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Don't automatically try to preserve polygon elevations, but instead provide

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a method() to inherit elevations from another polygon.  This gives the calling
layer much more control over preserving or not preserving elevations.
This commit is contained in:
curt 2003-03-13 20:25:02 +00:00
parent ba3114a8b5
commit d70cd72fbd
2 changed files with 93 additions and 97 deletions
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173
src/Lib/Polygon/polygon.cxx
View file

@ -42,7 +42,8 @@ SG_USING_STD(endl);
#include "polygon.hxx"
// Constructor
TGPolygon::TGPolygon( void ) {
TGPolygon::TGPolygon( void )
{
}
@ -51,6 +52,83 @@ TGPolygon::~TGPolygon( void ) {
}
// Set the elevations of points in the current polgyon based on the
// elevations of points in source. For points that are not found in
// source, propogate the value from the nearest matching point.
void TGPolygon::inherit_elevations( const TGPolygon &source ) {
TGTriNodes nodes;
nodes.clear();
int i, j;
// build a list of points from the source and dest polygons
for ( i = 0; i < source.contours(); ++i ) {
for ( j = 0; j < source.contour_size(i); ++j ) {
Point3D p = source.get_pt( i, j );
nodes.unique_add( p );
}
}
// traverse the dest polygon and build a mirror image but with
// elevations from the source polygon
for ( i = 0; i < poly.size(); ++i ) {
for ( j = 0; j < poly[i].size(); ++j ) {
Point3D p = poly[i][j];
int index = nodes.find( p );
if ( index >= 0 ) {
Point3D ref = nodes.get_node( index );
poly[i][j].setz( ref.z() );
}
}
}
// now post process result to catch any nodes that weren't updated
// (because the clipping process may have added points which
// weren't in the original.)
double last = -9999.0;
for ( i = 0; i < poly.size(); ++i ) {
// go front ways
last = -9999.0;
for ( j = 0; j < poly[i].size(); ++j ) {
Point3D p = poly[i][j];
if ( p.z() > -9000 ) {
last = p.z();
} else {
if ( last > -9000 ) {
poly[i][j].setz( last );
}
}
}
// go back ways
last = -9999.0;
for ( j = poly[i].size() - 1; j >= 0; --j ) {
Point3D p = poly[i][j];
if ( p.z() > -9000 ) {
last = p.z();
} else {
if ( last > -9000 ) {
poly[i][j].setz( last );
}
}
}
}
}
// Set the elevations of all points to the specified values
void TGPolygon::set_elevations( double elev ) {
for ( unsigned i = 0; i < poly.size(); ++i ) {
for ( unsigned int j = 0; j < poly[i].size(); ++j ) {
poly[i][j].setz( elev );
}
}
}
// Calculate theta of angle (a, b, c)
static double calc_angle(point2d a, point2d b, point2d c) {
point2d u, v;
@ -255,95 +333,6 @@ void make_gpc_poly( const TGPolygon& in, gpc_polygon *out ) {
}
// Set the elevations of points in dest based on the elevations of
// points in source. For points in dest that are not in source,
// propogate the value from the nearest matching point.
static TGPolygon preserve_elevations( const TGPolygon &source,
const TGPolygon &dest )
{
TGTriNodes nodes;
nodes.clear();
int i, j;
// build a list of points from the source polygon
for ( i = 0; i < source.contours(); ++i ) {
for ( j = 0; j < source.contour_size(i); ++j ) {
Point3D p = source.get_pt( i, j );
nodes.unique_add( p );
}
}
// traverse the dest polygon and build a mirror image but with
// elevations from the source polygon
TGPolygon result;
result.erase();
for ( i = 0; i < dest.contours(); ++i ) {
for ( j = 0; j < dest.contour_size(i); ++j ) {
Point3D p = dest.get_pt( i, j );
int index = nodes.find( p );
if ( index >= 0 ) {
Point3D ref = nodes.get_node( index );
p.setz( ref.z() );
} else {
p.setz( -9999.0 );
}
result.add_node( i, p );
}
}
// now post process result to catch any nodes that weren't updated
// (because the clipping process may have added points which
// weren't in the original.)
double last = -9999.0;
for ( i = 0; i < result.contours(); ++i ) {
// go front ways
last = -9999.0;
for ( j = 0; j < result.contour_size(i); ++j ) {
Point3D p = result.get_pt( i, j );
if ( p.z() > -9000 ) {
last = p.z();
} else {
if ( last > -9000 ) {
p.setz( last );
result.set_pt( i, j, p );
}
}
}
// go back ways
last = -9999.0;
for ( j = result.contour_size(i) - 1; j >= 0; --j ) {
Point3D p = result.get_pt( i, j );
if ( p.z() > -9000 ) {
last = p.z();
} else {
if ( last > -9000 ) {
p.setz( last );
result.set_pt( i, j, p );
}
}
}
// finally drop ten and punt on any points that are still
// elevation-less and set their elevations to zero.
for ( j = 0; j < result.contour_size(i); ++j ) {
Point3D p = result.get_pt( i, j );
if ( p.z() < -9000 ) {
p.setz( 0.0 );
result.set_pt( i, j, p );
}
}
}
return result;
}
// Set operation type
typedef enum {
POLY_DIFF, // Difference
@ -403,7 +392,7 @@ TGPolygon polygon_clip( clip_op poly_op, const TGPolygon& subject,
for ( int j = 0; j < gpc_result->contour[i].num_vertices; j++ ) {
Point3D p( gpc_result->contour[i].vertex[j].x,
gpc_result->contour[i].vertex[j].y,
0 );
-9999.0 );
// junkp = in_nodes.get_node( index );
// fprintf(junkfp, "%.4f %.4f\n", junkp.x(), junkp.y());
result.add_node(i, p);
@ -422,8 +411,6 @@ TGPolygon polygon_clip( clip_op poly_op, const TGPolygon& subject,
gpc_free_polygon( gpc_clip );
gpc_free_polygon( gpc_result );
result = preserve_elevations( clip, result );
return result;
}

17
src/Lib/Polygon/polygon.hxx
View file

@ -54,10 +54,10 @@ class TGPolygon {
private:
polytype poly; // polygons
point_list inside_list; // point inside list
int_list hole_list; // hole flag list
polytype poly; // polygons
point_list inside_list; // point inside list
int_list hole_list; // hole flag list
public:
// Constructor and destructor
@ -149,6 +149,15 @@ public:
return false;
}
// Set the elevations of points in the current polgyon based on
// the elevations of points in source. For points that are not
// found in source, propogate the value from the nearest matching
// point.
void inherit_elevations( const TGPolygon &source );
// Set the elevations of all points to the specified values
void set_elevations( double elev );
// shift every point in the polygon by lon, lat
void shift( double lon, double lat );