Added processing of DTED files.

src/Lib/HGT/CMakeLists.txt

@@ -1,4 +1,5 @@
 add_library(HGT STATIC
+    dted.cxx dted.hxx
     hgt.cxx hgt.hxx
     srtmbase.cxx srtmbase.hxx
 )

src/Lib/HGT/dted.cxx

@@ -0,0 +1,234 @@
+// dted.cxx -- SRTM "dted" data management class
+//
+// Written by James Hester based on hgt code of
+// Curtis Olson, started February 2003.
+//
+// Copyright (C) 2003  Curtis L. Olson  - http://www.flightgear.org/~curt
+// Copyright (C) 2018  James Hester 
+//
+// 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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA.
+//
+// $Id: hgt.cxx,v 1.7 2005-12-19 16:06:45 curt Exp $
+
+
+#ifdef HAVE_CONFIG_H
+#  include <config.h>
+#endif
+
+#include <simgear/compiler.h>
+
+#include <stdlib.h>   // atof()
+#include <iostream>
+
+#ifdef SG_HAVE_STD_INCLUDES
+#  include <cerrno>
+#else
+#  include <errno.h>
+#endif
+
+#ifdef _MSC_VER
+#  include <direct.h>
+#endif
+
+#include <simgear/constants.h>
+#include <simgear/io/lowlevel.hxx>
+#include <simgear/misc/sg_dir.hxx>
+#include <simgear/debug/logstream.hxx>
+
+
+#include "dted.hxx"
+
+using std::cout;
+using std::endl;
+using std::string;
+
+
+TGDted::TGDted( int _res ) 
+{
+    dted_resolution = _res;
+
+    data = new short int[MAX_DTED_SIZE][MAX_DTED_SIZE];
+    output_data = new short int[MAX_DTED_SIZE][MAX_DTED_SIZE];
+}
+
+
+TGDted::TGDted( int _res, const SGPath &file )
+{
+    dted_resolution = _res;
+    data = new short int[MAX_DTED_SIZE][MAX_DTED_SIZE];
+    output_data = new short int[MAX_DTED_SIZE][MAX_DTED_SIZE];
+
+    TGDted::open( file );
+}
+
+
+// open an DTED file
+bool
+TGDted::open ( const SGPath &f ) {
+    SGPath file_name = f;
+
+    // open input file (or read from stdin)
+    if ( file_name.str() ==  "-" ) {
+        cout << "Loading DTED data file: stdin" << endl;
+        if ( (fd = gzdopen(0, "r")) == NULL ) { // 0 == STDIN_FILENO
+            cout << "ERROR: opening stdin" << endl;
+            return false;
+        }
+    } else {
+        if ( file_name.extension() == "zip" ) {
+            // extract the .zip file to /tmp and point the file name
+            // to the extracted file
+            tmp_dir = simgear::Dir::tempDir("dted");
+            
+            cout << "Extracting " << file_name.str() << " to " << tmp_dir.path().str() << endl;
+            string command = "unzip -d \"" + tmp_dir.path().str() + "\" " + file_name.base();
+            if ( system( command.c_str() ) != -1 )
+            {
+                simgear::PathList files = tmp_dir.children(simgear::Dir::TYPE_FILE | simgear::Dir::NO_DOT_OR_DOTDOT);
+                for (const SGPath& file : files) {
+                    string ext = file.lower_extension();
+                    if ( ext == "dted" ) {
+                        file_name = file;
+                        break;
+                    }
+                }
+            
+                remove_tmp_file = true;
+                cout << "Proceeding with " << file_name.str() << endl;
+            } else {
+                SG_LOG(SG_GENERAL, SG_ALERT, "Failed to issue system call " << command );
+                exit(1);
+            }
+        }
+
+        cout << "Loading DTED data file: " << file_name.str() << endl;
+        if ( (fd = gzopen( file_name.c_str(), "rb" )) == NULL ) {
+            SGPath file_name_gz = file_name;
+            file_name_gz.append( ".gz" );
+            if ( (fd = gzopen( file_name_gz.c_str(), "rb" )) == NULL ) {
+                cout << "ERROR: opening " << file_name.str() << " or "
+                     << file_name_gz.str() << " for reading!" << endl;
+                return false;
+            }
+        }
+    }
+
+    // Determine originx/originy from file contents
+    // User Header Label
+    char header[3];
+    char location[7];
+    int degrees,minutes,seconds;
+    char hemisphere;
+    // Check header
+    gzread(fd,header,3);
+    if (strncmp(header,"UHL",3) != 0) {
+	    cout << "UHL User Header Label not found" << endl;
+	    return false;
+    }
+    gzread(fd,header,1);  //dummy
+    gzread(fd,location,8);//longitude
+    sscanf(location,"%3d%2d%2d%c",&degrees,&minutes,&seconds,&hemisphere);
+    originx = degrees *3600 + minutes*60 + seconds;
+    if(hemisphere == 'W') {
+	   originx = - originx;
+    } 
+    gzread(fd,location,8);//latitude
+    sscanf(location,"%3d%2d%2d%c",&degrees,&minutes,&seconds,&hemisphere);
+    originy = degrees *3600 + minutes*60 + seconds;
+    if(hemisphere == 'S') {
+	   originy = - originy;
+    } 
+    cout << "  Origin = " << originx << ", " << originy << endl;
+
+    return true;
+}
+
+
+// close an DTED file
+bool
+TGDted::close () {
+    gzclose(fd);
+    return true;
+}
+
+
+// load an DTED file
+bool
+TGDted::load( ) {
+    int size;
+    if ( dted_resolution == 1 ) {
+        cols = rows = size = 3601;
+        col_step = row_step = 1;
+    } else if ( dted_resolution == 3 ) {
+        cols = rows = size = 1201;
+        col_step = row_step = 3;
+    } else {
+        cout << "Unknown DTED resolution, only 1 and 3 arcsec formats" << endl;
+        cout << " are supported!" << endl;
+        return false;
+    }
+    if (sgIsLittleEndian()) {
+	    cout << "Little Endian: swapping input values" << endl;
+    }
+
+    //Skip headers 
+    gzseek(fd,3428,SEEK_SET); 
+    unsigned short int latct, longct;
+    short int *var;
+    int dummy;  //to read column header
+    for ( int col = 0; col < size; ++col ) {
+	    dummy = 0;  // zero out all bytes
+	    longct = 0;
+	    latct = 0;
+	    gzread(fd,&dummy,1);   //sentinel
+	    if(dummy != 170) {
+		    cout << "Failed to find sentinel at col " << col << endl;
+		    return false;
+	    }
+	    gzread(fd,&dummy,3);   //block count
+	    gzread(fd,&longct,2);   //Longitude count
+	    gzread(fd,&latct,2);   //Latitude count
+            if ( sgIsLittleEndian() ) {
+	        sgEndianSwap(&longct);
+	    }
+	    // cout << "Longitude count " << longct << endl;
+            for ( int row = 0; row < size; ++row ) {
+                var = &data[col][row];
+                if ( gzread ( fd, var, 2 ) != sizeof(short) ) {
+                return false;
+                }
+                if ( sgIsLittleEndian() ) { 
+		    sgEndianSwap( (unsigned short int*)var); 
+	        }
+            }
+	    gzread(fd,&dummy,4);   //Checksum
+	    // Check values are right
+	    if (col == 0) {
+		    cout << data[col][0] << endl;
+		    cout << data[col][1] << endl;
+		    cout << data[col][2] << endl;
+	    }
+    }
+
+    return true;
+}
+
+
+
+TGDted::~TGDted() {
+    // printf("class TGSrtmBase DEstructor called.\n");
+    delete [] data;
+    delete [] output_data;
+}

src/Lib/HGT/dted.hxx

@@ -0,0 +1,84 @@
+// dted.hxx -- SRTM "dted" data management class
+//
+// Written by James Hester based on hgt.hxx, which was
+// written by Curtis Olson who started February 2003.
+//
+// Copyright (C) 2003  Curtis L. Olson  - http://www.flightgear.org/~curt
+// Copyright (c) 2018  James Hester
+//
+// 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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA.
+//
+
+
+#ifndef _DTED_HXX
+#define _DTED_HXX
+
+#ifdef HAVE_CONFIG_H
+#  include <config.h>
+#endif
+
+#include <simgear/compiler.h>
+
+#include "srtmbase.hxx"
+
+#include <zlib.h>
+
+#include <string>
+
+#include <simgear/bucket/newbucket.hxx>
+#include <simgear/misc/sg_path.hxx>
+
+#define MAX_DTED_SIZE 3601
+
+
+class TGDted : public TGSrtmBase {
+
+private:
+
+    // file pointer for input
+    gzFile fd;
+
+    int dted_resolution;
+    
+    // pointers to the actual grid data allocated here
+    short int (*data)[MAX_DTED_SIZE];
+    short int (*output_data)[MAX_DTED_SIZE];
+
+public:
+
+    // Constructor, _res must be either "1" for the 1arcsec data or
+    // "3" for the 3arcsec data.
+    TGDted( int _res );
+    TGDted( int _res, const SGPath &file );
+
+    // Destructor
+    ~TGDted();
+
+    // open an DTED file (use "-" if input is coming from stdin)
+    bool open ( const SGPath &file );
+
+    // close an DTED file
+    bool close();
+
+    // load an dted file
+    bool load();
+
+    virtual short height( int x, int y ) const { return data[x][y]; }
+};
+
+
+#endif // _DTED_HXX
+
+

src/Prep/DemChop/CMakeLists.txt

@@ -19,6 +19,17 @@ target_link_libraries(hgtchop
 
 install(TARGETS hgtchop RUNTIME DESTINATION bin)
 
+add_executable(dtedchop dtedchop.cxx)
+
+target_link_libraries(dtedchop 
+    HGT
+	${ZLIB_LIBRARY}
+	${SIMGEAR_CORE_LIBRARIES}
+	${SIMGEAR_CORE_LIBRARY_DEPENDENCIES})
+
+install(TARGETS dtedchop RUNTIME DESTINATION bin)
+
+
 if(TIFF_FOUND)
 if(MSVC AND CMAKE_CL_64)
 	set( SRTMCHOP_LIBRARIES ${JPEG_LIBRARY} )

src/Prep/DemChop/dtedchop.cxx

@@ -0,0 +1,110 @@
+// dtedchop.cxx -- chop up a dted file into it's corresponding pieces and stuff
+//                them into the workspace directory
+//
+// Adapted by James Hester from hgtchop 
+// Written by Curtis Olson, started March 1999.
+//
+// Copyright (C) 1997  Curtis L. Olson  - http://www.flightgear.org/~curt
+// Copyright (C) 2018  James Hester
+//
+// 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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA.
+//
+
+#ifdef HAVE_CONFIG_H
+#  include <config.h>
+#endif
+
+#include <simgear/compiler.h>
+
+#include <cstdlib>
+#include <string>
+#include <iostream>
+
+#include <simgear/bucket/newbucket.hxx>
+#include <simgear/debug/logstream.hxx>
+#include <simgear/misc/sg_path.hxx>
+#include <simgear/misc/sg_dir.hxx>
+
+#include <Include/version.h>
+#include <HGT/dted.hxx>
+
+using std::cout;
+using std::endl;
+using std::string;
+
+
+int main(int argc, char **argv) {
+    sglog().setLogLevels( SG_ALL, SG_WARN );
+    SG_LOG( SG_GENERAL, SG_ALERT, "dtedchop version " << getTGVersion() << "\n" );
+
+    if ( argc != 4 ) {
+        cout << "Usage " << argv[0] << " <resolution> <dted_file> <work_dir>" << endl;
+        cout << endl;
+        cout << "\tresolution must be either 1 or 3 (1-arc-sec or 3-arc-sec)" << endl;
+
+        return EXIT_FAILURE;
+    }
+
+    int resolution = std::stoi(string(argv[1]));
+    string dted_name = string(argv[2]);
+    string work_dir = string(argv[3]);
+
+    // determine if file is 1arc-sec or 3arc-sec variety
+    if ( resolution != 1 && resolution != 3 ) {
+        cout << "ERROR: resolution must be 1 or 3." << endl;
+        return EXIT_FAILURE;
+    }
+
+    SGPath sgp( work_dir );
+    simgear::Dir workDir(sgp);
+    workDir.create(0755);
+
+    TGDted dted(resolution, dted_name);
+    dted.load();
+    dted.close();
+
+    SGGeod min = SGGeod::fromDeg( dted.get_originx() / 3600.0 + SG_HALF_BUCKET_SPAN,
+                                  dted.get_originy() / 3600.0 + SG_HALF_BUCKET_SPAN );
+    SGGeod max = SGGeod::fromDeg( (dted.get_originx() + dted.get_cols() * dted.get_col_step()) / 3600.0 - SG_HALF_BUCKET_SPAN,
+                                  (dted.get_originy() + dted.get_rows() * dted.get_row_step()) / 3600.0 - SG_HALF_BUCKET_SPAN );
+    SGBucket b_min( min );
+    SGBucket b_max( max );
+
+    if ( b_min == b_max ) {
+        dted.write_area( work_dir, b_min );
+    } else {
+        SGBucket b_cur;
+
+        int dx, dy;
+        sgBucketDiff(b_min, b_max, &dx, &dy);
+
+        cout << "DTED file spans tile boundaries (ok)" << endl;
+        cout << "  dx = " << dx << "  dy = " << dy << endl;
+
+        if ( (dx > 20) || (dy > 20) ) {
+            cout << "somethings really wrong!!!!" << endl;
+            return EXIT_FAILURE;
+        }
+
+        for ( int j = 0; j <= dy; ++j ) {
+            for ( int i = 0; i <= dx; ++i ) {
+                b_cur = b_min.sibling(i, j);
+                dted.write_area( work_dir, b_cur );
+            }
+        }
+    }
+
+    return EXIT_SUCCESS;
+}