private static EdgeTable build_lmt( LmtTable lmt_table,
ScanBeamTreeEntries sbte,
IPoly p,
int type, //poly type SUBJ/CLIP
OperationType op)
{
/* Create the entire input polygon edge table in one go */
EdgeTable edge_table = new EdgeTable();
for ( int c= 0; c < p.InnerPolygonCount; c++)
{
IPoly ip = p.GetInnerPoly(c);
if( !ip.IsContributing(0) )
{
/* Ignore the non-contributing contour */
ip.SetContributing(0, true);
}
else
{
/* Perform contour optimisation */
int num_vertices= 0;
int e_index = 0 ;
edge_table = new EdgeTable();
for ( int i= 0; i < ip.PointCount; i++)
{
if( OPTIMAL(ip, i) )
{
double x = ip.GetX(i);
double y = ip.GetY(i);
edge_table.addNode( x, y );
/* Record vertex in the scanbeam table */
add_to_sbtree( sbte, ip.GetY(i) );
num_vertices++;
}
}
/* Do the contour forward pass */
for ( int min= 0; min < num_vertices; min++)
{
/* If a forward local minimum... */
if( edge_table.FWD_MIN( min ) )
{
/* Search for the next local maximum... */
int num_edges = 1;
int max = NEXT_INDEX( min, num_vertices );
while( edge_table.NOT_FMAX( max ) )
{
num_edges++;
max = NEXT_INDEX( max, num_vertices );
}
/* Build the next edge list */
int v = min;
EdgeNode e = edge_table.getNode( e_index );
e.bstate[BELOW] = BundleState.UNBUNDLED;
e.bundle[BELOW, CLIP] = 0;
e.bundle[BELOW, SUBJ] = 0;
for ( int i= 0; i < num_edges; i++)
{
EdgeNode ei = edge_table.getNode( e_index+i );
EdgeNode ev = edge_table.getNode( v );
ei.xb = ev.vertex.X;
ei.bot.X = ev.vertex.X;
ei.bot.Y = ev.vertex.Y;
v = NEXT_INDEX(v, num_vertices);
ev = edge_table.getNode( v );
ei.top.X= ev.vertex.X;
ei.top.Y= ev.vertex.Y;
ei.dx= (ev.vertex.X - ei.bot.X) / (ei.top.Y - ei.bot.Y);
ei.type = type;
ei.outp[ABOVE] = null ;
ei.outp[BELOW] = null;
ei.next = null;
ei.prev = null;
ei.succ = ((num_edges > 1) && (i < (num_edges - 1))) ? edge_table.getNode(e_index+i+1) : null;
ei.pred = ((num_edges > 1) && (i > 0)) ? edge_table.getNode(e_index+i-1) : null ;
ei.next_bound = null ;
ei.bside[CLIP] = (op == OperationType.GPC_DIFF) ? RIGHT : LEFT;
ei.bside[SUBJ] = LEFT ;
}
insert_bound( bound_list(lmt_table, edge_table.getNode(min).vertex.Y), e);
#if DEBUG
Console.WriteLine("fwd");
lmt_table.print();
#endif
e_index += num_edges;
}
}
/* Do the contour reverse pass */
for ( int min= 0; min < num_vertices; min++)
{
/* If a reverse local minimum... */
if ( edge_table.REV_MIN( min ) )
{
/* Search for the previous local maximum... */
int num_edges= 1;
int max = PREV_INDEX(min, num_vertices);
while( edge_table.NOT_RMAX( max ) )
{
num_edges++;
max = PREV_INDEX(max, num_vertices);
}
/* Build the previous edge list */
int v = min;
EdgeNode e = edge_table.getNode( e_index );
e.bstate[BELOW] = BundleState.UNBUNDLED;
e.bundle[BELOW, CLIP] = 0;
e.bundle[BELOW, SUBJ] = 0;
for (int i= 0; i < num_edges; i++)
{
EdgeNode ei = edge_table.getNode( e_index+i );
EdgeNode ev = edge_table.getNode( v );
ei.xb = ev.vertex.X;
ei.bot.X = ev.vertex.X;
ei.bot.Y = ev.vertex.Y;
v= PREV_INDEX(v, num_vertices);
ev = edge_table.getNode( v );
ei.top.X = ev.vertex.X;
ei.top.Y = ev.vertex.Y;
ei.dx = (ev.vertex.X - ei.bot.X) / (ei.top.Y - ei.bot.Y);
ei.type = type;
ei.outp[ABOVE] = null;
ei.outp[BELOW] = null;
ei.next = null ;
ei.prev = null;
ei.succ = ((num_edges > 1) && (i < (num_edges - 1))) ? edge_table.getNode(e_index+i+1) : null;
ei.pred = ((num_edges > 1) && (i > 0)) ? edge_table.getNode(e_index+i-1) : null ;
ei.next_bound = null ;
ei.bside[CLIP] = (op == OperationType.GPC_DIFF) ? RIGHT : LEFT;
ei.bside[SUBJ] = LEFT;
}
insert_bound( bound_list(lmt_table, edge_table.getNode(min).vertex.Y), e);
#if DEBUG
Console.WriteLine("rev");
lmt_table.print();
#endif
e_index+= num_edges;
}
}
}
}
return edge_table;
}
private static RectangleF[] create_contour_bboxes( IPoly p )
{
RectangleF[] box = new RectangleF[p.InnerPolygonCount] ;
/* Construct contour bounding boxes */
for ( int c= 0; c < p.InnerPolygonCount; c++)
{
IPoly inner_poly = p.GetInnerPoly(c);
box[c] = inner_poly.Bounds;
}
return box;
}
