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flightgear/Triangulate/triangle.cxx
curt b18c82c33b Dynamically update "error" until the resulting tile data scales within 
a lower and upper bounds.
1999-04-05 02:16:51 +00:00

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// triangle.cxx -- "Triangle" interface class
//
// Written by Curtis Olson, started March 1999.
//
// Copyright (C) 1999 Curtis L. Olson - curt@flightgear.org
//
// 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)
#include "triangle.hxx"
#include "tripoly.hxx"
// Constructor
FGTriangle::FGTriangle( void ) {
}
// Destructor
FGTriangle::~FGTriangle( void ) {
}
// populate this class based on the specified gpc_polys list
int
FGTriangle::build( const point_list& corner_list,
const point_list& fit_list,
const FGgpcPolyList& gpc_polys )
{
FGTriPoly poly;
int index;
in_nodes.clear();
trisegs.clear();
// Point3D junkp;
// int junkc = 0;
// char junkn[256];
// FILE *junkfp;
// traverse the dem corner and fit lists and gpc_polys building a
// unified node list and converting the polygons so that they
// reference the node list by index (starting at zero) rather than
// listing the points explicitely
// first the corners since these are important
const_point_list_iterator f_current, f_last;
f_current = corner_list.begin();
f_last = corner_list.end();
for ( ; f_current != f_last; ++f_current ) {
index = in_nodes.unique_add( *f_current );
}
// next process the polygons
gpc_polygon *gpc_poly;
const_gpcpoly_iterator current, last;
// process polygons in priority order
cout << "prepairing node list and polygons" << endl;
for ( int i = 0; i < FG_MAX_AREA_TYPES; ++i ) {
polylist[i].clear();
// cout << "area type = " << i << endl;
current = gpc_polys.polys[i].begin();
last = gpc_polys.polys[i].end();
for ( ; current != last; ++current ) {
gpc_poly = *current;
cout << "processing a polygon, contours = "
<< gpc_poly->num_contours << endl;
if (gpc_poly->num_contours <= 0 ) {
cout << "FATAL ERROR! no contours in this polygon" << endl;
exit(-1);
}
if (gpc_poly->num_contours > 1 ) {
cout << "FATAL ERROR! no multi-contour support" << endl;
sleep(2);
// exit(-1);
}
for ( int j = 0; j < gpc_poly->num_contours; j++ ) {
cout << " processing contour, nodes = "
<< gpc_poly->contour[j].num_vertices << endl;
poly.erase();
// sprintf(junkn, "g.%d", junkc++);
// junkfp = fopen(junkn, "w");
for ( int k = 0; k < gpc_poly->contour[j].num_vertices; k++ ) {
Point3D p( gpc_poly->contour[j].vertex[k].x,
gpc_poly->contour[j].vertex[k].y,
0 );
index = in_nodes.unique_add( p );
// junkp = in_nodes.get_node( index );
// fprintf(junkfp, "%.4f %.4f\n", junkp.x(), junkp.y());
poly.add_node(index);
// cout << index << endl;
}
// fprintf(junkfp, "%.4f %.4f\n",
// gpc_poly->contour[j].vertex[0].x,
// gpc_poly->contour[j].vertex[0].y);
// fclose(junkfp);
poly.calc_point_inside( in_nodes );
polylist[i].push_back(poly);
}
}
}
// last, do the rest of the height nodes
f_current = fit_list.begin();
f_last = fit_list.end();
for ( ; f_current != f_last; ++f_current ) {
index = in_nodes.course_add( *f_current );
}
for ( int i = 0; i < FG_MAX_AREA_TYPES; ++i ) {
if ( polylist[i].size() ) {
cout << get_area_name((AreaType)i) << " = "
<< polylist[i].size() << endl;
}
}
// traverse the polygon lists and build the segment (edge) list
// that is used by the "Triangle" lib.
int i1, i2;
point_list node_list = in_nodes.get_node_list();
for ( int i = 0; i < FG_MAX_AREA_TYPES; ++i ) {
// cout << "area type = " << i << endl;
tripoly_list_iterator tp_current, tp_last;
tp_current = polylist[i].begin();
tp_last = polylist[i].end();
// process each polygon in list
for ( ; tp_current != tp_last; ++tp_current ) {
poly = *tp_current;
for ( int j = 0; j < (int)(poly.size()) - 1; ++j ) {
i1 = poly.get_pt_index( j );
i2 = poly.get_pt_index( j + 1 );
// calc_line_params(i1, i2, &m, &b);
trisegs.unique_divide_and_add( node_list, FGTriSeg(i1, i2) );
}
i1 = poly.get_pt_index( 0 );
i2 = poly.get_pt_index( poly.size() - 1 );
// calc_line_params(i1, i2, &m, &b);
trisegs.unique_divide_and_add( node_list, FGTriSeg(i1, i2) );
}
}
return 0;
}
static void write_out_data(struct triangulateio *out) {
FILE *node = fopen("tile.node", "w");
fprintf(node, "%d 2 %d 0\n",
out->numberofpoints, out->numberofpointattributes);
for (int i = 0; i < out->numberofpoints; i++) {
fprintf(node, "%d %.6f %.6f %.2f\n",
i, out->pointlist[2*i], out->pointlist[2*i + 1], 0.0);
}
fclose(node);
FILE *ele = fopen("tile.ele", "w");
fprintf(ele, "%d 3 0\n", out->numberoftriangles);
for (int i = 0; i < out->numberoftriangles; i++) {
fprintf(ele, "%d ", i);
for (int j = 0; j < out->numberofcorners; j++) {
fprintf(ele, "%d ", out->trianglelist[i * out->numberofcorners + j]);
}
for (int j = 0; j < out->numberoftriangleattributes; j++) {
fprintf(ele, "%.6f ",
out->triangleattributelist[i
* out->numberoftriangleattributes
+ j]
);
}
fprintf(ele, "\n");
}
fclose(ele);
FILE *fp = fopen("tile.poly", "w");
fprintf(fp, "0 2 1 0\n");
fprintf(fp, "%d 0\n", out->numberofsegments);
for (int i = 0; i < out->numberofsegments; ++i) {
fprintf(fp, "%d %d %d\n",
i, out->segmentlist[2*i], out->segmentlist[2*i + 1]);
}
fprintf(fp, "%d\n", out->numberofholes);
for (int i = 0; i < out->numberofholes; i++) {
fprintf(fp, "%d %.6f %.6f\n",
i, out->holelist[2*i], out->holelist[2*i + 1]);
}
fprintf(fp, "%d\n", out->numberofregions);
for (int i = 0; i < out->numberofregions; i++) {
fprintf(fp, "%d %.6f %.6f %.6f\n",
i, out->regionlist[4*i], out->regionlist[4*i + 1],
out->regionlist[4*i + 2]);
}
fclose(fp);
}
// triangulate each of the polygon areas
int FGTriangle::run_triangulate() {
FGTriPoly poly;
Point3D p;
struct triangulateio in, out, vorout;
int counter;
// point list
point_list node_list = in_nodes.get_node_list();
in.numberofpoints = node_list.size();
in.pointlist = (REAL *) malloc(in.numberofpoints * 2 * sizeof(REAL));
point_list_iterator tn_current, tn_last;
tn_current = node_list.begin();
tn_last = node_list.end();
counter = 0;
for ( ; tn_current != tn_last; ++tn_current ) {
in.pointlist[counter++] = tn_current->x();
in.pointlist[counter++] = tn_current->y();
}
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] = 0.0;
}
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
triseg_list seg_list = trisegs.get_seg_list();
in.numberofsegments = seg_list.size();
in.segmentlist = (int *) malloc(in.numberofsegments * 2 * sizeof(int));
in.segmentmarkerlist = (int *) NULL;
triseg_list_iterator s_current, s_last;
s_current = seg_list.begin();
s_last = seg_list.end();
counter = 0;
for ( ; s_current != s_last; ++s_current ) {
in.segmentlist[counter++] = s_current->get_n1();
in.segmentlist[counter++] = s_current->get_n2();
}
// hole list (make holes for airport ignore areas)
in.numberofholes = polylist[(int)AirportIgnoreArea].size();
in.holelist = (REAL *) malloc(in.numberofholes * 2 * sizeof(REAL));
tripoly_list_iterator h_current, h_last;
h_current = polylist[(int)AirportIgnoreArea].begin();
h_last = polylist[(int)AirportIgnoreArea].end();
counter = 0;
for ( ; h_current != h_last; ++h_current ) {
poly = *h_current;
p = poly.get_point_inside();
in.holelist[counter++] = p.x();
in.holelist[counter++] = p.y();
}
// region list
in.numberofregions = 0;
for ( int i = 0; i < FG_MAX_AREA_TYPES; ++i ) {
in.numberofregions += polylist[i].size();
}
in.regionlist = (REAL *) malloc(in.numberofregions * 4 * sizeof(REAL));
counter = 0;
for ( int i = 0; i < FG_MAX_AREA_TYPES; ++i ) {
tripoly_list_iterator h_current, h_last;
h_current = polylist[(int)i].begin();
h_last = polylist[(int)i].end();
for ( ; h_current != h_last; ++h_current ) {
poly = *h_current;
p = poly.get_point_inside();
in.regionlist[counter++] = p.x(); // x coord
in.regionlist[counter++] = p.y(); // y coord
in.regionlist[counter++] = i; // region attribute
in.regionlist[counter++] = -1.0; // area constraint (unused)
}
}
// 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), preserve the convex hull (c), number everything
// from zero (z), assign a regional attribute to each element (A),
// and produce an edge list (e), and a triangle neighbor list (n).
string tri_options = "pczq10Aen";
// string tri_options = "pzAen";
// string tri_options = "pczq15S400Aen";
cout << "Triangulation with options = " << tri_options << endl;
triangulate(tri_options.c_str(), &in, &out, &vorout);
// TEMPORARY
write_out_data(&out);
// now copy the results back into the corresponding FGTriangle
// structures
// nodes
out_nodes.clear();
for ( int i = 0; i < out.numberofpoints; i++ ) {
Point3D p( out.pointlist[2*i], out.pointlist[2*i + 1], 0.0 );
// cout << "point = " << p << endl;
out_nodes.simple_add( p );
}
// 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 0;
}
// $Log$
// Revision 1.16 1999/04/05 02:17:11 curt
// Dynamically update "error" until the resulting tile data scales within
// a lower and upper bounds.
//
// Revision 1.15 1999/04/03 05:22:58 curt
// Found a bug in dividing and adding unique verticle segments which could
// cause the triangulator to end up in an infinite loop. Basically the code
// was correct, but the verticle line test was a bit to selective.
//
// Revision 1.14 1999/03/31 23:47:09 curt
// Debugging output tweaks.
//
// Revision 1.13 1999/03/29 13:11:07 curt
// Shuffled stl type names a bit.
// Began adding support for tri-fanning (or maybe other arrangments too.)
//
// Revision 1.12 1999/03/27 05:30:12 curt
// Handle corner nodes separately from the rest of the fitted nodes.
// Add fitted nodes in after corners and polygon nodes since the fitted nodes
// are less important. Subsequent nodes will "snap" to previous nodes if
// they are "close enough."
// Need to manually divide segments to prevent "T" intersetions which can
// confound the triangulator. Hey, I got to use a recursive method!
// Pass along correct triangle attributes to output file generator.
// Do fine grained node snapping for corners and polygons, but course grain
// node snapping for fitted terrain nodes.
//
// Revision 1.11 1999/03/23 22:02:51 curt
// Refinements in naming and organization.
//
// Revision 1.10 1999/03/22 23:49:02 curt
// Modifications to facilitate conversion to output format.
//
// Revision 1.9 1999/03/21 15:48:02 curt
// Removed Dem2node from the Tools fold.
// Tweaked the triangulator options to add quality mesh refinement.
//
// Revision 1.8 1999/03/21 14:02:06 curt
// Added a mechanism to dump out the triangle structures for viewing.
// Fixed a couple bugs in first pass at triangulation.
// - needed to explicitely initialize the polygon accumulator in triangle.cxx
// before each polygon rather than depending on the default behavior.
// - Fixed a problem with region attribute propagation where I wasn't generating
// the hole points correctly.
//
// Revision 1.7 1999/03/20 20:32:55 curt
// First mostly successful tile triangulation works. There's plenty of tweaking
// to do, but we are marching in the right direction.
//
// Revision 1.6 1999/03/20 13:22:11 curt
// Added trisegs.[ch]xx tripoly.[ch]xx.
//
// Revision 1.5 1999/03/20 02:21:52 curt
// Continue shaping the code towards triangulation bliss. Added code to
// calculate some point guaranteed to be inside a polygon.
//
// Revision 1.4 1999/03/19 22:29:04 curt
// Working on preparationsn for triangulation.
//
// Revision 1.3 1999/03/19 00:27:10 curt
// Continued work on triangulation preparation.
//
// Revision 1.2 1999/03/18 04:31:11 curt
// Let's not pass copies of huge structures on the stack ... ye might see a
// segfault ... :-)
//
// Revision 1.1 1999/03/17 23:51:59 curt
// Initial revision.
//
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