package MyUnion;

use strict;
use warnings;
use FindBin;

our $VERSION   = 0.001;
our @EXPORT_OK = qw/ wrap_ppunpo /;
 
use Inline C => Config => LIBS => 
    "-L$FindBin::Bin/lib -lgfortran -lpolypack";
 
use Inline C => <<'EOC';

extern void ppunpo_( 
    float* xclip, float* yclip, int* nclip,
    float* xpoly, float* ypoly, int* npoly,
    float* rwork, void*  iwork, int* nwork,
    void*  cback, int*   error 
);

AV* ary;    // AoA; collect output here, array (i.e. one call
            // to call-back function, below) per sub-path

static void urpp( float* xcra, float* ycra, int* ncra ) {
    int i;
    AV* pgone = newAV();
    for ( i = 0; i < *ncra; i ++ ) {
        AV* point = newAV();
        av_push( point, newSVnv( xcra[ i ]));
        av_push( point, newSVnv( ycra[ i ]));
        av_push( pgone, newRV_noinc( point ));
    }
    av_push( ary, newRV_noinc( pgone ));
}

SV* wrap_ppunpo( SV* ccp, SV* csp ) {
    AV* ccp_ary = SvRV( ccp );
    AV* csp_ary = SvRV( csp );
    int nccp    = av_top_index( ccp_ary ) + 1;
    int ncsp    = av_top_index( csp_ary ) + 1;
    int nwrk    = 20 * ( nccp + ncsp );

    float* xccp = malloc( nccp * sizeof( float ));
    float* yccp = malloc( nccp * sizeof( float ));
    float* xcsp = malloc( ncsp * sizeof( float ));
    float* ycsp = malloc( ncsp * sizeof( float ));
    float* work = malloc( nwrk * sizeof( float ));
    
    int i;
    AV* point;
    for ( i = 0; i < nccp; i ++ ) {
        point = SvRV( *av_fetch( ccp_ary, i, 0 ));
        xccp[ i ] = SvNV( *av_fetch( point, 0, 0 ));
        yccp[ i ] = SvNV( *av_fetch( point, 1, 0 ));
    }
    for ( i = 0; i < ncsp; i ++ ) {
        point = SvRV( *av_fetch( csp_ary, i, 0 ));
        xcsp[ i ] = SvNV( *av_fetch( point, 0, 0 ));
        ycsp[ i ] = SvNV( *av_fetch( point, 1, 0 ));
    }
    
    ary = newAV();
    
    int ierr;
    ppunpo_( 
        &xccp[0], &yccp[0], &nccp, 
        &xcsp[0], &ycsp[0], &ncsp, 
        &work[0], &work[0], &nwrk,
        &urpp, &ierr 
    );

    SV* ret;
    if ( ierr ) {
        av_undef( ary );
        ret = newSV( 0 );
    }
    else {
        ret = newRV_noinc( ary );
    }
    free( xccp );
    free( yccp );
    free( xcsp );
    free( ycsp );
    free( work );   // Note, this also frees memory 
                    // used by data passed to call-back

    return( ret );
}
 
EOC

1;