irr/src/CSceneCollisionManager.cpp

   1 // Copyright (C) 2002-2012 Nikolaus Gebhardt
   2 // This file is part of the "Irrlicht Engine".
   3 // For conditions of distribution and use, see copyright notice in irrlicht.h
   4
   5 #include "CSceneCollisionManager.h"
   6 #include "ICameraSceneNode.h"
   7 #include "SViewFrustum.h"
   8
   9 #include "irrMath.h"
  10
  11 namespace irr
  12 {
  13 namespace scene
  14 {
  15
  16 //! constructor
  17 CSceneCollisionManager::CSceneCollisionManager(ISceneManager *smanager, video::IVideoDriver *driver) :
  18                 SceneManager(smanager), Driver(driver)
  19 {
  20 #ifdef _DEBUG
  21         setDebugName("CSceneCollisionManager");
  22 #endif
  23
  24         if (Driver)
  25                 Driver->grab();
  26 }
  27
  28 //! destructor
  29 CSceneCollisionManager::~CSceneCollisionManager()
  30 {
  31         if (Driver)
  32                 Driver->drop();
  33 }
  34
  35 //! Returns a 3d ray which would go through the 2d screen coordinates.
  36 core::line3d<f32> CSceneCollisionManager::getRayFromScreenCoordinates(
  37                 const core::position2d<s32> &pos, const ICameraSceneNode *camera)
  38 {
  39         core::line3d<f32> ln(0, 0, 0, 0, 0, 0);
  40
  41         if (!SceneManager)
  42                 return ln;
  43
  44         if (!camera)
  45                 camera = SceneManager->getActiveCamera();
  46
  47         if (!camera)
  48                 return ln;
  49
  50         const scene::SViewFrustum *f = camera->getViewFrustum();
  51
  52         core::vector3df farLeftUp = f->getFarLeftUp();
  53         core::vector3df lefttoright = f->getFarRightUp() - farLeftUp;
  54         core::vector3df uptodown = f->getFarLeftDown() - farLeftUp;
  55
  56         const core::rect<s32> &viewPort = Driver->getViewPort();
  57         core::dimension2d<u32> screenSize(viewPort.getWidth(), viewPort.getHeight());
  58
  59         f32 dx = pos.X / (f32)screenSize.Width;
  60         f32 dy = pos.Y / (f32)screenSize.Height;
  61
  62         if (camera->isOrthogonal())
  63                 ln.start = f->cameraPosition + (lefttoright * (dx - 0.5f)) + (uptodown * (dy - 0.5f));
  64         else
  65                 ln.start = f->cameraPosition;
  66
  67         ln.end = farLeftUp + (lefttoright * dx) + (uptodown * dy);
  68
  69         return ln;
  70 }
  71
  72 } // end namespace scene
  73 } // end namespace irr