Line data    Source code

       1             : /* Copyright (C) 2021 Wildfire Games.
       2             :  * This file is part of 0 A.D.
       3             :  *
       4             :  * 0 A.D. is free software: you can redistribute it and/or modify
       5             :  * it under the terms of the GNU General Public License as published by
       6             :  * the Free Software Foundation, either version 2 of the License, or
       7             :  * (at your option) any later version.
       8             :  *
       9             :  * 0 A.D. is distributed in the hope that it will be useful,
      10             :  * but WITHOUT ANY WARRANTY; without even the implied warranty of
      11             :  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
      12             :  * GNU General Public License for more details.
      13             :  *
      14             :  * You should have received a copy of the GNU General Public License
      15             :  * along with 0 A.D.  If not, see <http://www.gnu.org/licenses/>.
      16             :  */
      17             : 
      18             : /*
      19             :  * CFrustum is a collection of planes which define a viewing space.
      20             :  */
      21             : 
      22             : /*
      23             : Usually associated with the camera, there are 6 planes which define the
      24             : view pyramid. But we allow more planes per frustum which may be used for
      25             : portal rendering, where a portal may have 3 or more edges.
      26             : */
      27             : 
      28             : #ifndef INCLUDED_FRUSTUM
      29             : #define INCLUDED_FRUSTUM
      30             : 
      31             : #include "maths/Plane.h"
      32             : 
      33             : class CBoundingBoxAligned;
      34             : class CMatrix3D;
      35             : 
      36             : class CFrustum
      37             : {
      38             : public:
      39             :     CFrustum();
      40             :     ~CFrustum();
      41             : 
      42             :     // Set the number of planes to use for calculations. This is clamped to
      43             :     // [0, MAX_NUM_FRUSTUM_PLANES].
      44             :     void SetNumPlanes(size_t num);
      45             : 
      46          16 :     size_t GetNumPlanes() const { return m_NumPlanes; }
      47             : 
      48             :     void AddPlane(const CPlane& plane);
      49             : 
      50             :     void Transform(const CMatrix3D& m);
      51             : 
      52             :     // The following methods return true if the shape is
      53             :     // partially or completely in front of the frustum planes.
      54             :     bool IsPointVisible(const CVector3D& point) const;
      55             :     bool DoesSegmentIntersect(const CVector3D& start, const CVector3D& end) const;
      56             :     bool IsSphereVisible(const CVector3D& center, float radius) const;
      57             :     bool IsBoxVisible(const CVector3D& position, const CBoundingBoxAligned& bounds) const;
      58             :     bool IsBoxVisible(const CBoundingBoxAligned& bounds) const;
      59             : 
      60         120 :     CPlane& operator[](size_t idx) { return m_Planes[idx]; }
      61          26 :     const CPlane& operator[](size_t idx) const { return m_Planes[idx]; }
      62             : 
      63             : private:
      64             :     static const size_t MAX_NUM_FRUSTUM_PLANES = 10;
      65             : 
      66             :     CPlane m_Planes[MAX_NUM_FRUSTUM_PLANES];
      67             :     size_t m_NumPlanes;
      68             : };
      69             : 
      70             : #endif // INCLUDED_FRUSTUM