public GE_Vector RotateBy(double dRotate)
{
double dLen = Math.Sqrt(m_X * m_X + m_Y * m_Y);
double dAng;
if (Geo.fequ(m_X, 0))
{
if (m_Y > 0)
{
dAng = Math.PI / 2;
}
else if (m_Y < 0)
{
dAng = Math.PI * 1.5;
}
else
{
dAng = 0;
}
}
else
{
dAng = Math.Atan(m_Y / m_X);
}
dAng = dAng + dRotate;
m_X = dLen * Math.Cos(dAng);
m_Y = dLen * Math.Sin(dAng);
return(new GE_Vector(m_X, m_Y));
}
//public double GetAngleTo(GE_Vector vector)
//{
// double dAng1, dAng2;
// if (Geo.fequ(m_X, 0)) { dAng1 = 0; }
// else { dAng1 = Math.Atan(m_Y / m_X); }
// if (Geo.fequ(vector.X, 0)) { dAng2 = 0; }
// else { dAng2 = Math.Atan(vector.Y / vector.X); }
// return Geo.Mid_angle(dAng1, dAng2);
//}
public double GetAngle()
{
double dAngle = 0;
if (Geo.fequ(m_Y, 0))
{
if (m_X >= 0)
{
dAngle = 0;
}
else
{
dAngle = Math.PI;
}
}
else
{
if (Geo.fequ(m_X, 0))
{
if (m_Y > 0)
{
dAngle = Math.PI / 2;
}
else
{
dAngle = Math.PI * 1.5;
}
}
else
{
dAngle = Math.Atan(Math.Abs(m_Y) / Math.Abs(m_X));
if (m_X > 0 && m_Y > 0)
{
//第一象限
}
else if (m_X > 0 && m_Y < 0)
{
//第四象限
dAngle = Math.PI * 2 - dAngle;
}
else if (m_X < 0 && m_Y > 0)
{
//第二象限
dAngle = Math.PI - dAngle;
}
else
{
//第三象限
dAngle = Math.PI + dAngle;
}
}
}
return(dAngle);
}