Adding documention comments for dynamic ratsnest

This commit is contained in:
Seth Hillbrand 2020-06-24 15:17:01 -07:00
parent 4c5f3cb5be
commit b02d3f683f
1 changed files with 9 additions and 0 deletions

View File

@ -437,11 +437,17 @@ bool RN_NET::NearestBicoloredPair( const RN_NET& aOtherNet, CN_ANCHOR_PTR& aNode
}
};
/// Sweep-line algorithm to cut the number of comparisons to find the closest point
///
/// Step 1: The outer loop needs to be the subset (selected nodes) as it is a linear search
for( const auto& nodeA : aOtherNet.m_nodes )
{
if( nodeA->GetNoLine() )
continue;
/// Step 2: O( log n ) search to identify a close element ordered by x
/// The fwd_it iterator will move forward through the elements while
/// the rev_it iterator will move backward through the same set
auto fwd_it = m_nodes.lower_bound( nodeA );
auto rev_it = std::make_reverse_iterator( fwd_it );
@ -454,12 +460,15 @@ bool RN_NET::NearestBicoloredPair( const RN_NET& aOtherNet, CN_ANCHOR_PTR& aNode
VECTOR2I::extended_type distX = nodeA->Pos().x - nodeB->Pos().x;
/// As soon as the x distance (primary sort) is larger than the smallest distance,
/// stop checking further elements
if( distX * distX > distMax )
break;
verify( nodeA, nodeB );
}
/// Step 3: using the same starting point, check points backwards for closer points
if( rev_it != m_nodes.rend() )
++rev_it;