Skip to content

Instantly share code, notes, and snippets.

@uobikiemukot
Last active November 3, 2023 12:12
Show Gist options
  • Save uobikiemukot/457338b890e96babf60b to your computer and use it in GitHub Desktop.
Save uobikiemukot/457338b890e96babf60b to your computer and use it in GitHub Desktop.
test program of reading /dev/input/event*
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <linux/input.h>
#include <fcntl.h>
#include <stdarg.h>
#include <stdint.h>
#include <string.h>
#include <linux/fb.h>
//#include <linux/vt.h>
//#include <linux/kd.h>
//#include <sys/stat.h>
#include <sys/mman.h>
//#include <sys/wait.h>
enum {
VERBOSE = true,
MAX_WIDTH = 1280,
MAX_HEIGHT = 1024,
VALUE_PRESSED = 1,
VALUE_RELEASED = 0,
BITS_PER_BYTE = 8,
CURSOR_COLOR = 0x00FF00,
};
struct cursor_t {
int x, y;
};
struct mouse_t {
struct cursor_t current;
struct cursor_t pressed, released;
//bool button_pressed;
//bool button_released;
};
struct fb_t {
int fd;
unsigned char *fp;
int width, height; /* display resolution */
long screen_size; /* screen data size (byte) */
int line_length; /* line length (byte) */
int bytes_per_pixel;
int bits_per_pixel;
};
//const char *mouse_dev = "/dev/input/event8";
//const char *mouse_dev = "/dev/input/event9";
const char *mouse_dev = "/dev/input/by-path/pci-0000:00:1a.0-usb-0:1.2:1.1-event-mouse";
const char *fb_dev = "/dev/fb0";
const char *ev_type[EV_CNT] = {
[EV_SYN] = "EV_SYN",
[EV_KEY] = "EV_KEY",
[EV_REL] = "EV_REL",
[EV_ABS] = "EV_ABS",
[EV_MSC] = "EV_MSC",
[EV_SW] = "EV_SW",
[EV_LED] = "EV_LED",
[EV_SND] = "EV_SND",
[EV_REP] = "EV_REP",
[EV_FF] = "EV_FF",
[EV_PWR] = "EV_PWR",
[EV_FF_STATUS] = "EV_FF_STATUS",
[EV_MAX] = "EV_MAX",
};
const char *ev_code_syn[SYN_CNT] = {
[SYN_REPORT] = "SYN_REPORT",
[SYN_CONFIG] = "SYN_CONFIG",
[SYN_MT_REPORT] = "SYN_MT_REPORT",
[SYN_DROPPED] = "SYN_DROPPED",
[SYN_MAX] = "SYN_MAX",
};
const char *ev_code_rel[REL_CNT] = {
[REL_X] = "REL_X",
[REL_Y] = "REL_Y",
[REL_Z] = "REL_Z",
[REL_RX] = "REL_RX",
[REL_RY] = "REL_RY",
[REL_RZ] = "REL_RZ",
[REL_HWHEEL] = "REL_WHEEL",
[REL_DIAL] = "REL_DIAL",
[REL_WHEEL] = "REL_WHEEL",
[REL_MISC] = "REL_MISC",
[REL_MAX] = "REL_MAX",
};
const char *ev_code_key[KEY_CNT] = {
[BTN_LEFT] = "BTN_LEFT",
[BTN_RIGHT] = "BTN_RIGHT",
[BTN_MIDDLE] = "BTN_MIDDLE",
[BTN_SIDE] = "BTN_SIDE",
[BTN_EXTRA] = "BTN_EXTRA",
[BTN_FORWARD] = "BTN_FORWARD",
[BTN_BACK] = "BTN_BACK",
[BTN_TASK] = "BTN_TASK",
[KEY_MAX] = "KEY_MAX",
};
/* logging functions */
enum loglevel_t {
DEBUG = 0,
WARN,
ERROR,
FATAL,
};
void logging(enum loglevel_t loglevel, char *format, ...)
{
va_list arg;
static const char *loglevel2str[] = {
[DEBUG] = "DEBUG",
[WARN] = "WARN",
[ERROR] = "ERROR",
[FATAL] = "FATAL",
};
/* debug message is available on verbose mode */
if ((loglevel == DEBUG) && (VERBOSE == false))
return;
fprintf(stderr, ">>%s<<\t", loglevel2str[loglevel]);
va_start(arg, format);
vfprintf(stderr, format, arg);
va_end(arg);
}
/* misc functions */
int my_ceil(int val, int div)
{
if (div == 0)
return 0;
else
return (val + div - 1) / div;
}
/* framebuffer functions */
bool fb_init(struct fb_t *fb)
{
struct fb_fix_screeninfo finfo;
struct fb_var_screeninfo vinfo;
if ((fb->fd = open(fb_dev, O_RDWR)) < 0) {
perror("open");
return false;
}
if (ioctl(fb->fd, FBIOGET_FSCREENINFO, &finfo)) {
logging(ERROR, "ioctl: FBIOGET_FSCREENINFO failed\n");
return false;
}
if (ioctl(fb->fd, FBIOGET_VSCREENINFO, &vinfo)) {
logging(ERROR, "ioctl: FBIOGET_VSCREENINFO failed\n");
return false;
}
fb->width = vinfo.xres;
fb->height = vinfo.yres;
fb->screen_size = finfo.smem_len;
fb->line_length = finfo.line_length;
fb->bits_per_pixel = vinfo.bits_per_pixel;
fb->bytes_per_pixel = my_ceil(fb->bits_per_pixel, BITS_PER_BYTE);
if ((fb->fp = (unsigned char *) mmap(0, fb->screen_size,
PROT_WRITE | PROT_READ, MAP_SHARED, fb->fd, 0)) == MAP_FAILED)
return false;
return true;
}
void fb_die(struct fb_t *fb)
{
munmap(fb->fp, fb->screen_size);
close(fb->fd);
}
void fb_draw(struct fb_t *fb, struct cursor_t *cursor, uint32_t color)
{
memcpy(fb->fp + cursor->y * fb->line_length + cursor->x * fb->bytes_per_pixel, &color, fb->bytes_per_pixel);
}
/* mouse functions */
void init_mouse(struct mouse_t *mouse)
{
mouse->current.x = mouse->current.y = 0;
mouse->pressed.x = mouse->pressed.y = 0;
mouse->released.x = mouse->released.y = 0;
//mouse->button_pressed = false;
//mouse->button_released = false;
}
void print_event(struct input_event *ie)
{
switch (ie->type) {
case EV_SYN:
fprintf(stderr, "time:%ld.%06ld\ttype:%s\tcode:%s\tvalue:%d\n",
ie->time.tv_sec, ie->time.tv_usec, ev_type[ie->type],
ev_code_syn[ie->code], ie->value);
break;
case EV_REL:
fprintf(stderr, "time:%ld.%06ld\ttype:%s\tcode:%s\tvalue:%d\n",
ie->time.tv_sec, ie->time.tv_usec, ev_type[ie->type],
ev_code_rel[ie->code], ie->value);
break;
case EV_KEY:
fprintf(stderr, "time:%ld.%06ld\ttype:%s\tcode:%s\tvalue:%d\n",
ie->time.tv_sec, ie->time.tv_usec, ev_type[ie->type],
ev_code_key[ie->code], ie->value);
break;
default:
break;
}
}
void print_mouse_state(struct mouse_t *mouse)
{
fprintf(stderr, "\033[1;1H\033[2Kcurrent(%d, %d) pressed(%d, %d) released(%d, %d)",
mouse->current.x, mouse->current.y,
mouse->pressed.x, mouse->pressed.y,
mouse->released.x, mouse->released.y);
}
void cursor(struct input_event *ie, struct mouse_t *mouse)
{
if (ie->code == REL_X)
mouse->current.x += ie->value;
if (mouse->current.x < 0)
mouse->current.x = 0;
else if (mouse->current.x >= MAX_WIDTH)
mouse->current.x = MAX_WIDTH - 1;
if (ie->code == REL_Y)
mouse->current.y += ie->value;
if (mouse->current.y < 0)
mouse->current.y = 0;
else if (mouse->current.y >= MAX_HEIGHT)
mouse->current.y = MAX_HEIGHT - 1;
}
void button(struct input_event *ie, struct mouse_t *mouse)
{
if (ie->code != BTN_LEFT)
return;
if (ie->value == VALUE_PRESSED)
mouse->pressed = mouse->current;
if (ie->value == VALUE_RELEASED)
mouse->released = mouse->current;
}
/*
void sync(struct input_event *ie, struct mouse_t *mouse)
{
if (ie->code != SYN_REPORT)
return;
}
*/
void (*event_handler[EV_CNT])(struct input_event *ie, struct mouse_t *mouse) = {
//[EV_SYN] = sync,
[EV_REL] = cursor,
[EV_KEY] = button,
[EV_MAX] = NULL,
};
int main(int argc, char *argv[])
{
int fd;
const char *dev;
struct input_event ie;
struct mouse_t mouse;
struct fb_t fb;
dev = (argc > 1) ? argv[1]: mouse_dev;
if ((fd = open(dev, O_RDONLY)) == -1) {
perror("opening device");
exit(EXIT_FAILURE);
}
init_mouse(&mouse);
fb_init(&fb);
while (read(fd, &ie, sizeof(struct input_event))) {
//print_event(&ie);
print_mouse_state(&mouse);
fb_draw(&fb, &mouse.current, CURSOR_COLOR);
if (event_handler[ie.type])
event_handler[ie.type](&ie, &mouse);
}
fb_die(&fb);
close(fd);
return EXIT_SUCCESS;
}
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment