// spheroid
XY s_forward(LP lp)
{
XY xy;
xy.x = xy.y = 0;
double fa;
if (mode)
{
fa = Math.Tan(lp.lam * fxb) * fxa;
}
else
{
fa = 0.5 * lp.lam;
}
if (Math.Abs(lp.phi) < EPS)
{
xy.x = fa + fa;
xy.y = -phi0;
}
else
{
xy.y = 1.0 / Math.Tan(lp.phi);
fa = 2.0 * Math.Atan(fa * Math.Sin(lp.phi));
xy.x = Math.Sin(fa) * xy.y;
xy.y = lp.phi - phi0 + (1.0 - Math.Cos(fa)) * xy.y;
}
return(xy);
}
// general forward projection
// forward projection entry
public static XY pj_fwd(LP lp, PJ P)
{
XY xy;
// check for forward and latitude or longitude overange
double t = Math.Abs(lp.phi) - HALFPI;
if (t > EPS12 || Math.Abs(lp.lam) > 10.0)
{
xy.x = xy.y = Libc.HUGE_VAL;
pj_ctx_set_errno(P.ctx, -14);
return(xy);
}
// proceed with projection
Libc.errno = pj_errno = 0;
P.ctx.last_errno = 0;
if (Math.Abs(t) <= EPS12)
{
lp.phi = lp.phi < 0.0?-HALFPI:HALFPI;
}
else if (P.geoc)
{
lp.phi = Math.Atan(P.rone_es * Math.Tan(lp.phi));
}
lp.lam -= P.lam0; // compute del lp.lam
if (!P.over)
{
lp.lam = adjlon(lp.lam); // adjust del longitude
}
xy = P.fwd(lp); // project
if (P.ctx.last_errno != 0)
{
xy.x = xy.y = Libc.HUGE_VAL;
}
else // adjust for major axis and easting/northings
{
xy.x = P.fr_meter * (P.a * xy.x + P.x0);
xy.y = P.fr_meter * (P.a * xy.y + P.y0);
}
if (pj_errno == 0)
{
pj_errno = Libc.errno;
}
return(xy);
}
// general forward projection
// forward projection entry
public static XY pj_fwd(LP lp, PJ P)
{
XY xy;
// check for forward and latitude or longitude overange
double t=Math.Abs(lp.phi)-HALFPI;
if(t>EPS12||Math.Abs(lp.lam)>10.0)
{
xy.x=xy.y=Libc.HUGE_VAL;
pj_ctx_set_errno(P.ctx, -14);
return xy;
}
// proceed with projection
Libc.errno=pj_errno=0;
P.ctx.last_errno=0;
if(Math.Abs(t)<=EPS12) lp.phi=lp.phi<0.0?-HALFPI:HALFPI;
else if(P.geoc) lp.phi=Math.Atan(P.rone_es*Math.Tan(lp.phi));
lp.lam-=P.lam0; // compute del lp.lam
if(!P.over) lp.lam=adjlon(lp.lam); // adjust del longitude
// Check for NULL pointer
if (P.fwd != null)
{
xy = P.fwd(lp); // project
if (P.ctx.last_errno != 0)
{
xy.x = xy.y = Libc.HUGE_VAL;
}
else // adjust for major axis and easting/northings
{
xy.x = P.fr_meter * (P.a * xy.x + P.x0);
xy.y = P.fr_meter * (P.a * xy.y + P.y0);
}
}
else
{
xy.x = xy.y = Libc.HUGE_VAL;
}
if(pj_errno==0) pj_errno=Libc.errno;
return xy;
}
// spheroid
XY s_forward(LP lp)
{
XY xy;
xy.x=xy.y=0;
double fa;
if(mode) fa=Math.Tan(lp.lam*fxb)*fxa;
else fa=0.5*lp.lam;
if(Math.Abs(lp.phi)<EPS)
{
xy.x=fa+fa;
xy.y=-phi0;
}
else
{
xy.y=1.0/Math.Tan(lp.phi);
fa=2.0*Math.Atan(fa*Math.Sin(lp.phi));
xy.x=Math.Sin(fa)*xy.y;
xy.y=lp.phi-phi0+(1.0-Math.Cos(fa))*xy.y;
}
return xy;
}