/// <summary>
/// OBB之间是否接触
/// </summary>
public static bool IsContacted(OBB obb1, OBB obb2)
{
bool rect1Torect2IsContact = false;
bool rect2Torect1IsContact = false;
rect1Torect2IsContact = IsContact(obb1, obb2);
rect2Torect1IsContact = IsContact(obb2, obb1);
if (rect1Torect2IsContact == true &&
rect2Torect1IsContact == true)
{
return true;
}
return false;
}
/// <summary>
/// 构造OBB，OBB必须比AABB小！
/// </summary>
public void StructureOBB(Vector2 dir, float width, float height)
{
Obb = new OBB(new Vector2(X, Y), dir, width, height);
}
// 使用一个矩形的4条边作候选分离轴
static bool IsContact(OBB obb1, OBB obb2)
{
bool isInLine1 = false;
bool isInLine2 = false;
bool isInLine3 = false;
bool isInLine4 = false;
Vector2 line1p1 = obb1.GetPoints()[0];
Vector2 line1p2 = obb1.GetPoints()[1];
isInLine1 = RectAllPointIsInLine(line1p1, line1p2, obb2);
Vector2 line2p1 = obb1.GetPoints()[1];
Vector2 line2p2 = obb1.GetPoints()[2];
isInLine2 = RectAllPointIsInLine(line2p1, line2p2, obb2);
Vector2 line3p1 = obb1.GetPoints()[2];
Vector2 line3p2 = obb1.GetPoints()[3];
isInLine3 = RectAllPointIsInLine(line3p1, line3p2, obb2);
Vector2 line4p1 = obb1.GetPoints()[3];
Vector2 line4p2 = obb1.GetPoints()[0];
isInLine4 = RectAllPointIsInLine(line4p1, line4p2, obb2);
if (isInLine1 == true && isInLine2 == true &&
isInLine3 == true && isInLine4 == true)
{//全部边都满足 投影相交
return true;
}
return false;
}
//判断4个投影点有没有与指定线段相交
static bool RectAllPointIsInLine(Vector2 linep1, Vector2 linep2, OBB obb2)
{
//获取rect4的4个投影点
Vector2 pointPro1 = GetProjectionPoint(linep1, linep2, obb2.GetPoints()[0]);
Vector2 pointPro2 = GetProjectionPoint(linep1, linep2, obb2.GetPoints()[1]);
Vector2 pointPro3 = GetProjectionPoint(linep1, linep2, obb2.GetPoints()[2]);
Vector2 pointPro4 = GetProjectionPoint(linep1, linep2, obb2.GetPoints()[3]);
//根据line 的斜率选择映射到X/Y轴来计算
float k = (linep2.Y - linep1.Y) / (linep2.X - linep1.X);
#region ……
if (k > -0.25f && k <= 0.25)
{
//映射到X轴
List<float> rectPX = new List<float>();
rectPX.Add(pointPro1.X);
rectPX.Add(pointPro2.X);
rectPX.Add(pointPro3.X);
rectPX.Add(pointPro4.X);
return PointIsInLineSegment(linep1.X, linep2.X, rectPX);
}
else
{
//映射到Y轴
List<float> rectPY = new List<float>();
rectPY.Add(pointPro1.Y);
rectPY.Add(pointPro2.Y);
rectPY.Add(pointPro3.Y);
rectPY.Add(pointPro4.Y);
return PointIsInLineSegment(linep1.Y, linep2.Y, rectPY);
}
#endregion
}
/// <summary>
/// 构造OBB，OBB必须比AABB小！
/// </summary>
public void StructureOBB(Vector2 dir, float width, float height)
{
Obb = new OBB(new Vector2(X,Y), dir, width, height);
}