X-Git-Url: https://git.mxchange.org/?a=blobdiff_plain;f=simgear%2Fbucket%2Fnewbucket.cxx;h=0a2e542c3f706290728ee877a7e2a431a3faba31;hb=f205e918d9e1df28da3df69c6c58df6b6391916f;hp=f707d25217d58609896dbc3b6879cc915115989f;hpb=82459a2802a939434f9fc5b88d2b2aea58f0043d;p=simgear.git diff --git a/simgear/bucket/newbucket.cxx b/simgear/bucket/newbucket.cxx index f707d252..0a2e542c 100644 --- a/simgear/bucket/newbucket.cxx +++ b/simgear/bucket/newbucket.cxx @@ -3,7 +3,7 @@ * * Written by Curtis L. Olson, started February 1999. * - * Copyright (C) 1999 Curtis L. Olson - curt@flightgear.org + * Copyright (C) 1999 Curtis L. Olson - http://www.flightgear.org/~curt/ * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Library General Public @@ -15,29 +15,166 @@ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Library General Public License for more details. * - * You should have received a copy of the GNU Library General Public - * License along with this library; if not, write to the - * Free Software Foundation, Inc., 59 Temple Place - Suite 330, - * Boston, MA 02111-1307, USA. + * 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 Street, Fifth Floor, Boston, MA 02110-1301, USA. * * $Id$ **************************************************************************/ #ifdef HAVE_CONFIG_H -# include +# include #endif - #include -#include +#include #include "newbucket.hxx" +// default constructor +SGBucket::SGBucket() { +} + + +// constructor for specified location +SGBucket::SGBucket(const double dlon, const double dlat) { + set_bucket(dlon, dlat); +} + +SGBucket::SGBucket(const SGGeod& geod) { + set_bucket(geod); +} + +// create an impossible bucket if false +SGBucket::SGBucket(const bool is_good) { + set_bucket(0.0, 0.0); + if ( !is_good ) { + lon = -1000; + } +} + + +// Parse a unique scenery tile index and find the lon, lat, x, and y +SGBucket::SGBucket(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; +} + + +// Set the bucket params for the specified lat and lon +void SGBucket::set_bucket( double *lonlat ) { + set_bucket( lonlat[0], lonlat[1] ); +} + + +// Set the bucket params for the specified lat and lon +void SGBucket::set_bucket( double dlon, double dlat ) { + // + // latitude first + // + double span = sg_bucket_span( dlat ); + double diff = dlon - (double)(int)dlon; + + // cout << "diff = " << diff << " span = " << span << endl; + + /* Calculate the greatest integral longitude less than + * or equal to the given longitude (floor(dlon)), + * but attribute coordinates near the east border + * to the next tile. + */ + if ( (dlon >= 0) || (fabs(diff) < SG_EPSILON) ) { + lon = (int)dlon; + } else { + lon = (int)dlon - 1; + } + + // find subdivision or super lon if needed + if ( span < SG_EPSILON ) { + /* sg_bucket_span() never returns 0.0 + * or anything near it, so this really + * should not occur at any time. + */ + // polar cap + lon = 0; + x = 0; + } else if ( span <= 1.0 ) { + /* We have more than one tile per degree of + * longitude, so we need an x offset. + */ + x = (int)((dlon - lon) / span); + } else { + /* We have one or more degrees per tile, + * so we need to find the base longitude + * of that tile. + * + * First we calculate the integral base longitude + * (e.g. -85.5 => -86) and then find the greatest + * multiple of span that is less than or equal to + * that longitude. + * + * That way, the Greenwich Meridian is always + * a tile border. + * + * This gets us into trouble with the polar caps, + * which have width 360 and thus either span + * the range from 0 to 360 or from -360 to 0 + * degrees, depending on whether lon is positive + * or negative! + * + * We also get into trouble with the 8 degree tiles + * north of 88N and south of 88S, because the west- + * and east-most tiles in that range will cover 184W + * to 176W and 176E to 184E respectively, with their + * center at 180E/W! + */ + lon=(int)floor(floor((lon+SG_EPSILON)/span)*span); + /* Correct the polar cap issue */ + if ( lon < -180 ) { + lon = -180; + } + x = 0; + } + + // + // then latitude + // + diff = dlat - (double)(int)dlat; + + /* Again, a modified floor() function (see longitude) */ + if ( (dlat >= 0) || (fabs(diff) < SG_EPSILON) ) { + lat = (int)dlat; + } else { + lat = (int)dlat - 1; + } + /* Latitude base and offset are easier, as + * tiles always are 1/8 degree of latitude wide. + */ + y = (int)((dlat - lat) * 8); +} + + +void SGBucket::set_bucket(const SGGeod& geod) +{ + set_bucket(geod.getLongitudeDeg(), geod.getLatitudeDeg()); +} + // Build the path name for this bucket -string FGBucket::gen_base_path() const { +std::string SGBucket::gen_base_path() const { // long int index; int top_lon, top_lat, main_lon, main_lat; char hem, pole; @@ -75,29 +212,68 @@ string FGBucket::gen_base_path() const { main_lat *= -1; } - sprintf(raw_path, "%c%03d%c%02d/%c%03d%c%02d", + snprintf(raw_path, 256, "%c%03d%c%02d/%c%03d%c%02d", hem, top_lon, pole, top_lat, hem, main_lon, pole, main_lat); - FGPath path( raw_path ); + SGPath path( raw_path ); return path.str(); } +// return width of the tile in degrees +double SGBucket::get_width() const { + return sg_bucket_span( get_center_lat() ); +} + + +// return height of the tile in degrees +double SGBucket::get_height() const { + return SG_BUCKET_SPAN; +} + + +// return width of the tile in meters +double SGBucket::get_width_m() const { + double clat = (int)get_center_lat(); + if ( clat > 0 ) { + clat = (int)clat + 0.5; + } else { + clat = (int)clat - 0.5; + } + double clat_rad = clat * SGD_DEGREES_TO_RADIANS; + double cos_lat = cos( clat_rad ); + double local_radius = cos_lat * SG_EQUATORIAL_RADIUS_M; + double local_perimeter = local_radius * SGD_2PI; + double degree_width = local_perimeter / 360.0; + + return get_width() * degree_width; +} + + +// return height of the tile in meters +double SGBucket::get_height_m() const { + double perimeter = SG_EQUATORIAL_RADIUS_M * SGD_2PI; + double degree_height = perimeter / 360.0; + + return SG_BUCKET_SPAN * degree_height; +} + + // 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; +SGBucket sgBucketOffset( double dlon, double dlat, int dx, int dy ) { + SGBucket result( dlon, dlat ); + double clat = result.get_center_lat() + dy * SG_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 ); + double span = sg_bucket_span( clat ); // walk dx units in the lon direction double tmp = dlon + dx * span; @@ -114,7 +290,7 @@ FGBucket fgBucketOffset( double dlon, double dlat, int dx, int dy ) { // calculate the offset between two buckets -void fgBucketDiff( const FGBucket& b1, const FGBucket& b2, int *dx, int *dy ) { +void sgBucketDiff( const SGBucket& b1, const SGBucket& b2, int *dx, int *dy ) { // Latitude difference double c1_lat = b1.get_center_lat(); @@ -122,26 +298,42 @@ void fgBucketDiff( const FGBucket& b1, const FGBucket& b2, int *dx, int *dy ) { double diff_lat = c2_lat - c1_lat; #ifdef HAVE_RINT - *dy = (int)rint( diff_lat / FG_BUCKET_SPAN ); + *dy = (int)rint( diff_lat / SG_BUCKET_SPAN ); #else if ( diff_lat > 0 ) { - *dy = (int)( diff_lat / FG_BUCKET_SPAN + 0.5 ); + *dy = (int)( diff_lat / SG_BUCKET_SPAN + 0.5 ); } else { - *dy = (int)( diff_lat / FG_BUCKET_SPAN - 0.5 ); + *dy = (int)( diff_lat / SG_BUCKET_SPAN - 0.5 ); } #endif // longitude difference - double c1_lon = b1.get_center_lon(); - double c2_lon = b2.get_center_lon(); - double diff_lon = c2_lon - c1_lon; - double span; - if ( bucket_span(c1_lat) <= bucket_span(c2_lat) ) { - span = bucket_span(c1_lat); + double diff_lon=0.0; + double span=0.0; + + SGBucket tmp_bucket; + // To handle crossing the bucket size boundary + // we need to account for different size buckets. + + if ( sg_bucket_span(c1_lat) <= sg_bucket_span(c2_lat) ) + { + span = sg_bucket_span(c1_lat); } else { - span = bucket_span(c2_lat); + span = sg_bucket_span(c2_lat); + } + + diff_lon = b2.get_center_lon() - b1.get_center_lon(); + + if (diff_lon <0.0) + { + diff_lon -= b1.get_width()*0.5 + b2.get_width()*0.5 - span; + } + else + { + diff_lon += b1.get_width()*0.5 + b2.get_width()*0.5 - span; } + #ifdef HAVE_RINT *dx = (int)rint( diff_lon / span ); #else @@ -153,4 +345,13 @@ void fgBucketDiff( const FGBucket& b1, const FGBucket& b2, int *dx, int *dy ) { #endif } +void sgGetBuckets( const SGGeod& min, const SGGeod& max, std::vector& list ) { + double lon, lat, span; + for (lat = min.getLatitudeDeg(); lat <= max.getLatitudeDeg(); lat += SG_BUCKET_SPAN) { + span = sg_bucket_span( lat ); + for (lon = min.getLongitudeDeg(); lon <= max.getLongitudeDeg(); lon += span) { + list.push_back( SGBucket(lon , lat) ); + } + } +}