EIC code displayed by LXR master/​include/​opencascade/​Graphic3d_CullingTool.hxx	Source navigation Diff markup Identifier search General search
	Version: master test Revert   Change

File indexing completed on 2025-01-18 10:03:48

 // Created on: 2013-12-25
 // Created by: Varvara POSKONINA
 // Copyright (c) 1999-2014 OPEN CASCADE SAS
 //
 // This file is part of Open CASCADE Technology software library.
 //
 // This library is free software; you can redistribute it and/or modify it under
 // the terms of the GNU Lesser General Public License version 2.1 as published
 // by the Free Software Foundation, with special exception defined in the file
 // OCCT_LGPL_EXCEPTION.txt. Consult the file LICENSE_LGPL_21.txt included in OCCT
 // distribution for complete text of the license and disclaimer of any warranty.
 //
 // Alternatively, this file may be used under the terms of Open CASCADE
 // commercial license or contractual agreement.
 
 #ifndef _Graphic3d_CullingTool_HeaderFile
 #define _Graphic3d_CullingTool_HeaderFile
 
 #include <Graphic3d_Camera.hxx>
 #include <Graphic3d_Vec4.hxx>
 #include <Graphic3d_WorldViewProjState.hxx>
 
 //! Graphic3d_CullingTool class provides a possibility to store parameters of view volume,
 //! such as its vertices and equations, and contains methods detecting if given AABB overlaps view volume.
 class Graphic3d_CullingTool
 {
 public:
   //! Auxiliary structure holding non-persistent culling options.
   struct CullingContext
   {
     Standard_Real DistCull;  //!< culling distance
     Standard_Real SizeCull2; //!< squared culling size
 
     //! Empty constructor.
     CullingContext() : DistCull (-1.0), SizeCull2 (-1.0) {}
   };
 
   //! Auxiliary structure representing 3D plane.
   struct Plane
   {
     //! Creates default plane.
     Plane()
     : Origin (0.0, 0.0, 0.0),
       Normal (0.0, 0.0, 1.0) {}
 
     //! Creates plane with specific parameters.
     Plane (const Graphic3d_Vec3d& theOrigin,
            const Graphic3d_Vec3d& theNormal)
     : Origin (theOrigin),
       Normal (theNormal) {}
 
     Graphic3d_Vec3d Origin;
     Graphic3d_Vec3d Normal;
   };
 
 public:
 
   //! Creates an empty selector object with parallel projection type by default.
   Standard_EXPORT Graphic3d_CullingTool();
 
   //! Retrieves view volume's planes equations and its vertices from projection and world-view matrices.
   //! @param theCamera [in] camera definition
   //! @param theModelWorld [in] optional object transformation for computing frustum in object local coordinate system
   Standard_EXPORT void SetViewVolume (const Handle(Graphic3d_Camera)& theCamera,
                                       const Graphic3d_Mat4d& theModelWorld = Graphic3d_Mat4d());
 
   Standard_EXPORT void SetViewportSize (Standard_Integer theViewportWidth,
                                         Standard_Integer theViewportHeight,
                                         Standard_Real theResolutionRatio);
 
   //! Setup distance culling.
   Standard_EXPORT void SetCullingDistance (CullingContext& theCtx,
                                            Standard_Real theDistance) const;
 
   //! Setup size culling.
   Standard_EXPORT void SetCullingSize (CullingContext& theCtx,
                                        Standard_Real theSize) const;
 
   //! Caches view volume's vertices projections along its normals and AABBs dimensions.
   //! Must be called at the beginning of each BVH tree traverse loop.
   Standard_EXPORT void CacheClipPtsProjections();
 
   //! Checks whether given AABB should be entirely culled or not.
   //! @param theCtx    [in] culling properties
   //! @param theMinPnt [in] maximum point of AABB
   //! @param theMaxPnt [in] minimum point of AABB
   //! @param theIsInside [out] flag indicating if AABB is fully inside; initial value should be set to TRUE
   //! @return TRUE if AABB is completely outside of view frustum or culled by size/distance;
   //!         FALSE in case of partial or complete overlap (use theIsInside to distinguish)
   bool IsCulled (const CullingContext& theCtx,
                  const Graphic3d_Vec3d& theMinPnt,
                  const Graphic3d_Vec3d& theMaxPnt,
                  Standard_Boolean*      theIsInside = NULL) const
   {
     return IsOutFrustum(theMinPnt, theMaxPnt, theIsInside)
         || IsTooDistant(theCtx, theMinPnt, theMaxPnt, theIsInside)
         || IsTooSmall  (theCtx, theMinPnt, theMaxPnt);
   }
 
   //! Return the camera definition.
   const Handle(Graphic3d_Camera)& Camera() const { return myCamera; }
 
   //! Returns current projection matrix.
   const Graphic3d_Mat4d& ProjectionMatrix() const
   {
     return myProjectionMat;
   }
 
   //! Returns current world view transformation matrix.
   const Graphic3d_Mat4d& WorldViewMatrix() const
   {
     return myWorldViewMat;
   }
 
   Standard_Integer ViewportWidth() const
   {
     return myViewportWidth;
   }
 
   Standard_Integer ViewportHeight() const
   {
     return myViewportHeight;
   }
 
   //! Returns state of current world view projection transformation matrices.
   const Graphic3d_WorldViewProjState& WorldViewProjState() const
   {
     return myWorldViewProjState;
   }
 
   //! Returns camera eye position.
   const Graphic3d_Vec3d& CameraEye() const { return myCamEye; }
 
   //! Returns camera direction.
   const Graphic3d_Vec3d& CameraDirection() const { return myCamDir; }
 
 public:
 
   //! Calculates signed distance from plane to point.
   //! @param theNormal [in] the plane's normal.
   //! @param thePnt    [in]
   Standard_EXPORT Standard_Real SignedPlanePointDistance (const Graphic3d_Vec4d& theNormal,
                                                           const Graphic3d_Vec4d& thePnt);
 
   //! Detects if AABB overlaps view volume using separating axis theorem (SAT).
   //! @param theMinPnt   [in] maximum point of AABB
   //! @param theMaxPnt   [in] minimum point of AABB
   //! @param theIsInside [out] flag indicating if AABB is fully inside; initial value should be set to TRUE
   //! @return TRUE if AABB is completely outside of view frustum;
   //!         FALSE in case of partial or complete overlap (use theIsInside to distinguish)
   //! @sa SelectMgr_Frustum::hasOverlap()
   bool IsOutFrustum (const Graphic3d_Vec3d& theMinPnt,
                      const Graphic3d_Vec3d& theMaxPnt,
                      Standard_Boolean*      theIsInside = NULL) const
   {
     //     E1
     //    |_ E0
     //   /
     //    E2
     if (theMinPnt[0] > myMaxOrthoProjectionPts[0] // E0 test (x axis)
      || theMaxPnt[0] < myMinOrthoProjectionPts[0]
      || theMinPnt[1] > myMaxOrthoProjectionPts[1] // E1 test (y axis)
      || theMaxPnt[1] < myMinOrthoProjectionPts[1]
      || theMinPnt[2] > myMaxOrthoProjectionPts[2] // E2 test (z axis)
      || theMaxPnt[2] < myMinOrthoProjectionPts[2])
     {
       return true;
     }
     if (theIsInside != NULL
     && *theIsInside)
     {
       *theIsInside = theMinPnt[0] >= myMinOrthoProjectionPts[0] // E0 test (x axis)
                   && theMaxPnt[0] <= myMaxOrthoProjectionPts[0]
                   && theMinPnt[1] >= myMinOrthoProjectionPts[1] // E1 test (y axis)
                   && theMaxPnt[1] <= myMaxOrthoProjectionPts[1]
                   && theMinPnt[1] >= myMinOrthoProjectionPts[2] // E2 test (z axis)
                   && theMaxPnt[1] <= myMaxOrthoProjectionPts[2];
     }
 
     const Standard_Integer anIncFactor = myIsProjectionParallel ? 2 : 1;
     for (Standard_Integer aPlaneIter = 0; aPlaneIter < PlanesNB - 1; aPlaneIter += anIncFactor)
     {
       // frustum normals
       const Graphic3d_Vec3d& anAxis = myClipPlanes[aPlaneIter].Normal;
       const Graphic3d_Vec3d aPVertex (anAxis.x() > 0.0 ? theMaxPnt.x() : theMinPnt.x(),
                                       anAxis.y() > 0.0 ? theMaxPnt.y() : theMinPnt.y(),
                                       anAxis.z() > 0.0 ? theMaxPnt.z() : theMinPnt.z());
       const Standard_Real aPnt0 = aPVertex.Dot (anAxis);
       if (theIsInside == NULL
        && aPnt0 >= myMinClipProjectionPts[aPlaneIter]
        && aPnt0 <= myMaxClipProjectionPts[aPlaneIter])
       {
         continue;
       }
       
       const Graphic3d_Vec3d aNVertex (anAxis.x() > 0.0 ? theMinPnt.x() : theMaxPnt.x(),
                                       anAxis.y() > 0.0 ? theMinPnt.y() : theMaxPnt.y(),
                                       anAxis.z() > 0.0 ? theMinPnt.z() : theMaxPnt.z());
       const Standard_Real aPnt1 = aNVertex.Dot (anAxis);
 
       const Standard_Real aBoxProjMin = aPnt0 < aPnt1 ? aPnt0 : aPnt1;
       const Standard_Real aBoxProjMax = aPnt0 > aPnt1 ? aPnt0 : aPnt1;
       if (aBoxProjMin > myMaxClipProjectionPts[aPlaneIter]
        || aBoxProjMax < myMinClipProjectionPts[aPlaneIter])
       {
         return true;
       }
 
       if (theIsInside != NULL
       && *theIsInside)
       {
         *theIsInside = aBoxProjMin >= myMinClipProjectionPts[aPlaneIter]
                     && aBoxProjMax <= myMaxClipProjectionPts[aPlaneIter];
       }
     }
     return false;
   }
 
   //! Returns TRUE if given AABB should be discarded by distance culling criterion.
   //! @param theMinPnt   [in] maximum point of AABB
   //! @param theMaxPnt   [in] minimum point of AABB
   //! @param theIsInside [out] flag indicating if AABB is fully inside; initial value should be set to TRUE
   //! @return TRUE if AABB is completely behind culling distance;
   //!         FALSE in case of partial or complete overlap (use theIsInside to distinguish)
   bool IsTooDistant (const CullingContext&  theCtx,
                      const Graphic3d_Vec3d& theMinPnt,
                      const Graphic3d_Vec3d& theMaxPnt,
                      Standard_Boolean*      theIsInside = NULL) const
   {
     if (theCtx.DistCull <= 0.0)
     {
       return false;
     }
 
     // check distance to the bounding sphere as fast approximation
     const Graphic3d_Vec3d aSphereCenter = (theMinPnt + theMaxPnt) * 0.5;
     const Standard_Real   aSphereRadius = (theMaxPnt - theMinPnt).maxComp() * 0.5;
     const Standard_Real   aDistToCenter = (aSphereCenter - myCamEye).Modulus();
     if ((aDistToCenter - aSphereRadius) > theCtx.DistCull)
     {
       // clip if closest point is behind culling distance
       return true;
     }
     if (theIsInside != NULL
     && *theIsInside)
     {
       // check if farthest point is before culling distance
       *theIsInside = (aDistToCenter + aSphereRadius) <= theCtx.DistCull;
     }
     return false;
   }
 
   //! Returns TRUE if given AABB should be discarded by size culling criterion.
   bool IsTooSmall (const CullingContext&  theCtx,
                    const Graphic3d_Vec3d& theMinPnt,
                    const Graphic3d_Vec3d& theMaxPnt) const
   {
     if (theCtx.SizeCull2 <= 0.0)
     {
       return false;
     }
 
     const Standard_Real aBoxDiag2 = (theMaxPnt - theMinPnt).SquareModulus();
     if (myIsProjectionParallel)
     {
       return aBoxDiag2 < theCtx.SizeCull2;
     }
 
     // note that distances behind the Eye (aBndDist < 0) are not scaled correctly here,
     // but majority of such objects should be culled by frustum
     const Graphic3d_Vec3d aBndCenter = (theMinPnt + theMaxPnt) * 0.5;
     const Standard_Real   aBndDist   = (aBndCenter - myCamEye).Dot (myCamDir);
     return aBoxDiag2 < theCtx.SizeCull2 * aBndDist * aBndDist;
   }
 
 protected:
 
   //! Enumerates planes of view volume.
   enum
   {
     Plane_Left,
     Plane_Right,
     Plane_Bottom,
     Plane_Top,
     Plane_Near,
     Plane_Far,
     PlanesNB
   };
 
 protected:
 
   Plane                               myClipPlanes[PlanesNB]; //!< Planes
   NCollection_Array1<Graphic3d_Vec3d> myClipVerts;            //!< Vertices
 
   Handle(Graphic3d_Camera) myCamera; //!< camera definition
 
   // for caching clip points projections onto viewing area normals once per traverse
   // ORDER: LEFT, RIGHT, BOTTOM, TOP, NEAR, FAR
   Standard_Real myMaxClipProjectionPts[PlanesNB]; //!< Max view volume's vertices projections onto its normals
   Standard_Real myMinClipProjectionPts[PlanesNB]; //!< Min view volume's vertices projections onto its normals
 
   // for caching clip points projections onto AABB normals once per traverse
   // ORDER: E0, E1, E2
   Standard_Real myMaxOrthoProjectionPts[3]; //!< Max view volume's vertices projections onto normalized dimensions of AABB
   Standard_Real myMinOrthoProjectionPts[3]; //!< Min view volume's vertices projections onto normalized dimensions of AABB
 
   Standard_Boolean myIsProjectionParallel;
 
   Graphic3d_Mat4d myProjectionMat;
   Graphic3d_Mat4d myWorldViewMat;
 
   Standard_Integer myViewportWidth;
   Standard_Integer myViewportHeight;
 
   Graphic3d_WorldViewProjState myWorldViewProjState; //!< State of world view projection matrices.
 
   Graphic3d_Vec3d myCamEye;      //!< camera eye position for distance culling
   Graphic3d_Vec3d myCamDir;      //!< camera direction for size culling
   Standard_Real   myCamScale;    //!< camera scale for size culling
   Standard_Real   myPixelSize;   //!< pixel size for size culling
 
 };
 
 #endif // _Graphic3d_CullingTool_HeaderFile

This page was automatically generated by the 2.3.7 LXR engine. The LXR team