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flightgear/Tools/Lib/DEM/dem.hxx
1999-04-06 23:37:07 +00:00

154 lines
4.1 KiB
C++

// dem.hxx -- DEM management class
//
// Written by Curtis Olson, started March 1998.
//
// Copyright (C) 1998 Curtis L. Olson - curt@flightgear.org
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License as
// published by the Free Software Foundation; either version 2 of the
// License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful, but
// WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
// General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
//
// $Id$
#ifndef _DEM_HXX
#define _DEM_HXX
#ifndef __cplusplus
# error This library requires C++
#endif
#include <Bucket/newbucket.hxx>
#include <Misc/fgstream.hxx>
#define DEM_SIZE 1200
#define DEM_SIZE_1 1201
class FGDem {
private:
// file pointer for input
// gzFile fd;
fg_gzifstream *in;
// coordinates (in arc seconds) of south west corner
double originx, originy;
// number of columns and rows
int cols, rows;
// Distance between column and row data points (in arc seconds)
double col_step, row_step;
// pointers to the actual grid data allocated here
float (*dem_data)[DEM_SIZE_1];
float (*output_data)[DEM_SIZE_1];
// Current "A" Record Information
char dem_description[80], dem_quadrangle[80];
double dem_x1, dem_y1, dem_x2, dem_y2, dem_x3, dem_y3, dem_x4, dem_y4;
double dem_z1, dem_z2;
int dem_resolution, dem_num_profiles;
// Current "B" Record Information
int prof_col, prof_row;
int prof_num_cols, prof_num_rows;
double prof_x1, prof_y1;
int prof_data;
// temporary values for the class to use
char option_name[32];
int do_data;
int cur_col, cur_row;
// return next token from input stream
string next_token();
// return next integer from input stream
int next_int();
// return next double from input stream
double next_double();
// return next exponential num from input stream
double next_exp();
public:
// Constructor
FGDem( void );
FGDem( const string& file );
// Destructor
~FGDem( void );
// open a DEM file (use "-" if input is coming from stdin)
int open ( const string& file );
// close a DEM file
int close();
// parse a DEM file
int parse();
// read and parse DEM "A" record
int read_a_record();
// read and parse DEM "B" record
void read_b_record();
// write out the area of data covered by the specified bucket.
// Data is written out column by column starting at the lower left
// hand corner.
int write_area( const string& root, FGBucket& b, bool compress );
#if 0
// return the current altitude based on grid data. We should
// rewrite this to interpolate exact values, but for now this is
// good enough
double interpolate_altitude( double lon, double lat );
// Use least squares to fit a simpler data set to dem data
void fit( double error, FGBucket& p );
// Initialize output mesh structure
void outputmesh_init( void );
// Get the value of a mesh node
double outputmesh_get_pt( int i, int j );
// Set the value of a mesh node
void outputmesh_set_pt( int i, int j, double value );
// Write out a node file that can be used by the "triangle" program
void outputmesh_output_nodes( const string& fg_root, FGBucket& p );
#endif
// Informational methods
inline double get_originx() const { return originx; }
inline double get_originy() const { return originy; }
inline int get_cols() const { return cols; }
inline int get_rows() const { return rows; }
inline double get_col_step() const { return col_step; }
inline double get_row_step() const { return row_step; }
};
#endif // _DEM_HXX