godot/modules/mono/glue/GodotSharp/GodotSharp/Core/AABB.cs
2021-09-21 21:14:17 +05:45

743 lines
26 KiB
C#

#if REAL_T_IS_DOUBLE
using real_t = System.Double;
#else
using real_t = System.Single;
#endif
using System;
using System.Runtime.InteropServices;
namespace Godot
{
/// <summary>
/// Axis-Aligned Bounding Box. AABB consists of a position, a size, and
/// several utility functions. It is typically used for fast overlap tests.
/// </summary>
[Serializable]
[StructLayout(LayoutKind.Sequential)]
public struct AABB : IEquatable<AABB>
{
private Vector3 _position;
private Vector3 _size;
/// <summary>
/// Beginning corner. Typically has values lower than <see cref="End"/>.
/// </summary>
/// <value>Directly uses a private field.</value>
public Vector3 Position
{
get { return _position; }
set { _position = value; }
}
/// <summary>
/// Size from <see cref="Position"/> to <see cref="End"/>. Typically all components are positive.
/// If the size is negative, you can use <see cref="Abs"/> to fix it.
/// </summary>
/// <value>Directly uses a private field.</value>
public Vector3 Size
{
get { return _size; }
set { _size = value; }
}
/// <summary>
/// Ending corner. This is calculated as <see cref="Position"/> plus
/// <see cref="Size"/>. Setting this value will change the size.
/// </summary>
/// <value>
/// Getting is equivalent to <paramref name="value"/> = <see cref="Position"/> + <see cref="Size"/>,
/// setting is equivalent to <see cref="Size"/> = <paramref name="value"/> - <see cref="Position"/>
/// </value>
public Vector3 End
{
get { return _position + _size; }
set { _size = value - _position; }
}
/// <summary>
/// Returns an <see cref="AABB"/> with equivalent position and size, modified so that
/// the most-negative corner is the origin and the size is positive.
/// </summary>
/// <returns>The modified <see cref="AABB"/>.</returns>
public AABB Abs()
{
Vector3 end = End;
Vector3 topLeft = new Vector3(Mathf.Min(_position.x, end.x), Mathf.Min(_position.y, end.y), Mathf.Min(_position.z, end.z));
return new AABB(topLeft, _size.Abs());
}
/// <summary>
/// Returns the center of the <see cref="AABB"/>, which is equal
/// to <see cref="Position"/> + (<see cref="Size"/> / 2).
/// </summary>
/// <returns>The center.</returns>
public Vector3 GetCenter()
{
return _position + (_size * 0.5f);
}
/// <summary>
/// Returns <see langword="true"/> if this <see cref="AABB"/> completely encloses another one.
/// </summary>
/// <param name="with">The other <see cref="AABB"/> that may be enclosed.</param>
/// <returns>
/// A <see langword="bool"/> for whether or not this <see cref="AABB"/> encloses <paramref name="with"/>.
/// </returns>
public bool Encloses(AABB with)
{
Vector3 srcMin = _position;
Vector3 srcMax = _position + _size;
Vector3 dstMin = with._position;
Vector3 dstMax = with._position + with._size;
return srcMin.x <= dstMin.x &&
srcMax.x > dstMax.x &&
srcMin.y <= dstMin.y &&
srcMax.y > dstMax.y &&
srcMin.z <= dstMin.z &&
srcMax.z > dstMax.z;
}
/// <summary>
/// Returns this <see cref="AABB"/> expanded to include a given point.
/// </summary>
/// <param name="point">The point to include.</param>
/// <returns>The expanded <see cref="AABB"/>.</returns>
public AABB Expand(Vector3 point)
{
Vector3 begin = _position;
Vector3 end = _position + _size;
if (point.x < begin.x)
{
begin.x = point.x;
}
if (point.y < begin.y)
{
begin.y = point.y;
}
if (point.z < begin.z)
{
begin.z = point.z;
}
if (point.x > end.x)
{
end.x = point.x;
}
if (point.y > end.y)
{
end.y = point.y;
}
if (point.z > end.z)
{
end.z = point.z;
}
return new AABB(begin, end - begin);
}
/// <summary>
/// Returns the area of the <see cref="AABB"/>.
/// </summary>
/// <returns>The area.</returns>
public real_t GetArea()
{
return _size.x * _size.y * _size.z;
}
/// <summary>
/// Gets the position of one of the 8 endpoints of the <see cref="AABB"/>.
/// </summary>
/// <param name="idx">Which endpoint to get.</param>
/// <returns>An endpoint of the <see cref="AABB"/>.</returns>
public Vector3 GetEndpoint(int idx)
{
switch (idx)
{
case 0:
return new Vector3(_position.x, _position.y, _position.z);
case 1:
return new Vector3(_position.x, _position.y, _position.z + _size.z);
case 2:
return new Vector3(_position.x, _position.y + _size.y, _position.z);
case 3:
return new Vector3(_position.x, _position.y + _size.y, _position.z + _size.z);
case 4:
return new Vector3(_position.x + _size.x, _position.y, _position.z);
case 5:
return new Vector3(_position.x + _size.x, _position.y, _position.z + _size.z);
case 6:
return new Vector3(_position.x + _size.x, _position.y + _size.y, _position.z);
case 7:
return new Vector3(_position.x + _size.x, _position.y + _size.y, _position.z + _size.z);
default:
{
throw new ArgumentOutOfRangeException(nameof(idx),
$"Index is {idx}, but a value from 0 to 7 is expected.");
}
}
}
/// <summary>
/// Returns the normalized longest axis of the <see cref="AABB"/>.
/// </summary>
/// <returns>A vector representing the normalized longest axis of the <see cref="AABB"/>.</returns>
public Vector3 GetLongestAxis()
{
var axis = new Vector3(1f, 0f, 0f);
real_t maxSize = _size.x;
if (_size.y > maxSize)
{
axis = new Vector3(0f, 1f, 0f);
maxSize = _size.y;
}
if (_size.z > maxSize)
{
axis = new Vector3(0f, 0f, 1f);
}
return axis;
}
/// <summary>
/// Returns the <see cref="Vector3.Axis"/> index of the longest axis of the <see cref="AABB"/>.
/// </summary>
/// <returns>A <see cref="Vector3.Axis"/> index for which axis is longest.</returns>
public Vector3.Axis GetLongestAxisIndex()
{
var axis = Vector3.Axis.X;
real_t maxSize = _size.x;
if (_size.y > maxSize)
{
axis = Vector3.Axis.Y;
maxSize = _size.y;
}
if (_size.z > maxSize)
{
axis = Vector3.Axis.Z;
}
return axis;
}
/// <summary>
/// Returns the scalar length of the longest axis of the <see cref="AABB"/>.
/// </summary>
/// <returns>The scalar length of the longest axis of the <see cref="AABB"/>.</returns>
public real_t GetLongestAxisSize()
{
real_t maxSize = _size.x;
if (_size.y > maxSize)
maxSize = _size.y;
if (_size.z > maxSize)
maxSize = _size.z;
return maxSize;
}
/// <summary>
/// Returns the normalized shortest axis of the <see cref="AABB"/>.
/// </summary>
/// <returns>A vector representing the normalized shortest axis of the <see cref="AABB"/>.</returns>
public Vector3 GetShortestAxis()
{
var axis = new Vector3(1f, 0f, 0f);
real_t maxSize = _size.x;
if (_size.y < maxSize)
{
axis = new Vector3(0f, 1f, 0f);
maxSize = _size.y;
}
if (_size.z < maxSize)
{
axis = new Vector3(0f, 0f, 1f);
}
return axis;
}
/// <summary>
/// Returns the <see cref="Vector3.Axis"/> index of the shortest axis of the <see cref="AABB"/>.
/// </summary>
/// <returns>A <see cref="Vector3.Axis"/> index for which axis is shortest.</returns>
public Vector3.Axis GetShortestAxisIndex()
{
var axis = Vector3.Axis.X;
real_t maxSize = _size.x;
if (_size.y < maxSize)
{
axis = Vector3.Axis.Y;
maxSize = _size.y;
}
if (_size.z < maxSize)
{
axis = Vector3.Axis.Z;
}
return axis;
}
/// <summary>
/// Returns the scalar length of the shortest axis of the <see cref="AABB"/>.
/// </summary>
/// <returns>The scalar length of the shortest axis of the <see cref="AABB"/>.</returns>
public real_t GetShortestAxisSize()
{
real_t maxSize = _size.x;
if (_size.y < maxSize)
maxSize = _size.y;
if (_size.z < maxSize)
maxSize = _size.z;
return maxSize;
}
/// <summary>
/// Returns the support point in a given direction.
/// This is useful for collision detection algorithms.
/// </summary>
/// <param name="dir">The direction to find support for.</param>
/// <returns>A vector representing the support.</returns>
public Vector3 GetSupport(Vector3 dir)
{
Vector3 halfExtents = _size * 0.5f;
Vector3 ofs = _position + halfExtents;
return ofs + new Vector3(
dir.x > 0f ? -halfExtents.x : halfExtents.x,
dir.y > 0f ? -halfExtents.y : halfExtents.y,
dir.z > 0f ? -halfExtents.z : halfExtents.z);
}
/// <summary>
/// Returns a copy of the <see cref="AABB"/> grown a given amount of units towards all the sides.
/// </summary>
/// <param name="by">The amount to grow by.</param>
/// <returns>The grown <see cref="AABB"/>.</returns>
public AABB Grow(real_t by)
{
AABB res = this;
res._position.x -= by;
res._position.y -= by;
res._position.z -= by;
res._size.x += 2.0f * by;
res._size.y += 2.0f * by;
res._size.z += 2.0f * by;
return res;
}
/// <summary>
/// Returns <see langword="true"/> if the <see cref="AABB"/> is flat or empty,
/// or <see langword="false"/> otherwise.
/// </summary>
/// <returns>
/// A <see langword="bool"/> for whether or not the <see cref="AABB"/> has area.
/// </returns>
public bool HasNoArea()
{
return _size.x <= 0f || _size.y <= 0f || _size.z <= 0f;
}
/// <summary>
/// Returns <see langword="true"/> if the <see cref="AABB"/> has no surface (no size),
/// or <see langword="false"/> otherwise.
/// </summary>
/// <returns>
/// A <see langword="bool"/> for whether or not the <see cref="AABB"/> has area.
/// </returns>
public bool HasNoSurface()
{
return _size.x <= 0f && _size.y <= 0f && _size.z <= 0f;
}
/// <summary>
/// Returns <see langword="true"/> if the <see cref="AABB"/> contains a point,
/// or <see langword="false"/> otherwise.
/// </summary>
/// <param name="point">The point to check.</param>
/// <returns>
/// A <see langword="bool"/> for whether or not the <see cref="AABB"/> contains <paramref name="point"/>.
/// </returns>
public bool HasPoint(Vector3 point)
{
if (point.x < _position.x)
return false;
if (point.y < _position.y)
return false;
if (point.z < _position.z)
return false;
if (point.x > _position.x + _size.x)
return false;
if (point.y > _position.y + _size.y)
return false;
if (point.z > _position.z + _size.z)
return false;
return true;
}
/// <summary>
/// Returns the intersection of this <see cref="AABB"/> and <paramref name="with"/>.
/// </summary>
/// <param name="with">The other <see cref="AABB"/>.</param>
/// <returns>The clipped <see cref="AABB"/>.</returns>
public AABB Intersection(AABB with)
{
Vector3 srcMin = _position;
Vector3 srcMax = _position + _size;
Vector3 dstMin = with._position;
Vector3 dstMax = with._position + with._size;
Vector3 min, max;
if (srcMin.x > dstMax.x || srcMax.x < dstMin.x)
{
return new AABB();
}
min.x = srcMin.x > dstMin.x ? srcMin.x : dstMin.x;
max.x = srcMax.x < dstMax.x ? srcMax.x : dstMax.x;
if (srcMin.y > dstMax.y || srcMax.y < dstMin.y)
{
return new AABB();
}
min.y = srcMin.y > dstMin.y ? srcMin.y : dstMin.y;
max.y = srcMax.y < dstMax.y ? srcMax.y : dstMax.y;
if (srcMin.z > dstMax.z || srcMax.z < dstMin.z)
{
return new AABB();
}
min.z = srcMin.z > dstMin.z ? srcMin.z : dstMin.z;
max.z = srcMax.z < dstMax.z ? srcMax.z : dstMax.z;
return new AABB(min, max - min);
}
/// <summary>
/// Returns <see langword="true"/> if the <see cref="AABB"/> overlaps with <paramref name="with"/>
/// (i.e. they have at least one point in common).
///
/// If <paramref name="includeBorders"/> is <see langword="true"/>,
/// they will also be considered overlapping if their borders touch,
/// even without intersection.
/// </summary>
/// <param name="with">The other <see cref="AABB"/> to check for intersections with.</param>
/// <param name="includeBorders">Whether or not to consider borders.</param>
/// <returns>
/// A <see langword="bool"/> for whether or not they are intersecting.
/// </returns>
public bool Intersects(AABB with, bool includeBorders = false)
{
if (includeBorders)
{
if (_position.x > with._position.x + with._size.x)
return false;
if (_position.x + _size.x < with._position.x)
return false;
if (_position.y > with._position.y + with._size.y)
return false;
if (_position.y + _size.y < with._position.y)
return false;
if (_position.z > with._position.z + with._size.z)
return false;
if (_position.z + _size.z < with._position.z)
return false;
}
else
{
if (_position.x >= with._position.x + with._size.x)
return false;
if (_position.x + _size.x <= with._position.x)
return false;
if (_position.y >= with._position.y + with._size.y)
return false;
if (_position.y + _size.y <= with._position.y)
return false;
if (_position.z >= with._position.z + with._size.z)
return false;
if (_position.z + _size.z <= with._position.z)
return false;
}
return true;
}
/// <summary>
/// Returns <see langword="true"/> if the <see cref="AABB"/> is on both sides of <paramref name="plane"/>.
/// </summary>
/// <param name="plane">The <see cref="Plane"/> to check for intersection.</param>
/// <returns>
/// A <see langword="bool"/> for whether or not the <see cref="AABB"/> intersects the <see cref="Plane"/>.
/// </returns>
public bool IntersectsPlane(Plane plane)
{
Vector3[] points =
{
new Vector3(_position.x, _position.y, _position.z),
new Vector3(_position.x, _position.y, _position.z + _size.z),
new Vector3(_position.x, _position.y + _size.y, _position.z),
new Vector3(_position.x, _position.y + _size.y, _position.z + _size.z),
new Vector3(_position.x + _size.x, _position.y, _position.z),
new Vector3(_position.x + _size.x, _position.y, _position.z + _size.z),
new Vector3(_position.x + _size.x, _position.y + _size.y, _position.z),
new Vector3(_position.x + _size.x, _position.y + _size.y, _position.z + _size.z)
};
bool over = false;
bool under = false;
for (int i = 0; i < 8; i++)
{
if (plane.DistanceTo(points[i]) > 0)
{
over = true;
}
else
{
under = true;
}
}
return under && over;
}
/// <summary>
/// Returns <see langword="true"/> if the <see cref="AABB"/> intersects
/// the line segment between <paramref name="from"/> and <paramref name="to"/>.
/// </summary>
/// <param name="from">The start of the line segment.</param>
/// <param name="to">The end of the line segment.</param>
/// <returns>
/// A <see langword="bool"/> for whether or not the <see cref="AABB"/> intersects the line segment.
/// </returns>
public bool IntersectsSegment(Vector3 from, Vector3 to)
{
real_t min = 0f;
real_t max = 1f;
for (int i = 0; i < 3; i++)
{
real_t segFrom = from[i];
real_t segTo = to[i];
real_t boxBegin = _position[i];
real_t boxEnd = boxBegin + _size[i];
real_t cmin, cmax;
if (segFrom < segTo)
{
if (segFrom > boxEnd || segTo < boxBegin)
{
return false;
}
real_t length = segTo - segFrom;
cmin = segFrom < boxBegin ? (boxBegin - segFrom) / length : 0f;
cmax = segTo > boxEnd ? (boxEnd - segFrom) / length : 1f;
}
else
{
if (segTo > boxEnd || segFrom < boxBegin)
{
return false;
}
real_t length = segTo - segFrom;
cmin = segFrom > boxEnd ? (boxEnd - segFrom) / length : 0f;
cmax = segTo < boxBegin ? (boxBegin - segFrom) / length : 1f;
}
if (cmin > min)
{
min = cmin;
}
if (cmax < max)
{
max = cmax;
}
if (max < min)
{
return false;
}
}
return true;
}
/// <summary>
/// Returns a larger <see cref="AABB"/> that contains this <see cref="AABB"/> and <paramref name="with"/>.
/// </summary>
/// <param name="with">The other <see cref="AABB"/>.</param>
/// <returns>The merged <see cref="AABB"/>.</returns>
public AABB Merge(AABB with)
{
Vector3 beg1 = _position;
Vector3 beg2 = with._position;
var end1 = new Vector3(_size.x, _size.y, _size.z) + beg1;
var end2 = new Vector3(with._size.x, with._size.y, with._size.z) + beg2;
var min = new Vector3(
beg1.x < beg2.x ? beg1.x : beg2.x,
beg1.y < beg2.y ? beg1.y : beg2.y,
beg1.z < beg2.z ? beg1.z : beg2.z
);
var max = new Vector3(
end1.x > end2.x ? end1.x : end2.x,
end1.y > end2.y ? end1.y : end2.y,
end1.z > end2.z ? end1.z : end2.z
);
return new AABB(min, max - min);
}
/// <summary>
/// Constructs an <see cref="AABB"/> from a position and size.
/// </summary>
/// <param name="position">The position.</param>
/// <param name="size">The size, typically positive.</param>
public AABB(Vector3 position, Vector3 size)
{
_position = position;
_size = size;
}
/// <summary>
/// Constructs an <see cref="AABB"/> from a <paramref name="position"/>,
/// <paramref name="width"/>, <paramref name="height"/>, and <paramref name="depth"/>.
/// </summary>
/// <param name="position">The position.</param>
/// <param name="width">The width, typically positive.</param>
/// <param name="height">The height, typically positive.</param>
/// <param name="depth">The depth, typically positive.</param>
public AABB(Vector3 position, real_t width, real_t height, real_t depth)
{
_position = position;
_size = new Vector3(width, height, depth);
}
/// <summary>
/// Constructs an <see cref="AABB"/> from <paramref name="x"/>,
/// <paramref name="y"/>, <paramref name="z"/>, and <paramref name="size"/>.
/// </summary>
/// <param name="x">The position's X coordinate.</param>
/// <param name="y">The position's Y coordinate.</param>
/// <param name="z">The position's Z coordinate.</param>
/// <param name="size">The size, typically positive.</param>
public AABB(real_t x, real_t y, real_t z, Vector3 size)
{
_position = new Vector3(x, y, z);
_size = size;
}
/// <summary>
/// Constructs an <see cref="AABB"/> from <paramref name="x"/>,
/// <paramref name="y"/>, <paramref name="z"/>, <paramref name="width"/>,
/// <paramref name="height"/>, and <paramref name="depth"/>.
/// </summary>
/// <param name="x">The position's X coordinate.</param>
/// <param name="y">The position's Y coordinate.</param>
/// <param name="z">The position's Z coordinate.</param>
/// <param name="width">The width, typically positive.</param>
/// <param name="height">The height, typically positive.</param>
/// <param name="depth">The depth, typically positive.</param>
public AABB(real_t x, real_t y, real_t z, real_t width, real_t height, real_t depth)
{
_position = new Vector3(x, y, z);
_size = new Vector3(width, height, depth);
}
public static bool operator ==(AABB left, AABB right)
{
return left.Equals(right);
}
public static bool operator !=(AABB left, AABB right)
{
return !left.Equals(right);
}
/// <summary>
/// Returns <see langword="true"/> if this AABB and <paramref name="obj"/> are equal.
/// </summary>
/// <param name="obj">The other object to compare.</param>
/// <returns>Whether or not the AABB structure and the other object are equal.</returns>
public override bool Equals(object obj)
{
if (obj is AABB)
{
return Equals((AABB)obj);
}
return false;
}
/// <summary>
/// Returns <see langword="true"/> if this AABB and <paramref name="other"/> are equal
/// </summary>
/// <param name="other">The other AABB to compare.</param>
/// <returns>Whether or not the AABBs are equal.</returns>
public bool Equals(AABB other)
{
return _position == other._position && _size == other._size;
}
/// <summary>
/// Returns <see langword="true"/> if this AABB and <paramref name="other"/> are approximately equal,
/// by running <see cref="Vector3.IsEqualApprox(Vector3)"/> on each component.
/// </summary>
/// <param name="other">The other AABB to compare.</param>
/// <returns>Whether or not the AABBs structures are approximately equal.</returns>
public bool IsEqualApprox(AABB other)
{
return _position.IsEqualApprox(other._position) && _size.IsEqualApprox(other._size);
}
/// <summary>
/// Serves as the hash function for <see cref="AABB"/>.
/// </summary>
/// <returns>A hash code for this AABB.</returns>
public override int GetHashCode()
{
return _position.GetHashCode() ^ _size.GetHashCode();
}
/// <summary>
/// Converts this <see cref="AABB"/> to a string.
/// </summary>
/// <returns>A string representation of this AABB.</returns>
public override string ToString()
{
return $"{_position}, {_size}";
}
/// <summary>
/// Converts this <see cref="AABB"/> to a string with the given <paramref name="format"/>.
/// </summary>
/// <returns>A string representation of this AABB.</returns>
public string ToString(string format)
{
return $"{_position.ToString(format)}, {_size.ToString(format)}";
}
}
}