libinput/src/libinput-util.h

/*
 * Copyright © 2008 Kristian Høgsberg
 *
 * Permission to use, copy, modify, distribute, and sell this software and its
 * documentation for any purpose is hereby granted without fee, provided that
 * the above copyright notice appear in all copies and that both that copyright
 * notice and this permission notice appear in supporting documentation, and
 * that the name of the copyright holders not be used in advertising or
 * publicity pertaining to distribution of the software without specific,
 * written prior permission.  The copyright holders make no representations
 * about the suitability of this software for any purpose.  It is provided "as
 * is" without express or implied warranty.
 *
 * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
 * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
 * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
 * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
 * OF THIS SOFTWARE.
 */

#ifndef LIBINPUT_UTIL_H
#define LIBINPUT_UTIL_H

#include <unistd.h>
#include <math.h>

#include "libinput.h"

void
set_logging_enabled(int enabled);

void
log_info(const char *format, ...);

/*
 * This list data structure is a verbatim copy from wayland-util.h from the
 * Wayland project; except that wl_ prefix has been removed.
 */

struct list {
	struct list *prev;
	struct list *next;
};

void list_init(struct list *list);
void list_insert(struct list *list, struct list *elm);
void list_remove(struct list *elm);
int list_empty(const struct list *list);

#ifdef __GNUC__
#define container_of(ptr, sample, member)				\
	(__typeof__(sample))((char *)(ptr)	-			\
		 ((char *)&(sample)->member - (char *)(sample)))
#else
#define container_of(ptr, sample, member)				\
	(void *)((char *)(ptr)	-				        \
		 ((char *)&(sample)->member - (char *)(sample)))
#endif

#define list_for_each(pos, head, member)				\
	for (pos = 0, pos = container_of((head)->next, pos, member);	\
	     &pos->member != (head);					\
	     pos = container_of(pos->member.next, pos, member))

#define list_for_each_safe(pos, tmp, head, member)			\
	for (pos = 0, tmp = 0, 						\
	     pos = container_of((head)->next, pos, member),		\
	     tmp = container_of((pos)->member.next, tmp, member);	\
	     &pos->member != (head);					\
	     pos = tmp,							\
	     tmp = container_of(pos->member.next, tmp, member))

#define ARRAY_LENGTH(a) (sizeof (a) / sizeof (a)[0])
#define ARRAY_FOR_EACH(_arr, _elem) \
	for (size_t _i = 0; (_elem = &_arr[_i]) && _i < ARRAY_LENGTH(_arr); _i++)

#define min(a, b) (((a) < (b)) ? (a) : (b))
#define max(a, b) (((a) > (b)) ? (a) : (b))

#define LIBINPUT_EXPORT __attribute__ ((visibility("default")))

static inline void *
zalloc(size_t size)
{
	return calloc(1, size);
}

static inline void
msleep(unsigned int ms)
{
	usleep(ms * 1000);
}

enum directions {
	N  = 1 << 0,
	NE = 1 << 1,
	E  = 1 << 2,
	SE = 1 << 3,
	S  = 1 << 4,
	SW = 1 << 5,
	W  = 1 << 6,
	NW = 1 << 7,
	UNDEFINED_DIRECTION = 0xff
};

static inline int
vector_get_direction(int dx, int dy)
{
	int dir = UNDEFINED_DIRECTION;
	int d1, d2;
	double r;

	if (abs(dx) < 2 && abs(dy) < 2) {
		if (dx > 0 && dy > 0)
			dir = S | SE | E;
		else if (dx > 0 && dy < 0)
			dir = N | NE | E;
		else if (dx < 0 && dy > 0)
			dir = S | SW | W;
		else if (dx < 0 && dy < 0)
			dir = N | NW | W;
		else if (dx > 0)
			dir = NE | E | SE;
		else if (dx < 0)
			dir = NW | W | SW;
		else if (dy > 0)
			dir = SE | S | SW;
		else if (dy < 0)
			dir = NE | N | NW;
	} else {
		/* Calculate r within the interval  [0 to 8)
		 *
		 * r = [0 .. 2π] where 0 is North
		 * d_f = r / 2π  ([0 .. 1))
		 * d_8 = 8 * d_f
		 */
		r = atan2(dy, dx);
		r = fmod(r + 2.5*M_PI, 2*M_PI);
		r *= 4*M_1_PI;

		/* Mark one or two close enough octants */
		d1 = (int)(r + 0.9) % 8;
		d2 = (int)(r + 0.1) % 8;

		dir = (1 << d1) | (1 << d2);
	}

	return dir;
}

#endif /* LIBINPUT_UTIL_H */