Ejemplo n.º 1
0
	bool _stdcall PtIsOnArc( const LLPoint & llArcCenter, double dArcRadius,
		double dArcStartAzimuth, double dArcEndAzimuth, int nArcDirection,
		const LLPoint & llTestPt, int & bOnArc )

	{
		InverseResult invResult;
		if(!DistVincenty(llArcCenter, llTestPt, invResult))
			return false;
		double dDist = invResult.distance;
		double dCrs = invResult.azimuth;

		bOnArc = false;

		if(fabs(dDist - dArcRadius) > 0.5e-3) //Tol())
			bOnArc = false;
		else {
			double dArcExtent = GetArcExtent(dArcStartAzimuth, dArcEndAzimuth, nArcDirection, Tol());

			if(dArcExtent == M_2PI)
				bOnArc = true;
			else
			{
				double dSubExtent = GetArcExtent(dArcStartAzimuth, dCrs, nArcDirection, Tol());

				if(nArcDirection > 0) {
					if(dSubExtent <= dArcExtent)
						bOnArc = true;
				} else {
					if(dSubExtent >= dArcExtent)
						bOnArc = true;
				}
			}		
		}
		return true;
	}
Ejemplo n.º 2
0
    bool PtIsOnArc(const LLPoint &llArcCenter, double dArcRadius,
                   double dArcStartAzimuth, double dArcEndAzimuth, int nArcDirection,
                   const LLPoint &llTestPt, int &bOnArc)
    {
        InverseResult invResult;
        if (!DistVincenty(llArcCenter, llTestPt, invResult))
            return false;

        bOnArc = false;

        if (fabs(invResult.distance - dArcRadius) <= 0.5e-3)
        {
            const double dSubtendedAng1 = GetArcExtent(dArcStartAzimuth, dArcEndAzimuth, nArcDirection, kTol);

            if (dSubtendedAng1 == M_2PI)
                bOnArc = true;
            else
            {
                const double dSubtendedAng2 = GetArcExtent(dArcStartAzimuth, invResult.azimuth,
                                                     nArcDirection, kTol);

                if (nArcDirection > 0)
                {
                    if (dSubtendedAng2 <= dSubtendedAng1)
                        bOnArc = true;
                }
                else
                {
                    if (dSubtendedAng2 >= dSubtendedAng1)
                        bOnArc = true;
                }
            }
        }
        return true;
    }
Ejemplo n.º 3
0
    double DiscretizedArcLength(const LLPoint &center, double dRadius,
                                double dStartCrs, double dEndCrs,
                                int nOrient, int nSegments, double dTol)
    {
        nSegments = clamp(nSegments, 1, 128);

        double dError = 0.0;
        double dArcLength = 0.0;
        double dOldArcLength = 0.0;
        const double dSubtendedAngle = GetArcExtent(dStartCrs, dEndCrs, nOrient, dTol);

        // with k equal to 0 then there will only be nSegments subsegments calculated.
        // need to figure out how to make this flexible based on the value in dRadius.
        // Bigger radius need more segments than 16 and smaller segments need less.
        // For now 16 is enough to pass the 8260.54A test case.
        int k = 0;
        while (k == 0 || ((dError > kTol) && (k <= 0)))
        {
            const double dTheta = dSubtendedAngle / nSegments;
            const double dAltitude = 0.0;
            dArcLength = 0.0;

            for (int i = 0; i < nSegments; i++)
            {
                const double theta = dStartCrs + i * dTheta;
                const LLPoint p1 = DestVincenty(center, theta, dRadius);
                const LLPoint p2 = DestVincenty(center, theta + 0.5 * dTheta, dRadius);
                const LLPoint p3 = DestVincenty(center, theta + dTheta, dRadius);

                const VMath::Vector3 v1 = ECEF(p1, dAltitude);
                const VMath::Vector3 v2 = ECEF(p2, dAltitude);
                const VMath::Vector3 v3 = ECEF(p3, dAltitude);
                const VMath::Vector3 vChord1 = v2 - v1;
                const VMath::Vector3 vChord2 = v2 - v3;
                const double x1 = VMath::Vector3::Length(vChord1); //v2 - v1);
                const double x2 = VMath::Vector3::Length(vChord2); //v2 - v3);
                const double d = VMath::Vector3::Dot(vChord1, vChord2);

                if (IsNearZero(x1, kTol) && IsNearZero(x2, kTol) && IsNearZero(d, kTol))
                {
                    dArcLength = 0.0;
                    break;
                }

                const double xi = d / (x1 * x2);
                const double _x1_x2Sq = x1 / x2 - xi;
                const double sigma = sqrt(1.0 - (xi * xi));
                const double R = (x2 * sqrt((_x1_x2Sq * _x1_x2Sq) + (sigma * sigma))) / (2.0 * sigma);
                const double A = 2 * (M_PI - acos(xi));
                const double L = R * A;
                dArcLength += L;
            }
            nSegments *= 2;
            dError = fabs(dArcLength - dOldArcLength);
            dOldArcLength = dArcLength;
            k++;
        }
        return dArcLength;
    }