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Added a new "newbucket.[ch]xx" FGBucket class to replace the old

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fgBUCKET struct and C routines.  This FGBucket class adjusts the tile
width towards the poles to ensure the tiles are at least 8 miles wide.
This commit is contained in:
curt 1999-02-08 23:52:13 +00:00
parent 123c816048
commit 91efc5ad87
5 changed files with 450 additions and 2 deletions
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9
Bucket/Makefile.am
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@ -1,5 +1,12 @@
noinst_LIBRARIES = libBucket.a
libBucket_a_SOURCES = bucketutils.c bucketutils.h bucketutils.hxx
libBucket_a_SOURCES = bucketutils.c bucketutils.h bucketutils.hxx \
newbucket.cxx newbucket.hxx
bin_PROGRAMS = testbucket
testbucket_SOURCES = testbucket.cxx
testbucket_LDADD = $(top_builddir)/Lib/Bucket/libBucket.a
INCLUDES += -I$(top_builddir)

7
Bucket/bucketutils.h
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@ -63,7 +63,7 @@ void fgBucketParseIndex(long int index, fgBUCKET *p);
void fgBucketGenBasePath( const fgBUCKET *p, char *path);
// offset an bucket struct by the specified amounts in the X & Y direction
// offset a bucket struct by the specified amounts in the X & Y direction
void fgBucketOffset(fgBUCKET *in, fgBUCKET *out, int x, int y);
@ -85,6 +85,11 @@ void fgBucketGenIdxArray(fgBUCKET *p1, fgBUCKET *tiles, int width, int height);
// $Log$
// Revision 1.5 1999/02/08 23:52:15 curt
// Added a new "newbucket.[ch]xx" FGBucket class to replace the old
// fgBUCKET struct and C routines. This FGBucket class adjusts the tile
// width towards the poles to ensure the tiles are at least 8 miles wide.
//
// Revision 1.4 1998/12/09 18:48:09 curt
// Use C++ style comments.
//

107
Bucket/newbucket.cxx Normal file
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@ -0,0 +1,107 @@
/**************************************************************************
* newbucket.hxx -- new bucket routines for better world modeling
*
* Written by Curtis L. Olson, started February 1999.
*
* Copyright (C) 1999 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.
*
* $Id$
* (Log is kept at end of this file)
**************************************************************************/
#include "newbucket.hxx"
// Build the path name for this bucket
string FGBucket::gen_base_path() {
long int index;
int top_lon, top_lat, main_lon, main_lat;
char hem, pole;
char path[256];
index = gen_index();
path[0] = '\0';
top_lon = lon / 10;
main_lon = lon;
if ( (lon < 0) && (top_lon * 10 != lon) ) {
top_lon -= 1;
}
top_lon *= 10;
if ( top_lon >= 0 ) {
hem = 'e';
} else {
hem = 'w';
top_lon *= -1;
}
if ( main_lon < 0 ) {
main_lon *= -1;
}
top_lat = lat / 10;
main_lat = lat;
if ( (lat < 0) && (top_lat * 10 != lat) ) {
top_lat -= 1;
}
top_lat *= 10;
if ( top_lat >= 0 ) {
pole = 'n';
} else {
pole = 's';
top_lat *= -1;
}
if ( main_lat < 0 ) {
main_lat *= -1;
}
sprintf(path, "%c%03d%c%02d/%c%03d%c%02d",
hem, top_lon, pole, top_lat,
hem, main_lon, pole, main_lat);
return path;
}
// find the bucket which is offset by the specified tile units in the
// X & Y direction. We need the current lon and lat to resolve
// ambiguities when going from a wider tile to a narrower one above or
// below. This assumes that we are feeding in
FGBucket fgBucketOffset( double dlon, double dlat, int dx, int dy ) {
FGBucket result( dlon, dlat );
double clat = result.get_center_lat() + dy * FG_BUCKET_SPAN;
// walk dy units in the lat direction
result.set_bucket( dlon, clat );
// find the lon span for the new latitude
double span = bucket_span( clat );
// walk dx units in the lon direction
result.set_bucket( dlon + dx * span, clat );
return result;
}
// $Log$
// Revision 1.1 1999/02/08 23:52:16 curt
// Added a new "newbucket.[ch]xx" FGBucket class to replace the old
// fgBUCKET struct and C routines. This FGBucket class adjusts the tile
// width towards the poles to ensure the tiles are at least 8 miles wide.
//

297
Bucket/newbucket.hxx Normal file
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@ -0,0 +1,297 @@
/**************************************************************************
* newbucket.hxx -- new bucket routines for better world modeling
*
* Written by Curtis L. Olson, started February 1999.
*
* Copyright (C) 1999 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.
*
* $Id$
* (Log is kept at end of this file)
**************************************************************************/
#ifndef _NEWBUCKET_HXX
#define _NEWBUCKET_HXX
#include <Include/compiler.h>
#include <string>
FG_USING_STD(string);
FG_USING_NAMESPACE(std);
#include <stdio.h> // sprintf()
#include <Include/fg_constants.h>
#define FG_BUCKET_SPAN 0.125 // 1/8 of a degree
#define FG_HALF_BUCKET_SPAN 0.0625 // 1/2 of 1/8 of a degree = 1/16 = 0.0625
class FGBucket {
private:
double cx, cy; // centerpoint (lon, lat) in degrees of bucket
int lon; // longitude index (-180 to 179)
int lat; // latitude index (-90 to 89)
int x; // x subdivision (0 to 7)
int y; // y subdivision (0 to 7)
public:
// default constructor
FGBucket();
// create a bucket which would contain the specified lon/lat
FGBucket(const double lon, const double lat);
// create a bucket based on "long int" index
FGBucket(const long int bindex);
~FGBucket();
// Set the bucket params for the specified lat and lon
void set_bucket( double dlon, double dlat );
// Generate the unique scenery tile index for this bucket
long int gen_index();
// Build the path name for this bucket
string gen_base_path();
// return the center lon of a tile
double get_center_lon();
// return the center lat of a tile
double get_center_lat();
// friends
friend ostream& operator<< ( ostream&, const FGBucket& );
};
// return the horizontal tile span factor based on latitude
inline double bucket_span( double l ) {
if ( l >= 89.0 ) {
return 0.0;
} else if ( l >= 88.0 ) {
return 8.0;
} else if ( l >= 86.0 ) {
return 4.0;
} else if ( l >= 83.0 ) {
return 2.0;
} else if ( l >= 76.0 ) {
return 1.0;
} else if ( l >= 62.0 ) {
return 0.5;
} else if ( l >= 22.0 ) {
return 0.25;
} else if ( l >= -22.0 ) {
return 0.125;
} else if ( l >= -62.0 ) {
return 0.25;
} else if ( l >= -76.0 ) {
return 0.5;
} else if ( l >= -83.0 ) {
return 1.0;
} else if ( l >= -86.0 ) {
return 2.0;
} else if ( l >= -88.0 ) {
return 4.0;
} else if ( l >= -89.0 ) {
return 8.0;
} else {
return 0.0;
}
}
// Set the bucket params for the specified lat and lon
inline void FGBucket::set_bucket( double dlon, double dlat ) {
//
// latitude first
//
double span = bucket_span( dlat );
double diff = dlon - (double)(int)dlon;
// cout << "diff = " << diff << " span = " << span << endl;
if ( (dlon >= 0) || (fabs(diff) < FG_EPSILON) ) {
lon = (int)dlon;
} else {
lon = (int)dlon - 1;
}
// find subdivision or super lon if needed
if ( span < FG_EPSILON ) {
// polar cap
lon = 0;
x = 0;
} else if ( span <= 1.0 ) {
x = (int)((dlon - lon) / span);
} else {
if ( (dlon >= 0) || (fabs(diff) < FG_EPSILON) ) {
lon = (int)( (int)(lon / span) * span);
} else {
// cout << " lon = " << lon
// << " tmp = " << (int)((lon-1) / span) << endl;
lon = (int)( (int)((lon + 1) / span) * span - span);
if ( lon < -180 ) {
lon = -180;
}
}
x = 0;
}
//
// then latitude
//
diff = dlat - (double)(int)dlat;
if ( (dlat >= 0) || (fabs(diff) < FG_EPSILON) ) {
lat = (int)dlat;
} else {
lat = (int)dlat - 1;
}
y = (int)((dlat - lat) * 8);
}
// default constructor
inline FGBucket::FGBucket() {}
// constructor for specified location
inline FGBucket::FGBucket(const double dlon, const double dlat) {
set_bucket(dlon, dlat);
}
// Parse a unique scenery tile index and find the lon, lat, x, and y
inline FGBucket::FGBucket(const long int bindex) {
long int index = bindex;
lon = index >> 14;
index -= lon << 14;
lon -= 180;
lat = index >> 6;
index -= lat << 6;
lat -= 90;
y = index >> 3;
index -= y << 3;
x = index;
}
// default destructor
inline FGBucket::~FGBucket() {}
// Generate the unique scenery tile index for this bucket
//
// The index is constructed as follows:
//
// 9 bits - to represent 360 degrees of longitude (-180 to 179)
// 8 bits - to represent 180 degrees of latitude (-90 to 89)
//
// Each 1 degree by 1 degree tile is further broken down into an 8x8
// grid. So we also need:
//
// 3 bits - to represent x (0 to 7)
// 3 bits - to represent y (0 to 7)
inline long int FGBucket::gen_index() {
return ((lon + 180) << 14) + ((lat + 90) << 6) + (y << 3) + x;
}
// return the center lon of a tile
inline double FGBucket::get_center_lon() {
double span = bucket_span( lat + y / 8.0 + FG_HALF_BUCKET_SPAN );
if ( span >= 1.0 ) {
return lon + span / 2.0;
} else {
return lon + x * span + span / 2.0;
}
}
// return the center lat of a tile
inline double FGBucket::get_center_lat() {
return lat + y / 8.0 + FG_HALF_BUCKET_SPAN;
}
// offset a bucket struct by the specified tile units in the X & Y
// direction
FGBucket fgBucketOffset( double dlon, double dlat, int x, int y );
/*
// Given a lat/lon, fill in the local tile index array
void fgBucketGenIdxArray(fgBUCKET *p1, fgBUCKET *tiles, int width, int height);
inline bool
operator== ( const fgBUCKET& b1, const fgBUCKET& b2 )
{
return ( b1.lon == b2.lon &&
b1.lat == b2.lat &&
b1.x == b2.x &&
b1.y == b2.y );
}
inline string
fgBucketGenIndex( const fgBUCKET& p )
{
char index_str[256];
sprintf( index_str, "%ld", fgBucketGenIndex( &p ) );
return string( index_str );
}
inline string
fgBucketGenBasePath( const fgBUCKET& p )
{
char base_path[256];
fgBucketGenBasePath( &p, base_path );
return string( base_path );
}
*/
inline ostream&
operator<< ( ostream& out, const FGBucket& b )
{
return out << b.lon << ":" << b.x << ", " << b.lat << ":" << b.y;
}
#endif // _NEWBUCKET_HXX
// $Log$
// Revision 1.1 1999/02/08 23:52:16 curt
// Added a new "newbucket.[ch]xx" FGBucket class to replace the old
// fgBUCKET struct and C routines. This FGBucket class adjusts the tile
// width towards the poles to ensure the tiles are at least 8 miles wide.
//

32
Bucket/testbucket.cxx Normal file
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@ -0,0 +1,32 @@
// test new bucket routines
#include "newbucket.cxx"
main() {
double lat = 21.9625;
double lon = -110.0 + 0.0625;
/*
while ( lon < 180 ) {
FGBucket b1( lon, lat );
long int index = b1.gen_index();
FGBucket b2( index );
cout << lon << "," << lat << " ";
cout << b2 << " " << b2.get_center_lon() << ","
<< b2.get_center_lat() << endl;
lon += 0.125;
}
*/
FGBucket b1;
for ( int j = 2; j >= -2; j-- ) {
for ( int i = -2; i < 3; i++ ) {
b1 = fgBucketOffset(lon, lat, i, j);
cout << "(" << i << "," << j << ")" << b1 << "\t";
}
cout << endl;
}
}