simgear/Bucket/bucketutils.h
curt 91efc5ad87 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.
1999-02-08 23:52:13 +00:00

136 lines
3.8 KiB
C

// bucketutils.h -- support routines to handle fgBUCKET operations
//
// Written by Curtis Olson, started January 1998.
//
// Copyright (C) 1997 Curtis L. Olson - curt@infoplane.com
//
// 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 _BUCKETUTILS_H
#define _BUCKETUTILS_H
#ifdef __cplusplus
extern "C" {
#endif
typedef struct {
int lon; // longitude (-180 to 179)
int lat; // latitude (-90 to 89)
int x; // x (0 to 7)
int y; // y (0 to 7)
} fgBUCKET;
/* Generate the unique scenery tile index containing the specified
lon/lat parameters.
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) */
long int fgBucketGenIndex( const fgBUCKET *p);
// Parse a unique scenery tile index and find the lon, lat, x, and y
void fgBucketParseIndex(long int index, fgBUCKET *p);
// Build a path name from an tile index
void fgBucketGenBasePath( const fgBUCKET *p, char *path);
// offset a bucket struct by the specified amounts in the X & Y direction
void fgBucketOffset(fgBUCKET *in, fgBUCKET *out, int x, int y);
// Given a lat/lon in degrees, find the "bucket" or tile that it falls
// within
void fgBucketFind(double lon, double lat, fgBUCKET *p);
// Given a lat/lon, fill in the local tile index array
void fgBucketGenIdxArray(fgBUCKET *p1, fgBUCKET *tiles, int width, int height);
#ifdef __cplusplus
}
#endif
#endif // _BUCKETUTILS_H
// $Log$
// 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.
//
// Revision 1.3 1998/12/07 21:08:03 curt
// Added a const in a couple places to get rid of annoying compiler warnings.
//
// Revision 1.2 1998/07/04 00:46:48 curt
// typedef'd struct fgBUCKET.
//
// Revision 1.1 1998/04/08 23:28:59 curt
// Adopted Gnu automake/autoconf system.
//
// Revision 1.2 1998/01/24 00:03:28 curt
// Initial revision.
//
// Revision 1.1 1998/01/23 20:06:52 curt
// tileutils.* renamed to bucketutils.*
//
// Revision 1.6 1998/01/22 02:59:42 curt
// Changed #ifdef FILE_H to #ifdef _FILE_H
//
// Revision 1.5 1998/01/14 02:19:05 curt
// Makde offset_bucket visible to outside.
//
// Revision 1.4 1998/01/13 00:23:12 curt
// Initial changes to support loading and management of scenery tiles. Note,
// there's still a fair amount of work left to be done.
//
// Revision 1.3 1998/01/10 00:01:48 curt
// Misc api changes and tweaks.
//
// Revision 1.2 1998/01/08 02:22:28 curt
// Continue working on basic features.
//
// Revision 1.1 1998/01/07 23:50:52 curt
// "area" renamed to "tile"
//
// Revision 1.1 1998/01/07 23:23:40 curt
// Initial revision.
//