urho3d/Engine/Math/Polyhedron.h

//
// Urho3D Engine
// Copyright (c) 2008-2012 Lasse Öörni
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
//

#pragma once

#include "Vector3.h"

class BoundingBox;
class Frustum;
class Matrix3;
class Matrix3x4;
class Plane;

/// A convex volume built from polygon faces.
class Polyhedron
{
public:
    /// Construct empty.
    Polyhedron()
    {
    }
    
    /// Copy-construct from another polyhedron.
    Polyhedron(const Polyhedron& polyhedron) :
        faces_(polyhedron.faces_)
    {
    }
    
    /// Construct from a list of faces.
    Polyhedron(const Vector<PODVector<Vector3> >& faces) :
        faces_(faces)
    {
    }
    
    /// Construct from a bounding box.
    Polyhedron(const BoundingBox& box)
    {
        Define(box);
    }
    
    /// Construct from a frustum.
    Polyhedron(const Frustum& frustum)
    {
        Define(frustum);
    }
    
    /// Destruct.
    ~Polyhedron();
    
    /// Define from a bounding box.
    void Define(const BoundingBox& box);
    /// Define from a frustum.
    void Define(const Frustum& frustum);
    /// Add a triangle face.
    void AddFace(const Vector3& v0, const Vector3& v1, const Vector3& v2);
    /// Add a quadrilateral face.
    void AddFace(const Vector3& v0, const Vector3& v1, const Vector3& v2, const Vector3& v3);
    /// Add an arbitrary face.
    void AddFace(const PODVector<Vector3>& face);
    /// Clip with a plane.
    void Clip(const Plane& plane);
    /// Clip with a bounding box.
    void Clip(const BoundingBox& box);
    /// Clip with a frustum.
    void Clip(const Frustum& box);
    /// Clear all faces.
    void Clear();
    /// Transform with a 3x3 matrix.
    void Transform(const Matrix3& transform);
    /// Transform with a 3x4 matrix.
    void Transform(const Matrix3x4& transform);
    
    /// Return transformed with a 3x3 matrix.
    Polyhedron Transformed(const Matrix3& transform) const;
    /// Return transformed with a 3x4 matrix.
    Polyhedron Transformed(const Matrix3x4& transform) const;
    /// Return whether is empty.
    bool Empty() const { return faces_.Empty(); }
    
    /// Polygon faces.
    Vector<PODVector<Vector3> > faces_;
    
private:
    /// %Set a triangle face by index.
    void SetFace(unsigned index, const Vector3& v0, const Vector3& v1, const Vector3& v2);
    /// %Set a quadrilateral face by index.
    void SetFace(unsigned index, const Vector3& v0, const Vector3& v1, const Vector3& v2, const Vector3& v3);
    /// Internal vector for clipped vertices.
    PODVector<Vector3> clippedVertices_;
    /// Internal vector for the new face being constructed.
    PODVector<Vector3> outFace_;
};