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1 | // Created on: 2013-12-25 |
2 | // Created by: Varvara POSKONINA |
3 | // Copyright (c) 1999-2014 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 _OpenGl_BVHTreeSelector_HeaderFile |
17 | #define _OpenGl_BVHTreeSelector_HeaderFile |
18 | |
19 | #include <Graphic3d_Camera.hxx> |
20 | |
21 | #include <OpenGl_Vec.hxx> |
22 | |
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 |
25 | //! view volume. |
26 | class OpenGl_BVHTreeSelector |
27 | { |
28 | public: |
29 | |
30 | //! Creates an empty selector object with parallel projection type by default. |
31 | Standard_EXPORT OpenGl_BVHTreeSelector(); |
32 | |
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); |
35 | |
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; |
42 | |
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(); |
46 | |
47 | //! Returnes the state of projection matrix previously saved in selector. |
48 | Standard_EXPORT const Standard_Size ProjectionState() { return myProjectionState; } |
49 | |
50 | //! Returnes the link for changing the state of projection matrix. |
51 | Standard_EXPORT Standard_Size& ChangeProjectionState() { return myProjectionState; } |
52 | |
53 | //! Returnes the state of model view matrix previously saved in selector. |
54 | Standard_EXPORT const Standard_Size ModelViewState() { return myModelViewState; } |
55 | |
56 | //! Returnes the link for changing the state of model view matrix. |
57 | Standard_EXPORT Standard_Size& ChangeModelViewState() { return myModelViewState; } |
58 | |
59 | protected: |
60 | |
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); |
66 | |
67 | protected: |
68 | |
69 | //! Enumerates planes of view volume. |
70 | enum |
71 | { |
72 | Plane_Top, |
73 | Plane_Bottom, |
74 | Plane_Left, |
75 | Plane_Right, |
76 | Plane_Near, |
77 | Plane_Far, |
78 | PlanesNB |
79 | }; |
80 | |
81 | //! Enumerates vertices of view volume. |
82 | enum |
83 | { |
84 | ClipVert_LeftTopNear, |
85 | ClipVert_LeftBottomNear, |
86 | ClipVert_RightTopNear, |
87 | ClipVert_RightBottomNear, |
88 | ClipVert_LeftTopFar, |
89 | ClipVert_LeftBottomFar, |
90 | ClipVert_RightTopFar, |
91 | ClipVert_RightBottomFar, |
92 | ClipVerticesNB |
93 | }; |
94 | |
95 | protected: |
96 | |
97 | OpenGl_Vec4 myClipPlanes[PlanesNB]; //!< Plane equations |
98 | OpenGl_Vec4 myClipVerts[ClipVerticesNB]; //!< Vertices |
99 | |
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 |
104 | |
105 | // for caching clip points projections onto AABB normals once per traverse |
106 | // ORDER: E0, E1, E2 |
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 |
109 | |
110 | Standard_Boolean myIsProjectionParallel; |
111 | |
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. |
114 | |
115 | }; |
116 | |
117 | #endif // _OpenGl_BVHTreeSelector_HeaderFile |