urho3d/Source/Urho3D/Math/BoundingBox.h

// Copyright (c) 2008-2023 the Urho3D project
// License: MIT

#pragma once

#include "../Math/Rect.h"
#include "../Math/Vector3.h"

#ifdef URHO3D_SSE
#include <xmmintrin.h>
#endif

namespace Urho3D
{

class Polyhedron;
class Frustum;
class Matrix3;
class Matrix4;
class Matrix3x4;
class Sphere;

/// Three-dimensional axis-aligned bounding box.
/// @allfloats
class URHO3D_API BoundingBox
{
public:
    /// Construct with zero size.
    BoundingBox() noexcept :
        min_(M_INFINITY, M_INFINITY, M_INFINITY),
        max_(-M_INFINITY, -M_INFINITY, -M_INFINITY)
    {
    }

    /// Copy-construct from another bounding box.
    BoundingBox(const BoundingBox& box) noexcept :
        min_(box.min_),
        max_(box.max_)
    {
    }

    /// Construct from a rect, with the Z dimension left zero.
    explicit BoundingBox(const Rect& rect) noexcept :
        min_(Vector3(rect.min_, 0.0f)),
        max_(Vector3(rect.max_, 0.0f))
    {
    }

    /// Construct from minimum and maximum vectors.
    BoundingBox(const Vector3& min, const Vector3& max) noexcept :
        min_(min),
        max_(max)
    {
    }

    /// Construct from minimum and maximum floats (all dimensions same).
    BoundingBox(float min, float max) noexcept :
        min_(Vector3(min, min, min)),
        max_(Vector3(max, max, max))
    {
    }

#ifdef URHO3D_SSE
    /// @nobind
    BoundingBox(__m128 min, __m128 max) noexcept
    {
        _mm_storeu_ps(&min_.x_, min);
        _mm_storeu_ps(&max_.x_, max);
    }
#endif

    /// Construct from an array of vertices.
    BoundingBox(const Vector3* vertices, unsigned count) :
        min_(M_INFINITY, M_INFINITY, M_INFINITY),
        max_(-M_INFINITY, -M_INFINITY, -M_INFINITY)
    {
        Define(vertices, count);
    }

    /// Construct from a frustum.
    explicit BoundingBox(const Frustum& frustum) :
        min_(M_INFINITY, M_INFINITY, M_INFINITY),
        max_(-M_INFINITY, -M_INFINITY, -M_INFINITY)
    {
        Define(frustum);
    }

    /// Construct from a polyhedron.
    explicit BoundingBox(const Polyhedron& poly) :
        min_(M_INFINITY, M_INFINITY, M_INFINITY),
        max_(-M_INFINITY, -M_INFINITY, -M_INFINITY)
    {
        Define(poly);
    }

    /// Construct from a sphere.
    explicit BoundingBox(const Sphere& sphere) :
        min_(M_INFINITY, M_INFINITY, M_INFINITY),
        max_(-M_INFINITY, -M_INFINITY, -M_INFINITY)
    {
        Define(sphere);
    }

    /// Assign from another bounding box.
    BoundingBox& operator =(const BoundingBox& rhs) noexcept
    {
        min_ = rhs.min_;
        max_ = rhs.max_;
        return *this;
    }

    /// Assign from a Rect, with the Z dimension left zero.
    BoundingBox& operator =(const Rect& rhs) noexcept
    {
        min_ = Vector3(rhs.min_, 0.0f);
        max_ = Vector3(rhs.max_, 0.0f);
        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 another bounding box.
    void Define(const BoundingBox& box)
    {
        Define(box.min_, box.max_);
    }

    /// Define from a Rect.
    void Define(const Rect& rect)
    {
        Define(Vector3(rect.min_, 0.0f), Vector3(rect.max_, 0.0f));
    }

    /// Define from minimum and maximum vectors.
    void Define(const Vector3& min, const Vector3& max)
    {
        min_ = min;
        max_ = max;
    }

    /// 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);
    }

    /// Define from a point.
    void Define(const Vector3& point)
    {
        min_ = max_ = point;
    }

    /// Merge a point.
    void Merge(const Vector3& point)
    {
#ifdef URHO3D_SSE
        __m128 vec = _mm_set_ps(1.f, point.z_, point.y_, point.x_);
        _mm_storeu_ps(&min_.x_, _mm_min_ps(_mm_loadu_ps(&min_.x_), vec));
        _mm_storeu_ps(&max_.x_, _mm_max_ps(_mm_loadu_ps(&max_.x_), vec));
#else
        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_;
#endif
    }

    /// Merge another bounding box.
    void Merge(const BoundingBox& box)
    {
#ifdef URHO3D_SSE
        _mm_storeu_ps(&min_.x_, _mm_min_ps(_mm_loadu_ps(&min_.x_), _mm_loadu_ps(&box.min_.x_)));
        _mm_storeu_ps(&max_.x_, _mm_max_ps(_mm_loadu_ps(&max_.x_), _mm_loadu_ps(&box.max_.x_)));
#else
        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_;
#endif
    }

    /// 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 polyhedron.
    void Define(const Polyhedron& poly);
    /// 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 polyhedron.
    void Merge(const Polyhedron& poly);
    /// Merge a sphere.
    void Merge(const Sphere& sphere);
    /// Clip with another bounding box. The box can become degenerate (undefined) as a result.
    void Clip(const BoundingBox& box);
    /// Transform with a 3x3 matrix.
    void Transform(const Matrix3& transform);
    /// Transform with a 3x4 matrix.
    void Transform(const Matrix3x4& transform);

    /// Clear to undefined state.
    void Clear()
    {
#ifdef URHO3D_SSE
        _mm_storeu_ps(&min_.x_, _mm_set1_ps(M_INFINITY));
        _mm_storeu_ps(&max_.x_, _mm_set1_ps(-M_INFINITY));
#else
        min_ = Vector3(M_INFINITY, M_INFINITY, M_INFINITY);
        max_ = Vector3(-M_INFINITY, -M_INFINITY, -M_INFINITY);
#endif
    }

    /// Return true if this bounding box is defined via a previous call to Define() or Merge().
    bool Defined() const
    {
        return min_.x_ != M_INFINITY;
    }

    /// Return center.
    /// @property
    Vector3 Center() const { return (max_ + min_) * 0.5f; }

    /// Return size.
    /// @property
    Vector3 Size() const { return max_ - min_; }

    /// Return half-size.
    /// @property
    Vector3 HalfSize() const { return (max_ - min_) * 0.5f; }

    /// Return transformed by a 3x3 matrix.
    BoundingBox Transformed(const Matrix3& transform) const;
    /// Return transformed by a 3x4 matrix.
    BoundingBox Transformed(const Matrix3x4& transform) const;
    /// Return projected by a 4x4 projection matrix.
    Rect Projected(const Matrix4& projection) const;
    /// Return distance to point.
    float DistanceToPoint(const Vector3& point) const;

    /// Test if a point is inside.
    Intersection IsInside(const Vector3& point) const
    {
        if (point.x_ < min_.x_ || point.x_ > max_.x_ || point.y_ < min_.y_ || point.y_ > max_.y_ ||
            point.z_ < min_.z_ || point.z_ > max_.z_)
            return OUTSIDE;
        else
            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_ || box.max_.y_ < min_.y_ || box.min_.y_ > max_.y_ ||
            box.max_.z_ < min_.z_ || box.min_.z_ > max_.z_)
            return OUTSIDE;
        else if (box.min_.x_ < min_.x_ || box.max_.x_ > max_.x_ || box.min_.y_ < min_.y_ || box.max_.y_ > max_.y_ ||
                 box.min_.z_ < min_.z_ || box.max_.z_ > max_.z_)
            return INTERSECTS;
        else
            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_ || box.max_.y_ < min_.y_ || box.min_.y_ > max_.y_ ||
            box.max_.z_ < min_.z_ || box.min_.z_ > max_.z_)
            return OUTSIDE;
        else
            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 as string.
    String ToString() const;

    /// Minimum vector.
    Vector3 min_;
    float dummyMin_{}; // This is never used, but exists to pad the min_ value to four floats.
    /// Maximum vector.
    Vector3 max_;
    float dummyMax_{}; // This is never used, but exists to pad the max_ value to four floats.
};

}