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add geodinfo(<lat>, <lon>) function that returns an array [<elev>, <matdata>]

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or nil if no terrain intersection could be made (tile not loaded yet).
<matdata> is a hash with information about the surface material, or nil
if no material is assigned (shouldn't really happen, but one never knows).

Example:

  var ac = geo.aircraft_position();
  var data = geoddata(ac.lat(), ac.lon());
  debug.dump(data);

  # which outputs
  [ 294.5862574369132, { light_coverage : 0, bumpiness : 0, load_resistance : 1e+30,
  solid : 1, names : [ "pc_taxiway", "dirt_rwytaxiway" ], friction_factor : 1,
  rolling_friction : 0.02 } ]

With this information it can be determined how far an object would sink in,
if the coordinate is on a runway, etc.

  foreach (var n; data[1].names)
      if (string.match(n, "p[ac]_*"))
          im_on_a_runway();
This commit is contained in:
mfranz 2007-06-23 15:25:41 +00:00
parent ee23145936
commit 3461466c81
1 changed files with 43 additions and 3 deletions
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46
src/Scripting/NasalSys.cxx
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@ -19,11 +19,13 @@
#include <simgear/math/sg_random.h>
#include <simgear/misc/sg_path.hxx>
#include <simgear/misc/interpolator.hxx>
#include <simgear/scene/material/mat.hxx>
#include <simgear/structure/commands.hxx>
#include <simgear/math/sg_geodesy.hxx>
#include <Main/globals.hxx>
#include <Main/fg_props.hxx>
#include <Scenery/scenery.hxx>
#include "NasalSys.hxx"
@ -377,8 +379,8 @@ static naRef f_systime(naContext c, naRef me, int argc, naRef* args)
// Convert a cartesian point to a geodetic lat/lon/altitude.
static naRef f_carttogeod(naContext c, naRef me, int argc, naRef* args)
{
const double RAD2DEG = 180.0 / SGD_PI;
double lat, lon, alt, xyz[3];
static const float RAD2DEG = 1./0.0174532925199;
if(argc != 3) naRuntimeError(c, "carttogeod() expects 3 arguments");
for(int i=0; i<3; i++)
xyz[i] = naNumValue(args[i]).num;
@ -392,10 +394,10 @@ static naRef f_carttogeod(naContext c, naRef me, int argc, naRef* args)
return vec;
}
// Convert a cartesian point to a geodetic lat/lon/altitude.
// Convert a geodetic lat/lon/altitude to a cartesian point.
static naRef f_geodtocart(naContext c, naRef me, int argc, naRef* args)
{
static const float DEG2RAD = 0.0174532925199;
const double DEG2RAD = SGD_PI / 180.0;
if(argc != 3) naRuntimeError(c, "geodtocart() expects 3 arguments");
double lat = naNumValue(args[0]).num * DEG2RAD;
double lon = naNumValue(args[1]).num * DEG2RAD;
@ -409,6 +411,43 @@ static naRef f_geodtocart(naContext c, naRef me, int argc, naRef* args)
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
}
// Table of extension functions. Terminate with zeros.
static struct { char* name; naCFunction func; } funcs[] = {
{ "getprop", f_getprop },
@ -426,6 +465,7 @@ static struct { char* name; naCFunction func; } funcs[] = {
{ "systime", f_systime },
{ "carttogeod", f_carttogeod },
{ "geodtocart", f_geodtocart },
{ "geodinfo", f_geodinfo },
{ 0, 0 }
};