/* Assigns values to the semimajor axis, semiminor axis, and radius of sphere.
Initializes the forward and/or inverse mapping function. */
int LSsphdz (
char *projection, /* I: projection name string */
float coordinates[8], /* I: general coordinate info */
double *parm, /* I: Projection parameters */
double *radius, /* O: Radius of the sphere */
double corner[2] /* I: UL x,y for UL corner */
)
{
double r_major; /* major axis */
double r_minor; /* minor axis */
double orient; /* orientation */
int ret = 0; /* return code */
long isph; /* spheroid code number also known as datum */
long zone; /* zone code */
/* Initialize global variables for the mapping */
zone = (long) coordinates[4];
isph = (long) coordinates[5];
orient = coordinates[6];
pixel_size = coordinates[7];
sin_orien = sin (orient);
cos_orien = cos (orient);
ul_corner[0] = corner[0];
ul_corner[1] = corner[1];
/* Initialize the variables using GCTP */
ret = sphdz (isph, parm, &r_major, &r_minor, radius);
if (ret != 0)
return (ret);
if (zone == 0)
zone = 31L;
/* Do the forward or inverse transformation setup, depending on whether
inverse is specified */
#ifdef INV
if (!strcmp (projection, "GCTP_UTM"))
ret = utminvint(r_major, r_minor, scale_factor, zone);
else if (!strcmp (projection, "GCTP_PS"))
ret = psinvint(r_major, r_minor, parm[4], parm[5], parm[6], parm[7]);
else if (!strcmp (projection, "GCTP_ALBERS"))
ret = alberinvint(r_major, r_minor, parm[2], parm[3], parm[4], parm[5],
parm[6], parm[7]);
#else
if (!strcmp (projection, "GCTP_UTM"))
ret = utmforint(r_major, r_minor, scale_factor, zone);
else if (!strcmp (projection, "GCTP_PS"))
ret = psforint(r_major, r_minor, parm[4], parm[5], parm[6], parm[7]);
else if (!strcmp (projection, "GCTP_ALBERS"))
ret = alberforint(r_major, r_minor, parm[2], parm[3], parm[4], parm[5],
parm[6], parm[7]);
#endif
return (ret);
}
int gctpc_get_latlon(unsigned char **sec, double **lon, double **lat) {
int gdt;
unsigned char *gds;
double r_maj; /* major axis */
double r_min; /* minor axis */
double lat1; /* first standard parallel */
double lat2; /* second standard parallel */
double c_lon; /* center longitude */
double c_lat; /* center latitude */
double false_east; /* x offset in meters */
double false_north;
double dx, dy;
double x0, y0;
long int (*inv_fn)();
double *llat, *llon, rlon, rlat;
int i, nnx, nny, nres, nscan;
unsigned int nnpnts;
long long_i;
gdt = code_table_3_1(sec);
gds = sec[3];
/* only process certain grids */
if (gdt != 10 && gdt != 20 && gdt != 30 && gdt != 31) return 1;
get_nxny(sec, &nnx, &nny, &nnpnts, &nres, &nscan);
/* potentially staggered */
if (nnx < 1 || nny < 1) return 1;
llat = *lat;
llon = *lon;
if (llat != NULL) {
free(llat);
free(llon);
*lat = *lon = llat = llon = NULL;
}
inv_fn = NULL;
dx = dy = 0.0;
if (gdt == 10) { // mercator
/* get earth axis */
axes_earth(sec, &r_maj, &r_min);
dy = GDS_Mercator_dy(gds);
dx = GDS_Mercator_dx(gds);
/* central point */
c_lon = GDS_Mercator_ori_angle(gds) * (M_PI/180.0);
c_lat = GDS_Mercator_latD(gds) * (M_PI/180.0);
/* find the eastling and northing of of the 1st grid point */
false_east = false_north = 0.0;
long_i = merforint(r_maj,r_min,c_lon,c_lat,false_east,false_north);
rlon = GDS_Mercator_lon1(gds) * (M_PI/180.0);
rlat = GDS_Mercator_lat1(gds) * (M_PI/180.0);
long_i = merfor(rlon, rlat, &x0, &y0);
/* initialize for 1st grid point */
x0 = -x0;
y0 = -y0;
long_i = merinvint(r_maj,r_min,c_lon,c_lat,x0,y0);
inv_fn = &merinv;
}
else if (gdt == 20) { // polar stereographic
/* get earth axis */
axes_earth(sec, &r_maj, &r_min);
dy = GDS_Polar_dy(gds);
dx = GDS_Polar_dx(gds);
/* central point */
c_lon = GDS_Polar_lov(gds) * (M_PI/180.0);
c_lat = GDS_Polar_lad(gds) * (M_PI/180.0);
/* find the eastling and northing of of the 1st grid point */
false_east = false_north = 0.0;
long_i = psforint(r_maj,r_min,c_lon,c_lat,false_east,false_north);
rlon = GDS_Polar_lon1(gds) * (M_PI/180.0);
rlat = GDS_Polar_lat1(gds) * (M_PI/180.0);
long_i = psfor(rlon, rlat, &x0, &y0);
/* initialize for 1st grid point */
x0 = -x0;
y0 = -y0;
long_i = psinvint(r_maj,r_min,c_lon,c_lat,x0,y0);
inv_fn = &psinv;
}
else if (gdt == 30) { // lambert conformal conic
/* get earth axis */
axes_earth(sec, &r_maj, &r_min);
dy = GDS_Lambert_dy(gds);
dx = GDS_Lambert_dx(gds);
//printf(">>> gctpc dx %lf, dy %lf\n", dx, dy);
/* latitudes of tangent/intersection */
lat1 = GDS_Lambert_Latin1(gds) * (M_PI/180.0);
lat2 = GDS_Lambert_Latin2(gds) * (M_PI/180.0);
/* central point */
c_lon = GDS_Lambert_Lov(gds) * (M_PI/180.0);
c_lat = GDS_Lambert_LatD(gds) * (M_PI/180.0);
/* find the eastling and northing of of the 1st grid point */
false_east = false_north = 0.0;
long_i = lamccforint(r_maj,r_min,lat1,lat2,c_lon,c_lat,false_east,false_north);
rlon = GDS_Lambert_Lo1(gds) * (M_PI/180.0);
rlat = GDS_Lambert_La1(gds) * (M_PI/180.0);
long_i = lamccfor(rlon, rlat, &x0, &y0);
/* initialize for 1st grid point */
x0 = -x0;
y0 = -y0;
long_i = lamccinvint(r_maj,r_min,lat1,lat2,c_lon,c_lat,x0,y0);
inv_fn = &lamccinv;
}
else if (gdt == 31) { // albers equal area
/* get earth axis */
axes_earth(sec, &r_maj, &r_min);
dy = GDS_Albers_dy(gds);
dx = GDS_Albers_dx(gds);
/* latitudes of tangent/intersection */
lat1 = GDS_Albers_Latin1(gds) * (M_PI/180.0);
lat2 = GDS_Albers_Latin2(gds) * (M_PI/180.0);
/* central point */
c_lon = GDS_Albers_Lov(gds) * (M_PI/180.0);
c_lat = GDS_Albers_LatD(gds) * (M_PI/180.0);
/* find the eastling and northing of of the 1st grid point */
false_east = false_north = 0.0;
long_i = alberforint(r_maj,r_min,lat1,lat2,c_lon,c_lat,false_east,false_north);
rlon = GDS_Albers_Lo1(gds) * (M_PI/180.0);
rlat = GDS_Albers_La1(gds) * (M_PI/180.0);
long_i = alberfor(rlon, rlat, &x0, &y0);
/* initialize for 1st grid point */
x0 = -x0;
y0 = -y0;
long_i = alberinvint(r_maj,r_min,lat1,lat2,c_lon,c_lat,x0,y0);
inv_fn = &alberinv;
}
if (inv_fn == NULL) return 1;
if ((*lat = llat = (double *) malloc(nnpnts * sizeof(double))) == NULL) {
fatal_error("gctpc_get_latlon memory allocation failed","");
}
if ((*lon = llon = (double *) malloc(nnpnts * sizeof(double))) == NULL) {
fatal_error("gctpc_get_latlon memory allocation failed","");
}
/* put x[] and y[] values in lon and lat */
if (stagger(sec, nnpnts, llon, llat)) fatal_error("gctpc: stagger problem","");
printf(">> stagger gctpc x00 %lf y00 %lf\n",llon[0], llat[0]);
#pragma omp parallel for schedule(static) private(i)
for (i = 0; i < nnpnts; i++) {
inv_fn(llon[i]*dx, llat[i]*dy, llon+i, llat+i);
llat[i] *= (180.0 / M_PI);
llon[i] *= (180.0 / M_PI);
if (llon[i] < 0.0) llon[i] += 360.0;
}
return 0;
}
