openpilot is an open source driver assistance system. openpilot performs the functions of Automated Lane Centering and Adaptive Cruise Control for over 200 supported car makes and models.
You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
 
 
 
 
 
 

92 lines
1.9 KiB

#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include <assert.h>
#include <unistd.h>
#include <fcntl.h>
#include <dirent.h>
#include <sys/poll.h>
#include <linux/input.h>
#include "touch.h"
static int find_dev() {
int err;
int ret = -1;
DIR *dir = opendir("/dev/input");
assert(dir);
struct dirent* de = NULL;
while ((de = readdir(dir))) {
if (strncmp(de->d_name, "event", 5)) continue;
int fd = openat(dirfd(dir), de->d_name, O_RDONLY);
assert(fd >= 0);
unsigned char ev_bits[KEY_MAX / 8 + 1];
err = ioctl(fd, EVIOCGBIT(EV_ABS, sizeof(ev_bits)), ev_bits);
assert(err >= 0);
const int x_key = ABS_MT_POSITION_X / 8;
const int y_key = ABS_MT_POSITION_Y / 8;
if ((ev_bits[x_key] & (ABS_MT_POSITION_X - x_key)) &&
(ev_bits[y_key] & (ABS_MT_POSITION_Y - y_key))) {
ret = fd;
break;
}
close(fd);
}
closedir(dir);
return ret;
}
void touch_init(TouchState *s) {
s->fd = find_dev();
assert(s->fd >= 0);
}
int touch_poll(TouchState *s, int* out_x, int* out_y, int timeout) {
assert(out_x && out_y);
bool up = false;
while (true) {
struct pollfd polls[] = {{
.fd = s->fd,
.events = POLLIN,
}};
int err = poll(polls, 1, timeout);
if (err < 0) {
return -1;
}
if (!(polls[0].revents & POLLIN)) {
break;
}
struct input_event event;
err = read(polls[0].fd, &event, sizeof(event));
if (err < sizeof(event)) {
return -1;
}
switch (event.type) {
case EV_ABS:
if (event.code == ABS_MT_POSITION_X) {
s->last_x = event.value;
} else if (event.code == ABS_MT_POSITION_Y) {
s->last_y = event.value;
}
up = true;
break;
default:
break;
}
}
if (up) {
// adjust for flippening
*out_x = s->last_y;
*out_y = 1080 - s->last_x;
}
return up;
}