fix squiggly wires (#343)

src/Renderer/DrawBlock/BusWire.fs

@@ -201,19 +201,27 @@ let logSegmentsInModel (model: Model) (wireSegmentIdPairs: (int*ConnectionId) li
 
 /// Given the coordinates of two port locations that correspond
 /// to the endpoints of a wire, as well as the final port orientation 
-/// this function returns a list of wire vertices
+/// this function returns a list of wire vertices.
+/// The starting segment will always be from a Right Edge (and so in increasing X direction)
 let makeInitialWireVerticesList (wireStartPos : XYPos) (wireEndPos : XYPos) (portOrientation : Edge) = 
     let xStart, yStart, xEnd, yEnd = wireStartPos.X, wireStartPos.Y, wireEndPos.X, wireEndPos.Y
 
-    let nubLength = Constants.nubLength
+    let nubLength =
+        let xDelta = xEnd - xStart
+        let yDelta = abs (yEnd - yStart)
+        match portOrientation with
+        | CommonTypes.Edge.Left when xDelta > 0 -> min nubLength (xDelta / 2.)
+        | CommonTypes.Edge.Top
+        | CommonTypes.Edge.Bottom when xDelta > 0 -> min nubLength xDelta
+        | _ -> nubLength
     /// This is a fixed-length horizontal stick with a zero-length vertical after it.
     /// It starts nearly all the wires
     let rightNub = [
             {X = xStart; Y = yStart};
             {X = xStart+nubLength; Y = yStart}; //Stick horizontal
             {X = xStart+nubLength; Y = yStart}; //Length 0 vertical
         ]
-    let rightwards = xStart - xEnd + 20. < 0
+    let rightwards = xStart - xEnd  < 0
     let downwards = yStart - yEnd  < 0
     match rightwards, downwards with //add 20 to prevent issues in the case that the ports are directly on in line with one another
     | true, true ->
@@ -346,7 +354,8 @@ let xyVerticesToSegments connId (xyVerticesList: XYPos list) =
 
 /// Given the coordinates of two port locations that correspond
 /// to the endpoints of a wire, as well as the orientation of the final port
-/// this function returns a list of Segment(s).
+/// this function returns a list of Segment(s).
+/// The starting segment will always be from a Right Edge (and so in increasing X direction)
 let makeInitialSegmentsList 
         (hostId : ConnectionId) 
         (startPos : XYPos) 

src/Renderer/DrawBlock/BusWireRoute.fs

@@ -516,7 +516,7 @@ let snapToNet (model: Model) (wireToRoute: Wire) : Wire =
 let smartAutoroute (model: Model) (wire: Wire) : Wire =
 
     let initialWire = (autoroute model wire)
-
+    
     // Snapping to Net only if model.SnapToNet toggled to be true
     let snappedToNetWire =
         match model.SnapToNet with
@@ -533,6 +533,7 @@ let smartAutoroute (model: Model) (wire: Wire) : Wire =
             tryShiftHorizontalSeg maxCallsToShiftHorizontalSeg model intersectedBoxes snappedToNetWire
         )
         |> Option.defaultValue snappedToNetWire
+
 
 
 //-----------------------------------------------------------------------------------------------------------//

src/Renderer/DrawBlock/BusWireRoutingHelpers.fs

@@ -117,6 +117,7 @@ module Constants =
     let overlapTolerance = 2.
     /// corners with max length edge larger than this are not removed
     let separateCaptureOverlap = 6. // Larger than as overlapTolerance, smaller than minSegmentSeparation
+    let minWireLengthToSeparate = 10. // prevents short wires being squiggly
     let maxCornerSize = 100.
     /// How close are segment extensions caused by corner removal allowed to
     /// get to other elements? Maybe needs to be smaller than some otehr things for

src/Renderer/DrawBlock/BusWireSeparate.fs

@@ -150,7 +150,8 @@ let makeLines (wiresToRoute: ConnectionId list) (ori: Orientation) (model: Model
     /// Which segments in wires are included as Lines?
     let selectSegments (wire: Wire) (orient: Orientation) (seg: Segment) =
         let numSegs = wire.Segments.Length
-        ori = orient && seg.Index <> 0 && seg.Index <> numSegs - 1 && not (seg.IsZero()) //|| (segN -1).IsZero() || (segN 1).IsZero())
+        let wireLength = euclideanDistance wire.StartPos wire.EndPos
+        ori = orient && seg.Index <> 0 && seg.Index <> numSegs - 1 && not (seg.IsZero()) && wireLength > minWireLengthToSeparate
 
     /// Lines coming from wire segments
     /// Manually routed segments are considered fixed
@@ -169,7 +170,6 @@ let makeLines (wiresToRoute: ConnectionId list) (ori: Orientation) (model: Model
                     match wireIsRoutable, seg.Mode, seg.Index=2, seg.Index=segs.Length-3 with
                     | _, Manual , _ , _
                     | false, _, _, _ ->
-                        //printf $"\n**Wire {pWire wire} is manual**\n"
                         FIXEDMANUALSEG
                     | _, _ , true , _ when segs[ 1 ].IsZero() -> 
                         FIXEDSEG
@@ -881,7 +881,6 @@ let separateModelSegmentsOneOrientation (wires: ConnectionId list) (ori: Orienta
 /// Perform complete wire segment separation and ordering for all orientations.
 /// wiresToRoute: set of wires to have segments separated and ordered
 let separateAndOrderModelSegments (wiresToRoute: ConnectionId list) (model: Model) : Model =
-
         // Currently: separate all wires - not just those (in wiresToRoute) that
         // have changed. This prevents unrouted segments from pinning new segments.
         // TODO: see whetehr something better can be worked out,a nd whetehr routing segments