From 6d2340957dac62165c779fd3a56566594b6906d4 Mon Sep 17 00:00:00 2001
From: Drew DeVault <sir@cmpwn.com>
Date: Wed, 11 Feb 2015 21:32:25 -0700
Subject: [PATCH] Fix remaining issues with fluid dynamics

---
 TrueCraft.Core/Logic/Blocks/FluidBlock.cs | 26 +++++++++++++++++------
 TrueCraft.Core/Logic/Blocks/LavaBlock.cs  |  2 ++
 2 files changed, 22 insertions(+), 6 deletions(-)

diff --git a/TrueCraft.Core/Logic/Blocks/FluidBlock.cs b/TrueCraft.Core/Logic/Blocks/FluidBlock.cs
index 6fe61e2..4cc8f7c 100644
--- a/TrueCraft.Core/Logic/Blocks/FluidBlock.cs
+++ b/TrueCraft.Core/Logic/Blocks/FluidBlock.cs
@@ -36,12 +36,14 @@ namespace TrueCraft.Core.Logic.Blocks
         protected abstract byte FlowingID { get; }
         protected abstract byte StillID { get; }
 
+        protected virtual bool AllowSourceCreation { get { return true; } }
+
         private static readonly Coordinates3D[] Neighbors =
             {
-                Coordinates3D.Left,
-                Coordinates3D.Right,
-                Coordinates3D.Forwards,
-                Coordinates3D.Backwards
+                Coordinates3D.North,
+                Coordinates3D.South,
+                Coordinates3D.East,
+                Coordinates3D.West
             };
 
         /// <summary>
@@ -93,7 +95,7 @@ namespace TrueCraft.Core.Logic.Blocks
 
         private void AutomataUpdate(IMultiplayerServer server, IWorld world, Coordinates3D coords)
         {
-            if (world.GetBlockID(coords) != ID)
+            if (world.GetBlockID(coords) != FlowingID && world.GetBlockID(coords) != StillID)
                 return;
             server.BlockUpdatesEnabled = false;
             var again = DoAutomata(server, world, coords);
@@ -183,7 +185,7 @@ namespace TrueCraft.Core.Logic.Blocks
                                 neighboringSourceBlocks++;
                         }
                     }
-                    if (neighboringSourceBlocks >= 2)
+                    if (neighboringSourceBlocks >= 2 && AllowSourceCreation)
                         currentLevel = 0;
                     if (highestNeighboringFluid > 0)
                         currentLevel = (byte)(highestNeighboringFluid + 1);
@@ -278,6 +280,18 @@ namespace TrueCraft.Core.Logic.Blocks
                             outwardFlow.Add(new LiquidFlow(zCoordinateCheck, (byte)(currentLevel + 1)));
                     }
                 }
+
+                // Occasionally, there are scenarios where the nearest candidate hole is not acceptable, but
+                // there is space immediately next to the block. We should fill that space.
+                if (outwardFlow.Count == 0 && blockBelow.ID != FlowingID && blockBelow.ID != StillID)
+                {
+                    for (int i = 0; i < Neighbors.Length; i++)
+                    {
+                        var b = world.BlockRepository.GetBlockProvider(world.GetBlockID(coords + Neighbors[i]));
+                        if (!b.Opaque && b.ID != StillID && b.ID != FlowingID)
+                            outwardFlow.Add(new LiquidFlow(Neighbors[i] + coords, (byte)(currentLevel + 1)));
+                    }
+                }
             }
             return outwardFlow.ToArray();
         }
diff --git a/TrueCraft.Core/Logic/Blocks/LavaBlock.cs b/TrueCraft.Core/Logic/Blocks/LavaBlock.cs
index 11eac8b..6f46bed 100644
--- a/TrueCraft.Core/Logic/Blocks/LavaBlock.cs
+++ b/TrueCraft.Core/Logic/Blocks/LavaBlock.cs
@@ -33,6 +33,8 @@ namespace TrueCraft.Core.Logic.Blocks
 
         public override string DisplayName { get { return "Lava"; } }
 
+        protected override bool AllowSourceCreation { get { return false; } }
+
         protected override double SecondsBetweenUpdates { get { return 2; } }
 
         private byte _MaximumFluidDepletion { get; set; }