mwe

commit a86c2b9c85b331fae8c45ee8d2f7c6013fc3c7f8
parent 6a93fddf92a5a6efc0dcde3654d0304dd9feb1fc
Author: krasjet
Date: 2021-02-03 02:03Z

sdl: add joystick

Diffstat:
M
input/joystick.c
 | 
6
+++---
M
input/joystick_nonblock.c
 | 
2
+-
M
sdl/Makefile
 | 
1
+
M
sdl/README
 | 
2
++
A
sdl/joystick.c
 | 
70
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

5 files changed, 77 insertions(+), 4 deletions(-)
diff --git a/input/joystick.c b/input/joystick.c
@@ -35,7 +35,7 @@ main(void)
   /* open joystick device */
   fd = open("/dev/input/js0", O_RDONLY);
   if (fd < 0)
-    die("can't open joystick device");
+    die("fail to open joystick device");
 
   /* get joystick name */
   if (ioctl(fd, JSIOCGNAME(sizeof(name)), name) < 0)
@@ -44,12 +44,12 @@ main(void)
 
   /* get number of axes */
   if (ioctl(fd, JSIOCGAXES, &axis_cnt) < 0)
-    die("can't get number of axes");
+    die("fail to get number of axes");
   printf("axes: %d\n", axis_cnt);
 
   /* get number of buttons */
   if (ioctl(fd, JSIOCGBUTTONS, &btn_cnt) < 0)
-    die("can't get number of buttons");
+    die("fail to get number of buttons");
   printf("buttons: %d\n", btn_cnt);
 
   /* install signal handler for grace shutdown (Ctrl-C) */
diff --git a/input/joystick_nonblock.c b/input/joystick_nonblock.c
@@ -34,7 +34,7 @@ main(void)
   /* open joystick device in non-blocking mode */
   fd = open("/dev/input/js0", O_RDONLY | O_NONBLOCK);
   if (fd < 0)
-    die("can't open joystick");
+    die("fail to open joystick device");
 
   /* install signal handler for grace shutdown (Ctrl-C) */
   signal(SIGINT, sig_handler);
diff --git a/sdl/Makefile b/sdl/Makefile
@@ -11,6 +11,7 @@ BINS = \
 	fb \
 	simple \
 	mouse \
+	joystick \
 	nogui \
 	gl_simple \
 	gl_triangle_compat \
diff --git a/sdl/README b/sdl/README
@@ -7,6 +7,8 @@ simple.c:
   the basis of any SDL application. does nothing by itself.
 mouse.c:
   access mouse position
+joystick.c:
+  read joystick input
 nogui.c:
   SDL without GUI
 gl_simple.c
diff --git a/sdl/joystick.c b/sdl/joystick.c
@@ -0,0 +1,70 @@
+/* joystick.c: read joystick input */
+#include <SDL2/SDL.h>
+#include <signal.h>
+
+static volatile int done = 0;
+
+static void
+die(const char *msg)
+{
+  SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "%s\n", msg);
+  exit(EXIT_FAILURE);
+}
+
+static void
+on_signal(int signum)
+{
+  (void)signum;
+  done = 1;
+}
+
+int
+main(void)
+{
+  SDL_Joystick *js;
+
+  if (SDL_Init(SDL_INIT_JOYSTICK) != 0)
+    die("fail to init sdl");
+
+  js = SDL_JoystickOpen(0);
+  if (!js)
+    die("fail to open joystick device");
+
+  /* install signal handler for grace shutdown */
+  signal(SIGINT, on_signal);
+
+  while (!done) {
+    SDL_Event evt;
+
+    while (SDL_PollEvent(&evt)) {
+      switch(evt.type) {
+      case SDL_JOYAXISMOTION:
+        puts("axis event:");
+        printf("  number: %d\n", evt.jaxis.axis);
+        printf("  value: %d\n", evt.jaxis.value);
+        printf("  time: %d\n", evt.jaxis.timestamp);
+        break;
+      case SDL_JOYHATMOTION:
+        puts("hat motion event:");
+        printf("  number: %d\n", evt.jhat.hat);
+        printf("  value: %d\n", evt.jhat.value);
+        printf("  time: %d\n", evt.jhat.timestamp);
+        break;
+      case SDL_JOYBUTTONDOWN:
+        puts("button down event:");
+        printf("  number: %d\n", evt.jbutton.button);
+        printf("  time: %d\n", evt.jbutton.timestamp);
+        break;
+      case SDL_JOYBUTTONUP:
+        puts("button up event:");
+        printf("  number: %d\n", evt.jbutton.button);
+        printf("  time: %d\n", evt.jbutton.timestamp);
+        break;
+      }
+    }
+  }
+
+  SDL_JoystickClose(js);
+  SDL_Quit();
+  return 0;
+}