flightgear/Triangulate/triangle.cxx

// 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 FGgpcPolyList& gpc_polys ) {
    int index;
    // traverse the gpc_polys and build a unified node list and a set
    // of Triangle PSLG that reference the node list by index
    // (starting at zero)

    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 ) {
	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;

	    FGTriPoly poly;

	    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(5);
		// exit(-1);
	    }

	    for ( int j = 0; j < gpc_poly->num_contours; j++ ) {
		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 = trinodes.unique_add( p );
		    poly.add_node(index);
		    // cout << index << endl;
		}
		poly.calc_point_inside( trinodes );

		polylist[i].push_back(poly);
	    }
	}
    }

    for ( int i = 0; i < FG_MAX_AREA_TYPES; ++i ) {
	if ( polylist[i].size() ) {
	    cout << get_area_name((AreaType)i) << " = " 
		 << polylist[i].size() << endl;
	}
    }
    return 0;
}


// do actual triangulation
int FGTriangle::do_triangulate( const FGTriPoly& poly ) {
    trinode_list node_list;
    struct triangulateio in, out;
    int counter;

    // define input points
    node_list = trinodes.get_node_list();

    in.numberofpoints = node_list.size();
    in.numberofpointattributes = 0;
    in.pointlist = (REAL *) malloc(in.numberofpoints * 2 * sizeof(REAL));

    trinode_list_iterator current, last;
    current = node_list.begin();
    last = node_list.end();
    counter = 0;
    for ( ; current != last; ++current ) {
	in.pointlist[counter++] = current->x();
	in.pointlist[counter++] = current->y();
    }

    return 0;
}


// triangulate each of the polygon areas
int FGTriangle::triangulate() {
    FGTriPoly poly;
    struct triangulateio in, out;

    trinode_list node_list = trinodes.get_node_list();

    // point list
    in.numberofpoints = node_list.size();
    in.numberofpointattributes = 1;
    in.pointlist = (REAL *) malloc(in.numberofpoints * 2 * sizeof(REAL));

    trinode_list_iterator tn_current, tn_last;
    tn_current = node_list.begin();
    tn_last = node_list.end();
    int counter = 0;
    for ( ; tn_current != tn_last; ++tn_current ) {
	in.pointlist[counter++] = tn_current->x();
	in.pointlist[counter++] = tn_current->y();
    }

    in.pointattributelist = (REAL *) NULL;
    in.pointmarkerlist = (int *) NULL;

    // segment list
    in.numberofsegments = 0;

    tripoly_list_iterator tp_current, tp_last;
    for ( int i = 0; i < FG_MAX_AREA_TYPES; ++i ) {
	cout << "area type = " << i << endl;
	tp_current = polylist[i].begin();
	tp_last = polylist[i].end();
	for ( ; tp_current != tp_last; ++tp_current ) {
	    poly = *tp_current;
	    in.numberofsegments += poly.size() + 1;
	}
    }

    in.numberofsegments = 0;

  in.numberofholes = 0;
  in.numberofregions = 1;
  in.regionlist = (REAL *) malloc(in.numberofregions * 4 * sizeof(REAL));
  in.regionlist[0] = 0.5;
  in.regionlist[1] = 5.0;
  in.regionlist[2] = 7.0;            /* Regional attribute (for whole mesh). */
  in.regionlist[3] = 0.1;          /* Area constraint that will not be used. */

  /*
    tripoly_list_iterator current, last;
    for ( int i = 0; i < FG_MAX_AREA_TYPES; ++i ) {
	cout << "area type = " << i << endl;
	current = polylist[i].begin();
	last = polylist[i].end();
	for ( ; current != last; ++current ) {
	    poly = *current;
	    cout << "triangulating a polygon, size = " << poly.size() << endl;

	    do_triangulate( poly );
	}
    }
    */
    return 0;
}


// $Log$
// 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.
//