void SHAPE_POLY_SET::fractureSingle( POLYGON& paths )
{
FractureEdgeSet edges;
FractureEdgeSet border_edges;
FractureEdge* root = NULL;
bool first = true;
if( paths.size() == 1 )
return;
int num_unconnected = 0;
BOOST_FOREACH( SHAPE_LINE_CHAIN& path, paths )
{
int index = 0;
FractureEdge *prev = NULL, *first_edge = NULL;
int x_min = std::numeric_limits<int>::max();
for( int i = 0; i < path.PointCount(); i++ )
{
const VECTOR2I& p = path.CPoint( i );
if( p.x < x_min )
x_min = p.x;
}
for( int i = 0; i < path.PointCount(); i++ )
{
FractureEdge* fe = new FractureEdge( first, &path, index++ );
if( !root )
root = fe;
if( !first_edge )
first_edge = fe;
if( prev )
prev->m_next = fe;
if( i == path.PointCount() - 1 )
fe->m_next = first_edge;
prev = fe;
edges.push_back( fe );
if( !first )
{
if( fe->m_p1.x == x_min )
border_edges.push_back( fe );
}
if( !fe->m_connected )
num_unconnected++;
}
first = false; // first path is always the outline
}
static int processEdge( FractureEdgeSet& edges, FractureEdge* edge )
{
int x = edge->m_p1.x;
int y = edge->m_p1.y;
int min_dist = std::numeric_limits<int>::max();
int x_nearest = 0;
FractureEdge* e_nearest = NULL;
for( FractureEdgeSet::iterator i = edges.begin(); i != edges.end(); ++i )
{
if( !(*i)->matches( y ) )
continue;
int x_intersect;
if( (*i)->m_p1.y == (*i)->m_p2.y ) // horizontal edge
x_intersect = std::max ( (*i)->m_p1.x, (*i)->m_p2.x );
else
x_intersect = (*i)->m_p1.x + rescale((*i)->m_p2.x - (*i)->m_p1.x, y - (*i)->m_p1.y, (*i)->m_p2.y - (*i)->m_p1.y );
int dist = ( x - x_intersect );
if( dist >= 0 && dist < min_dist && (*i)->m_connected )
{
min_dist = dist;
x_nearest = x_intersect;
e_nearest = (*i);
}
}
if( e_nearest && e_nearest->m_connected )
{
int count = 0;
FractureEdge* lead1 = new FractureEdge( true, VECTOR2I( x_nearest, y ), VECTOR2I( x, y ) );
FractureEdge* lead2 = new FractureEdge( true, VECTOR2I( x, y ), VECTOR2I( x_nearest, y ) );
FractureEdge* split_2 = new FractureEdge( true, VECTOR2I( x_nearest, y ), e_nearest->m_p2 );
edges.push_back( split_2 );
edges.push_back( lead1 );
edges.push_back( lead2 );
FractureEdge* link = e_nearest->m_next;
e_nearest->m_p2 = VECTOR2I( x_nearest, y );
e_nearest->m_next = lead1;
lead1->m_next = edge;
FractureEdge*last;
for( last = edge; last->m_next != edge; last = last->m_next )
{
last->m_connected = true;
count++;
}
last->m_connected = true;
last->m_next = lead2;
lead2->m_next = split_2;
split_2->m_next = link;
return count + 1;
}
return 0;
}
void SHAPE_POLY_SET::fractureSingle( POLYGON& paths )
{
FractureEdgeSet edges;
FractureEdgeSet border_edges;
FractureEdge* root = NULL;
bool first = true;
if( paths.size() == 1 )
return;
int num_unconnected = 0;
for( SHAPE_LINE_CHAIN& path : paths )
{
int index = 0;
FractureEdge *prev = NULL, *first_edge = NULL;
int x_min = std::numeric_limits<int>::max();
for( int i = 0; i < path.PointCount(); i++ )
{
const VECTOR2I& p = path.CPoint( i );
if( p.x < x_min )
x_min = p.x;
}
for( int i = 0; i < path.PointCount(); i++ )
{
FractureEdge* fe = new FractureEdge( first, &path, index++ );
if( !root )
root = fe;
if( !first_edge )
first_edge = fe;
if( prev )
prev->m_next = fe;
if( i == path.PointCount() - 1 )
fe->m_next = first_edge;
prev = fe;
edges.push_back( fe );
if( !first )
{
if( fe->m_p1.x == x_min )
border_edges.push_back( fe );
}
if( !fe->m_connected )
num_unconnected++;
}
first = false; // first path is always the outline
}
// keep connecting holes to the main outline, until there's no holes left...
while( num_unconnected > 0 )
{
int x_min = std::numeric_limits<int>::max();
FractureEdge* smallestX = NULL;
// find the left-most hole edge and merge with the outline
for( FractureEdgeSet::iterator i = border_edges.begin(); i != border_edges.end(); ++i )
{
int xt = (*i)->m_p1.x;
if( ( xt < x_min ) && ! (*i)->m_connected )
{
x_min = xt;
smallestX = *i;
}
}
num_unconnected -= processEdge( edges, smallestX );
}
paths.clear();
SHAPE_LINE_CHAIN newPath;
newPath.SetClosed( true );
FractureEdge* e;
for( e = root; e->m_next != root; e = e->m_next )
newPath.Append( e->m_p1 );
newPath.Append( e->m_p1 );
for( FractureEdgeSet::iterator i = edges.begin(); i != edges.end(); ++i )
delete *i;
paths.push_back( newPath );
}