1 // Created on: 2015-03-16 2 // Created by: Varvara POSKONINA 3 // Copyright (c) 2005-2014 OPEN CASCADE SAS 4 // 5 // This file is part of Open CASCADE Technology software library. 6 // 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. 12 // 13 // Alternatively, this file may be used under the terms of Open CASCADE 14 // commercial license or contractual agreement. 15 16 #ifndef _SelectMgr_Frustum_HeaderFile 17 #define _SelectMgr_Frustum_HeaderFile 18 19 #include <BVH_Box.hxx> 20 #include <gp_Pnt.hxx> 21 #include <gp_Vec.hxx> 22 #include <gp_XYZ.hxx> 23 #include <SelectMgr_BaseFrustum.hxx> 24 #include <TColgp_HArray1OfPnt.hxx> 25 #include <TColgp_Array1OfPnt2d.hxx> 26 27 //! This is an internal class containing representation of rectangular selecting frustum, created in case 28 //! of point and box selection, and algorithms for overlap detection between selecting 29 //! frustum and sensitive entities. The principle of frustum calculation: 30 //! - for point selection: on a near view frustum plane rectangular neighborhood of 31 //! user-picked point is created according to the pixel tolerance 32 //! given and then this rectangle is projected onto far view frustum 33 //! plane. This rectangles define the parallel bases of selecting frustum; 34 //! - for box selection: box points are projected onto near and far view frustum planes. 35 //! These 2 projected rectangles define parallel bases of selecting frustum. 36 //! Overlap detection tests are implemented according to the terms of separating axis 37 //! theorem (SAT). 38 //! Vertex order: 39 //! - for triangular frustum: V0_Near, V1_Near, V2_Near, 40 //! V0_Far, V1_Far, V2_Far; 41 //! - for rectangular frustum: LeftTopNear, LeftTopFar, 42 //! LeftBottomNear,LeftBottomFar, 43 //! RightTopNear, RightTopFar, 44 //! RightBottomNear, RightBottomFar. 45 //! Plane order in array: 46 //! - for triangular frustum: V0V1, V1V2, V0V2, Near, Far; 47 //! - for rectangular frustum: Top, Bottom, Left, Right, Near, Far. 48 //! Uncollinear edge directions order: 49 //! - for rectangular frustum: Horizontal, Vertical, 50 //! LeftLower, RightLower, 51 //! LeftUpper, RightUpper; 52 //! - for triangular frustum: V0_Near - V0_Far, V1_Near - V1_Far, V2_Near - V2_Far, 53 //! V1_Near - V0_Near, V2_Near - V1_Near, V2_Near - V0_Near. 54 template <int N> 55 class SelectMgr_Frustum : public SelectMgr_BaseFrustum 56 { 57 public: 58 SelectMgr_Frustum()59 SelectMgr_Frustum() : SelectMgr_BaseFrustum() {}; 60 61 protected: 62 63 // SAT Tests for different objects 64 65 //! Returns true if selecting volume is overlapped by axis-aligned bounding box 66 //! with minimum corner at point theMinPt and maximum at point theMaxPt 67 Standard_Boolean hasOverlap (const SelectMgr_Vec3& theBoxMin, 68 const SelectMgr_Vec3& theBoxMax, 69 Standard_Boolean* theInside = NULL) const; 70 71 //! SAT intersection test between defined volume and given point 72 Standard_Boolean hasOverlap (const gp_Pnt& thePnt) const; 73 74 //! SAT intersection test between defined volume and given segment 75 Standard_Boolean hasOverlap (const gp_Pnt& thePnt1, 76 const gp_Pnt& thePnt2) const; 77 78 //! SAT intersection test between frustum given and planar convex polygon represented as ordered point set 79 Standard_Boolean hasOverlap (const TColgp_Array1OfPnt& theArrayOfPnts, 80 gp_Vec& theNormal) const; 81 82 //! SAT intersection test between defined volume and given triangle 83 Standard_Boolean hasOverlap (const gp_Pnt& thePnt1, 84 const gp_Pnt& thePnt2, 85 const gp_Pnt& thePnt3, 86 gp_Vec& theNormal) const; 87 88 private: 89 90 //! Checks if AABB and frustum are separated along the given axis 91 Standard_Boolean isSeparated (const SelectMgr_Vec3& theBoxMin, 92 const SelectMgr_Vec3& theBoxMax, 93 const gp_XYZ& theDirect, 94 Standard_Boolean* theInside) const; 95 96 //! Checks if triangle and frustum are separated along the given axis 97 Standard_Boolean isSeparated (const gp_Pnt& thePnt1, 98 const gp_Pnt& thePnt2, 99 const gp_Pnt& thePnt3, 100 const gp_XYZ& theAxis) const; 101 102 protected: 103 104 gp_Vec myPlanes[N + 2]; //!< Plane equations 105 gp_Pnt myVertices[N * 2]; //!< Vertices coordinates 106 107 Standard_Real myMaxVertsProjections[N + 2]; //!< Cached projections of vertices onto frustum plane directions 108 Standard_Real myMinVertsProjections[N + 2]; //!< Cached projections of vertices onto frustum plane directions 109 Standard_Real myMaxOrthoVertsProjections[3]; //!< Cached projections of vertices onto directions of ortho unit vectors 110 Standard_Real myMinOrthoVertsProjections[3]; //!< Cached projections of vertices onto directions of ortho unit vectors 111 112 gp_Vec myEdgeDirs[6]; //!< Cached edge directions 113 }; 114 115 #include <SelectMgr_Frustum.lxx> 116 117 #endif // _SelectMgr_Frustum_HeaderFile 118