router: snap to clearance boundaries in Highlight Collisions mode

Fixes: lp:1655819
* https://bugs.launchpad.net/kicad/+bug/1655819

common/geometry/shape.cpp

@@ -27,12 +27,13 @@
 
 bool SHAPE::Parse( std::stringstream& aStream )
 {
-    assert ( false );
+    assert( false );
     return false;
-};
+}
 
-const std::string SHAPE::Format( ) const
+
+const std::string SHAPE::Format() const
 {
-    assert ( false );
-    return std::string("");
-};
+    assert( false );
+    return std::string( "" );
+}

common/geometry/shape_line_chain.cpp

@@ -1,7 +1,7 @@
 /*
  * This program source code file is part of KiCad, a free EDA CAD application.
  *
- * Copyright (C) 2013 CERN
+ * Copyright (C) 2013-2017 CERN
  * @author Tomasz Wlostowski <tomasz.wlostowski@cern.ch>
  *
  * This program is free software; you can redistribute it and/or
@@ -587,3 +587,28 @@ bool SHAPE_LINE_CHAIN::Parse( std::stringstream& aStream )
 
     return true;
 }
+
+
+const VECTOR2I SHAPE_LINE_CHAIN::PointAlong( int aPathLength ) const
+{
+    int total = 0;
+
+    if( aPathLength == 0 )
+        return CPoint( 0 );
+
+    for( int i = 0; i < SegmentCount(); i++ )
+    {
+        const SEG& s = CSegment( i );
+        int l = s.Length();
+
+        if( total + l >= aPathLength )
+        {
+            VECTOR2I d( s.B - s.A );
+            return s.A + d.Resize( aPathLength - total );
+        }
+
+        total += l;
+    }
+
+    return CPoint( -1 );
+}

include/geometry/shape_line_chain.h

@@ -571,7 +571,7 @@ public:
         return false;
     }
 
-    bool CompareGeometry( const SHAPE_LINE_CHAIN & aOther ) const;
+    bool CompareGeometry( const SHAPE_LINE_CHAIN& aOther ) const;
 
     void Move( const VECTOR2I& aVector ) override
     {
@@ -584,6 +584,8 @@ public:
         return false;
     }
 
+    const VECTOR2I PointAlong( int aPathLength ) const;
+
 private:
     /// array of vertices
     std::vector<VECTOR2I> m_points;

pcbnew/router/pns_line_placer.cpp

@@ -1,7 +1,7 @@
 /*
  * KiRouter - a push-and-(sometimes-)shove PCB router
  *
- * Copyright (C) 2013-2014 CERN
+ * Copyright (C) 2013-2017 CERN
  * Copyright (C) 2016 KiCad Developers, see AUTHORS.txt for contributors.
  * Author: Tomasz Wlostowski <tomasz.wlostowski@cern.ch>
  *
@@ -413,11 +413,128 @@ bool LINE_PLACER::rhWalkOnly( const VECTOR2I& aP, LINE& aNewHead )
 bool LINE_PLACER::rhMarkObstacles( const VECTOR2I& aP, LINE& aNewHead )
 {
     buildInitialLine( aP, m_head );
+
+    auto obs = m_currentNode->NearestObstacle( &m_head );
+
+    if( obs )
+    {
+        int cl = m_currentNode->GetClearance( obs->m_item, &m_head );
+        auto hull = obs->m_item->Hull( cl, m_head.Width() );
+
+        auto nearest = hull.NearestPoint( aP );
+        Dbg()->AddLine( hull, 2, 10000 );
+
+        if( ( nearest - aP ).EuclideanNorm() < m_head.Width() )
+        {
+            buildInitialLine( nearest, m_head );
+        }
+    }
+
     aNewHead = m_head;
+
     return static_cast<bool>( m_currentNode->CheckColliding( &m_head ) );
 }
 
 
+const LINE LINE_PLACER::reduceToNearestObstacle( const LINE& aOriginalLine )
+{
+    auto l0  = aOriginalLine.CLine();
+
+    if ( !l0.PointCount() )
+        return aOriginalLine;
+
+    int l = l0.Length();
+    int step = l / 2;
+    VECTOR2I target;
+
+    LINE l_test( aOriginalLine );
+
+    while( step > 0 )
+    {
+        target = l0.PointAlong( l );
+        SHAPE_LINE_CHAIN l_cur( l0 );
+
+        int index = l_cur.Split( target );
+
+        l_test.SetShape( l_cur.Slice( 0, index ) );
+
+        if ( m_currentNode->CheckColliding( &l_test ) )
+            l -= step;
+        else
+            l += step;
+
+        step /= 2;
+    }
+
+    l = l_test.CLine().Length();
+
+    while( m_currentNode->CheckColliding( &l_test ) && l > 0 )
+    {
+        l--;
+        target = l0.PointAlong( l );
+        SHAPE_LINE_CHAIN l_cur( l0 );
+
+        int index = l_cur.Split( target );
+
+        l_test.SetShape( l_cur.Slice( 0, index ) );
+    }
+
+    return l_test;
+}
+
+
+bool LINE_PLACER::rhStopAtNearestObstacle( const VECTOR2I& aP, LINE& aNewHead )
+{
+    LINE l0;
+    l0 = m_head;
+
+    buildInitialLine( aP, l0 );
+
+    LINE l_cur = reduceToNearestObstacle( l0 );
+
+    const auto l_shape = l_cur.CLine();
+
+    if( l_shape.SegmentCount() == 0 )
+    {
+        return false;
+    }
+
+    if( l_shape.SegmentCount() == 1 )
+    {
+        auto s = l_shape.CSegment( 0 );
+
+        VECTOR2I dL( DIRECTION_45( s ).Left().ToVector() );
+        VECTOR2I dR( DIRECTION_45( s ).Right().ToVector() );
+
+        SEG leadL( s.B, s.B + dL );
+        SEG leadR( s.B, s.B + dR );
+
+        SEG segL( s.B, leadL.LineProject( aP ) );
+        SEG segR( s.B, leadR.LineProject( aP ) );
+
+        LINE finishL( l0, SHAPE_LINE_CHAIN( segL.A, segL.B ) );
+        LINE finishR( l0, SHAPE_LINE_CHAIN( segR.A, segR.B ) );
+
+        LINE reducedL = reduceToNearestObstacle( finishL );
+        LINE reducedR = reduceToNearestObstacle( finishR );
+
+        int lL = reducedL.CLine().Length();
+        int lR = reducedR.CLine().Length();
+
+        if( lL > lR )
+            l_cur.Line().Append( reducedL.CLine() );
+        else
+            l_cur.Line().Append( reducedR.CLine() );
+
+        l_cur.Line().Simplify();
+    }
+
+    m_head = l_cur;
+    aNewHead = m_head;
+    return true;
+}
+
+
 bool LINE_PLACER::rhShoveOnly( const VECTOR2I& aP, LINE& aNewHead )
 {
     LINE initTrack( m_head );
@@ -1027,7 +1144,7 @@ void LINE_PLACER::SetOrthoMode( bool aOrthoMode )
 }
 
 
-bool LINE_PLACER::buildInitialLine( const VECTOR2I& aP, LINE& aHead )
+bool LINE_PLACER::buildInitialLine( const VECTOR2I& aP, LINE& aHead, bool aInvertPosture )
 {
     SHAPE_LINE_CHAIN l;
 
@@ -1043,7 +1160,10 @@ bool LINE_PLACER::buildInitialLine( const VECTOR2I& aP, LINE& aHead )
         }
         else
         {
-            l = m_direction.BuildInitialTrace( m_p_start, aP );
+            if ( aInvertPosture )
+                l = m_direction.Right().BuildInitialTrace( m_p_start, aP );
+            else
+                l = m_direction.BuildInitialTrace( m_p_start, aP );
         }
 
         if( l.SegmentCount() > 1 && m_orthoMode )

pcbnew/router/pns_line_placer.h

@@ -1,7 +1,7 @@
 /*
  * KiRouter - a push-and-(sometimes-)shove PCB router
  *
- * Copyright (C) 2013-2014 CERN
+ * Copyright (C) 2013-2017 CERN
  * Copyright (C) 2016 KiCad Developers, see AUTHORS.txt for contributors.
  * Author: Tomasz Wlostowski <tomasz.wlostowski@cern.ch>
  *
@@ -335,6 +335,11 @@ private:
      */
     void routeStep( const VECTOR2I& aP );
 
+    const LINE reduceToNearestObstacle( const LINE& aOriginalLine );
+
+    bool rhStopAtNearestObstacle( const VECTOR2I& aP, LINE& aNewHead );
+
+
     ///> route step, walkaround mode
     bool rhWalkOnly( const VECTOR2I& aP, LINE& aNewHead);
 
@@ -346,7 +351,7 @@ private:
 
     const VIA makeVia( const VECTOR2I& aP );
 
-    bool buildInitialLine( const VECTOR2I& aP, LINE& aHead );
+    bool buildInitialLine( const VECTOR2I& aP, LINE& aHead, bool aInvertPosture = false );
 
     ///> current routing direction
     DIRECTION_45 m_direction;