This repository has been archived by the owner on Feb 11, 2021. It is now read-only.
testjoystick.c
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/* Simple program to test the SDL joystick routines */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "SDL.h"
#define SCREEN_WIDTH 640
#define SCREEN_HEIGHT 480
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void
WatchJoystick(SDL_Joystick * joystick)
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SDL_Surface *screen;
const char *name;
int i, done;
SDL_Event event;
int x, y, draw;
SDL_Rect axis_area[6][2];
/* Set a video mode to display joystick axis position */
screen = SDL_SetVideoMode(SCREEN_WIDTH, SCREEN_HEIGHT, 16, 0);
if (screen == NULL) {
fprintf(stderr, "Couldn't set video mode: %s\n", SDL_GetError());
return;
}
/* Print info about the joystick we are watching */
name = SDL_JoystickName(SDL_JoystickIndex(joystick));
printf("Watching joystick %d: (%s)\n", SDL_JoystickIndex(joystick),
name ? name : "Unknown Joystick");
printf("Joystick has %d axes, %d hats, %d balls, and %d buttons\n",
SDL_JoystickNumAxes(joystick), SDL_JoystickNumHats(joystick),
SDL_JoystickNumBalls(joystick), SDL_JoystickNumButtons(joystick));
/* Initialize drawing rectangles */
memset(axis_area, 0, (sizeof axis_area));
draw = 0;
/* Loop, getting joystick events! */
done = 0;
while (!done) {
while (SDL_PollEvent(&event)) {
switch (event.type) {
case SDL_JOYAXISMOTION:
printf("Joystick %d axis %d value: %d\n",
event.jaxis.which,
event.jaxis.axis, event.jaxis.value);
break;
case SDL_JOYHATMOTION:
printf("Joystick %d hat %d value:",
event.jhat.which, event.jhat.hat);
if (event.jhat.value == SDL_HAT_CENTERED)
printf(" centered");
if (event.jhat.value & SDL_HAT_UP)
printf(" up");
if (event.jhat.value & SDL_HAT_RIGHT)
printf(" right");
if (event.jhat.value & SDL_HAT_DOWN)
printf(" down");
if (event.jhat.value & SDL_HAT_LEFT)
printf(" left");
printf("\n");
break;
case SDL_JOYBALLMOTION:
printf("Joystick %d ball %d delta: (%d,%d)\n",
event.jball.which,
event.jball.ball, event.jball.xrel, event.jball.yrel);
break;
case SDL_JOYBUTTONDOWN:
printf("Joystick %d button %d down\n",
event.jbutton.which, event.jbutton.button);
break;
case SDL_JOYBUTTONUP:
printf("Joystick %d button %d up\n",
event.jbutton.which, event.jbutton.button);
break;
case SDL_KEYDOWN:
if (event.key.keysym.sym != SDLK_ESCAPE) {
break;
}
/* Fall through to signal quit */
case SDL_QUIT:
done = 1;
break;
default:
break;
}
}
/* Update visual joystick state */
for (i = 0; i < SDL_JoystickNumButtons(joystick); ++i) {
SDL_Rect area;
area.x = i * 34;
area.y = SCREEN_HEIGHT - 34;
area.w = 32;
area.h = 32;
if (SDL_JoystickGetButton(joystick, i) == SDL_PRESSED) {
SDL_FillRect(screen, &area, 0xFFFF);
} else {
SDL_FillRect(screen, &area, 0x0000);
}
SDL_UpdateRects(screen, 1, &area);
}
for (i = 0;
i < SDL_JoystickNumAxes(joystick) / 2
&& i < SDL_arraysize(axis_area); ++i) {
/* Erase previous axes */
SDL_FillRect(screen, &axis_area[i][draw], 0x0000);
/* Draw the X/Y axis */
draw = !draw;
x = (((int) SDL_JoystickGetAxis(joystick, i * 2 + 0)) + 32768);
x *= SCREEN_WIDTH;
x /= 65535;
if (x < 0) {
x = 0;
} else if (x > (SCREEN_WIDTH - 16)) {
x = SCREEN_WIDTH - 16;
}
y = (((int) SDL_JoystickGetAxis(joystick, i * 2 + 1)) + 32768);
y *= SCREEN_HEIGHT;
y /= 65535;
if (y < 0) {
y = 0;
} else if (y > (SCREEN_HEIGHT - 16)) {
y = SCREEN_HEIGHT - 16;
}
axis_area[i][draw].x = (Sint16) x;
axis_area[i][draw].y = (Sint16) y;
axis_area[i][draw].w = 16;
axis_area[i][draw].h = 16;
SDL_FillRect(screen, &axis_area[i][draw], 0xFFFF);
SDL_UpdateRects(screen, 2, axis_area[i]);
}
}
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}
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int
main(int argc, char *argv[])
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{
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const char *name;
int i;
SDL_Joystick *joystick;
/* Initialize SDL (Note: video is required to start event loop) */
if (SDL_Init(SDL_INIT_VIDEO | SDL_INIT_JOYSTICK) < 0) {
fprintf(stderr, "Couldn't initialize SDL: %s\n", SDL_GetError());
exit(1);
}
/* Print information about the joysticks */
printf("There are %d joysticks attached\n", SDL_NumJoysticks());
for (i = 0; i < SDL_NumJoysticks(); ++i) {
name = SDL_JoystickName(i);
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printf("Joystick %d: %s\n", i, name ? name : "Unknown Joystick");
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joystick = SDL_JoystickOpen(i);
if (joystick == NULL) {
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fprintf(stderr, "SDL_JoystickOpen(%d) failed: %s\n", i,
SDL_GetError());
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} else {
printf(" axes: %d\n", SDL_JoystickNumAxes(joystick));
printf(" balls: %d\n", SDL_JoystickNumBalls(joystick));
printf(" hats: %d\n", SDL_JoystickNumHats(joystick));
printf(" buttons: %d\n", SDL_JoystickNumButtons(joystick));
SDL_JoystickClose(joystick);
}
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}
if (argv[1]) {
joystick = SDL_JoystickOpen(atoi(argv[1]));
if (joystick == NULL) {
printf("Couldn't open joystick %d: %s\n", atoi(argv[1]),
SDL_GetError());
} else {
WatchJoystick(joystick);
SDL_JoystickClose(joystick);
}
}
SDL_QuitSubSystem(SDL_INIT_VIDEO | SDL_INIT_JOYSTICK);
return (0);
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}