+// Convert a cartesian point to a geodetic lat/lon/altitude.
+static naRef f_carttogeod(naContext c, naRef me, int argc, naRef* args)
+{
+ double lat, lon, alt, xyz[3];
+ if(argc != 3) naRuntimeError(c, "carttogeod() expects 3 arguments");
+ for(int i=0; i<3; i++)
+ xyz[i] = naNumValue(args[i]).num;
+ sgCartToGeod(xyz, &lat, &lon, &alt);
+ lat *= SG_RADIANS_TO_DEGREES;
+ lon *= SG_RADIANS_TO_DEGREES;
+ naRef vec = naNewVector(c);
+ naVec_append(vec, naNum(lat));
+ naVec_append(vec, naNum(lon));
+ naVec_append(vec, naNum(alt));
+ return vec;
+}
+
+// Convert a geodetic lat/lon/altitude to a cartesian point.
+static naRef f_geodtocart(naContext c, naRef me, int argc, naRef* args)
+{
+ if(argc != 3) naRuntimeError(c, "geodtocart() expects 3 arguments");
+ double lat = naNumValue(args[0]).num * SG_DEGREES_TO_RADIANS;
+ double lon = naNumValue(args[1]).num * SG_DEGREES_TO_RADIANS;
+ double alt = naNumValue(args[2]).num;
+ double xyz[3];
+ sgGeodToCart(lat, lon, alt, xyz);
+ naRef vec = naNewVector(c);
+ naVec_append(vec, naNum(xyz[0]));
+ naVec_append(vec, naNum(xyz[1]));
+ naVec_append(vec, naNum(xyz[2]));
+ return vec;
+}
+
+// For given geodetic point return array with elevation, and a material data
+// hash, or nil if there's no information available (tile not loaded). If
+// information about the material isn't available, then nil is returned instead
+// of the hash.
+static naRef f_geodinfo(naContext c, naRef me, int argc, naRef* args)
+{
+#define HASHSET(s,l,n) naHash_set(matdata, naStr_fromdata(naNewString(c),s,l),n)
+ if(argc != 2) naRuntimeError(c, "geodinfo() expects 2 arguments: lat, lon");
+ double lat = naNumValue(args[0]).num;
+ double lon = naNumValue(args[1]).num;
+ double elev;
+ const SGMaterial *mat;
+ if(!globals->get_scenery()->get_elevation_m(lat, lon, 10000.0, elev, &mat))
+ return naNil();
+ naRef vec = naNewVector(c);
+ naVec_append(vec, naNum(elev));
+ naRef matdata = naNil();
+ if(mat) {
+ matdata = naNewHash(c);
+ naRef names = naNewVector(c);
+ const vector<string> n = mat->get_names();
+ for(unsigned int i=0; i<n.size(); i++)
+ naVec_append(names, naStr_fromdata(naNewString(c),
+ const_cast<char*>(n[i].c_str()), n[i].size()));
+ HASHSET("names", 5, names);
+ HASHSET("solid", 5, naNum(mat->get_solid()));
+ HASHSET("friction_factor", 15, naNum(mat->get_friction_factor()));
+ HASHSET("rolling_friction", 16, naNum(mat->get_rolling_friction()));
+ HASHSET("load_resistance", 15, naNum(mat->get_load_resistance()));
+ HASHSET("bumpiness", 9, naNum(mat->get_bumpiness()));
+ HASHSET("light_coverage", 14, naNum(mat->get_light_coverage()));
+ }
+ naVec_append(vec, matdata);
+ return vec;
+#undef HASHSET
+}
+