Unity如何實(shí)現(xiàn)圖形相交檢測(cè)

/// <summary>
/// 圓形區(qū)間
/// </summary>
public struct CircleArea
 {
 public Vector2 o;
 public float r;
 }

/// <summary>
/// 判斷圓形與圓形相交
/// </summary>
/// <param name="circleArea"></param>
/// <param name="target"></param>
/// <returns></returns>
public static bool Circle(CircleArea circleArea, CircleArea target)
 {
  return (circleArea.o - target.o).sqrMagnitude < (circleArea.r + target.r) * (circleArea.r + target.r);
 }

/// <summary>
/// 線段與點(diǎn)的最短距離。
/// </summary>
/// <param name="x0">線段起點(diǎn)</param>
/// <param name="u">線段向量</param>
/// <param name="x">求解點(diǎn)</param>
/// <returns></returns>
public static float SqrDistanceBetweenSegmentAndPoint(Vector2 x0, Vector2 u, Vector2 x)
 {
 float t = Vector2.Dot(x - x0, u) / u.sqrMagnitude;
 return (x - (x0 + Mathf.Clamp01(t) * u)).sqrMagnitude;
 }

/// <summary>
/// 膠囊體
/// </summary>
 public struct CapsuleArea
 {
 public Vector2 X0;
 public Vector2 U;
 public float d;
 }

/// <summary>
/// 判斷膠囊體與圓形相交
/// </summary>
/// <param name="capsuleArea"></param>
/// <param name="circleArea"></param>
/// <returns></returns>
public static bool Capsule(CapsuleArea capsuleArea, CircleArea circleArea)
 {
  float sqrD = SegmentPointSqrDistance(capsuleArea.X0, capsuleArea.U, circleArea.o);
  return sqrD < (circleArea.r + capsuleArea.d) * (circleArea.r + capsuleArea.d);
 }

/// <summary>
/// 扇形區(qū)間。
/// </summary>
 public struct SectorArea
 {
  public Vector2 o;
  public float r;
  public Vector2 direction;
  public float angle;
 }

/// <summary>
/// 判斷圓形與扇形相交。
/// </summary>
/// <param name="sectorArea"></param>
/// <param name="target"></param>
/// <returns></returns>
  public static bool Sector(SectorArea sectorArea, CircleArea target)
  {
   Vector2 tempDistance = target.o - sectorArea.o;
   float halfAngle = Mathf.Deg2Rad * sectorArea.angle / 2;
   if (tempDistance.sqrMagnitude < (sectorArea.r + target.r) * (sectorArea.r + target.r))
   {
    if (Vector3.Angle(tempDistance, sectorArea.direction) < sectorArea.angle / 2)
    {
     return true;
    }
    else
    {
     Vector2 targetInSectorAxis = new Vector2(Vector2.Dot(tempDistance,
      sectorArea.direction), Mathf.Abs(Vector2.Dot(tempDistance, new Vector2(-sectorArea.direction.y, sectorArea.direction.x))));
     Vector2 directionInSectorAxis = sectorArea.r * new Vector2(Mathf.Cos(halfAngle), Mathf.Sin(halfAngle));
     return SegmentPointSqrDistance(Vector2.zero, directionInSectorAxis, targetInSectorAxis) <= target.r * target.r;
    }
   }
   return false;
  }

/// <summary>
/// 多邊形區(qū)域。
/// </summary>
public struct PolygonArea
 {
  public Vector2[] vertexes;
 }

/// <summary>
/// 判斷多邊形與圓形相交
/// </summary>
/// <param name="polygonArea"></param>
/// <param name="target"></param>
/// <returns></returns>
public static bool PolygonS(PolygonArea polygonArea, CircleArea target)
  {
   if (polygonArea.vertexes.Length < 3)
   {
    Debug.Log("多邊形邊數(shù)小于3.");
    return false;
   }
   #region 定義臨時(shí)變量
   //圓心
   Vector2 circleCenter = target.o;
   //半徑的平方
   float sqrR = target.r * target.r;
   //多邊形頂點(diǎn)
   Vector2[] polygonVertexes = polygonArea.vertexes;
   //圓心指向頂點(diǎn)的向量數(shù)組
   Vector2[] directionBetweenCenterAndVertexes = new Vector2[polygonArea.vertexes.Length];
   //多邊形的邊
   Vector2[] polygonEdges = new Vector2[polygonArea.vertexes.Length];
   for (int i = 0; i < polygonArea.vertexes.Length; i++)
   {
    directionBetweenCenterAndVertexes[i] = polygonVertexes[i] - circleCenter;
    polygonEdges[i] = polygonVertexes[i] - polygonVertexes[(i + 1)% polygonArea.vertexes.Length];
   }
   #endregion
 
   #region 以下為圓心處于多邊形內(nèi)的判斷。
   //總夾角
   float totalAngle = Vector2.SignedAngle(directionBetweenCenterAndVertexes[polygonVertexes.Length - 1], directionBetweenCenterAndVertexes[0]);
   for (int i = 0; i < polygonVertexes.Length - 1; i++)
    totalAngle += Vector2.SignedAngle(directionBetweenCenterAndVertexes[i], directionBetweenCenterAndVertexes[i + 1]);
   if (Mathf.Abs(Mathf.Abs(totalAngle) - 360f) < 0.1f)
    return true;
   #endregion
   #region 以下為多邊形的邊與圓形相交的判斷。
   for (int i = 0; i < polygonEdges.Length; i++)
    if (SegmentPointSqrDistance(polygonVertexes[i], polygonEdges[i], circleCenter) < sqrR)
     return true;
   #endregion
   return false;
  }

/// <summary>
/// AABB區(qū)域
/// </summary>
public struct AABBArea
 {
  public Vector2 center;
  public Vector2 extents;
 }

/// <summary>
/// 判斷AABB與圓形相交
/// </summary>
/// <param name="aABBArea"></param>
/// <param name="target"></param>
/// <returns></returns>
public static bool AABB(AABBArea aABBArea, CircleArea target)
  {
   Vector2 v = Vector2.Max(aABBArea.center - target.o, -(aABBArea.center - target.o));
   Vector2 u = Vector2.Max(v - aABBArea.extents,Vector2.zero);
   return u.sqrMagnitude < target.r * target.r;
  }

/// <summary>
/// OBB區(qū)域
/// </summary>
public struct OBBArea
 {
  public Vector2 center;
  public Vector2 extents;
  public float angle;
 }

/// <summary>
/// 判斷OBB與圓形相交
/// </summary>
/// <param name="oBBArea"></param>
/// <param name="target"></param>
/// <returns></returns>
public static bool OBB(OBBArea oBBArea, CircleArea target)
  {
   Vector2 p = oBBArea.center - target.o;
   p = Quaternion.AngleAxis(-oBBArea.angle, Vector3.forward) * p;
   Vector2 v = Vector2.Max(p, -p);
   Vector2 u = Vector2.Max(v - oBBArea.extents, Vector2.zero);
   return u.sqrMagnitude < target.r * target.r;
  }