minetest/irr/include/aabbox3d.h
2024-03-26 21:39:02 +01:00

390 lines
11 KiB
C++

// Copyright (C) 2002-2012 Nikolaus Gebhardt
// This file is part of the "Irrlicht Engine".
// For conditions of distribution and use, see copyright notice in irrlicht.h
#pragma once
#include "irrMath.h"
#include "plane3d.h"
#include "line3d.h"
namespace irr
{
namespace core
{
//! Axis aligned bounding box in 3d dimensional space.
/** Has some useful methods used with occlusion culling or clipping.
*/
template <class T>
class aabbox3d
{
public:
//! Default Constructor.
constexpr aabbox3d() :
MinEdge(-1, -1, -1), MaxEdge(1, 1, 1) {}
//! Constructor with min edge and max edge.
constexpr aabbox3d(const vector3d<T> &min, const vector3d<T> &max) :
MinEdge(min), MaxEdge(max) {}
//! Constructor with only one point.
constexpr aabbox3d(const vector3d<T> &init) :
MinEdge(init), MaxEdge(init) {}
//! Constructor with min edge and max edge as single values, not vectors.
constexpr aabbox3d(T minx, T miny, T minz, T maxx, T maxy, T maxz) :
MinEdge(minx, miny, minz), MaxEdge(maxx, maxy, maxz) {}
// operators
//! Equality operator
/** \param other box to compare with.
\return True if both boxes are equal, else false. */
constexpr inline bool operator==(const aabbox3d<T> &other) const
{
return (MinEdge == other.MinEdge && other.MaxEdge == MaxEdge);
}
//! Inequality operator
/** \param other box to compare with.
\return True if both boxes are different, else false. */
constexpr inline bool operator!=(const aabbox3d<T> &other) const
{
return !(MinEdge == other.MinEdge && other.MaxEdge == MaxEdge);
}
// functions
//! Resets the bounding box to a one-point box.
/** \param x X coord of the point.
\param y Y coord of the point.
\param z Z coord of the point. */
void reset(T x, T y, T z)
{
MaxEdge.set(x, y, z);
MinEdge = MaxEdge;
}
//! Resets the bounding box.
/** \param initValue New box to set this one to. */
void reset(const aabbox3d<T> &initValue)
{
*this = initValue;
}
//! Resets the bounding box to a one-point box.
/** \param initValue New point. */
void reset(const vector3d<T> &initValue)
{
MaxEdge = initValue;
MinEdge = initValue;
}
//! Adds a point to the bounding box
/** The box grows bigger, if point was outside of the box.
\param p: Point to add into the box. */
void addInternalPoint(const vector3d<T> &p)
{
addInternalPoint(p.X, p.Y, p.Z);
}
//! Adds another bounding box
/** The box grows bigger, if the new box was outside of the box.
\param b: Other bounding box to add into this box. */
void addInternalBox(const aabbox3d<T> &b)
{
addInternalPoint(b.MaxEdge);
addInternalPoint(b.MinEdge);
}
//! Adds a point to the bounding box
/** The box grows bigger, if point is outside of the box.
\param x X coordinate of the point to add to this box.
\param y Y coordinate of the point to add to this box.
\param z Z coordinate of the point to add to this box. */
void addInternalPoint(T x, T y, T z)
{
if (x > MaxEdge.X)
MaxEdge.X = x;
if (y > MaxEdge.Y)
MaxEdge.Y = y;
if (z > MaxEdge.Z)
MaxEdge.Z = z;
if (x < MinEdge.X)
MinEdge.X = x;
if (y < MinEdge.Y)
MinEdge.Y = y;
if (z < MinEdge.Z)
MinEdge.Z = z;
}
//! Get center of the bounding box
/** \return Center of the bounding box. */
vector3d<T> getCenter() const
{
return (MinEdge + MaxEdge) / 2;
}
//! Get extent of the box (maximal distance of two points in the box)
/** \return Extent of the bounding box. */
vector3d<T> getExtent() const
{
return MaxEdge - MinEdge;
}
//! Get radius of the bounding sphere
/** \return Radius of the bounding sphere. */
T getRadius() const
{
const T radius = getExtent().getLength() / 2;
return radius;
}
//! Check if the box is empty.
/** This means that there is no space between the min and max edge.
\return True if box is empty, else false. */
bool isEmpty() const
{
return MinEdge.equals(MaxEdge);
}
//! Get the volume enclosed by the box in cubed units
T getVolume() const
{
const vector3d<T> e = getExtent();
return e.X * e.Y * e.Z;
}
//! Get the surface area of the box in squared units
T getArea() const
{
const vector3d<T> e = getExtent();
return 2 * (e.X * e.Y + e.X * e.Z + e.Y * e.Z);
}
//! Stores all 8 edges of the box into an array
/** \param edges: Pointer to array of 8 edges. */
void getEdges(vector3d<T> *edges) const
{
const core::vector3d<T> middle = getCenter();
const core::vector3d<T> diag = middle - MaxEdge;
/*
Edges are stored in this way:
Hey, am I an ascii artist, or what? :) niko.
/3--------/7
/ | / |
/ | / |
1---------5 |
| /2- - -|- -6
| / | /
|/ | /
0---------4/
*/
edges[0].set(middle.X + diag.X, middle.Y + diag.Y, middle.Z + diag.Z);
edges[1].set(middle.X + diag.X, middle.Y - diag.Y, middle.Z + diag.Z);
edges[2].set(middle.X + diag.X, middle.Y + diag.Y, middle.Z - diag.Z);
edges[3].set(middle.X + diag.X, middle.Y - diag.Y, middle.Z - diag.Z);
edges[4].set(middle.X - diag.X, middle.Y + diag.Y, middle.Z + diag.Z);
edges[5].set(middle.X - diag.X, middle.Y - diag.Y, middle.Z + diag.Z);
edges[6].set(middle.X - diag.X, middle.Y + diag.Y, middle.Z - diag.Z);
edges[7].set(middle.X - diag.X, middle.Y - diag.Y, middle.Z - diag.Z);
}
//! Repairs the box.
/** Necessary if for example MinEdge and MaxEdge are swapped. */
void repair()
{
T t;
if (MinEdge.X > MaxEdge.X) {
t = MinEdge.X;
MinEdge.X = MaxEdge.X;
MaxEdge.X = t;
}
if (MinEdge.Y > MaxEdge.Y) {
t = MinEdge.Y;
MinEdge.Y = MaxEdge.Y;
MaxEdge.Y = t;
}
if (MinEdge.Z > MaxEdge.Z) {
t = MinEdge.Z;
MinEdge.Z = MaxEdge.Z;
MaxEdge.Z = t;
}
}
// Check if MaxEdge > MinEdge
bool isValid() const
{
if (MinEdge.X > MaxEdge.X)
return false;
if (MinEdge.Y > MaxEdge.Y)
return false;
if (MinEdge.Z > MaxEdge.Z)
return false;
return true;
}
//! Calculates a new interpolated bounding box.
/** d=0 returns other, d=1 returns this, all other values blend between
the two boxes.
\param other Other box to interpolate between
\param d Value between 0.0f and 1.0f.
\return Interpolated box. */
aabbox3d<T> getInterpolated(const aabbox3d<T> &other, f32 d) const
{
f32 inv = 1.0f - d;
return aabbox3d<T>((other.MinEdge * inv) + (MinEdge * d),
(other.MaxEdge * inv) + (MaxEdge * d));
}
//! Determines if a point is within this box.
/** Border is included (IS part of the box)!
\param p: Point to check.
\return True if the point is within the box and false if not */
bool isPointInside(const vector3d<T> &p) const
{
return (p.X >= MinEdge.X && p.X <= MaxEdge.X &&
p.Y >= MinEdge.Y && p.Y <= MaxEdge.Y &&
p.Z >= MinEdge.Z && p.Z <= MaxEdge.Z);
}
//! Determines if a point is within this box and not its borders.
/** Border is excluded (NOT part of the box)!
\param p: Point to check.
\return True if the point is within the box and false if not. */
bool isPointTotalInside(const vector3d<T> &p) const
{
return (p.X > MinEdge.X && p.X < MaxEdge.X &&
p.Y > MinEdge.Y && p.Y < MaxEdge.Y &&
p.Z > MinEdge.Z && p.Z < MaxEdge.Z);
}
//! Check if this box is completely inside the 'other' box.
/** \param other: Other box to check against.
\return True if this box is completely inside the other box,
otherwise false. */
bool isFullInside(const aabbox3d<T> &other) const
{
return (MinEdge.X >= other.MinEdge.X && MinEdge.Y >= other.MinEdge.Y && MinEdge.Z >= other.MinEdge.Z &&
MaxEdge.X <= other.MaxEdge.X && MaxEdge.Y <= other.MaxEdge.Y && MaxEdge.Z <= other.MaxEdge.Z);
}
//! Returns the intersection of this box with another, if possible.
aabbox3d<T> intersect(const aabbox3d<T> &other) const
{
aabbox3d<T> out;
if (!intersectsWithBox(other))
return out;
out.MaxEdge.X = min_(MaxEdge.X, other.MaxEdge.X);
out.MaxEdge.Y = min_(MaxEdge.Y, other.MaxEdge.Y);
out.MaxEdge.Z = min_(MaxEdge.Z, other.MaxEdge.Z);
out.MinEdge.X = max_(MinEdge.X, other.MinEdge.X);
out.MinEdge.Y = max_(MinEdge.Y, other.MinEdge.Y);
out.MinEdge.Z = max_(MinEdge.Z, other.MinEdge.Z);
return out;
}
//! Determines if the axis-aligned box intersects with another axis-aligned box.
/** \param other: Other box to check a intersection with.
\return True if there is an intersection with the other box,
otherwise false. */
bool intersectsWithBox(const aabbox3d<T> &other) const
{
return (MinEdge.X <= other.MaxEdge.X && MinEdge.Y <= other.MaxEdge.Y && MinEdge.Z <= other.MaxEdge.Z &&
MaxEdge.X >= other.MinEdge.X && MaxEdge.Y >= other.MinEdge.Y && MaxEdge.Z >= other.MinEdge.Z);
}
//! Tests if the box intersects with a line
/** \param line: Line to test intersection with.
\return True if there is an intersection , else false. */
bool intersectsWithLine(const line3d<T> &line) const
{
return intersectsWithLine(line.getMiddle(), line.getVector().normalize(),
(T)(line.getLength() * 0.5));
}
//! Tests if the box intersects with a line
/** \param linemiddle Center of the line.
\param linevect Vector of the line.
\param halflength Half length of the line.
\return True if there is an intersection, else false. */
bool intersectsWithLine(const vector3d<T> &linemiddle,
const vector3d<T> &linevect, T halflength) const
{
const vector3d<T> e = getExtent() * (T)0.5;
const vector3d<T> t = getCenter() - linemiddle;
if ((fabs(t.X) > e.X + halflength * fabs(linevect.X)) ||
(fabs(t.Y) > e.Y + halflength * fabs(linevect.Y)) ||
(fabs(t.Z) > e.Z + halflength * fabs(linevect.Z)))
return false;
T r = e.Y * (T)fabs(linevect.Z) + e.Z * (T)fabs(linevect.Y);
if (fabs(t.Y * linevect.Z - t.Z * linevect.Y) > r)
return false;
r = e.X * (T)fabs(linevect.Z) + e.Z * (T)fabs(linevect.X);
if (fabs(t.Z * linevect.X - t.X * linevect.Z) > r)
return false;
r = e.X * (T)fabs(linevect.Y) + e.Y * (T)fabs(linevect.X);
if (fabs(t.X * linevect.Y - t.Y * linevect.X) > r)
return false;
return true;
}
//! Classifies a relation with a plane.
/** \param plane Plane to classify relation to.
\return Returns ISREL3D_FRONT if the box is in front of the plane,
ISREL3D_BACK if the box is behind the plane, and
ISREL3D_CLIPPED if it is on both sides of the plane. */
EIntersectionRelation3D classifyPlaneRelation(const plane3d<T> &plane) const
{
vector3d<T> nearPoint(MaxEdge);
vector3d<T> farPoint(MinEdge);
if (plane.Normal.X > (T)0) {
nearPoint.X = MinEdge.X;
farPoint.X = MaxEdge.X;
}
if (plane.Normal.Y > (T)0) {
nearPoint.Y = MinEdge.Y;
farPoint.Y = MaxEdge.Y;
}
if (plane.Normal.Z > (T)0) {
nearPoint.Z = MinEdge.Z;
farPoint.Z = MaxEdge.Z;
}
if (plane.Normal.dotProduct(nearPoint) + plane.D > (T)0)
return ISREL3D_FRONT;
if (plane.Normal.dotProduct(farPoint) + plane.D > (T)0)
return ISREL3D_CLIPPED;
return ISREL3D_BACK;
}
//! The near edge
vector3d<T> MinEdge;
//! The far edge
vector3d<T> MaxEdge;
};
//! Typedef for a f32 3d bounding box.
typedef aabbox3d<f32> aabbox3df;
//! Typedef for an integer 3d bounding box.
typedef aabbox3d<s32> aabbox3di;
} // end namespace core
} // end namespace irr