public Vector2_DW Rotate(Vector2_DW ptBase, double angleDegree)
{
Vector2_DW ptRet = new Vector2_DW();
Vector2_DW vec = this - ptBase;
double angleRadium = ToolsMath_DW.Angle2Radium(angleDegree);
double xOffset = (vec.X * Math.Cos(angleRadium) - vec.Y * Math.Sin(angleRadium));
double yOffset = (vec.X * Math.Sin(angleRadium) + vec.Y * Math.Cos(angleRadium));
ptRet = ptBase + new Vector2_DW(xOffset, yOffset);
return(ptRet);
}
//返回两向量的夹角(角度制)
static public double Angle(Vector3_DW lhs, Vector3_DW rhs)
{
double ll = lhs.Magnitude();
double rl = rhs.Magnitude();
if (ToolsMath_DW.IsZero(ll) || ToolsMath_DW.IsZero(rl))
{
return(0);
}
double angle = Math.Acos((lhs.X * rhs.X + lhs.Y * rhs.Y + lhs.Z * rhs.Z) / (ll * rl));
angle *= (180 / Math.PI);
return(angle);
}
public Vector2_DW Mirror(Vector2_DW lineSt, Vector2_DW lineEnd)
{
Vector2_DW ptRet = new Vector2_DW();
Vector2_DW vecPer = (lineSt - lineEnd);
Vector2_DW vec = new Vector2_DW(-vecPer.Y, vecPer.X);
Vector2_DW ptTmp = new Vector2_DW(this + vec);
Vector2_DW ptIntersect = new Vector2_DW();
if (ToolsMath_DW.LineXLine(this, ptTmp, lineSt, lineEnd, ref ptIntersect) != LineIntersectType.None)
{
ptRet = ptIntersect + ptIntersect - this;
}
return(ptRet);
}
/// <summary>
/// 判断直线段与矩形是否相交(注:当线段全部在矩形内,也认为相交)
/// 1,线段端点是否在矩形内,在,true
/// 2,线段包围框是否和矩形相交,否,false
/// 3,矩形四个顶点是否在线段两侧,在true,不在,false
/// </summary>
/// <param name="lStScreen"></param>
/// <param name="lEndScreen"></param>
/// <param name="bx"></param>
/// <returns></returns>
public static bool LineSegmenXBox(Vector2_DW lStScreen, Vector2_DW lEndScreen, Box2D bx)
{
if (ToolsMath_DW.PtInBox(bx, lStScreen) &&
ToolsMath_DW.PtInBox(bx, lEndScreen))
{
return(true);
}
Box2D bxLine = ToolsMath_DW.GetLineMinBox(lStScreen, lEndScreen);
if (!ToolsMath_DW.BoxXBox(bx, bxLine))
{
return(false);
}
Vector2_DW vecLn = lStScreen - lEndScreen;
Vector2_DW vBxLeftUpper = bx._min - lEndScreen;
Vector2_DW vBxRightTop = (new Vector2_DW(bx._max.X, bx._min.Y)) - lEndScreen;
Vector2_DW vBxRightBtm = bx._max - lEndScreen;
Vector2_DW vBxLeftBtm = (new Vector2_DW(bx._min.X, bx._max.Y)) - lEndScreen;
double f1 = Vector2_DW.Cross(vecLn, vBxLeftUpper);
double f2 = Vector2_DW.Cross(vecLn, vBxRightTop);
double f3 = Vector2_DW.Cross(vecLn, vBxRightBtm);
double f4 = Vector2_DW.Cross(vecLn, vBxLeftBtm);
if ((f1 >= 0 && f2 >= 0 && f3 >= 0 && f4 >= 0)
||
(f1 <= 0 && f2 <= 0 && f3 <= 0 && f4 <= 0))
{
return(false);
}
else
{
return(true);
}
}
//返回两个向量之间的夹角(角度制)(0-180)
static public double Angle(Vector2_DW from, Vector2_DW to)
{
return(Math.Acos(ToolsMath_DW.Clamp(Vector2_DW.Dot(from.Normalize(), to.Normalize()), -1f, 1f)) * 57.29578f);
}
