1 // dem.hxx -- DEM management class
3 // Written by Curtis Olson, started March 1998.
5 // Copyright (C) 1998 Curtis L. Olson - curt@flightgear.org
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 // (Log is kept at end of this file)
30 # error This library requires C++
34 #include <Bucket/newbucket.hxx>
35 #include <Misc/fgstream.hxx>
39 #define DEM_SIZE_1 1201
46 // file pointer for input
50 // coordinates (in arc seconds) of south west corner
51 double originx, originy;
53 // number of columns and rows
56 // Distance between column and row data points (in arc seconds)
57 double col_step, row_step;
59 // pointers to the actual grid data allocated here
60 float (*dem_data)[DEM_SIZE_1];
61 float (*output_data)[DEM_SIZE_1];
63 // Current "A" Record Information
64 char dem_description[80], dem_quadrangle[80];
65 double dem_x1, dem_y1, dem_x2, dem_y2, dem_x3, dem_y3, dem_x4, dem_y4;
66 double dem_z1, dem_z2;
67 int dem_resolution, dem_num_profiles;
69 // Current "B" Record Information
70 int prof_col, prof_row;
71 int prof_num_cols, prof_num_rows;
72 double prof_x1, prof_y1;
75 // temporary values for the class to use
80 // return next token from input stream
83 // return next integer from input stream
86 // return next double from input stream
89 // return next exponential num from input stream
96 FGDem( const string& file );
101 // open a DEM file (use "-" if input is coming from stdin)
102 int open ( const string& file );
110 // read and parse DEM "A" record
113 // read and parse DEM "B" record
114 void read_b_record();
116 // write out the area of data covered by the specified bucket.
117 // Data is written out column by column starting at the lower left
119 int write_area( const string& root, FGBucket& b, bool compress );
122 // return the current altitude based on grid data. We should
123 // rewrite this to interpolate exact values, but for now this is
125 double interpolate_altitude( double lon, double lat );
127 // Use least squares to fit a simpler data set to dem data
128 void fit( double error, FGBucket& p );
130 // Initialize output mesh structure
131 void outputmesh_init( void );
133 // Get the value of a mesh node
134 double outputmesh_get_pt( int i, int j );
136 // Set the value of a mesh node
137 void outputmesh_set_pt( int i, int j, double value );
139 // Write out a node file that can be used by the "triangle" program
140 void outputmesh_output_nodes( const string& fg_root, FGBucket& p );
143 // Informational methods
144 inline double get_originx() const { return originx; }
145 inline double get_originy() const { return originy; }
146 inline int get_cols() const { return cols; }
147 inline int get_rows() const { return rows; }
148 inline double get_col_step() const { return col_step; }
149 inline double get_row_step() const { return row_step; }
157 // Revision 1.13 1999/03/13 17:40:39 curt
158 // Moved point interpolation and least squares fitting to contruction program
160 // Moved leastsqs.* to Lib/Math/
162 // Revision 1.12 1999/03/12 22:53:09 curt
163 // Added a routine to dump out the portion of the dem data covered by a
164 // specified bucket. Other changes related to needs of scenery tools overhaul.
166 // Revision 1.11 1999/03/11 23:31:57 curt
167 // Tweaks to use newbucket.hxx
169 // Revision 1.10 1999/03/10 01:09:13 curt
170 // Tweaks to go along with scenery tools overhaul.
171 // Added a new constructor that accepts the file name.
173 // Revision 1.9 1998/10/16 19:08:14 curt
174 // Portability updates from Bernie Bright.
176 // Revision 1.8 1998/09/19 17:59:46 curt
177 // Use c++ streams (fg_gzifstream). Also converted many character arrays to
180 // Revision 1.7 1998/07/04 00:47:19 curt
181 // typedef'd struct fgBUCKET.
183 // Revision 1.6 1998/06/05 18:14:40 curt
184 // Abort out early when reading the "A" record if it doesn't look like
185 // a proper DEM file.
187 // Revision 1.5 1998/04/22 13:14:46 curt
188 // Fixed a bug in zlib usage.
190 // Revision 1.4 1998/04/21 17:03:41 curt
191 // Prepairing for C++ integration.
193 // Revision 1.3 1998/04/18 03:53:06 curt
194 // Added zlib support.
196 // Revision 1.2 1998/04/14 02:43:28 curt
197 // Used "new" to auto-allocate large DEM parsing arrays in class constructor.
199 // Revision 1.1 1998/04/08 22:57:23 curt
200 // Adopted Gnu automake/autoconf system.
202 // Revision 1.2 1998/03/23 20:35:42 curt
203 // Updated to use FG_EPSILON
205 // Revision 1.1 1998/03/19 02:54:47 curt
206 // Reorganized into a class lib called fgDEM.
208 // Revision 1.1 1998/03/19 01:46:29 curt