kicad-developers team mailing list archive

[Chris Pavlina <pavlina.chris@xxxxxxxxx>]

If you place a wire segment and then backtrack over it, you end up with 
a broken wire in the end:

http://misc.c4757p.com/backtrack.mp4

This is because the two segments are merged together, rather than the 
second *subtracting* from the first, even though the latter case is the 
way it's shown as you're drawing. This patch fixes that by adding a 
function to erase backtracks.

--
Chris

commit d18fec08e34f7b509553fc72ee0616eeda6579a6
Author: Chris Pavlina <cpavlin1@xxxxxxxxxxxxxx>
Date:   Mon Jun 22 16:16:50 2015 -0400

    Remove backtracking segments when drawing wires

diff --git a/eeschema/bus-wire-junction.cpp b/eeschema/bus-wire-junction.cpp
index a33f7b5..eb86ba5 100644
--- a/eeschema/bus-wire-junction.cpp
+++ b/eeschema/bus-wire-junction.cpp
@@ -43,6 +43,7 @@
 #include <sch_text.h>
 #include <sch_component.h>
 #include <sch_sheet.h>
+#include <trigo.h>
 
 
 static void AbortCreateNewLine( EDA_DRAW_PANEL* aPanel, wxDC* aDC );
@@ -53,6 +54,45 @@ static DLIST< SCH_ITEM > s_wires;       // when creating a new set of wires,
 
 
 /**
+ * In a contiguous list of wires, remove wires that backtrack over the previous
+ * wire. Example:
+ *
+ * Wire is added:
+ * ---------------------------------------->
+ *
+ * A second wire backtracks over it:
+ * -------------------<====================>
+ *
+ * RemoveBacktracks is called:
+ * ------------------->
+ */
+static void RemoveBacktracks( DLIST<SCH_ITEM>& aWires )
+{
+    SCH_LINE* last_line = NULL;
+
+    EDA_ITEM* first = aWires.GetFirst();
+    for( EDA_ITEM* p = first; p; p = p->Next() )
+    {
+        SCH_LINE *line = dynamic_cast<SCH_LINE*>( p );
+
+        if( p != first )
+        {
+            wxASSERT_MSG( last_line->GetEndPoint() == line->GetStartPoint(),
+                    "RemoveBacktracks() requires contiguous lines" );
+            if( IsPointOnSegment( last_line->GetStartPoint(), line->GetStartPoint(),
+                        line->GetEndPoint() ) )
+            {
+                last_line->SetEndPoint( line->GetEndPoint() );
+                delete s_wires.Remove( line );
+                p = line;
+            }
+        }
+        last_line = line;
+    }
+}
+
+
+/**
  * Mouse capture callback for drawing line segments.
  */
 static void DrawSegment( EDA_DRAW_PANEL* aPanel, wxDC* aDC, const wxPoint& aPosition,
@@ -261,6 +301,9 @@ void SCH_EDIT_FRAME::EndSegment( wxDC* DC )
 
     SaveCopyInUndoList( oldItems, UR_WIRE_IMAGE );
 
+    // Remove segments backtracking over others
+    RemoveBacktracks( s_wires );
+
     // Add the new wires
     screen->Append( s_wires );