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             :  * CBrush, a class representing a convex object
      20             :  */
      21             : 
      22             : #ifndef INCLUDED_BRUSH
      23             : #define INCLUDED_BRUSH
      24             : 
      25             : #include "maths/Vector3D.h"
      26             : 
      27             : #include <vector>
      28             : 
      29             : class CBoundingBoxAligned;
      30             : class CFrustum;
      31             : class CPlane;
      32             : 
      33             : 
      34             : /**
      35             :  * Class CBrush: Represents a convex object, supports some CSG operations.
      36             :  */
      37          13 : class CBrush
      38             : {
      39             : public:
      40             :     CBrush();
      41             : 
      42             :     /**
      43             :      * CBrush: Construct a brush from a bounds object.
      44             :      *
      45             :      * @param bounds the CBoundingBoxAligned object to construct the brush from.
      46             :      */
      47             :     CBrush(const CBoundingBoxAligned& bounds);
      48             : 
      49             :     /**
      50             :      * IsEmpty: Returns whether the brush is empty.
      51             :      *
      52             :      * @return @c true if the brush is empty, @c false otherwise
      53             :      */
      54           1 :     bool IsEmpty() const { return m_Vertices.size() == 0; }
      55             : 
      56             :     /**
      57             :      * Bounds: Calculate the axis-aligned bounding box for this brush.
      58             :      *
      59             :      * @param result the resulting bounding box is stored here
      60             :      */
      61             :     void Bounds(CBoundingBoxAligned& result) const;
      62             : 
      63             :     /**
      64             :      * Slice: Cut the object along the given plane, resulting in a smaller (or even empty) brush representing
      65             :      * the part of the object that lies in front of the plane (as defined by the positive direction of its
      66             :      * normal vector).
      67             :      *
      68             :      * @param plane the slicing plane
      69             :      * @param result the resulting brush is stored here
      70             :      */
      71             :     void Slice(const CPlane& plane, CBrush& result) const;
      72             : 
      73             :     /**
      74             :      * Intersect: Intersect the brush with the given frustum.
      75             :      *
      76             :      * @param frustum the frustum to intersect with
      77             :      * @param result the resulting brush is stored here
      78             :      */
      79             :     void Intersect(const CFrustum& frustum, CBrush& result) const;
      80             : 
      81             :     /**
      82             :      * Returns vertices in the brush. Intended for testing purposes; you should not need to use
      83             :      * this method directly.
      84             :      */
      85             :     const std::vector<CVector3D>& GetVertices() const;
      86             : 
      87             :     /**
      88             :      * Writes a vector of the faces in this brush to @p out. Each face is itself a vector, listing the vertex indices
      89             :      * that make up the face, starting and ending with the same index. Intended for testing purposes; you should not
      90             :      * need to use this method directly.
      91             :      */
      92             :     void GetFaces(std::vector<std::vector<size_t>>& out) const;
      93             : 
      94             : private:
      95             :     static const size_t NO_VERTEX = ~0u;
      96             : 
      97             :     typedef std::vector<CVector3D> Vertices;
      98             :     typedef std::vector<size_t> FaceIndices;
      99             : 
     100             :     /// Collection of unique vertices that make up this shape.
     101             :     Vertices m_Vertices;
     102             : 
     103             :     /**
     104             :      * Holds the face definitions of this brush. Each face is a sequence of indices into m_Vertices that starts and ends with
     105             :      * the same vertex index, completing a loop through all the vertices that make up the face. This vector holds all the face
     106             :      * sequences back-to-back, thus looking something like 'x---xy--------yz--z' in the general case.
     107             :      */
     108             :     FaceIndices m_Faces;
     109             : 
     110             :     struct Helper;
     111             : };
     112             : 
     113             : #endif // INCLUDED_BRUSH