e5f9e1c8f2702044a5d5641fc3976f8366b5e895
[occt.git] / src / SelectMgr / SelectMgr_Frustum.hxx
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 <SelectMgr_BaseFrustum.hxx>
22 #include <TColgp_HArray1OfPnt.hxx>
23 #include <TColgp_Array1OfPnt2d.hxx>
24
25 //! This is an internal class containing representation of rectangular selecting frustum, created in case
26 //! of point and box selection, and algorithms for overlap detection between selecting
27 //! frustum and sensitive entities. The principle of frustum calculation:
28 //! - for point selection: on a near view frustum plane rectangular neighborhood of
29 //!                        user-picked point is created according to the pixel tolerance
30 //!                        given and then this rectangle is projected onto far view frustum
31 //!                        plane. This rectangles define the parallel bases of selecting frustum;
32 //! - for box selection: box points are projected onto near and far view frustum planes.
33 //!                      These 2 projected rectangles define parallel bases of selecting frustum.
34 //! Overlap detection tests are implemented according to the terms of separating axis
35 //! theorem (SAT).
36 //! Vertex order:
37 //! - for triangular frustum: V0_Near, V1_Near, V2_Near,
38 //!                           V0_Far, V1_Far, V2_Far;
39 //! - for rectangular frustum: LeftTopNear, LeftTopFar,
40 //!                            LeftBottomNear,LeftBottomFar,
41 //!                            RightTopNear, RightTopFar,
42 //!                            RightBottomNear, RightBottomFar.
43 //! Plane order in array:
44 //! - for triangular frustum: V0V1, V1V2, V0V2, Near, Far;
45 //! - for rectangular frustum: Top, Bottom, Left, Right, Near, Far.
46 //! Uncollinear edge directions order:
47 //! - for rectangular frustum: Horizontal, Vertical,
48 //!                            LeftLower, RightLower,
49 //!                            LeftUpper, RightUpper;
50 //! - for triangular frustum: V0_Near - V0_Far, V1_Near - V1_Far, V2_Near - V2_Far,
51 //!                           V1_Near - V0_Near, V2_Near - V1_Near, V2_Near - V0_Near.
52 template <int N>
53 class SelectMgr_Frustum : public SelectMgr_BaseFrustum
54 {
55 public:
56
57   SelectMgr_Frustum() : SelectMgr_BaseFrustum() {};
58
59 protected:
60
61   // SAT Tests for different objects
62
63   //! Returns true if selecting volume is overlapped by axis-aligned bounding box
64   //! with minimum corner at point theMinPt and maximum at point theMaxPt
65   Standard_Boolean hasOverlap (const SelectMgr_Vec3& theBoxMin,
66                                const SelectMgr_Vec3& theBoxMax,
67                                Standard_Boolean*     theInside = NULL);
68
69   //! SAT intersection test between defined volume and given point
70   Standard_Boolean hasOverlap (const gp_Pnt& thePnt);
71
72   //! SAT intersection test between defined volume and given segment
73   Standard_Boolean hasOverlap (const gp_Pnt& thePnt1,
74                                const gp_Pnt& thePnt2);
75
76   //! SAT intersection test between frustum given and planar convex polygon represented as ordered point set
77   Standard_Boolean hasOverlap (const Handle(TColgp_HArray1OfPnt)& theArrayOfPnts,
78                                SelectMgr_Vec3& theNormal);
79
80   //! SAT intersection test between defined volume and given triangle
81   Standard_Boolean hasOverlap (const gp_Pnt& thePnt1,
82                                const gp_Pnt& thePnt2,
83                                const gp_Pnt& thePnt3,
84                                SelectMgr_Vec3& theNormal);
85
86 private:
87
88   //! Checks if AABB and frustum are separated along the given axis
89   Standard_Boolean isSeparated (const SelectMgr_Vec3& theBoxMin,
90                                 const SelectMgr_Vec3& theBoxMax,
91                                 const SelectMgr_Vec3& theDirect,
92                                 Standard_Boolean*     theInside) const;
93
94   //! Checks if triangle and frustum are separated along the given axis
95   Standard_Boolean isSeparated (const gp_Pnt& thePnt1,
96                                 const gp_Pnt& thePnt2,
97                                 const gp_Pnt& thePnt3,
98                                 const SelectMgr_Vec3& theAxis) const;
99
100 protected:
101
102   SelectMgr_Vec3 myPlanes[N + 2];        //!< Plane equations
103   SelectMgr_Vec3 myVertices[N * 2];      //!< Vertices coordinates
104
105   Standard_Real myMaxVertsProjections[N + 2];      //!< Cached projections of vertices onto frustum plane directions
106   Standard_Real myMinVertsProjections[N + 2];      //!< Cached projections of vertices onto frustum plane directions
107   Standard_Real myMaxOrthoVertsProjections[3];     //!< Cached projections of vertices onto directions of ortho unit vectors
108   Standard_Real myMinOrthoVertsProjections[3];     //!< Cached projections of vertices onto directions of ortho unit vectors
109
110   SelectMgr_Vec3 myEdgeDirs[6];                    //!< Cached edge directions
111 };
112
113 #include <SelectMgr_Frustum.lxx>
114
115 #endif // _SelectMgr_Frustum_HeaderFile