irrlicht-code/examples/19.MouseAndJoystick/main.cpp

/** Example 019 Mouse and Joystick

This tutorial builds on example 04.Movement which showed how to
handle keyboard events in Irrlicht.  Here we'll handle mouse events
and joystick events, if you have a joystick connected and a device
that supports joysticks. These are currently Windows, Linux and SDL
devices.
*/

#ifdef _MSC_VER
#pragma comment(lib, "Irrlicht.lib")
#endif

#include <irrlicht.h>
#include "driverChoice.h"

using namespace irr;

/*
Just as we did in example 04.Movement with keys, we'll store the latest state of the
mouse and the first joystick, updating them as we receive events.

Note that instead of working with events we could work with CursorControl, aka
device->getCursorControl(), to get the current mouse state.
With events you get every mouse movement since the last device->run(), 
while CursorControl will always return the current state at the moment you check it.
CursorControl will be able to get cursor positions even if the mouse is outside the 
active Window, while the behavior of mouse-events for this is a bit system dependent 
and also can be influenced by system calls for mouse-grabbing.
Events tend to work on more devices (especially mobile devices) where CursorControl might
not be available. Also on some systems (X11) checking the mouse position with CursorControl
can be rather slow compared to events.
Often it depends a bit on the type of game which solution is preferable, just be aware
that you have some choice for this.
*/
class MyEventReceiver : public IEventReceiver
{
public:
	// We'll create a struct to record info on the mouse state
	struct SMouseState
	{
		core::position2di Position;
		bool LeftButtonDown;
		bool WasMouseMoved;
		SMouseState() : LeftButtonDown(false), WasMouseMoved(false) { }
	} MouseState;

	// This is the one method that we have to implement
	virtual bool OnEvent(const SEvent& event)
	{
		// Remember the mouse state
		if (event.EventType == irr::EET_MOUSE_INPUT_EVENT)
		{
			switch(event.MouseInput.Event)
			{
			case EMIE_LMOUSE_PRESSED_DOWN:
				MouseState.LeftButtonDown = true;
				break;

			case EMIE_LMOUSE_LEFT_UP:
				MouseState.LeftButtonDown = false;
				break;

			case EMIE_MOUSE_MOVED:
				MouseState.Position.X = event.MouseInput.X;
				MouseState.Position.Y = event.MouseInput.Y;
				MouseState.WasMouseMoved = true;
				break;

			default:
				// We won't use the wheel
				break;
			}
		}

		// The state of each connected joystick is sent to us
		// once every run() of the Irrlicht device.  Store the
		// state of the first joystick, ignoring other joysticks.
		if (event.EventType == irr::EET_JOYSTICK_INPUT_EVENT
			&& event.JoystickEvent.Joystick == 0)
		{
			JoystickState = event.JoystickEvent;
		}

		return false;
	}

	const SEvent::SJoystickEvent & GetJoystickState(void) const
	{
		return JoystickState;
	}

	const SMouseState & GetMouseState(void) const
	{
		return MouseState;
	}

	void ResetMouseMoved()
	{
		MouseState.WasMouseMoved = false;
	}

private:
	SEvent::SJoystickEvent JoystickState;
};


/*
The event receiver for remembering the events is ready, the actual responses
will be made inside the render loop, right before drawing the scene. So lets
just create an irr::IrrlichtDevice and the scene node we want to move.
*/
int main()
{
	// ask user for driver
	video::E_DRIVER_TYPE driverType=driverChoiceConsole();
	if (driverType==video::EDT_COUNT)
		return 1;

	// create device
	MyEventReceiver receiver;

	IrrlichtDevice* device = createDevice(driverType,
			core::dimension2d<u32>(640, 480), 16, false, false, false, &receiver);

	if (device == 0)
		return 1; // could not create selected driver.


	/*
		Joysticks have to be activated to generate events.
		So lets's do that and also print out some info to the console
		about all the joysticks we found and can use.
	*/
	core::array<SJoystickInfo> joystickInfo;
	if(device->activateJoysticks(joystickInfo))
	{
		std::cout << "Joystick support is enabled and " << joystickInfo.size() << " joystick(s) are present." << std::endl;

		for(u32 joystick = 0; joystick < joystickInfo.size(); ++joystick)
		{
			std::cout << "Joystick " << joystick << ":" << std::endl;
			std::cout << "\tName: '" << joystickInfo[joystick].Name.c_str() << "'" << std::endl;
			std::cout << "\tAxes: " << joystickInfo[joystick].Axes << std::endl;
			std::cout << "\tButtons: " << joystickInfo[joystick].Buttons << std::endl;

			std::cout << "\tHat is: ";

			switch(joystickInfo[joystick].PovHat)
			{
			case SJoystickInfo::POV_HAT_PRESENT:
				std::cout << "present" << std::endl;
				break;

			case SJoystickInfo::POV_HAT_ABSENT:
				std::cout << "absent" << std::endl;
				break;

			case SJoystickInfo::POV_HAT_UNKNOWN:
			default:
				std::cout << "unknown" << std::endl;
				break;
			}
		}
	}
	else
	{
		std::cout << "Joystick support is not enabled." << std::endl;
	}

	// Set some window caption text
	core::stringw tmp = L"Irrlicht Joystick Example (";
	tmp += joystickInfo.size();
	tmp += " joysticks)";
	device->setWindowCaption(tmp.c_str());

	video::IVideoDriver* driver = device->getVideoDriver();
	scene::ISceneManager* smgr = device->getSceneManager();

	/*
	We'll create an arrow mesh and move it around either with the joystick axis/hat,
	or make it follow the mouse pointer. */
	scene::ISceneNode * node = smgr->addMeshSceneNode(
		smgr->addArrowMesh( "Arrow",
				video::SColor(255, 255, 0, 0),
				video::SColor(255, 0, 255, 0),
				16,16,
				2.f, 1.3f,
				0.1f, 0.6f
				)
		);
	node->setMaterialFlag(video::EMF_LIGHTING, false);

	scene::ICameraSceneNode * camera = smgr->addCameraSceneNode();
	camera->setPosition(core::vector3df(0, 0, -10));

	// As in example 04, we'll use framerate independent movement.
	u32 then = device->getTimer()->getRealTime();
	const f32 MOVEMENT_SPEED = 5.f;

	// Ignore all events which happened until now.
	// Like mouse events triggered while we chose our driver.
	device->clearSystemMessages();

	while(device->run())
	{
		// Work out a frame delta time.
		const u32 now = device->getTimer()->getRealTime();
		const f32 frameDeltaTime = (f32)(now - then) / 1000.f; // Time in seconds
		then = now;

		bool movedWithJoystick = false;
		core::vector3df nodePosition = node->getPosition();

		if(joystickInfo.size() > 0)	// if we have at least one joystick
		{
			f32 moveHorizontal = 0.f; // Range is -1.f for full left to +1.f for full right
			f32 moveVertical = 0.f; // -1.f for full down to +1.f for full up.

			const SEvent::SJoystickEvent & joystickData = receiver.GetJoystickState();

			// We receive the full analog range of the axes, and so have to implement our
			// own dead zone.  This is an empirical value, since some joysticks have more
			// jitter or creep around the center point than others.  We'll use 5% of the
			// range as the dead zone, but generally you would want to give the user the
			// option to change this.
			const f32 DEAD_ZONE = 0.05f;

			moveHorizontal =
				(f32)joystickData.Axis[SEvent::SJoystickEvent::AXIS_X] / 32767.f;
			if(fabs(moveHorizontal) < DEAD_ZONE)
				moveHorizontal = 0.f;

			moveVertical =
				(f32)joystickData.Axis[SEvent::SJoystickEvent::AXIS_Y] / -32767.f;
			if(fabs(moveVertical) < DEAD_ZONE)
				moveVertical = 0.f;

			// POV hat info is only currently supported on Windows, but the value is
			// guaranteed to be 65535 if it's not supported, so we can check its range.
			const u16 povDegrees = joystickData.POV / 100;
			if(povDegrees < 360)
			{
				if(povDegrees > 0 && povDegrees < 180)
					moveHorizontal = 1.f;
				else if(povDegrees > 180)
					moveHorizontal = -1.f;

				if(povDegrees > 90 && povDegrees < 270)
					moveVertical = -1.f;
				else if(povDegrees > 270 || povDegrees < 90)
					moveVertical = +1.f;
			}

			if(!core::equals(moveHorizontal, 0.f) || !core::equals(moveVertical, 0.f))
			{
				nodePosition.X += MOVEMENT_SPEED * frameDeltaTime * moveHorizontal;
				nodePosition.Y += MOVEMENT_SPEED * frameDeltaTime * moveVertical;
				movedWithJoystick = true;

				// We only go back to following mouse when it moves again
				receiver.ResetMouseMoved();
			}
		}

		// If the arrow node isn't being moved with the joystick, then have it follow the mouse cursor.
		if (!movedWithJoystick && receiver.GetMouseState().WasMouseMoved)
		{
			// Create a ray through the mouse cursor.
			core::line3df ray = smgr->getSceneCollisionManager()->getRayFromScreenCoordinates(
				receiver.GetMouseState().Position, camera);

			// And intersect the ray with a plane around the node facing towards the camera.
			core::plane3df plane(nodePosition, core::vector3df(0, 0, -1));
			core::vector3df mousePosition;
			if(plane.getIntersectionWithLine(ray.start, ray.getVector(), mousePosition))
			{
				// We now have a mouse position in 3d space; move towards it.
				core::vector3df toMousePosition(mousePosition - nodePosition);
				const f32 availableMovement = MOVEMENT_SPEED * frameDeltaTime;

				if(toMousePosition.getLength() <= availableMovement)
				{
					nodePosition = mousePosition; // Jump to the final position
				}
				else
				{
					nodePosition += toMousePosition.normalize() * availableMovement; // Move towards it
				}
			}
		}

		node->setPosition(nodePosition);

		// Turn lighting on and off depending on whether the left mouse button is down.
		node->setMaterialFlag(video::EMF_LIGHTING, receiver.GetMouseState().LeftButtonDown);

		driver->beginScene(video::ECBF_COLOR | video::ECBF_DEPTH, video::SColor(255,113,113,133));
		smgr->drawAll(); // draw the 3d scene
		driver->endScene();
	}

	/*
	In the end, delete the Irrlicht device.
	*/
	device->drop();

	return 0;
}

/*
**/