* Spacenav lib hack

 * Copyright © 2019 František Kučera (Frantovo.cz, GlobalCode.info)

#define _GNU_SOURCE

#include <stdio.h>

#include <stdint.h>

#include <dlfcn.h>

#include <stdlib.h>

#include <pthread.h>

static Display* spacenav_hack_dpy;

static Window spacenav_hack_win;

static pthread_t spacenav_hack_thread;

// from proto_x11.c (spacenavd)

static Atom xa_event_motion, xa_event_bpress, xa_event_brelease, xa_event_cmd;

static float x11_sens = 1.0;

/**

 * This function is based on proto_x11.c (spacenavd) written by:

 * Copyright (C) 2007-2019 John Tsiombikas <nuclear@member.fsf.org>

 * and published under GNU GPLv3+

 * 

 * @param ev

 * @param dpy

 * @param win

 */

static void send_xevent(spnav_event *ev, Display* dpy, Window win) {

	int i;

	XEvent xevent;

	if (!dpy) return;

	// if(setjmp(jbuf)) return;

	xevent.type = ClientMessage;

	xevent.xclient.send_event = False;

	xevent.xclient.display = dpy;

	xevent.xclient.window = win;

	switch (ev->type) {

		case SPNAV_EVENT_MOTION:

			xevent.xclient.message_type = xa_event_motion;

			xevent.xclient.format = 16;

			for (i = 0; i < 6; i++) {

				float val = (float) ev->motion.data[i] * x11_sens;

				xevent.xclient.data.s[i + 2] = (short) val;

			}

			xevent.xclient.data.s[0] = xevent.xclient.data.s[1] = 0;

			xevent.xclient.data.s[8] = ev->motion.period;

			break;

		case SPNAV_EVENT_BUTTON:

			xevent.xclient.message_type = ev->button.press ? xa_event_bpress : xa_event_brelease;

			xevent.xclient.format = 16;

			xevent.xclient.data.s[2] = ev->button.bnum;

			break;

		default:

			break;

	}

	XSendEvent(dpy, win, False, 0, &xevent);

	XFlush(dpy);

}

static void* spacenav_hack_translate_events(void* arg) {

	pthread_setname_np(pthread_self(), "spacenav-hack"); // can be found with: ps H -o 'pid tid cmd comm'

	spnav_event event;

	while (1) {

		if (spnav_wait_event(&event)) {

			//fprintf(stderr, "spnav-lib-hack: got event\n");

			XLockDisplay(spacenav_hack_dpy);

			send_xevent(&event, spacenav_hack_dpy, spacenav_hack_win);

			XUnlockDisplay(spacenav_hack_dpy);

		}

	}

}

int spnav_x11_open(Display* dpy, Window win) {

	spacenav_hack_dpy = dpy;

	spacenav_hack_win = win;

	int result = spnav_open();

	fprintf(stderr, "spnav-lib-hack: instead of spnav_x11_open(%p, 0x%lx) calling spnav_open() = %d\n", dpy, win, result);

	if (result == 0) {

		xa_event_motion = XInternAtom(dpy, "MotionEvent", False);

		xa_event_bpress = XInternAtom(dpy, "ButtonPressEvent", False);

		xa_event_brelease = XInternAtom(dpy, "ButtonReleaseEvent", False);

		xa_event_cmd = XInternAtom(dpy, "CommandEvent", False);

		XInitThreads();

		pthread_create(&spacenav_hack_thread, NULL, spacenav_hack_translate_events, NULL);

	}

	return result;

/*

int spnav_x11_event(const XEvent* xev, spnav_event* event) {

	xev.

	static int (*real_spnav_x11_event)(const XEvent*, spnav_event*) = NULL;

	if (!real_spnav_x11_event) real_spnav_x11_event = dlsym(RTLD_NEXT, "spnav_x11_event");

	int result = real_spnav_x11_event(xev, event);

	if (result == SPNAV_EVENT_MOTION || result == SPNAV_EVENT_BUTTON) fprintf(stderr, "spnav-lib-hack: spnav_x11_event() = %d\n", result);

	return result;

}

 */

/*

int spnav_x11_open(Display* dpy, Window win) {

	static int (*real_spnav_x11_open)(Display*, Window) = NULL;

	if (!real_spnav_x11_open) real_spnav_x11_open = dlsym(RTLD_NEXT, "spnav_x11_open");

	int result = real_spnav_x11_open(dpy, win);

	fprintf(stderr, "spnav-lib-hack: spnav_x11_open() = %d\n", result);

	return result;

}

 */

/*

int spnav_open() {

	return -1;

}

 */

/*

int spnav_open() {

	static int (*real_spnav_open)() = NULL;

	if (!real_spnav_open) real_spnav_open = dlsym(RTLD_NEXT, "spnav_open");

	int result = real_spnav_open();

	// fprintf(stderr, "spnav-lib-hack: spnav_open() = %d\n", result);

	return result;

}

 */