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
#define _CRT_SECURE_NO_WARNINGS
#pragma comment(lib, "Irrlicht.lib")
#endif
Just as we did in example 04.Movement, we'll store the latest state of the mouse and the first joystick, updating them as we receive events.
class MyEventReceiver : public IEventReceiver
{
public:
struct SMouseState
{
bool LeftButtonDown;
SMouseState() : LeftButtonDown(false) { }
} MouseState;
virtual bool OnEvent(const SEvent& event)
{
{
switch(event.MouseInput.Event)
{
MouseState.LeftButtonDown = true;
break;
MouseState.LeftButtonDown = false;
break;
MouseState.Position.X = event.MouseInput.X;
MouseState.Position.Y = event.MouseInput.Y;
break;
default:
break;
}
}
&& event.JoystickEvent.Joystick == 0)
{
JoystickState = event.JoystickEvent;
}
return false;
}
const SEvent::SJoystickEvent & GetJoystickState(void) const
{
return JoystickState;
}
const SMouseState & GetMouseState(void) const
{
return MouseState;
}
MyEventReceiver()
{
}
private:
SEvent::SJoystickEvent JoystickState;
};
The event receiver for keeping the pressed keys 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. We also create some other additional scene nodes, to show that there are also some different possibilities to move and animate scene nodes.
int main()
{
return 1;
MyEventReceiver receiver;
core::dimension2d<u32>(640, 480), 16, false, false, false, &receiver);
if (device == 0)
return 1;
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;
}
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
)
);
scene::ICameraSceneNode * camera = smgr->addCameraSceneNode();
u32 then = device->getTimer()->getTime();
const f32 MOVEMENT_SPEED = 5.f;
while(device->run())
{
const u32 now = device->getTimer()->getTime();
const f32 frameDeltaTime = (
f32)(now - then) / 1000.f;
then = now;
bool movedWithJoystick = false;
if(joystickInfo.size() > 0)
{
f32 moveHorizontal = 0.f;
const SEvent::SJoystickEvent & joystickData = receiver.GetJoystickState();
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;
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;
}
{
nodePosition.X += MOVEMENT_SPEED * frameDeltaTime * moveHorizontal;
nodePosition.Y += MOVEMENT_SPEED * frameDeltaTime * moveVertical;
movedWithJoystick = true;
}
}
if(!movedWithJoystick)
{
core::line3df ray = smgr->getSceneCollisionManager()->getRayFromScreenCoordinates(
receiver.GetMouseState().Position, camera);
if(plane.getIntersectionWithLine(ray.start, ray.getVector(), mousePosition))
{
const f32 availableMovement = MOVEMENT_SPEED * frameDeltaTime;
if(toMousePosition.getLength() <= availableMovement)
nodePosition = mousePosition;
else
nodePosition += toMousePosition.normalize() * availableMovement;
}
}
node->setPosition(nodePosition);
driver->beginScene(true, true, video::SColor(255,113,113,133));
smgr->drawAll();
driver->endScene();
}
In the end, delete the Irrlicht device.
device->drop();
return 0;
}