1 // ATCutils.cxx - Utility functions for the ATC / AI system
3 // Written by David Luff, started March 2002.
5 // Copyright (C) 2002 David C Luff - david.luff@nottingham.ac.uk
7 // This program is free software; you can redistribute it and/or
8 // modify it under the terms of the GNU General Public License as
9 // published by the Free Software Foundation; either version 2 of the
10 // License, or (at your option) any later version.
12 // This program is distributed in the hope that it will be useful, but
13 // WITHOUT ANY WARRANTY; without even the implied warranty of
14 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 // General Public License for more details.
17 // You should have received a copy of the GNU General Public License
18 // along with this program; if not, write to the Free Software
19 // Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
22 #include <simgear/math/point3d.hxx>
23 #include <simgear/constants.h>
25 //#include <iomanip.h>
27 #include "ATCutils.hxx"
29 // Convert any number to spoken digits
30 string ConvertNumToSpokenDigits(string n) {
31 //cout << "n = " << n << endl;
32 string nums[10] = {"zero", "one", "two", "three", "four", "five", "six", "seven", "eight", "nine"};
33 string pt = "decimal";
36 for(unsigned int i=0; i<n.length(); ++i) {
37 //cout << "n.substr(" << i << ",1 = " << n.substr(i,1) << endl;
38 if(n.substr(i,1) == " ") {
40 } else if(n.substr(i,1) == ".") {
43 str += nums[atoi((n.substr(i,1)).c_str())];
45 if(i != (n.length()-1)) { // ie. don't add a space at the end.
53 // Convert a 2 digit rwy number to a spoken-style string
54 string ConvertRwyNumToSpokenString(int n) {
55 string nums[10] = {"zero", "one", "two", "three", "four", "five", "six", "seven", "eight", "nine"};
56 // Basic error/sanity checking
64 n = 36; // Is this right?
72 str += " "; //Changed this for the benefit of the voice token parser - prefer the "-" in the visual output though.
77 // Return the phonetic letter of a letter represented as an integer 1->26
78 string GetPhoneticIdent(int i) {
79 // TODO - Check i is between 1 and 26 and wrap if necessary
81 case 1 : return("alpha");
82 case 2 : return("bravo");
83 case 3 : return("charlie");
84 case 4 : return("delta");
85 case 5 : return("echo");
86 case 6 : return("foxtrot");
87 case 7 : return("golf");
88 case 8 : return("hotel");
89 case 9 : return("india");
90 case 10 : return("juliet");
91 case 11 : return("kilo");
92 case 12 : return("lima");
93 case 13 : return("mike");
94 case 14 : return("november");
95 case 15 : return("oscar");
96 case 16 : return("papa");
97 case 17 : return("quebec");
98 case 18 : return("romeo");
99 case 19 : return("sierra");
100 case 20 : return("tango");
101 case 21 : return("uniform");
102 case 22 : return("victor");
103 case 23 : return("whiskey");
104 case 24 : return("x-ray");
105 case 25 : return("yankee");
106 case 26 : return("zulu");
108 // We shouldn't get here
112 // Given two positions (lat & lon in degrees), get the HORIZONTAL separation (in meters)
113 double dclGetHorizontalSeparation(Point3D pos1, Point3D pos2) {
114 double x; //East-West separation
115 double y; //North-South separation
116 double z; //Horizontal separation - z = sqrt(x^2 + y^2)
118 double lat1 = pos1.lat() * SG_DEGREES_TO_RADIANS;
119 double lon1 = pos1.lon() * SG_DEGREES_TO_RADIANS;
120 double lat2 = pos2.lat() * SG_DEGREES_TO_RADIANS;
121 double lon2 = pos2.lon() * SG_DEGREES_TO_RADIANS;
123 y = sin(fabs(lat1 - lat2)) * SG_EQUATORIAL_RADIUS_M;
124 x = sin(fabs(lon1 - lon2)) * SG_EQUATORIAL_RADIUS_M * (cos((lat1 + lat2) / 2.0));
130 // Given a point and a line, get the HORIZONTAL shortest distance from the point to a point on the line.
131 // Expects to be fed orthogonal co-ordinates, NOT lat & lon !
132 // The units of the separation will be those of the input.
133 double dclGetLinePointSeparation(double px, double py, double x1, double y1, double x2, double y2) {
136 double magline = sqrt(vecx*vecx + vecy*vecy);
137 double u = ((px-x1)*(x2-x1) + (py-y1)*(y2-y1)) / (magline * magline);
138 double x0 = x1 + u*(x2-x1);
139 double y0 = y1 + u*(y2-y1);
142 double d = sqrt(vecx*vecx + vecy*vecy);
149 // Given a position (lat/lon/elev), heading and vertical angle (degrees), and distance (meters), calculate the new position.
150 // This function assumes the world is spherical. If geodetic accuracy is required use the functions is sg_geodesy instead!
151 // Assumes that the ground is not hit!!! Expects heading and angle in degrees, distance in meters.
152 Point3D dclUpdatePosition(Point3D pos, double heading, double angle, double distance) {
153 //cout << setprecision(10) << pos.lon() << ' ' << pos.lat() << '\n';
154 heading *= DCL_DEGREES_TO_RADIANS;
155 angle *= DCL_DEGREES_TO_RADIANS;
156 double lat = pos.lat() * DCL_DEGREES_TO_RADIANS;
157 double lon = pos.lon() * DCL_DEGREES_TO_RADIANS;
158 double elev = pos.elev();
159 //cout << setprecision(10) << lon*DCL_RADIANS_TO_DEGREES << ' ' << lat*DCL_RADIANS_TO_DEGREES << '\n';
161 double horiz_dist = distance * cos(angle);
162 double vert_dist = distance * sin(angle);
164 double north_dist = horiz_dist * cos(heading);
165 double east_dist = horiz_dist * sin(heading);
167 //cout << distance << ' ' << horiz_dist << ' ' << vert_dist << ' ' << north_dist << ' ' << east_dist << '\n';
169 double delta_lat = asin(north_dist / (double)SG_EQUATORIAL_RADIUS_M);
170 double delta_lon = asin(east_dist / (double)SG_EQUATORIAL_RADIUS_M) * (1.0 / cos(lat)); // I suppose really we should use the average of the original and new lat but we'll assume that this will be good enough.
171 //cout << delta_lon*DCL_RADIANS_TO_DEGREES << ' ' << delta_lat*DCL_RADIANS_TO_DEGREES << '\n';
175 //cout << setprecision(10) << lon*DCL_RADIANS_TO_DEGREES << ' ' << lat*DCL_RADIANS_TO_DEGREES << '\n';
177 //cout << setprecision(15) << DCL_DEGREES_TO_RADIANS * DCL_RADIANS_TO_DEGREES << '\n';
179 return(Point3D(lon*DCL_RADIANS_TO_DEGREES, lat*DCL_RADIANS_TO_DEGREES, elev));
182 // Get a heading in degrees from one lat/lon to another.
183 // This function assumes the world is spherical. If geodetic accuracy is required use the functions is sg_geodesy instead!
184 // Warning - at the moment we are not checking for identical points - currently it returns 90 in this instance.
185 double GetHeadingFromTo(Point3D A, Point3D B) {
186 double latA = A.lat() * DCL_DEGREES_TO_RADIANS;
187 double lonA = A.lon() * DCL_DEGREES_TO_RADIANS;
188 double latB = B.lat() * DCL_DEGREES_TO_RADIANS;
189 double lonB = B.lon() * DCL_DEGREES_TO_RADIANS;
190 double xdist = sin(lonB - lonA) * (double)SG_EQUATORIAL_RADIUS_M * cos((latA+latB)/2.0);
191 double ydist = sin(latB - latA) * (double)SG_EQUATORIAL_RADIUS_M;
195 return(atan(xdist/ydist) * DCL_RADIANS_TO_DEGREES);
196 } else if (ydist == 0) {
199 return(180.0 - atan(xdist/fabs(ydist)) * DCL_RADIANS_TO_DEGREES);
203 return(360.0 - atan(fabs(xdist)/ydist) * DCL_RADIANS_TO_DEGREES);
204 } else if (ydist == 0) {
207 return(180.0 + atan(xdist/ydist) * DCL_RADIANS_TO_DEGREES);
212 // Given a heading (in degrees), bound it from 0 -> 360
213 void dclBoundHeading(double &hdg) {