Single LandTable Load Improvement (#289)

* Implemented single landtable loading through background worker in SALVL.

* Fixed uncleared data on single landtable load. Moved reset for level select if a project is still loaded.

* Properly disable project save button if a project is loaded when a single landtable is loaded. Uncheck selected level in level menu strip item if single landtable is loaded.

Author: ItsEasyActually

Libraries/SAEditorCommon/DataTypes/LevelData.cs

@@ -379,6 +379,11 @@ public static void Clear()
 			ClearSETItems();
 			ClearLevelGeoAnims();
 			ClearLevelGeometry();
+			StartPositions = null;
+			DeathZones = null;
+			leveleff = null;
+			LevelSplines = null;
+			InvalidateRenderState();
 
 			changes.Push("Clear Stage");
 		}

Libraries/SAEditorCommon/UI/SceneGraphControl.cs

@@ -264,9 +264,12 @@ void LoadFullTree()
 				}
 			}
 
-			foreach (SplineData splineData in LevelData.LevelSplines)
+			if (LevelData.LevelSplines != null)
 			{
-				splineNode.Nodes.Add("spline_" + splineData.Code.ToString("X"));
+				foreach (SplineData splineData in LevelData.LevelSplines)
+				{
+					splineNode.Nodes.Add("spline_" + splineData.Code.ToString("X"));
+				}
 			}
 
 			if (LevelData.MissionSETItems != null && LevelData.MissionSETItems[LevelData.Character] != null)

SALVL/DrawLevel.cs

@@ -142,10 +142,13 @@ internal void DrawLevel()
 			#endregion
 
 			#region Adding splines
-			if (viewSplinesToolStripMenuItem.Checked)
+			if (LevelData.LevelSplines != null)
 			{
-				foreach (SplineData spline in LevelData.LevelSplines)
-					renderlist_set.AddRange(spline.Render(d3ddevice, cam, transform));
+				if (viewSplinesToolStripMenuItem.Checked)
+				{
+					foreach (SplineData spline in LevelData.LevelSplines)
+						renderlist_set.AddRange(spline.Render(d3ddevice, cam, transform));
+				}
 			}
 			#endregion