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flightgear/Clipper/clipper.cxx

283 lines
7.5 KiB
C++

// clipper.cxx -- top level routines to take a series of arbitrary areas and
// produce a tight fitting puzzle pieces that combine to make a
// tile
//
// Written by Curtis Olson, started February 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 <Debug/logstream.hxx>
#include <Include/fg_constants.h>
#include <Misc/fgstream.hxx>
#include <Polygon/names.hxx>
#include "clipper.hxx"
// Constructor
FGClipper::FGClipper( void ) {
}
// Destructor
FGClipper::~FGClipper( void ) {
}
// Initialize Clipper (allocate and/or connect structures)
bool FGClipper::init() {
v_list.num_vertices = 0;
v_list.vertex = new gpc_vertex[FG_MAX_VERTICES];;
return true;
}
// Load a polygon definition file
bool FGClipper::load_polys(const string& path) {
string poly_name;
AreaType poly_type = DefaultArea;
int contours, count, i, j;
double startx, starty, x, y, lastx, lasty;
FG_LOG( FG_CLIPPER, FG_INFO, "Loading " << path << " ..." );
fg_gzifstream in( path );
if ( !in ) {
FG_LOG( FG_CLIPPER, FG_ALERT, "Cannot open file: " << path );
exit(-1);
}
gpc_polygon *poly = new gpc_polygon;
poly->num_contours = 0;
poly->contour = NULL;
in >> skipcomment;
while ( !in.eof() ) {
in >> poly_name;
cout << "poly name = " << poly_name << endl;
poly_type = get_area_type( poly_name );
cout << "poly type (int) = " << (int)poly_type << endl;
in >> contours;
cout << "num contours = " << contours << endl;
for ( i = 0; i < contours; ++i ) {
in >> count;
if ( count < 3 ) {
FG_LOG( FG_CLIPPER, FG_ALERT,
"Polygon with less than 3 data points." );
exit(-1);
}
in >> startx;
in >> starty;
v_list.vertex[0].x = startx;
v_list.vertex[0].y = starty;
FG_LOG( FG_CLIPPER, FG_BULK, "0 = "
<< startx << ", " << starty );
for ( j = 1; j < count - 1; ++j ) {
in >> x;
in >> y;
v_list.vertex[j].x = x;
v_list.vertex[j].y = y;
FG_LOG( FG_CLIPPER, FG_BULK, j << " = " << x << ", " << y );
}
v_list.num_vertices = count - 1;
in >> lastx;
in >> lasty;
if ( (fabs(startx - lastx) < FG_EPSILON)
&& (fabs(starty - lasty) < FG_EPSILON) ) {
// last point same as first, discard
} else {
v_list.vertex[count - 1].x = lastx;
v_list.vertex[count - 1].y = lasty;
++v_list.num_vertices;
FG_LOG( FG_CLIPPER, FG_BULK, count - 1 << " = "
<< lastx << ", " << lasty );
}
gpc_add_contour( poly, &v_list );
}
in >> skipcomment;
}
int area = (int)poly_type;
if ( area < FG_MAX_AREA_TYPES ) {
polys_in.polys[area].push_back(poly);
} else {
FG_LOG( FG_CLIPPER, FG_ALERT, "Polygon type out of range = "
<< (int)poly_type);
exit(-1);
}
// FILE *ofp= fopen("outfile", "w");
// gpc_write_polygon(ofp, &polys.landuse);
return true;
}
// Do actually clipping work
bool FGClipper::clip_all(const point2d& min, const point2d& max) {
gpc_polygon accum, result_union, tmp;
gpc_polygon *result_diff, *remains;
gpcpoly_iterator current, last;
FG_LOG( FG_CLIPPER, FG_INFO, "Running master clipper" );
accum.num_contours = 0;
cout << " (" << min.x << "," << min.y << ") ("
<< max.x << "," << max.y << ")" << endl;
// set up clipping tile
v_list.vertex[0].x = min.x;
v_list.vertex[0].y = min.y;
v_list.vertex[1].x = max.x;
v_list.vertex[1].y = min.y;
v_list.vertex[2].x = max.x;
v_list.vertex[2].y = max.y;
v_list.vertex[3].x = min.x;
v_list.vertex[3].y = max.y;
v_list.num_vertices = 4;
polys_in.safety_base.num_contours = 0;
polys_in.safety_base.contour = NULL;
gpc_add_contour( &polys_in.safety_base, &v_list );
// process polygons in priority order
for ( int i = 0; i < FG_MAX_AREA_TYPES; ++i ) {
cout << "num polys of this type = " << polys_in.polys[i].size() << endl;
current = polys_in.polys[i].begin();
last = polys_in.polys[i].end();
for ( ; current != last; ++current ) {
FG_LOG( FG_CLIPPER, FG_DEBUG, get_area_name( (AreaType)i )
<< " = " << (*current)->contour->num_vertices );
#ifdef EXTRA_SAFETY_CLIP
// clip to base tile
gpc_polygon_clip(GPC_INT, *current, &polys_in.safety_base, &tmp);
#else
tmp = *current;
#endif
// clip current polygon against previous higher priority
// stuff
result_diff = new gpc_polygon;
result_diff->num_contours = 0;
result_diff->contour = NULL;
if ( accum.num_contours == 0 ) {
*result_diff = tmp;
result_union = tmp;
} else {
gpc_polygon_clip(GPC_DIFF, &tmp, &accum, result_diff);
gpc_polygon_clip(GPC_UNION, &tmp, &accum, &result_union);
}
/*
cout << "original contours = " << tmp.num_contours << endl;
for ( int j = 0; j < tmp.num_contours; j++ ) {
for (int k = 0;k < tmp.contour[j].num_vertices;k++ ) {
cout << tmp.contour[j].vertex[k].x << ","
<< tmp.contour[j].vertex[k].y << endl;
}
}
cout << "clipped contours = " << result_diff->num_contours << endl;
for ( int j = 0; j < result_diff->num_contours; j++ ) {
for (int k = 0;k < result_diff->contour[j].num_vertices;k++ ) {
cout << result_diff->contour[j].vertex[k].x << ","
<< result_diff->contour[j].vertex[k].y << endl;
}
}
*/
// only add to output list if the clip left us with a polygon
if ( result_diff->num_contours > 0 ) {
polys_clipped.polys[i].push_back(result_diff);
}
accum = result_union;
}
}
// finally, what ever is left over goes to base terrain
// clip to accum against original base tile
remains = new gpc_polygon;
remains->num_contours = 0;
remains->contour = NULL;
gpc_polygon_clip(GPC_DIFF, &polys_in.safety_base, &accum,
remains);
if ( remains->num_contours > 0 ) {
polys_clipped.polys[0].push_back(remains);
}
// tmp output accum
FILE *ofp= fopen("accum", "w");
gpc_write_polygon(ofp, &accum);
// tmp output safety_base
ofp= fopen("remains", "w");
gpc_write_polygon(ofp, remains);
return true;
}
// $Log$
// Revision 1.7 1999/03/30 13:41:38 curt
// Working towards better handling of multi-contoured polygons.
//
// Revision 1.6 1999/03/27 05:20:53 curt
// Pass along default area explicitely to triangulator.
//
// Revision 1.5 1999/03/19 22:28:46 curt
// Only add non-null polygons to output list.
//
// Revision 1.4 1999/03/19 00:26:18 curt
// Fixed a clipping bug (polygons specified in wrong order).
// Touched up a few compiler warnings.
//
// Revision 1.3 1999/03/17 23:48:58 curt
// minor renaming and a bit of rearranging.
//
// Revision 1.2 1999/03/13 23:51:33 curt
// Renamed main.cxx to testclipper.cxx
// Converted clipper routines to a class FGClipper.
//
// Revision 1.1 1999/03/01 15:39:39 curt
// Initial revision.
//