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Working on polygon triangulation/tesselation.

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This commit is contained in:
curt 2000-05-09 00:24:41 +00:00
parent 3c914ac718
commit 7e21f8b28f
5 changed files with 248 additions and 38 deletions
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7
src/Airports/GenAirports/Makefile.am
View file

@ -37,7 +37,12 @@ genapts_LDADD = \
$(top_builddir)/src/Lib/Polygon/libPolygon.a \
$(top_builddir)/src/Lib/poly2tri/libpoly2tri.a \
$(top_builddir)/src/Lib/Build/libBuild.a \
$(top_builddir)/src/Lib/Triangle/libTriangle.a \
-lsgbucket -lsgdebug -lsgmath -lsgmisc -lz -lgpc \
$(base_LIBS)
INCLUDES += -I$(top_builddir) -I$(top_builddir)/src -I$(top_builddir)/src/Lib
INCLUDES += \
-I$(top_builddir) \
-I$(top_builddir)/src \
-I$(top_builddir)/src/Lib \
-I$(top_builddir)/src/Construct

12
src/Airports/GenAirports/build.cxx
View file

@ -44,9 +44,11 @@
#include <simgear/misc/texcoord.hxx>
#include <Array/array.hxx>
#include <Build/poly_support.hxx>
#include <Build/trinodes.hxx>
#include <Polygon/index.hxx>
#include <Polygon/polygon.hxx>
#include <Triangulate/trieles.hxx>
#include "convex_hull.hxx"
#include "point2d.hxx"
@ -960,6 +962,16 @@ void build_airport( string airport_raw, string_list& runways_raw,
}
base_nodes = add_nodes_to_poly( base_nodes, tmp_nodes );
// new stripper approach
cout << "Ready to try new striper" << endl;
cout << "First calculate a 'point inside' for each contour and hole"
<< endl;
/* 1 */ calc_points_inside( base_nodes );
for ( int i = 0; i < base_nodes.contours(); ++i ) {
cout << base_nodes.get_point_inside( i ) << endl;
}
/* 2 */ triele_list base_tris = polygon_tesselate( base_nodes, -1 );
// generate convex hull and strip version
FGPolygon base_strips = polygon_to_tristrip( base_nodes );

4
src/Airports/GenAirports/main.cxx
View file

@ -296,9 +296,7 @@ int main( int argc, char **argv ) {
exit(-1);
}
// throw away the first 3 lines
in.getline(tmp, 256);
in.getline(tmp, 256);
// throw away the first line
in.getline(tmp, 256);
last_airport = "";

252
src/Lib/Geometry/poly_support.cxx
View file

@ -36,6 +36,7 @@ extern "C" {
#include <Triangle/triangle.h>
}
#include "poly_support.hxx"
#include "trinodes.hxx"
@ -225,25 +226,39 @@ Point3D calc_point_inside( const FGPolygon& p, const int contour,
}
// basic triangulation of a polygon with out adding points or
// splitting edges
static triele_list triangulate_contour( const point_list contour,
const point_list holes ) {
// basic triangulation of a polygon contour out adding points or
// splitting edges. If contour >= 0 just tesselate the specified
// contour.
triele_list polygon_tesselate( const FGPolygon poly, const int contour ) {
// triangle list
triele_list elelist;
struct triangulateio in, out, vorout;
int counter;
int counter, offset;
// point list
double max_x = contour[0].x();
in.numberofpoints = contour.size();
double max_x = poly.get_contour(0)[0].x();
int total_pts = 0;
for ( int i = 0; i < poly.contours(); ++i ) {
if ( (contour < 0) || poly.get_hole_flag(i) || (i == contour) ) {
total_pts += poly.contour_size( i );
}
}
in.numberofpoints = total_pts;
in.pointlist = (REAL *) malloc(in.numberofpoints * 2 * sizeof(REAL));
for ( int i = 0; i < in.numberofpoints; ++i ) {
in.pointlist[2*i] = contour[i].x();
in.pointlist[2*i + 1] = contour[i].y();
if ( contour[i].x() > max_x ) {
max_x = contour[i].x();
counter = 0;
for ( int i = 0; i < poly.contours(); ++i ) {
if ( (contour < 0) || poly.get_hole_flag(i) || (i == contour) ) {
point_list contour = poly.get_contour( i );
for ( int j = 0; j < (int)contour.size(); ++j ) {
in.pointlist[2*counter] = contour[j].x();
in.pointlist[2*counter + 1] = contour[j].y();
if ( contour[j].x() > max_x ) {
max_x = contour[j].x();
}
++counter;
}
}
}
@ -251,8 +266,15 @@ static triele_list triangulate_contour( const point_list contour,
in.pointattributelist = (REAL *) malloc(in.numberofpoints *
in.numberofpointattributes *
sizeof(REAL));
for ( int i = 0; i < in.numberofpoints * in.numberofpointattributes; ++i) {
in.pointattributelist[i] = contour[i].z();
counter = 0;
for ( int i = 0; i < poly.contours(); ++i ) {
if ( (contour < 0) || poly.get_hole_flag(i) || (i == contour) ) {
point_list contour = poly.get_contour( i );
for ( int j = 0; j < (int)contour.size(); ++j ) {
in.pointattributelist[counter] = contour[j].z();
++counter;
}
}
}
in.pointmarkerlist = (int *) malloc(in.numberofpoints * sizeof(int));
@ -264,26 +286,42 @@ static triele_list triangulate_contour( const point_list contour,
in.numberoftriangles = 0;
// segment list
in.numberofsegments = contour.size();
in.numberofsegments = total_pts;
in.segmentlist = (int *) malloc(in.numberofsegments * 2 * sizeof(int));
in.segmentmarkerlist = (int *) malloc(in.numberofsegments * sizeof(int));
counter = 0;
for ( int i = 0; i < in.numberofsegments - 1; ++i ) {
in.segmentlist[counter++] = i;
in.segmentlist[counter++] = i + 1;
offset = 0;
for ( int i = 0; i < poly.contours(); ++i ) {
point_list contour = poly.get_contour( i );
for ( int j = 0; j < (int)contour.size() - 1; ++j ) {
in.segmentlist[counter++] = i + offset;
in.segmentlist[counter++] = i + offset + 1;
in.segmentmarkerlist[i] = 0;
}
in.segmentlist[counter++] = in.numberofsegments - 1;
in.segmentlist[counter++] = 0;
in.segmentmarkerlist[in.numberofsegments - 1] = 0;
in.segmentlist[counter++] = (int)contour.size() + offset - 1;
in.segmentlist[counter++] = 0 + offset;
in.segmentmarkerlist[(int)contour.size() - 1] = 0;
offset += contour.size();
}
// hole list
in.numberofholes = holes.size() + 1;
int hole_count = 0;
for ( int i = 0; i < poly.contours(); ++i ) {
if ( poly.get_hole_flag( i ) ) {
++hole_count;
}
}
in.numberofholes = hole_count + 1;
in.holelist = (REAL *) malloc(in.numberofholes * 2 * sizeof(REAL));
counter = 0;
for ( int i = 0; i < (int)holes.size(); ++i ) {
in.holelist[counter++] = holes[i].x();
in.holelist[counter++] = holes[i].y();
for ( int i = 0; i < poly.contours(); ++i ) {
if ( poly.get_hole_flag( i ) ) {
in.holelist[counter++] = poly.get_point_inside(i).x();
in.holelist[counter++] = poly.get_point_inside(i).y();
}
}
// outside of polygon
in.holelist[counter++] = max_x + 1.0;
@ -379,12 +417,159 @@ static triele_list triangulate_contour( const point_list contour,
}
// basic triangulation of a polygon with out adding points or
// splitting edges and without regard for holes
static triele_list contour_tesselate( const point_list contour ) {
// triangle list
triele_list elelist;
struct triangulateio in, out, vorout;
int counter;
// point list
double max_x = contour[0].x();
in.numberofpoints = contour.size();
in.pointlist = (REAL *) malloc(in.numberofpoints * 2 * sizeof(REAL));
for ( int i = 0; i < in.numberofpoints; ++i ) {
in.pointlist[2*i] = contour[i].x();
in.pointlist[2*i + 1] = contour[i].y();
if ( contour[i].x() > max_x ) {
max_x = contour[i].x();
}
}
in.numberofpointattributes = 1;
in.pointattributelist = (REAL *) malloc(in.numberofpoints *
in.numberofpointattributes *
sizeof(REAL));
for ( int i = 0; i < in.numberofpoints * in.numberofpointattributes; ++i) {
in.pointattributelist[i] = contour[i].z();
}
in.pointmarkerlist = (int *) malloc(in.numberofpoints * sizeof(int));
for ( int i = 0; i < in.numberofpoints; ++i) {
in.pointmarkerlist[i] = 0;
}
// triangle list
in.numberoftriangles = 0;
// segment list
in.numberofsegments = contour.size();
in.segmentlist = (int *) malloc(in.numberofsegments * 2 * sizeof(int));
in.segmentmarkerlist = (int *) malloc(in.numberofsegments * sizeof(int));
counter = 0;
for ( int i = 0; i < in.numberofsegments - 1; ++i ) {
in.segmentlist[counter++] = i;
in.segmentlist[counter++] = i + 1;
in.segmentmarkerlist[i] = 0;
}
in.segmentlist[counter++] = in.numberofsegments - 1;
in.segmentlist[counter++] = 0;
in.segmentmarkerlist[in.numberofsegments - 1] = 0;
// hole list
in.numberofholes = 1;
in.holelist = (REAL *) malloc(in.numberofholes * 2 * sizeof(REAL));
// outside of polygon
counter = 0;
in.holelist[counter++] = max_x + 1.0;
in.holelist[counter++] = 0.0;
// region list
in.numberofregions = 0;
in.regionlist = (REAL *) NULL;
// prep the output structures
out.pointlist = (REAL *) NULL; // Not needed if -N switch used.
// Not needed if -N switch used or number of point attributes is zero:
out.pointattributelist = (REAL *) NULL;
out.pointmarkerlist = (int *) NULL; // Not needed if -N or -B switch used.
out.trianglelist = (int *) NULL; // Not needed if -E switch used.
// Not needed if -E switch used or number of triangle attributes is zero:
out.triangleattributelist = (REAL *) NULL;
out.neighborlist = (int *) NULL; // Needed only if -n switch used.
// Needed only if segments are output (-p or -c) and -P not used:
out.segmentlist = (int *) NULL;
// Needed only if segments are output (-p or -c) and -P and -B not used:
out.segmentmarkerlist = (int *) NULL;
out.edgelist = (int *) NULL; // Needed only if -e switch used.
out.edgemarkerlist = (int *) NULL; // Needed if -e used and -B not used.
vorout.pointlist = (REAL *) NULL; // Needed only if -v switch used.
// Needed only if -v switch used and number of attributes is not zero:
vorout.pointattributelist = (REAL *) NULL;
vorout.edgelist = (int *) NULL; // Needed only if -v switch used.
vorout.normlist = (REAL *) NULL; // Needed only if -v switch used.
// TEMPORARY
// write_out_data(&in);
// Triangulate the points. Switches are chosen to read and write
// a PSLG (p), number everything from zero (z), and produce an
// edge list (e), and a triangle neighbor list (n).
// no new points on boundary (Y), no internal segment
// splitting (YY), no quality refinement (q)
string tri_options;
tri_options = "pzYYen";
cout << "Triangulation with options = " << tri_options << endl;
triangulate( (char *)tri_options.c_str(), &in, &out, &vorout );
// TEMPORARY
// write_out_data(&out);
// now copy the results back into the corresponding FGTriangle
// structures
// triangles
elelist.clear();
int n1, n2, n3;
double attribute;
for ( int i = 0; i < out.numberoftriangles; ++i ) {
n1 = out.trianglelist[i * 3];
n2 = out.trianglelist[i * 3 + 1];
n3 = out.trianglelist[i * 3 + 2];
if ( out.numberoftriangleattributes > 0 ) {
attribute = out.triangleattributelist[i];
} else {
attribute = 0.0;
}
// cout << "triangle = " << n1 << " " << n2 << " " << n3 << endl;
elelist.push_back( FGTriEle( n1, n2, n3, attribute ) );
}
// free mem allocated to the "Triangle" structures
free(in.pointlist);
free(in.pointattributelist);
free(in.pointmarkerlist);
free(in.regionlist);
free(out.pointlist);
free(out.pointattributelist);
free(out.pointmarkerlist);
free(out.trianglelist);
free(out.triangleattributelist);
// free(out.trianglearealist);
free(out.neighborlist);
free(out.segmentlist);
free(out.segmentmarkerlist);
free(out.edgelist);
free(out.edgemarkerlist);
free(vorout.pointlist);
free(vorout.pointattributelist);
free(vorout.edgelist);
free(vorout.normlist);
return elelist;
}
// Find a point inside the polygon without regard for holes
static Point3D point_inside_hole( point_list contour ) {
point_list holes;
holes.clear();
triele_list elelist = triangulate_contour( contour, holes );
triele_list elelist = contour_tesselate( contour );
if ( elelist.size() <= 0 ) {
cout << "Error polygon triangulated to zero triangles!" << endl;
exit(-1);
@ -404,7 +589,8 @@ static Point3D point_inside_hole( point_list contour ) {
}
// Find a point inside the polygon without regard for holes
// Find a point inside a specific polygon contour taking holes into
// consideration
static Point3D point_inside_contour( const FGPolygon p, int contour ) {
point_list holes;
holes.clear();
@ -416,8 +602,7 @@ static Point3D point_inside_contour( const FGPolygon p, int contour ) {
}
}
triele_list elelist = triangulate_contour( p.get_contour( contour ),
holes );
triele_list elelist = polygon_tesselate( p, contour );
if ( elelist.size() <= 0 ) {
cout << "Error polygon triangulated to zero triangles!" << endl;
exit(-1);
@ -442,8 +627,12 @@ static Point3D point_inside_contour( const FGPolygon p, int contour ) {
// assigning attribute areas
void calc_points_inside( FGPolygon& p ) {
// first calculate an inside point for all holes
cout << "calculating points for poly with contours = " << p.contours()
<< endl;
for ( int i = 0; i < p.contours(); ++i ) {
if ( p.get_hole_flag( i ) ) {
cout << " hole = " << i << endl;
Point3D hole_pt = point_inside_hole( p.get_contour( i ) );
p.set_point_inside( i, hole_pt );
}
@ -453,6 +642,7 @@ void calc_points_inside( FGPolygon& p ) {
// into consideration the holes
for ( int i = 0; i < p.contours(); ++i ) {
if ( ! p.get_hole_flag( i ) ) {
cout << " enclosing contour = " << i << endl;
Point3D inside_pt = point_inside_contour( p, i );
p.set_point_inside( i, inside_pt );
}

9
src/Lib/Geometry/poly_support.hxx
View file

@ -35,18 +35,23 @@
#include <simgear/math/fg_types.hxx>
#include <Polygon/polygon.hxx>
#include <Triangulate/trieles.hxx>
#include "trinodes.hxx"
// basic triangulation of a polygon contour out adding points or
// splitting edges. If contour >= 0 just tesselate the specified
// contour.
triele_list polygon_tesselate( const FGPolygon poly, const int contour );
// calculate some "arbitrary" point inside the specified contour for
// assigning attribute areas. This requires data structures outside
// of "FGPolygon" which is why it is living over here in "Lib/Build"
Point3D calc_point_inside( const FGPolygon& p, const int contour,
const FGTriNodes& trinodes );
void calc_points_inside( const FGPolygon& p );
void calc_points_inside( FGPolygon& p );
#endif // _POLY_SUPPORT_HXX