# include "config.h"
#endif
-#include <simgear/debug/logstream.hxx>
-
#include <stdlib.h>
+#include <math.h>
#include <algorithm>
+#include <simgear/debug/logstream.hxx>
#include <simgear/structure/commands.hxx>
#include <simgear/structure/exception.hxx>
FGMetarEnvironmentCtrl::FGMetarEnvironmentCtrl ()
: env( new FGInterpolateEnvironmentCtrl ),
_icao( "" ),
+ metar_loaded( false ),
search_interval_sec( 60.0 ), // 1 minute
same_station_interval_sec( 900.0 ), // 15 minutes
search_elapsed( 9999.0 ),
fetch_elapsed( 9999.0 ),
+ last_apt( 0 ),
proxy_host( fgGetNode("/sim/presets/proxy/host", true) ),
proxy_port( fgGetNode("/sim/presets/proxy/port", true) ),
proxy_auth( fgGetNode("/sim/presets/proxy/authentication", true) ),
metar_max_age( fgGetNode("/environment/params/metar-max-age-min", true) ),
+
+ // Interpolation constant definitions.
+ EnvironmentUpdatePeriodSec( 0.2 ),
+ MaxWindChangeKtsSec( 0.2 ),
+ MaxVisChangePercentSec( 0.05 ),
+ MaxPressureChangeInHgSec( 0.0033 ),
+ MaxCloudAltitudeChangeFtSec( 20.0 ),
+ MaxCloudThicknessChangeFtSec( 50.0 ),
+ MaxCloudInterpolationHeightFt( 5000.0 ),
+
_error_count( 0 ),
_stale_count( 0 ),
_dt( 0.0 ),
- _error_dt( 0.0 ),
- last_apt(0)
+ _error_dt( 0.0 )
{
#if defined(ENABLE_THREADS)
thread = new MetarThread(this);
void
FGMetarEnvironmentCtrl::update_env_config ()
{
- fgSetupWind( fgGetDouble("/environment/metar/base-wind-range-from"),
- fgGetDouble("/environment/metar/base-wind-range-to"),
- fgGetDouble("/environment/metar/base-wind-speed-kt"),
- fgGetDouble("/environment/metar/gust-wind-speed-kt") );
+ double dir_from;
+ double dir_to;
+ double speed;
+ double gust;
+ double vis;
+ double pressure;
+ double temp;
+ double dewpoint;
+
+ if (metar_loaded) {
+ // Generate interpolated values between the METAR and the current
+ // configuration.
+
+ // Pick up the METAR wind values and convert them into a vector.
+ double metar[2];
+ double metar_speed = fgGetDouble("/environment/metar/base-wind-speed-kt");
+ double metar_heading = fgGetDouble("/environment/metar/base-wind-range-from");
+
+ metar[0] = metar_speed * sin((metar_heading / 180.0) * M_PI);
+ metar[1] = metar_speed * cos((metar_heading / 180.0) * M_PI);
+
+ // Convert the current wind values and convert them into a vector
+ double current[2];
+ double current_speed =
+ fgGetDouble("/environment/config/boundary/entry/wind-speed-kt");
+ double current_heading = fgGetDouble(
+ "/environment/config/boundary/entry/wind-from-heading-deg");
+
+ current[0] = current_speed * sin((current_heading / 180.0) * M_PI);
+ current[1] = current_speed * cos((current_heading / 180.0) * M_PI);
+
+ // Determine the maximum component-wise value that the wind can change.
+ // First we determine the fraction in the X and Y component, then
+ // factor by the maximum wind change.
+ double x = fabs(current[0] - metar[0]);
+ double y = fabs(current[1] - metar[1]);
+ double dx = x / (x + y);
+ double dy = 1 - dx;
+
+ double maxdx = dx * MaxWindChangeKtsSec;
+ double maxdy = dy * MaxWindChangeKtsSec;
+
+ // Interpolate each component separately.
+ current[0] = interpolate_val(current[0], metar[0], maxdx);
+ current[1] = interpolate_val(current[1], metar[1], maxdy);
+
+ // Now convert back to polar coordinates.
+ if ((current[0] == 0.0) && (current[1] == 0.0)) {
+ // Special case where there is no wind (otherwise atan2 barfs)
+ speed = 0.0;
+ dir_from = current_heading;
+
+ } else {
+ // Some real wind to convert back from. Work out the speed
+ // and direction value in degrees.
+ speed = sqrt((current[0] * current[0]) + (current[1] * current[1]));
+ dir_from = (atan2(current[0], current[1]) * 180.0 / M_PI);
+
+ // Normalize the direction.
+ if (dir_from < 0.0)
+ dir_from += 360.0;
+
+ SG_LOG( SG_GENERAL, SG_DEBUG, "Wind : " << dir_from << "@" << speed);
+ }
+
+ // Now handle the visibility. We convert both visibility values
+ // to X-values, then interpolate from there, then back to real values.
+ // The length_scale is fixed to 1000m, so the visibility changes by
+ // by MaxVisChangePercentSec or 1000m X MaxVisChangePercentSec,
+ // whichever is more.
+ double currentvis =
+ fgGetDouble("/environment/config/boundary/entry/visibility-m");
+ double metarvis = fgGetDouble("/environment/metar/min-visibility-m");
+ double currentxval = log(1000.0 + currentvis);
+ double metarxval = log(1000.0 + metarvis);
+
+ currentxval = interpolate_val(currentxval, metarxval, MaxVisChangePercentSec);
+
+ // Now convert back from an X-value to a straightforward visibility.
+ vis = exp(currentxval) - 1000.0;
+
+ pressure = interpolate_prop(
+ "/environment/config/boundary/entry/pressure-sea-level-inhg",
+ "/environment/metar/pressure-inhg",
+ MaxPressureChangeInHgSec);
+
+ dir_to = fgGetDouble("/environment/metar/base-wind-range-to");
+ gust = fgGetDouble("/environment/metar/gust-wind-speed-kt");
+ temp = fgGetDouble("/environment/metar/temperature-degc");
+ dewpoint = fgGetDouble("/environment/metar/dewpoint-degc");
+
+ // Set the cloud layers by interpolating over the METAR versions.
+ SGPropertyNode * clouds = fgGetNode("/environment/metar/clouds");
+
+ vector<SGPropertyNode_ptr> layers = clouds->getChildren("layer");
+ vector<SGPropertyNode_ptr>::const_iterator layer;
+ vector<SGPropertyNode_ptr>::const_iterator layers_end = layers.end();
+
+ const char *cl = "/environment/clouds/layer[%i]";
+ double aircraft_alt = fgGetDouble("/position/altitude-ft");
+ char s[128];
+ int i;
+
+ for (i = 0, layer = layers.begin(); layer != layers_end; ++layer, i++) {
+ double currentval;
+ double requiredval;
+
+ // In the case of clouds, we want to avoid writing if nothing has
+ // changed, as these properties are tied to the renderer and will
+ // cause the clouds to be updated, reseting the texture locations.
+
+ // We don't interpolate the coverage values as no-matter how we
+ // do it, it will be quite a sudden change of texture. Better to
+ // have a single change than four or five.
+ snprintf(s, 128, cl, i);
+ strncat(s, "/coverage", 128);
+ const char* coverage = (*layer)->getStringValue("coverage", "clear");
+ if (strncmp(fgGetString(s), coverage, 128) != 0)
+ fgSetString(s, coverage);
+
+ snprintf(s, 128, cl, i);
+ strncat(s, "/elevation-ft", 128);
+ double current_alt = fgGetDouble(s);
+ double required_alt = (*layer)->getDoubleValue("elevation-ft");
+
+ if (current_alt < -9000 || required_alt < -9000
+ || fabs(aircraft_alt - required_alt) > MaxCloudInterpolationHeightFt) {
+ // We don't interpolate any values that are too high above us,
+ // or too far below us to be visible. Nor do we interpolate
+ // values to or from -9999, which is used as a placeholder
+ // when there isn't actually a cloud layer present.
+ snprintf(s, 128, cl, i);
+ strncat(s, "/elevation-ft", 128);
+ if (current_alt != required_alt)
+ fgSetDouble(s, required_alt);
+
+ snprintf(s, 128, cl, i);
+ strncat(s, "/thickness-ft", 128);
+ if (fgGetDouble(s) != (*layer)->getDoubleValue("thickness-ft"))
+ fgSetDouble(s, (*layer)->getDoubleValue("thickness-ft"));
+
+ } else {
+ // Interpolate the other values in the usual way
+ if (current_alt != required_alt) {
+ current_alt = interpolate_val(current_alt,
+ required_alt,
+ MaxCloudAltitudeChangeFtSec);
+ fgSetDouble(s, current_alt);
+ }
+
+ snprintf(s, 128, cl, i);
+ strncat(s, "/thickness-ft", 128);
+ currentval = fgGetDouble(s);
+ requiredval = (*layer)->getDoubleValue("thickness-ft");
+
+ if (currentval != requiredval) {
+ currentval = interpolate_val(currentval,
+ requiredval,
+ MaxCloudThicknessChangeFtSec);
+ fgSetDouble(s, currentval);
+ }
+ }
+ }
+
+ } else {
+ // We haven't already loaded a METAR, so apply it immediately.
+ dir_from = fgGetDouble("/environment/metar/base-wind-range-from");
+ dir_to = fgGetDouble("/environment/metar/base-wind-range-to");
+ speed = fgGetDouble("/environment/metar/base-wind-speed-kt");
+ gust = fgGetDouble("/environment/metar/gust-wind-speed-kt");
+ vis = fgGetDouble("/environment/metar/min-visibility-m");
+ pressure = fgGetDouble("/environment/metar/pressure-inhg");
+ temp = fgGetDouble("/environment/metar/temperature-degc");
+ dewpoint = fgGetDouble("/environment/metar/dewpoint-degc");
+
+ // Set the cloud layers by copying over the METAR versions.
+ SGPropertyNode * clouds = fgGetNode("/environment/metar/clouds");
+
+ vector<SGPropertyNode_ptr> layers = clouds->getChildren("layer");
+ vector<SGPropertyNode_ptr>::const_iterator layer;
+ vector<SGPropertyNode_ptr>::const_iterator layers_end = layers.end();
+
+ const char *cl = "/environment/clouds/layer[%i]";
+ char s[128];
+ int i;
+
+ for (i = 0, layer = layers.begin(); layer != layers_end; ++layer, i++) {
+ snprintf(s, 128, cl, i);
+ strncat(s, "/coverage", 128);
+ fgSetString(s, (*layer)->getStringValue("coverage", "clear"));
+
+ snprintf(s, 128, cl, i);
+ strncat(s, "/elevation-ft", 128);
+ fgSetDouble(s, (*layer)->getDoubleValue("elevation-ft"));
+
+ snprintf(s, 128, cl, i);
+ strncat(s, "/thickness-ft", 128);
+ fgSetDouble(s, (*layer)->getDoubleValue("thickness-ft"));
+
+ snprintf(s, 128, cl, i);
+ strncat(s, "/span-m", 128);
+ fgSetDouble(s, 40000.0);
+ }
+ }
+
+ fgSetupWind(dir_from, dir_to, speed, gust);
+ fgDefaultWeatherValue("visibility-m", vis);
+ set_temp_at_altitude(temp, station_elevation_ft);
+ set_dewpoint_at_altitude(dewpoint, station_elevation_ft);
+ fgDefaultWeatherValue("pressure-sea-level-inhg", pressure);
+
+ // We've now successfully loaded a METAR into the configuration
+ metar_loaded = true;
+}
+
+double FGMetarEnvironmentCtrl::interpolate_prop(const char * currentname,
+ const char * requiredname,
+ double dt)
+{
+ double currentval = fgGetDouble(currentname);
+ double requiredval = fgGetDouble(requiredname);
+ return interpolate_val(currentval, requiredval, dt);
+}
+
+double FGMetarEnvironmentCtrl::interpolate_val(double currentval,
+ double requiredval,
+ double dt)
+{
+ double dval = EnvironmentUpdatePeriodSec * dt;
- fgDefaultWeatherValue( "visibility-m",
- fgGetDouble("/environment/metar/min-visibility-m") );
- set_temp_at_altitude( fgGetDouble("/environment/metar/temperature-degc"),
- station_elevation_ft );
- set_dewpoint_at_altitude( fgGetDouble("/environment/metar/dewpoint-degc"),
- station_elevation_ft );
- fgDefaultWeatherValue( "pressure-sea-level-inhg",
- fgGetDouble("/environment/metar/pressure-inhg") );
+ if (fabs(currentval - requiredval) < dval) return requiredval;
+ if (currentval < requiredval) return (currentval + dval);
+ if (currentval > requiredval) return (currentval - dval);
+ return requiredval;
}
void
const SGPropertyNode *latitude
= fgGetNode( "/position/latitude-deg", true );
+ metar_loaded = false;
bool found_metar = false;
long max_age = metar_max_age->getLongValue();
// Don't check max age during init so that we don't loop over a lot
= fgGetNode( "/position/latitude-deg", true );
search_elapsed += delta_time_sec;
fetch_elapsed += delta_time_sec;
+ interpolate_elapsed += delta_time_sec;
// if time for a new search request, push it onto the request
// queue
SG_LOG( SG_GENERAL, SG_WARN,
"Unable to find any airports with metar" );
}
+ } else if ( interpolate_elapsed > EnvironmentUpdatePeriodSec ) {
+ // Interpolate the current configuration closer to the actual METAR
+ update_env_config();
+ env->reinit();
+ interpolate_elapsed = 0.0;
}
#if !defined(ENABLE_THREADS)
vector<SGMetarCloud> cv = m->getClouds();
vector<SGMetarCloud>::const_iterator cloud;
- const char *cl = "/environment/clouds/layer[%i]";
+ const char *cl = "/environment/metar/clouds/layer[%i]";
for (i = 0, cloud = cv.begin(); cloud != cv.end(); cloud++, i++) {
const char *coverage_string[5] =
{ "clear", "few", "scattered", "broken", "overcast" };
projects / flightgear.git / commitdiff