Rotate camera based on player's target

[Yustme]

Hi,

How can I rotate the camera based on the direction the player is looking at from a constant distance?

This is the code i got so far:

Code: Select all

void rotate(vector3df rot, ISceneNode* box)
{
	matrix4 m;
	m.setRotationDegrees(box->getRotation());
	matrix4 n;
	n.setRotationDegrees(rot);
	m *= n;
	box->setRotation(m.getRotationDegrees());
	box->updateAbsolutePosition();
}


int main()
{
  IrrlichtDevice *device;
  CIrrEventReceiver* receiver = new CIrrEventReceiver();
  device = createDevice(EDT_DIRECT3D9, dimension2d<s32>(800, 600), 32, false, false, false, receiver);
   
  if (device == 0)
     return 1;


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

   // the thing we want to look at
   ISceneNode* box = smgr->addCubeSceneNode();
   ISceneNode* sphere = smgr->addSphereSceneNode();
   sphere->setPosition(vector3df(0.0,0.0,-100.0));
   box->setPosition(vector3df(0.0,0.0,-10.0));

   // add camera
   ICameraSceneNode* cam = smgr->addCameraSceneNode(); //box
   cam->setTarget( box->getAbsolutePosition() );
   cam->setFarValue(10000);
	 

   smgr->addSkyBoxSceneNode
   (
     driver->getTexture("data/irrlicht2_up.jpg"),
     driver->getTexture("data/irrlicht2_dn.jpg"),
     driver->getTexture("data/irrlicht2_lf.jpg"),
     driver->getTexture("data/irrlicht2_rt.jpg"),
     driver->getTexture("data/irrlicht2_ft.jpg"),
     driver->getTexture("data/irrlicht2_bk.jpg")
   );
	

  ICursorControl* cursor = device->getCursorControl();
  cursor->grab();
  cursor->setVisible(false);
  core::position2d<f32> cursorCenterPos = cursor->getRelativePosition();
	

   while(device->run())
   {

      // window is active, so render scene
      if (device->isWindowActive())
      {
				receiver->endEventProcess();
         if (driver->beginScene(true, true, video::SColor(255, 100, 100, 140)))
         {
            smgr->drawAll();

            driver->endScene();
         }
				
	f32 deltaYaw = 0;
	f32 deltaPitch = 0;
	position2d<f32> cursorDelta = cursor->getRelativePosition() - cursorCenterPos;
				
	if (cursor)
	{
		if (cursorDelta.X || cursorDelta.Y)
		{
			deltaYaw = cursorDelta.X * 50.0; //cMouseSensitivity;
			deltaPitch = -cursorDelta.Y * 50.0; //cMouseSensitivity;
			cursor->setPosition(cursorCenterPos);
			cursorCenterPos = cursor->getRelativePosition();
		}
	}

	rotate(vector3df(0, deltaYaw, 0), box);

	if(receiver->isKeyPressed(KEY_KEY_W))
	{
		box->setPosition(box->getPosition() + core::vector3df(0.0,0.0,-1.0));
		box->updateAbsolutePosition();
		core::stringc s = "Box position: ";
		s += (int)box->getPosition().X;
		s += ", "; 
		s += (int)box->getPosition().Y;
		s += ", "; 
		s += (int)box->getPosition().Z;
		cout << s.c_str() << endl;

	}

	if(receiver->isKeyPressed(KEY_KEY_S))
	{
		box->setPosition(box->getPosition() + core::vector3df(0.0,0.0,1.0));
		box->updateAbsolutePosition();
		core::stringc s = "Box position: ";
		s += (int)box->getAbsolutePosition().X;
		s += ", "; 
		s += (int)box->getAbsolutePosition().Y;
		s += ", "; 
		s += (int)box->getAbsolutePosition().Z;
		cout << s.c_str() << endl;
	}			

			
	if(cam->getPosition().getDistanceFromSQ(box->getPosition()) > 50)
	{					 
		cam->setPosition(box->getAbsolutePosition() - cam->getTarget().normalize() * 50);
		cam->setTarget(box->getAbsolutePosition());
		vector3df ypos = cam->getPosition();

		ypos.Y += 25.0f;
		ypos.Y += cam->getPosition().Y;
		cam->setPosition(ypos);
		cam->updateAbsolutePosition();
	}


	receiver->startEventProcess();
      }
   }

   device->drop();
   cursor->drop();
   return 0;
}

Thanks in advance!