Ticket #7983: test_polygon_diff.cpp

/*
 * This sample calculates the diff of 2 polygons.
 * It works fine when compiled with g++ 4.4 and 4.6 with optimization -O2
 * When compiled with g++ 4.7 :
 * with optimization -O2 the result is false (void polygon)
 * with optimization -O1 or -00 the result is OK
 *
 * Note also the same issue exists with the sum of these 2 polygons.
 */

#include <vector>
#include <boost/polygon/polygon.hpp>

#include <stdio.h>

// Define some types used here from boost::polygon
namespace bpl = boost::polygon;         // bpl = boost polygon library
using namespace bpl::operators;         // +, -, =, ...

// Definitions needed by boost::polygon
typedef int                    coordinate_type;

/**
 * KI_POLYGON defines a single polygon ( boost::polygon_data type.
 */
typedef bpl::polygon_data<int> KI_POLYGON;

/**
 * KI_POLYGON_SET defines a set of single KI_POLYGON.
 * A KI_POLYGON_SET is used to store a set of polygons
 * when performing operations between 2 polygons
 * or 2 sets of polygons
 * The result of operations like and, xor... between 2 polygons
 * is always stored in a KI_POLYGON_SET, because these operations
 * can create many polygons
 */
typedef std::vector<KI_POLYGON>  KI_POLYGON_SET;

/**
 * KI_POLY_POINT defines a point for boost::polygon.
 * KI_POLY_POINT store x and y coordinates (int)
 */
typedef bpl::point_data<int>   KI_POLY_POINT;


int polyset_main[]=
{
    -10, -10,
    -10, 10,
    10, 10,
    10, -10
};
int polyset_main_corner_count = 4;

// polyset polygons count 2
int polyset_holes[]=
{
    -5, -5,
    -5, 5,
    5, 5,
    5, -5
};
int polyset_holes_corner_count = 4;

void CopyPolygons( KI_POLYGON_SET& aKiPolyList, int polyset[], int corners_count )
{
    std::vector<KI_POLY_POINT> cornerslist;

    KI_POLYGON poly;
    for( int ii = 0; ii < corners_count; ii++ )
    {
        int jj = ii * 2;
        cornerslist.push_back( KI_POLY_POINT( polyset[jj], polyset[jj+1] ) );
    }

    bpl::set_points( poly, cornerslist.begin(), cornerslist.end() );
    aKiPolyList.push_back( poly );
}

// Debug function: dump a KI_POLYGON_SET to stdout
// each corner is output under <xcoord>, <ycoord>
void dumpPolySet( const KI_POLYGON_SET& polyset )
{
    printf("// polyset polygons count %d\n", polyset.size());
    for( unsigned kk = 0; kk < polyset.size(); kk++ )
    {
        const KI_POLYGON& poly = polyset[kk];
        printf("**** polygon %d, corners count %d\n", kk, poly.size() );
        for( unsigned ij = 0; ij <  poly.size(); ij++ )
        {
            printf( "  %d, %d\n", (poly.begin() + ij)->x(),
                                    (poly.begin() + ij)->y() );
        }
        printf("\n");
    }
}


int main()
{
    KI_POLYGON_SET polys_main;
    CopyPolygons( polys_main, polyset_main, polyset_main_corner_count );

    KI_POLYGON_SET polys_holes;
    CopyPolygons( polys_holes, polyset_holes, polyset_holes_corner_count );

    polys_main -= polys_holes;

    dumpPolySet( polys_main );

    return 0;
}