testjoystick.c
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Copyright (C) 1997-2020 Sam Lantinga <slouken@libsdl.org>
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This software is provided 'as-is', without any express or implied
warranty. In no event will the authors be held liable for any damages
arising from the use of this software.
Permission is granted to anyone to use this software for any purpose,
including commercial applications, and to alter it and redistribute it
freely.
*/
/* Simple program to test the SDL joystick routines */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "SDL.h"
#ifdef __EMSCRIPTEN__
#include <emscripten/emscripten.h>
#endif
#ifndef SDL_JOYSTICK_DISABLED
#ifdef __IPHONEOS__
#define SCREEN_WIDTH 320
#define SCREEN_HEIGHT 480
#else
#define SCREEN_WIDTH 640
#define SCREEN_HEIGHT 480
#endif
SDL_Renderer *screen = NULL;
SDL_bool retval = SDL_FALSE;
SDL_bool done = SDL_FALSE;
static void
DrawRect(SDL_Renderer *r, const int x, const int y, const int w, const int h)
{
const SDL_Rect area = { x, y, w, h };
SDL_RenderFillRect(r, &area);
}
void
loop(void *arg)
{
SDL_Event event;
int i;
SDL_Joystick *joystick = (SDL_Joystick *)arg;
/* 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_JOYDEVICEREMOVED:
SDL_Log("Joystick device %d removed.\n", (int) event.jdevice.which);
SDL_Log("Our instance ID is %d\n", (int) SDL_JoystickInstanceID(joystick));
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);
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/* First button triggers a 0.5 second full strength rumble */
if (event.jbutton.button == 0) {
SDL_JoystickRumble(joystick, 0xFFFF, 0xFFFF, 500);
}
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break;
case SDL_JOYBUTTONUP:
SDL_Log("Joystick %d button %d up\n",
event.jbutton.which, event.jbutton.button);
break;
case SDL_KEYDOWN:
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;
}
}
/* 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);
if (SDL_JoystickGetAttached( joystick ) == 0) {
done = SDL_TRUE;
retval = SDL_TRUE; /* keep going, wait for reattach. */
}
#ifdef __EMSCRIPTEN__
if (done) {
emscripten_cancel_main_loop();
}
#endif
}
static SDL_bool
WatchJoystick(SDL_Joystick * joystick)
{
SDL_Window *window = NULL;
const char *name = NULL;
retval = SDL_FALSE;
done = SDL_FALSE;
/* 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);
SDL_RaiseWindow(window);
/* Print info about the joystick we are watching */
name = SDL_JoystickName(joystick);
SDL_Log("Watching joystick %d: (%s)\n", SDL_JoystickInstanceID(joystick),
name ? name : "Unknown Joystick");
SDL_Log("Joystick has %d axes, %d hats, %d balls, and %d buttons\n",
SDL_JoystickNumAxes(joystick), SDL_JoystickNumHats(joystick),
SDL_JoystickNumBalls(joystick), SDL_JoystickNumButtons(joystick));
/* Loop, getting joystick events! */
#ifdef __EMSCRIPTEN__
emscripten_set_main_loop_arg(loop, joystick, 0, 1);
#else
while (!done) {
loop(joystick);
}
#endif
SDL_DestroyRenderer(screen);
screen = NULL;
SDL_DestroyWindow(window);
return retval;
}
int
main(int argc, char *argv[])
{
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const char *name, *type;
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int i;
SDL_Joystick *joystick;
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SDL_SetHint(SDL_HINT_ACCELEROMETER_AS_JOYSTICK, "0");
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/* Enable standard application logging */
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SDL_LogSetPriority(SDL_LOG_CATEGORY_APPLICATION, SDL_LOG_PRIORITY_INFO);
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/* 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);
}
/* Print information about the joysticks */
SDL_Log("There are %d joysticks attached\n", SDL_NumJoysticks());
for (i = 0; i < SDL_NumJoysticks(); ++i) {
name = SDL_JoystickNameForIndex(i);
SDL_Log("Joystick %d: %s\n", i, name ? name : "Unknown Joystick");
joystick = SDL_JoystickOpen(i);
if (joystick == NULL) {
SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "SDL_JoystickOpen(%d) failed: %s\n", i,
SDL_GetError());
} else {
char guid[64];
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SDL_assert(SDL_JoystickFromInstanceID(SDL_JoystickInstanceID(joystick)) == joystick);
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SDL_JoystickGetGUIDString(SDL_JoystickGetGUID(joystick),
guid, sizeof (guid));
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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;
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case SDL_JOYSTICK_TYPE_THROTTLE:
type = "Throttle";
break;
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default:
type = "Unknown";
break;
}
SDL_Log(" type: %s\n", type);
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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);
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SDL_Log(" VID/PID: 0x%.4x/0x%.4x\n", SDL_JoystickGetVendor(joystick), SDL_JoystickGetProduct(joystick));
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SDL_JoystickClose(joystick);
}
}
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#if defined(__ANDROID__) || defined(__IPHONEOS__)
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if (SDL_NumJoysticks() > 0) {
#else
if (argv[1]) {
#endif
SDL_bool reportederror = SDL_FALSE;
SDL_bool keepGoing = SDL_TRUE;
SDL_Event event;
int device;
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#if defined(__ANDROID__) || defined(__IPHONEOS__)
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device = 0;
#else
device = atoi(argv[1]);
#endif
joystick = SDL_JoystickOpen(device);
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if (joystick != NULL) {
SDL_assert(SDL_JoystickFromInstanceID(SDL_JoystickInstanceID(joystick)) == joystick);
}
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while ( keepGoing ) {
if (joystick == NULL) {
if ( !reportederror ) {
SDL_Log("Couldn't open joystick %d: %s\n", device, SDL_GetError());
keepGoing = SDL_FALSE;
reportederror = SDL_TRUE;
}
} else {
reportederror = SDL_FALSE;
keepGoing = WatchJoystick(joystick);
SDL_JoystickClose(joystick);
}
joystick = NULL;
if (keepGoing) {
SDL_Log("Waiting for attach\n");
}
while (keepGoing) {
SDL_WaitEvent(&event);
if ((event.type == SDL_QUIT) || (event.type == SDL_FINGERDOWN)
|| (event.type == SDL_MOUSEBUTTONDOWN)) {
keepGoing = SDL_FALSE;
} else if (event.type == SDL_JOYDEVICEADDED) {
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device = event.jdevice.which;
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joystick = SDL_JoystickOpen(device);
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if (joystick != NULL) {
SDL_assert(SDL_JoystickFromInstanceID(SDL_JoystickInstanceID(joystick)) == joystick);
}
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break;
}
}
}
}
SDL_QuitSubSystem(SDL_INIT_VIDEO | SDL_INIT_JOYSTICK);
return 0;
}
#else
int
main(int argc, char *argv[])
{
SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "SDL compiled without Joystick support.\n");
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return 1;
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/* vi: set ts=4 sw=4 expandtab: */