Wire selection fixes:

- Fixed MathUtils.LineToPointDistance returning NaN if both points of the line are at the same position, preventing from selecting some wire nodes in the wiring mode.
- Added an indicator that shows when a node is highlighted.
- Wire nodes a higher preference for being highlighted than wire sections. Makes it easier to select nodes that are on top of another wire.

Closes #215

Barotrauma/BarotraumaClient/Source/Items/Components/Signal/Wire.cs

@@ -3,6 +3,7 @@ using Microsoft.Xna.Framework;
 using Microsoft.Xna.Framework.Graphics;
 using Microsoft.Xna.Framework.Input;
 using System.Collections.Generic;
+using System.Linq;
 
 namespace Barotrauma.Items.Components
 {
@@ -36,6 +37,12 @@ namespace Barotrauma.Items.Components
             }
         }
 
+        private static Sprite wireSprite;
+
+        private static Wire draggingWire;
+        private static int? selectedNodeIndex;
+        private static int? highlightedNodeIndex;
+        
         public void Draw(SpriteBatch spriteBatch, bool editing)
         {
             if (sections.Count == 0 && !IsActive)
@@ -69,7 +76,7 @@ namespace Barotrauma.Items.Components
 
             foreach (WireSection section in sections)
             {
-                section.Draw(spriteBatch, item.Color, drawOffset, depth, 0.3f);
+                section.Draw(spriteBatch, item.Submarine == null ? Color.Green : item.Color, drawOffset, depth, 0.3f);
             }
 
             if (IsActive && nodes.Count > 0 && Vector2.Distance(newNodePos, nodes[nodes.Count - 1]) > nodeDistance)
@@ -91,14 +98,15 @@ namespace Barotrauma.Items.Components
                 if (item.Submarine != null) drawPos += item.Submarine.Position + item.Submarine.HiddenSubPosition;
                 drawPos.Y = -drawPos.Y;
 
+                if ((highlightedNodeIndex == i && item.IsHighlighted) || (selectedNodeIndex == i && item.IsSelected))
+                {
+                    GUI.DrawRectangle(spriteBatch, drawPos + new Vector2(-10, -10), new Vector2(20, 20), Color.Red, false, 0.0f);
+                }
+
                 if (item.IsSelected)
                 {
                     GUI.DrawRectangle(spriteBatch, drawPos + new Vector2(-5, -5), new Vector2(10, 10), item.Color, true, 0.0f);
 
-                    if (highlightedNodeIndex == i)
-                    {
-                        GUI.DrawRectangle(spriteBatch, drawPos + new Vector2(-10, -10), new Vector2(20, 20), Color.Red, false, 0.0f);
-                    }
                 }
                 else
                 {
@@ -196,28 +204,36 @@ namespace Barotrauma.Items.Components
 
             //check which wire is highlighted with the cursor
             Wire highlighted = null;
-            float closestDist = 0.0f;
+            float closestDist = float.PositiveInfinity;
             foreach (Wire w in wires)
             {
                 Vector2 mousePos = GameMain.SubEditorScreen.Cam.ScreenToWorld(PlayerInput.MousePosition);
                 if (w.item.Submarine != null) mousePos -= (w.item.Submarine.Position + w.item.Submarine.HiddenSubPosition);
 
                 float dist = 0.0f;
-                if (w.GetClosestNodeIndex(mousePos, highlighted == null ? nodeSelectDist : closestDist, out dist) > -1)
+                int highlightedNode = w.GetClosestNodeIndex(mousePos, highlighted == null ? nodeSelectDist : closestDist, out dist);
+                if (highlightedNode > -1)
                 {
-                    highlighted = w;
+                    if (dist < closestDist)
-                    closestDist = dist;
+                    {
+                        highlightedNodeIndex = highlightedNode;
+                        highlighted = w;
+                        closestDist = dist;
+                    }
                 }
 
                 if (w.GetClosestSectionIndex(mousePos, highlighted == null ? sectionSelectDist : closestDist, out dist) > -1)
                 {
-                    highlighted = w;
+                    //prefer nodes over sections
-                    closestDist = dist;
+                    if (dist + nodeSelectDist * 0.5f < closestDist)
+                    {
+                        highlightedNodeIndex = null;
+                        highlighted = w;
+                        closestDist = dist + nodeSelectDist * 0.5f;
+                    }
                 }
-
             }
 
-
             if (highlighted != null)
             {
                 highlighted.item.IsHighlighted = true;

Barotrauma/BarotraumaShared/Source/Items/Components/Signal/Wire.cs

@@ -30,21 +30,13 @@ namespace Barotrauma.Items.Components
         const float nodeDistance = 32.0f;
         const float heightFromFloor = 128.0f;
 
-        static Sprite wireSprite;
-
         private List<Vector2> nodes;
         private List<WireSection> sections;
 
-        Connection[] connections;
+        private Connection[] connections;
 
         private Vector2 newNodePos;
 
-
-
-        private static Wire draggingWire;
-        private static int? selectedNodeIndex;
-        private static int? highlightedNodeIndex;
-
         public bool Hidden, Locked;
 
         public Connection[] Connections
@@ -55,11 +47,13 @@ namespace Barotrauma.Items.Components
         public Wire(Item item, XElement element)
             : base(item, element)
         {
+#if CLIENT
             if (wireSprite == null)
             {
                 wireSprite = new Sprite("Content/Items/wireHorizontal.png", new Vector2(0.5f, 0.5f));
                 wireSprite.Depth = 0.85f;
             }
+#endif
 
             nodes = new List<Vector2>();
             sections = new List<WireSection>();

Barotrauma/BarotraumaShared/Source/Utils/MathUtils.cs

@@ -336,6 +336,11 @@ namespace Barotrauma
             float xDiff = lineB.X - lineA.X;
             float yDiff = lineB.Y - lineA.Y;
 
+            if (xDiff == 0 && yDiff == 0)
+            {
+                return Vector2.Distance(lineA, point);
+            }
+
             return (float)(Math.Abs(xDiff * (lineA.Y - point.Y) - yDiff * (lineA.X - point.X)) /
                 Math.Sqrt(xDiff * xDiff + yDiff * yDiff));
         }