urho3d/Engine/Math/BoundingBox.h

//
// Urho3D Engine
// Copyright (c) 2008-2011 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 "Rect.h"
#include "Vector3.h"

class Frustum;
class Matrix3;
class Matrix4;
class Matrix3x4;
class Ray;
class Sphere;

/// Three-dimensional axis-aligned bounding box
class BoundingBox
{
public:
    /// Construct with zero size
    BoundingBox() :
        min_(Vector3::ZERO),
        max_(Vector3::ZERO),
        defined_(false)
    {
    }
    
    /// Copy-construct from another bounding box
    BoundingBox(const BoundingBox& box) :
        min_(box.min_),
        max_(box.max_),
        defined_(box.defined_)
    {
    }
    
    /// Construct from a rect, with the Z dimension left zero
    BoundingBox(const Rect& rect) :
        min_(Vector3(rect.min_, 0.0f)),
        max_(Vector3(rect.max_, 0.0f)),
        defined_(true)
    {
    }
    
    /// Construct from minimum and maximum vectors
    BoundingBox(const Vector3& min, const Vector3& max) :
        min_(min),
        max_(max),
        defined_(true)
    {
    }
    
    /// Construct from minimum and maximum floats (all dimensions same)
    BoundingBox(float min, float max) :
        min_(Vector3(min, min, min)),
        max_(Vector3(max, max, max)),
        defined_(true)
    {
    }
    
    /// Assign from another bounding box
    BoundingBox& operator = (const BoundingBox& rhs)
    {
        min_ = rhs.min_;
        max_ = rhs.max_;
        defined_ = rhs.defined_;
        
        return *this;
    }
    
    /// Assign from a Rect, with the Z dimension left zero
    BoundingBox& operator = (const Rect& rhs)
    {
        min_ = Vector3(rhs.min_, 0.0f);
        max_ = Vector3(rhs.max_, 0.0f);
        defined_ = true;
        
        return *this;
    }
    
    /// Test for equality with another bounding box
    bool operator == (const BoundingBox& rhs) const
    {
        return ((min_ == rhs.min_) && (max_ == rhs.max_));
    }
    
    /// Test for inequality with another bounding box
    bool operator != (const BoundingBox& rhs) const
    {
        return ((min_ != rhs.min_) || (max_ != rhs.max_));
    }
    
    /// Define from minimum and maximum vectors
    void Define(const Vector3& min, const Vector3& max)
    {
        min_ = min;
        max_ = max;
        defined_ = true;
    }
    
    /// Define from a point
    void Define(const Vector3& point)
    {
        min_ = max_ = point;
        defined_ = true;
    }
    
    /// Define from minimum and maximum floats (all dimensions same)
    void Define(float min, float max)
    {
        min_ = Vector3(min, min, min);
        max_ = Vector3(max, max, max);
        defined_ = true;
    }
    
    /// Merge a point
    void Merge(const Vector3& point)
    {
        if (!defined_)
        {
            min_ = max_ = point;
            defined_ = true;
            return;
        }
        
        if (point.x_ < min_.x_) min_.x_ = point.x_;
        if (point.y_ < min_.y_) min_.y_ = point.y_;
        if (point.z_ < min_.z_) min_.z_ = point.z_;
        if (point.x_ > max_.x_) max_.x_ = point.x_;
        if (point.y_ > max_.y_) max_.y_ = point.y_;
        if (point.z_ > max_.z_) max_.z_ = point.z_;
    }
    
    /// Merge another bounding box
    void Merge(const BoundingBox& box)
    {
        if (!defined_)
        {
            min_ = box.min_;
            max_ = box.max_;
            defined_ = true;
            return;
        }
    
        if (box.min_.x_ < min_.x_) min_.x_ = box.min_.x_;
        if (box.min_.y_ < min_.y_) min_.y_ = box.min_.y_;
        if (box.min_.z_ < min_.z_) min_.z_ = box.min_.z_;
        if (box.max_.x_ > max_.x_) max_.x_ = box.max_.x_;
        if (box.max_.y_ > max_.y_) max_.y_ = box.max_.y_;
        if (box.max_.z_ > max_.z_) max_.z_ = box.max_.z_;
    }
    
    /// Define from an array of vertices
    void Define(const Vector3* vertices, unsigned count);
    /// Define from a frustum
    void Define(const Frustum& frustum);
    /// Define from a sphere
    void Define(const Sphere& sphere);
    /// Merge an array of vertices
    void Merge(const Vector3* vertices, unsigned count);
    /// Merge a frustum
    void Merge(const Frustum& frustum);
    /// Merge a sphere
    void Merge(const Sphere& sphere);
    /// Intersect with another bounding box
    void Intersect(const BoundingBox& box);
    /// Transform with a 3x3 matrix
    void Transform(const Matrix3& transform);
    /// Transform with a 4x3 matrix
    void Transform(const Matrix3x4& transform);
    
    /// Return center
    Vector3 Center() const { return (max_ + min_) * 0.5f; }
    /// Return size
    Vector3 Size() const { return max_ - min_; }
    /// Return half-size
    Vector3 HalfSize() const { return (max_ - min_) * 0.5f; }
    
    /// Return transformed by a 3x3 matrix
    BoundingBox Transformed(const Matrix3& transform) const;
    /// Return transformed by a 4x3 matrix
    BoundingBox Transformed(const Matrix3x4& transform) const;
    /// Return projected by a 4x4 projection matrix
    Rect Projected(const Matrix4& projection) const;
    
    /// Test if a point is inside
    Intersection IsInside(const Vector3& point) const
    {
        if ((point.x_ < min_.x_) || (point.x_ > max_.x_))
            return OUTSIDE;
        if ((point.y_ < min_.y_) || (point.y_ > max_.y_))
            return OUTSIDE;
        if ((point.z_ < min_.z_) || (point.z_ > max_.z_))
            return OUTSIDE;
        
        return INSIDE;
    }
    
    /// Test if another bounding box is inside, outside or intersects
    Intersection IsInside(const BoundingBox& box) const
    {
        if ((box.max_.x_ < min_.x_) || (box.min_.x_ > max_.x_))
            return OUTSIDE;
        if ((box.max_.y_ < min_.y_) || (box.min_.y_ > max_.y_))
            return OUTSIDE;
        if ((box.max_.z_ < min_.z_) || (box.min_.z_ > max_.z_))
            return OUTSIDE;
        
        if ((box.min_.x_ < min_.x_) || (box.max_.x_ > max_.x_))
            return INTERSECTS;
        if ((box.min_.y_ < min_.y_) || (box.max_.y_ > max_.y_))
            return INTERSECTS;
        if ((box.min_.z_ < min_.z_) || (box.max_.z_ > max_.z_))
            return INTERSECTS;
        
        return INSIDE;
    }
    
    /// Test if another bounding box is (partially) inside or outside
    Intersection IsInsideFast(const BoundingBox& box) const
    {
        if ((box.max_.x_ < min_.x_) || (box.min_.x_ > max_.x_))
            return OUTSIDE;
        if ((box.max_.y_ < min_.y_) || (box.min_.y_ > max_.y_))
            return OUTSIDE;
        if ((box.max_.z_ < min_.z_) || (box.min_.z_ > max_.z_))
            return OUTSIDE;
        
        return INSIDE;
    }
    
    /// Test if a sphere is inside, outside or intersects
    Intersection IsInside(const Sphere& sphere) const;
    /// Test if a sphere is (partially) inside or outside
    Intersection IsInsideFast(const Sphere& sphere) const;
    /// Return ray hit distance, or infinity if no hit
    float Distance(const Ray& ray) const;
    
    /// Minimum vector
    Vector3 min_;
    /// Maximum vector
    Vector3 max_;
    /// Defined flag
    bool defined_;
};