From 52241a5ea326ce333cca18a335a4df85d96d1ffe Mon Sep 17 00:00:00 2001
From: Drew DeVault <sir@cmpwn.com>
Date: Mon, 20 Apr 2015 14:26:15 -0600
Subject: [PATCH] Fix falling sand entities

---
 TrueCraft.API/BoundingBox.cs                 | 4 ++--
 TrueCraft.Core/Entities/FallingSandEntity.cs | 6 +++---
 TrueCraft/PhysicsEngine.cs                   | 9 +++++----
 3 files changed, 10 insertions(+), 9 deletions(-)

diff --git a/TrueCraft.API/BoundingBox.cs b/TrueCraft.API/BoundingBox.cs
index 59f8b5a..37b8b13 100644
--- a/TrueCraft.API/BoundingBox.cs
+++ b/TrueCraft.API/BoundingBox.cs
@@ -146,7 +146,7 @@ namespace TrueCraft.API
 
         public void Intersects(ref BoundingBox box, out bool result)
         {
-            if ((this.Max.X >= box.Min.X) && (this.Min.X <= box.Max.X))
+            if ((this.Max.X > box.Min.X) && (this.Min.X < box.Max.X))
             {
                 if ((this.Max.Y < box.Min.Y) || (this.Min.Y > box.Max.Y))
                 {
@@ -154,7 +154,7 @@ namespace TrueCraft.API
                     return;
                 }
 
-                result = (this.Max.Z >= box.Min.Z) && (this.Min.Z <= box.Max.Z);
+                result = (this.Max.Z > box.Min.Z) && (this.Min.Z < box.Max.Z);
                 return;
             }
 
diff --git a/TrueCraft.Core/Entities/FallingSandEntity.cs b/TrueCraft.Core/Entities/FallingSandEntity.cs
index 974dd45..e02dba3 100644
--- a/TrueCraft.Core/Entities/FallingSandEntity.cs
+++ b/TrueCraft.Core/Entities/FallingSandEntity.cs
@@ -51,7 +51,7 @@ namespace TrueCraft.Core.Entities
         {
             get
             {
-                return new BoundingBox(Vector3.Zero, Vector3.One);
+                return new BoundingBox(Position, Position + Size);
             }
         }
 
@@ -71,7 +71,7 @@ namespace TrueCraft.Core.Entities
         {
             get
             {
-                return 0.4f;
+                return 0.04f;
             }
         }
 
@@ -79,7 +79,7 @@ namespace TrueCraft.Core.Entities
         {
             get
             {
-                return 0.2f;
+                return 0.02f;
             }
         }
 
diff --git a/TrueCraft/PhysicsEngine.cs b/TrueCraft/PhysicsEngine.cs
index c22c530..440ce1c 100644
--- a/TrueCraft/PhysicsEngine.cs
+++ b/TrueCraft/PhysicsEngine.cs
@@ -54,8 +54,9 @@ namespace TrueCraft
             if (multipler < 0.1) multipler = 0.1;
             lock (EntityLock)
             {
-                foreach (var entity in Entities)
+                for (int i = 0; i < Entities.Count; i++)
                 {
+                    var entity = Entities[i];
                     if (entity.BeginUpdate())
                     {
                         entity.Velocity -= new Vector3(0, entity.AccelerationDueToGravity * multipler, 0);
@@ -145,7 +146,7 @@ namespace TrueCraft
                         var boundingBox = BlockPhysicsProvider.GetBoundingBox(world, position);
                         if (boundingBox == null)
                             continue;
-                        blockBox = boundingBox.Value.OffsetBy(position);
+                        blockBox = boundingBox.Value.OffsetBy(position + new Vector3(0.5));
                         if (TempBoundingBox.Intersects(blockBox))
                         {
                             if (entity.Velocity.X < 0)
@@ -253,7 +254,7 @@ namespace TrueCraft
                         var boundingBox = BlockPhysicsProvider.GetBoundingBox(world, position);
                         if (boundingBox == null)
                             continue;
-                        blockBox = boundingBox.Value.OffsetBy(position);
+                        blockBox = boundingBox.Value.OffsetBy(position + new Vector3(0.5));
                         if (TempBoundingBox.Intersects(blockBox))
                         {
                             if (entity.Velocity.Y < 0)
@@ -351,7 +352,7 @@ namespace TrueCraft
                         var boundingBox = BlockPhysicsProvider.GetBoundingBox(world, position);
                         if (boundingBox == null)
                             continue;
-                        blockBox = boundingBox.Value.OffsetBy(position);
+                        blockBox = boundingBox.Value.OffsetBy(position + new Vector3(0.5));
                         if (TempBoundingBox.Intersects(blockBox))
                         {
                             if (entity.Velocity.Z < 0)