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Fixed a problem with dividing the tile up into land use areas (original scheme

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left really tiny slivers on the edges.)
This commit is contained in:
curt 2000-11-29 20:17:27 +00:00
parent ebd254dae0
commit 698ca7b1a6
1 changed files with 33 additions and 17 deletions
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50
src/BuildTiles/Main/main.cxx
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@ -219,6 +219,30 @@ static void inline add_to_polys ( FGPolygon &accum, const FGPolygon &poly) {
}
// make the area specified area, look up the land cover type, and add
// it to polys
static void make_area( const LandCover &cover, FGPolygon *polys,
double x1, double y1, double x2, double y2,
double half_dx, double half_dy )
{
// Look up the land cover for the square
int cover_value = cover.getValue( x1 + half_dx, y1 + half_dy );
cout << " position: " << x1 << ',' << y1 << ','
<< cover.getDescUSGS(cover_value) << endl;
AreaType area = translateUSGSCover(cover_value);
if (area != DefaultArea) {
// Create a square polygon and merge it into the list.
FGPolygon poly;
poly.erase();
poly.add_node(0, Point3D(x1, y1, 0.0));
poly.add_node(0, Point3D(x1, y2, 0.0));
poly.add_node(0, Point3D(x2, y2, 0.0));
poly.add_node(0, Point3D(x2, y1, 0.0));
add_to_polys(polys[area], poly);
}
}
// Generate polygons from la and-cover raster. Horizontally- or
// vertically-adjacent polygons will be merged automatically.
static int actual_load_landcover ( FGConstruct & c,
@ -245,6 +269,9 @@ static int actual_load_landcover ( FGConstruct & c,
double dx = 1.0 / 120.0;
double dy = dx;
double half_dx = dx * 0.5;
double half_dy = half_dx;
// Figure out how many units wide and high this tile is; each unit
// is 30 arc seconds.
// int x_span = int(120 * bucket_span(base_lat)); // arcsecs of longitude
@ -255,32 +282,21 @@ static int actual_load_landcover ( FGConstruct & c,
double x2 = x1 + dx;
double y2 = y1 + dy;
while ( x1 < max_lon ) {
while ( y1 < max_lat ) {
// Look up the land cover for the square
int cover_value = cover.getValue(x1 + (1.0/240.0),
y1 + (1.0/240.0));
cout << " position: " << x1 << ',' << y1 << ','
<< cover.getDescUSGS(cover_value) << endl;
AreaType area = translateUSGSCover(cover_value);
if (area != DefaultArea) {
// Create a square polygon and merge it into the list.
poly.erase();
poly.add_node(0, Point3D(x1, y1, 0.0));
poly.add_node(0, Point3D(x1, y2, 0.0));
poly.add_node(0, Point3D(x2, y2, 0.0));
poly.add_node(0, Point3D(x2, y1, 0.0));
add_to_polys(polys[area], poly);
}
while ( x1 < max_lon - (dx + half_dx) ) {
while ( y1 < max_lat - (dy + half_dy) ) {
make_area( cover, polys, x1, y1, x2, y2, half_dx, half_dy );
y1 = y2;
y2 += dy;
}
make_area( cover, polys, x1, y1, x2, max_lat, half_dx, half_dy );
x1 = x2;
x2 += dx;
y1 = base_lat;
y2 = y1 + dy;
}
make_area( cover, polys, x1, y1, max_lon, max_lat, half_dx, half_dy );
// Now that we're finished looking up land cover, we have a list
// of lists of polygons, one (possibly-empty) list for each area