project_pt()

int project_pt	(	const POINT2D *	P,
		double	distance,
		double	azimuth,
		POINT2D *	R
	)

Azimuth is angle in radians from vertical axis.

Definition at line 2421 of file measures.c.

{
        const double TWOPI = 2.0 * M_PI;
        double slope;
        /* Deal with azimuth out of (-360,360) range */
        int orbits = floor(azimuth / TWOPI);
        azimuth -= TWOPI * orbits;
        /* Convert from azimuth to conventional slope */
        slope = TWOPI - azimuth + M_PI_2;
        if (slope > 0 && slope >  TWOPI) slope -= TWOPI;
        if (slope < 0 && slope < -TWOPI) slope += TWOPI;
 
        double dx = cos(slope) * distance;
        double dy = sin(slope) * distance;
        R->x = P->x + dx;
        R->y = P->y + dy;
        return LW_TRUE;
}

References distance(), LW_TRUE, POINT2D::x, and POINT2D::y.

Referenced by lwpoint_project().

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