Talk:Canvas snippets: Difference between revisions

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Talk:Canvas snippets (view source)

Revision as of 02:08, 16 April 2015

5,226 bytes added ,  16 April 2015
m
→‎Orbital Map: http://forum.flightgear.org/viewtopic.php?f=75&t=25480&p=239076#p238962
m (→‎Orbital Map: http://forum.flightgear.org/viewtopic.php?f=75&t=25480&p=239076#p238962)
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<syntaxhighlight lang="nasal">
{{FGCquote
var sym_shuttle = {};
  |In case you people are still interested - this may be useful (world map with historic and predicted groundtrack, showing landing site and spacecraft position) and could be adapted to your mission control. Code is posted below, you need to supply inclination and orbital period - just use standard orbital dynamics formulae from Wikipedia. No warranties.
  |{{cite web |url=http://forum.flightgear.org/viewtopic.php?p=238962#p238962
    |title=<nowiki>Re: OpenRadar special use for especific space missions</nowiki>
    |author=<nowiki>Thorsten</nowiki>
    |date=<nowiki>Wed Apr 15</nowiki>
  }}
}}
 
<syntaxhighlight lang="nasal">var sym_shuttle = {};
var sym_landing_site = {};
var sym_landing_site = {};
var graph = {};
var samples = [];
var history = [];
var track_prediction = [];
var update_loop_flag = 0;
var lat_to_m = 110952.0; # latitude degrees to meters
var m_to_lat = 9.01290648208234e-06; # meters to latitude degrees
var lon_to_m = 0.0; # needs to be calculated dynamically
var m_to_lon = 0.0; # we do this on startup
var delete_from_vector = func(vec, index) {
var n = index+1;
var vec_end = subvec(vec, n);
setsize(vec, n-1);
return vec~vec_end; 
}
var calc_geo = func(lat) {
lon_to_m  = math.cos(lat*math.pi/180.0) * lat_to_m;
m_to_lon = 1.0/lon_to_m;
}
var lat_to_y = func (lat) {
return 200.0 - lat /90. * 200.0;
}
var lon_to_x = func (lon) {
return 400.0 + lon /180. * 400.0;
}


var create_map = func {
var create_map = func {


var window = canvas.Window.new([800,400],"dialog");
var window = canvas.Window.new([800,400],"dialog").set("title", "Trajectory Map");
 
# we need to explicitly re-define this to get a handle to stop the update loop
# upon closing the window
 
window.del = func()
{
  #print("Cleaning up...\n");
  update_loop_flag = 0;
  call(canvas.Window.del, [], me);
};
 
 
var mapCanvas = window.createCanvas().set("background", canvas.style.getColor("bg_color"));
var mapCanvas = window.createCanvas().set("background", canvas.style.getColor("bg_color"));
var root = mapCanvas.createGroup();
var root = mapCanvas.createGroup();


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canvas.parsesvg(sym_landing_site, "/gui/dialogs/images/ndb_symbol.svg");
canvas.parsesvg(sym_landing_site, "/gui/dialogs/images/ndb_symbol.svg");
sym_landing_site.setScale(0.6);
sym_landing_site.setScale(0.6);
graph = root.createChild("group");




update_loop_flag = 1;
map_update();
map_update();


}
}
Line 153: Line 221:
var map_update = func {
var map_update = func {


if (update_loop_flag == 0 ) {return;}


var lat = getprop("/position/latitude-deg");
var lat = getprop("/position/latitude-deg");
var lon = getprop("/position/longitude-deg");
var lon = getprop("/position/longitude-deg");


var x = 400.0 + lon /180. * 400.0 -10.0;
var x = lon_to_x(lon);
var y = 200.0 - lat /90. * 200.0 -10.0;
var y = lat_to_y(lat);


var heading = getprop("/orientation/heading-deg");
 
var heading = getprop("/orientation/heading-deg") * 3.1415/180.0;


sym_shuttle.setTranslation(x,y);
sym_shuttle.setTranslation(x,y);
#symbol.setRotation(heading);
sym_shuttle.setRotation(heading);


x = 400.0 + landing_site.lon()/180 * 400.0 -10.0;
x = lon_to_x(landing_site.lon()) - 10.0;
y = 200.0 - landing_site.lat()/90. * 200.0 -10.0;
y = lat_to_y(landing_site.lat()) - 10.0;


sym_landing_site.setTranslation(x,y);
sym_landing_site.setTranslation(x,y);
prediction_update();
plot_tracks();


settimer(map_update, 1.0);
settimer(map_update, 1.0);


}
}
var plot_tracks = func  {
graph.removeAllChildren();
var plot = graph.createChild("path", "data")
                                  .setStrokeLineWidth(2)
                                  .setColor(0,0,1)
                                  .moveTo(history[0][0],history[0][1]);
     
      for (var i = 1; i< (size(history)-1); i=i+1)
        {
        var set = history[i+1];
        if (history[i+1][0] > history[i][0])
            {
            plot.lineTo(set[0], set[1]);
            }
        else
            {
            plot.moveTo(set[0], set[1]);
            }
        }
var pred_plot = graph.createChild("path", "data")
                                  .setStrokeLineWidth(2)
                                  .setColor(1,0,0)
                                  .moveTo(track_prediction[0][0],track_prediction[0][1]);
     
      for (var i = 1; i< (size(track_prediction)-1); i=i+1)
        {
        var set = track_prediction[i+1];
        if (track_prediction[i+1][0] > track_prediction[i][0])
            {
            pred_plot.lineTo(set[0], set[1]);
            }
        else
            {
            pred_plot.moveTo(set[0], set[1]);
            }
        }
}
var history_init = func {
var lat = getprop("/position/latitude-deg");
var lon = getprop("/position/longitude-deg");
var x =  lon_to_x(lon);
var y =  lat_to_y(lat);
for (var i = 0; i < 1000; i = i+1)
  {
  var set = [x,y];
  append(history,set);
  }
history_update();
}
var history_update = func {
history = delete_from_vector(history,0);
var lat = getprop("/position/latitude-deg");
var lon = getprop("/position/longitude-deg");
var x =  lon_to_x(lon);
var y =  lat_to_y(lat);
append(history, [x,y]);
settimer(history_update, 10.0);
}
var prediction_update = func {
setsize(track_prediction,0);
var earth_motion_degs = 0.00416666666;
var lat = getprop("/position/latitude-deg");
var lon = getprop("/position/longitude-deg");
calc_geo(lat);
var orbiter_motion_north_fps = getprop("/fdm/jsbsim/velocities/v-north-fps");
var orbital_speed_fps = getprop("/fdm/jsbsim/velocities/eci-velocity-mag-fps");
var orbital_period = getprop("/fdm/jsbsim/systems/orbital/orbital-period-s");
var rising_flag = 0.0;
if (orbiter_motion_north_fps > 0.0) {rising_flag = 1;}
else {rising_flag = -1.0};
var inclination = getprop("/fdm/jsbsim/systems/orbital/inclination-deg");
var inclination_rad = inclination * math.pi/180.0;
var sinphi = (lat/ inclination);
sinphi = math.min(sinphi, 1.0);
sinphi = math.max(sinphi,-1.0);
var phi = math.asin(sinphi);
if (rising_flag == -1) {phi = math.pi - phi;}
var lon_rising = lon - phi * 180.0/math.pi;
if (lon_rising < 0.0) {lon_rising = lon_rising + 360.0;}
var dt =  120.0;
var offset = 0.0;
var increment = 2.0 * math.pi * dt/orbital_period;
for (var i = 0; i<40; i = i+1)
  {
  var arg = phi + i * increment;
  var pred_lat = math.asin(math.sin(arg) * math.sin(inclination_rad));
  var pred_lon = math.atan2(math.cos(inclination_rad) * math.sin(arg), math.cos(arg));
 
  pred_lat = pred_lat * 180.0/math.pi;
  pred_lon = pred_lon * 180.0/math.pi;
  pred_lon = pred_lon + lon_rising - earth_motion_degs * i * dt;
  if (i==0) 
      {
      offset = lon - pred_lon;
      }
  pred_lon = pred_lon + offset;
  if (pred_lon > 180) {pred_lon = pred_lon - 360;}
  if (pred_lon < -180) {pred_lon = pred_lon + 360.0;}
  var x =  lon_to_x(pred_lon);
  var y =  lat_to_y(pred_lat);
  append(track_prediction, [x,y]);
  }
}
history_init();
</syntaxhighlight>
</syntaxhighlight>


Retrieved from "https://wiki.flightgear.org/Special:MobileDiff/83584"

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