1 // Created on: 2013-12-25
2 // Created by: Varvara POSKONINA
3 // Copyright (c) 1999-2014 OPEN CASCADE SAS
5 // This file is part of Open CASCADE Technology software library.
7 // This library is free software; you can redistribute it and/or modify it under
8 // the terms of the GNU Lesser General Public License version 2.1 as published
9 // by the Free Software Foundation, with special exception defined in the file
10 // OCCT_LGPL_EXCEPTION.txt. Consult the file LICENSE_LGPL_21.txt included in OCCT
11 // distribution for complete text of the license and disclaimer of any warranty.
13 // Alternatively, this file may be used under the terms of Open CASCADE
14 // commercial license or contractual agreement.
16 #ifndef _OpenGl_BVHTreeSelector_HeaderFile
17 #define _OpenGl_BVHTreeSelector_HeaderFile
19 #include <Graphic3d_Camera.hxx>
21 #include <OpenGl_Vec.hxx>
23 //! BVHTreeSelector class provides a possibility to store parameters of view volume,
24 //! such as its vertices and equations, and contains methods detecting if given AABB overlaps
26 class OpenGl_BVHTreeSelector
30 //! Creates an empty selector object with parallel projection type by default.
31 Standard_EXPORT OpenGl_BVHTreeSelector();
33 //! Retrieves view volume's planes equations and its vertices from projection and modelview matrices.
34 Standard_EXPORT void SetViewVolume (const Handle(Graphic3d_Camera)& theCamera);
36 //! Detects if AABB overlaps view volume using separating axis theorem (SAT).
37 //! @param theMinPt [in] maximum point of AABB.
38 //! @param theMaxPt [in] minimum point of AABB.
39 //! @return Standard_True, if AABB is in viewing area, Standard_False otherwise.
40 Standard_EXPORT Standard_Boolean Intersect (const OpenGl_Vec4& theMinPt,
41 const OpenGl_Vec4& theMaxPt) const;
43 //! Caches view volume's vertices projections along its normals and AABBs dimensions.
44 //! Must be called at the beginning of each BVH tree traverse loop.
45 Standard_EXPORT void CacheClipPtsProjections();
47 //! Returnes the state of projection matrix previously saved in selector.
48 Standard_EXPORT const Standard_Size ProjectionState() { return myProjectionState; }
50 //! Returnes the link for changing the state of projection matrix.
51 Standard_EXPORT Standard_Size& ChangeProjectionState() { return myProjectionState; }
53 //! Returnes the state of model view matrix previously saved in selector.
54 Standard_EXPORT const Standard_Size ModelViewState() { return myModelViewState; }
56 //! Returnes the link for changing the state of model view matrix.
57 Standard_EXPORT Standard_Size& ChangeModelViewState() { return myModelViewState; }
61 //! Calculates signed distance from plane to point.
62 //! @param theNormal [in] the plane's normal.
63 //! @param thePnt [in]
64 Standard_EXPORT Standard_ShortReal SignedPlanePointDistance (const OpenGl_Vec4& theNormal,
65 const OpenGl_Vec4& thePnt);
69 //! Enumerates planes of view volume.
81 //! Enumerates vertices of view volume.
85 ClipVert_LeftBottomNear,
86 ClipVert_RightTopNear,
87 ClipVert_RightBottomNear,
89 ClipVert_LeftBottomFar,
91 ClipVert_RightBottomFar,
97 OpenGl_Vec4 myClipPlanes[PlanesNB]; //!< Plane equations
98 OpenGl_Vec4 myClipVerts[ClipVerticesNB]; //!< Vertices
100 // for caching clip points projections onto viewing area normals once per traverse
101 // ORDER: TOP, BOTTOM, LEFT, RIGHT, NEAR, FAR
102 Standard_ShortReal myMaxClipProjectionPts[PlanesNB]; //!< Max view volume's vertices projections onto its normals
103 Standard_ShortReal myMinClipProjectionPts[PlanesNB]; //!< Min view volume's vertices projections onto its normals
105 // for caching clip points projections onto AABB normals once per traverse
107 Standard_ShortReal myMaxOrthoProjectionPts[3]; //!< Max view volume's vertices projections onto normalized dimensions of AABB
108 Standard_ShortReal myMinOrthoProjectionPts[3]; //!< Min view volume's vertices projections onto normalized dimensions of AABB
110 Standard_Boolean myIsProjectionParallel;
112 Standard_Size myProjectionState; //! Caches the state of projection matrix to prevent unnecessary updates.
113 Standard_Size myModelViewState; //! Caches the state of model view matrix to prevent unnecessary updates.
117 #endif // _OpenGl_BVHTreeSelector_HeaderFile