPlayerIndex(), SDL_JoystickGetAttached(), SDL_JoystickGetAxis(), SDL_JoystickGetAxisInitialState(), SDL_JoystickGetBall(), SDL_JoystickGetButton(), SDL_JoystickGetGUID(), SDL_JoystickGetHat(), SDL_JoystickGetPlayerIndex(), SDL_JoystickGetProduct(), SDL_JoystickGetProductVersion(), SDL_JoystickGetSerial(), SDL_JoystickGetType(), SDL_JoystickGetVendor(), SDL_JoystickHasLED(), SDL_JoystickInstanceID(), SDL_JoystickIsHaptic(), SDL_JoystickName(), SDL_JoystickNumAxes(), SDL_JoystickNumBalls(), SDL_JoystickNumButtons(), SDL_JoystickNumHats(), SDL_JoystickOpen(), SDL_JoystickRumble(), SDL_JoystickRumbleTriggers(), SDL_JoystickSetLED(), SDL_JoystickSetPlayerIndex(), SDL_JoystickSetVirtualAxis(), SDL_JoystickSetVirtualButton(), SDL_JoystickSetVirtualHat(), SDL_JoystickUpdate(), SDL_PrivateJoystickAddSensor(), SDL_PrivateJoystickAddTouchpad(), SDL_PrivateJoystickAxis(), SDL_PrivateJoystickBall(), SDL_PrivateJoystickBatteryLevel(), SDL_PrivateJoystickButton(), SDL_PrivateJoystickForceRecentering(), SDL_PrivateJoystickHat(), SDL_PrivateJoystickRemoved(), SDL_PrivateJoystickSensor(), SDL_PrivateJoystickTouchpad(), SDL_PrivateJoystickValid(), and WatchJoystick().

screen

SDL_Renderer* screen = NULL

static

Definition at line 36 of file testjoystick.c.

Referenced by loop(), and main().

window

SDL_Window* window = NULL

static

Definition at line 35 of file testjoystick.c.