TrainControllerUi/src/trainControllerUI/jsbackend/SDL_Joysticks.cpp

/*
 * Copyright (c) 2015-2017 Alex Spataru <alex_spataru@outlook.com>
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */

#include <QFile>
#include <QDebug>
#include <QTimer>
#include <QApplication>
#include "SDL_Joysticks.h"

SDL_Joysticks::SDL_Joysticks(QObject *parent)
	: QObject(parent)
{
	if (SDL_Init(SDL_INIT_HAPTIC | SDL_INIT_GAMECONTROLLER))
	{
		qDebug() << "Cannot initialize SDL:" << SDL_GetError();
		qApp->quit();
	}

	SDL_SetHint(SDL_HINT_JOYSTICK_ALLOW_BACKGROUND_EVENTS, "1");

	SDL_JoystickEventState(SDL_ENABLE);

	int count = SDL_NumJoysticks();

	for (int i = 0; i < count; ++i)
		configureJoystick(i);

	QTimer::singleShot(10, Qt::PreciseTimer, this, SLOT(update()));
}

SDL_Joysticks::~SDL_Joysticks()
{
	for (QMap<int, QJoystickDevice *>::iterator i = m_joysticks.begin();
	        i != m_joysticks.end(); ++i)
	{
		delete i.value();
	}

	SDL_Quit();
}

/**
 * Returns a list with all the registered joystick devices
 */
QMap<int, QJoystickDevice *> SDL_Joysticks::joysticks()
{
	int index = 0;
	QMap<int, QJoystickDevice *> joysticks;
	for (QMap<int, QJoystickDevice *>::iterator it = m_joysticks.begin();
	        it != m_joysticks.end(); ++it)
	{
		it.value()->id = index;
		joysticks[index++] = it.value();
	}

	return joysticks;
}

/**
 * Based on the data contained in the \a request, this function will instruct
 * the appropriate joystick to rumble for
 */
void SDL_Joysticks::rumble(const QJoystickRumble &request)
{
	SDL_Haptic *haptic = SDL_HapticOpen(request.joystick->id);

	if (haptic)
	{
		SDL_HapticRumbleInit(haptic);
		SDL_HapticRumblePlay(haptic, request.strength, request.length);
	}
}

/**
 * Polls for new SDL events and reacts to each event accordingly.
 */
void SDL_Joysticks::update()
{
	SDL_Event event;

	while (SDL_PollEvent(&event))
	{
		switch (event.type)
		{
		case SDL_JOYDEVICEADDED:
			configureJoystick(&event);
			break;
		case SDL_JOYDEVICEREMOVED:
		{
			SDL_Joystick *js = SDL_JoystickFromInstanceID(event.jdevice.which);
			if (js)
			{
				SDL_JoystickClose(js);
			}

			SDL_GameController *gc = SDL_GameControllerFromInstanceID(
			                             event.cdevice.which);
			if (gc)
			{
				SDL_GameControllerClose(gc);
			}
		}

		delete m_joysticks[event.jdevice.which];
		m_joysticks.remove(event.jdevice.which);

		emit countChanged();
		break;
		case SDL_JOYAXISMOTION:
			emit axisEvent(getAxisEvent(&event));
			break;
		case SDL_CONTROLLERAXISMOTION:
			emit axisEvent(getAxisEvent(&event));
			break;
		case SDL_JOYBUTTONUP:
			emit buttonEvent(getButtonEvent(&event));
			break;
		case SDL_JOYBUTTONDOWN:
			emit buttonEvent(getButtonEvent(&event));
			break;
		case SDL_JOYHATMOTION:
			emit POVEvent(getPOVEvent(&event));
			break;
		}
	}

	QTimer::singleShot(10, Qt::PreciseTimer, this, SLOT(update()));
}

void SDL_Joysticks::configureJoystick(const SDL_Event *event)
{
	configureJoystick(event->jdevice.which);
}

void SDL_Joysticks::configureJoystick(int id)
{
	QJoystickDevice *joystick = getJoystick(id);

	if (!SDL_IsGameController(id))
	{
		SDL_Joystick *js = SDL_JoystickFromInstanceID(joystick->instanceID);
		if (js)
		{
			char guid[1024];
			SDL_JoystickGetGUIDString(SDL_JoystickGetGUID(js), guid,
			                          sizeof(guid));
		}
	}

	SDL_GameControllerOpen(id);

	emit countChanged();
}

/**
 * Returns the josytick device registered with the given \a id.
 * If no joystick with the given \a id is found, then the function will warn
 * the user through the console.
 */
QJoystickDevice *SDL_Joysticks::getJoystick(int id)
{
	QJoystickDevice *joystick = new QJoystickDevice;
	SDL_Joystick *sdl_joystick = SDL_JoystickOpen(id);

	if (sdl_joystick)
	{
		joystick->id = id;
		joystick->instanceID = SDL_JoystickInstanceID(sdl_joystick);
		joystick->blacklisted = false;
		joystick->name = SDL_JoystickName(sdl_joystick);

		/* Get joystick properties */
		int povs = SDL_JoystickNumHats(sdl_joystick);
		int axes = SDL_JoystickNumAxes(sdl_joystick);
		int buttons = SDL_JoystickNumButtons(sdl_joystick);

		/* Initialize POVs */
		for (int i = 0; i < povs; ++i)
			joystick->povs.append(0);

		/* Initialize axes */
		for (int i = 0; i < axes; ++i)
			joystick->axes.append(0);

		/* Initialize buttons */
		for (int i = 0; i < buttons; ++i)
			joystick->buttons.append(false);

		m_joysticks[joystick->instanceID] = joystick;
	}
	else
	{
		qWarning() << Q_FUNC_INFO << "Cannot find joystick with id:" << id;
	}

	return joystick;
}

/**
 * Reads the contents of the given \a event and constructs a new
 * \c QJoystickPOVEvent to be used with the \c QJoysticks system.
 */
QJoystickPOVEvent SDL_Joysticks::getPOVEvent(const SDL_Event
        *sdl_event)
{
	QJoystickPOVEvent event;

	if (!m_joysticks.contains(sdl_event->jdevice.which))
	{
		return event;
	}
	event.pov = sdl_event->jhat.hat;
	event.joystick = m_joysticks[sdl_event->jdevice.which];

	switch (sdl_event->jhat.value)
	{
	case SDL_HAT_RIGHTUP:
		event.angle = 45;
		break;
	case SDL_HAT_RIGHTDOWN:
		event.angle = 135;
		break;
	case SDL_HAT_LEFTDOWN:
		event.angle = 225;
		break;
	case SDL_HAT_LEFTUP:
		event.angle = 315;
		break;
	case SDL_HAT_UP:
		event.angle = 0;
		break;
	case SDL_HAT_RIGHT:
		event.angle = 90;
		break;
	case SDL_HAT_DOWN:
		event.angle = 180;
		break;
	case SDL_HAT_LEFT:
		event.angle = 270;
		break;
	default:
		event.angle = -1;
		break;
	}

	return event;
}

/**
 * Reads the contents of the given \a event and constructs a new
 * \c QJoystickAxisEvent to be used with the \c QJoysticks system.
 */
QJoystickAxisEvent SDL_Joysticks::getAxisEvent(const SDL_Event
        *sdl_event)
{
	QJoystickAxisEvent event;

	if (!m_joysticks.contains(sdl_event->cdevice.which))
	{
		return event;
	}

	event.axis = sdl_event->caxis.axis;
	event.value = static_cast<qreal>(sdl_event->caxis.value) / 32767;
	event.joystick = m_joysticks[sdl_event->cdevice.which];

	return event;
}

/**
 * Reads the contents of the given \a event and constructs a new
 * \c QJoystickButtonEvent to be used with the \c QJoysticks system.
 */
QJoystickButtonEvent SDL_Joysticks::getButtonEvent(
    const SDL_Event *sdl_event)
{
	QJoystickButtonEvent event;

	if (!m_joysticks.contains(sdl_event->jdevice.which))
	{
		return event;
	}

	event.button = sdl_event->jbutton.button;
	event.pressed = sdl_event->jbutton.state == SDL_PRESSED;
	event.joystick = m_joysticks[sdl_event->jdevice.which];
	event.joystick->buttons[event.button] = event.pressed;

	return event;
}