Fixed, Things mode: Undo for things cloning by Shift-dragging them was created incorrectly (cloned things were moved to their initial position, but not removed).

Fixed, Visual mode: fixed Classic sky texture generation artifact when Bilinear filtering was enabled in Visual mode.
Fixed, Visual mode: fixed Classic sky texture generation artifact when non-power-of-2 Sky textures were used.
Fixed, Visual mode: dynamic lights flickering on surfaces nearly-perpendicular to lights centers should be much harder to trigger now.

Source/Core/Data/DataManager.cs

@@ -2559,6 +2559,8 @@ namespace CodeImp.DoomBuilder.Data
 			// Set render settings...
 			device.SetRenderState(RenderState.ZEnable, false);
 			device.SetRenderState(RenderState.CullMode, Cull.None);
+			device.SetSamplerState(0, SamplerState.AddressU, TextureAddress.Clamp);
+			device.SetSamplerState(0, SamplerState.AddressV, TextureAddress.Clamp);
 			
 			// Setup matrices
 			Vector3 offset = new Vector3(0f, 0f, -1.8f); // Sphere size is 10 mu
@@ -2903,14 +2905,17 @@ namespace CodeImp.DoomBuilder.Data
 
 		private static Texture TextureFromBitmap(Device device, Image image)
 		{
-			MemoryStream ms = new MemoryStream();
-			image.Save(ms, ImageFormat.Png);
-			ms.Seek(0, SeekOrigin.Begin);
-			Texture result = Texture.FromStream(device, ms);
-			ms.Close();
-			ms.Dispose();
+			using(MemoryStream ms = new MemoryStream())
+			{
+				image.Save(ms, ImageFormat.Png);
+				ms.Seek(0, SeekOrigin.Begin);
 
-			return result;
+				// Classic skies textures can be NPo2 (and D3D Texture is resized to Po2 by default),
+				// so we need to explicitly specify the size
+				return Texture.FromStream(device, ms, (int) ms.Length,
+										  image.Size.Width, image.Size.Height, 0, Usage.None, Format.Unknown,
+										  Pool.Managed, Filter.None, Filter.None, 0);
+			}
 		}
 		
 		#endregion

Source/Core/GZBuilder/GZDoom/GldefsParser.cs

@@ -418,9 +418,6 @@ namespace CodeImp.DoomBuilder.GZBuilder.GZDoom
 							}
 						}
 
-						// Offset it slightly to avoid shading glitches
-						if(light.Offset.Z == 0.0f) light.Offset.Z = 0.1f;
-
 						// Add to the collection?
 						if(!skip) lightsbyname[lightname] = light;
 

Source/Core/Rendering/D3DDevice.cs

@@ -145,7 +145,7 @@ namespace CodeImp.DoomBuilder.Rendering
 			device.SetRenderState(RenderState.CullMode, Cull.None);
 			device.SetRenderState(RenderState.DestinationBlend, Blend.InverseSourceAlpha);
 			device.SetRenderState(RenderState.DiffuseMaterialSource, ColorSource.Color1);
-			device.SetRenderState(RenderState.DitherEnable, true);
+			//device.SetRenderState(RenderState.DitherEnable, true);
 			device.SetRenderState(RenderState.FillMode, FillMode.Solid);
 			device.SetRenderState(RenderState.FogEnable, false);
 			device.SetRenderState(RenderState.FogTableMode, FogMode.Linear);
@@ -154,6 +154,7 @@ namespace CodeImp.DoomBuilder.Rendering
 			device.SetRenderState(RenderState.NormalizeNormals, false);
 			device.SetRenderState(RenderState.PointSpriteEnable, false);
 			device.SetRenderState(RenderState.RangeFogEnable, false);
+			device.SetRenderState(RenderState.ShadeMode, ShadeMode.Flat); //mxd
 			device.SetRenderState(RenderState.SourceBlend, Blend.SourceAlpha);
 			device.SetRenderState(RenderState.SpecularEnable, false);
 			device.SetRenderState(RenderState.StencilEnable, false);

Source/Core/Resources/world3d.fx

@@ -237,7 +237,7 @@ float4 ps_vertex_color(PixelData pd) : COLOR
 float4 ps_lightpass(LitPixelData pd) : COLOR 
 {
 	//is face facing away from light source?
-	if(dot(pd.normal, (lightPosAndRadius.xyz - pd.pos_w)) < -0.1f) // (lightPosAndRadius.xyz - pd.pos_w) == direction from light to current pixel
+	if(dot(pd.normal, normalize(lightPosAndRadius.xyz - pd.pos_w)) < -0.1f) // (lightPosAndRadius.xyz - pd.pos_w) == direction from light to current pixel
 		clip(-1);
 
 	//is pixel in light range?

Source/Plugins/BuilderModes/ClassicModes/DragThingsMode.cs

@@ -54,7 +54,7 @@ namespace CodeImp.DoomBuilder.BuilderModes
 		private readonly Vector2D dragstartmappos;
 
 		//mxd. Offset from nearest grid intersection to dragstartmappos
-		private Vector2D dragstartoffset;
+		private readonly Vector2D dragstartoffset;
 
 		// Item used as reference for snapping to the grid
 		private readonly Thing dragitem;
@@ -63,6 +63,9 @@ namespace CodeImp.DoomBuilder.BuilderModes
 		// List of old thing positions
 		private readonly List<Vector2D> oldpositions;
 
+		//mxd
+		private bool makeundo;
+
 		//mxd
 		private class AlignData
 		{
@@ -111,11 +114,12 @@ namespace CodeImp.DoomBuilder.BuilderModes
 		#region ================== Constructor / Disposer
 
 		// Constructor to start dragging immediately
-		public DragThingsMode(EditMode basemode, Vector2D dragstartmappos)
+		public DragThingsMode(EditMode basemode, Vector2D dragstartmappos, bool makeundo)
 		{
 			// Initialize
 			this.dragstartmappos = dragstartmappos;
 			this.basemode = basemode;
+			this.makeundo = makeundo; //mxd
 
 			Cursor.Current = Cursors.AppStarting;
 
@@ -371,7 +375,8 @@ namespace CodeImp.DoomBuilder.BuilderModes
 				}
 
 				// Make undo for the dragging
-				General.Map.UndoRedo.CreateUndo((selectedthings.Count == 1 ? "Drag thing" : "Drag " + selectedthings.Count + " things"));
+				if(makeundo) //mxd
+					General.Map.UndoRedo.CreateUndo((selectedthings.Count == 1 ? "Drag thing" : "Drag " + selectedthings.Count + " things"));
 
 				// Move selected geometry to final position
 				if(aligndata != null && aligndata.Active) //mxd. Apply aligning

Source/Plugins/BuilderModes/ClassicModes/ThingsMode.cs

@@ -597,43 +597,54 @@ namespace CodeImp.DoomBuilder.BuilderModes
 					if(!BuilderPlug.Me.DontMoveGeometryOutsideMapBoundary || CanDrag()) //mxd
 					{ 
 						// Shift pressed? Clone things!
+						bool thingscloned = false;
 						if(General.Interface.ShiftState) 
 						{
 							ICollection<Thing> selection = General.Map.Map.GetSelectedThings(true);
-							foreach(Thing t in selection) 
+							if(selection.Count > 0)
 							{
-								Thing clone = InsertThing(t.Position);
-								t.CopyPropertiesTo(clone);
+								// Make undo
+								General.Map.UndoRedo.CreateUndo((selection.Count == 1 ? "Clone-drag thing" : "Clone-drag " + selection.Count + " things"));
 
-								// If the cloned item is an interpolation point or patrol point, then insert the point in the path
-								ThingTypeInfo info = General.Map.Data.GetThingInfo(t.Type);
-								int nextpointtagargnum = -1;
-
-								// Thing type can be changed in MAPINFO DoomEdNums block...
-								switch(info.ClassName.ToLowerInvariant())
+								// Clone things
+								foreach(Thing t in selection)
 								{
-									case "interpolationpoint":
-										nextpointtagargnum = 3;
-										break;
+									Thing clone = InsertThing(t.Position);
+									t.CopyPropertiesTo(clone);
 
-									case "patrolpoint":
-										nextpointtagargnum = 0;
-										break;
+									// If the cloned item is an interpolation point or patrol point, then insert the point in the path
+									ThingTypeInfo info = General.Map.Data.GetThingInfo(t.Type);
+									int nextpointtagargnum = -1;
+
+									// Thing type can be changed in MAPINFO DoomEdNums block...
+									switch(info.ClassName.ToLowerInvariant())
+									{
+										case "interpolationpoint":
+											nextpointtagargnum = 3;
+											break;
+
+										case "patrolpoint":
+											nextpointtagargnum = 0;
+											break;
+									}
+
+									// Apply changes?
+									if(nextpointtagargnum != -1)
+									{
+										if(t.Tag == 0) t.Tag = General.Map.Map.GetNewTag();
+										t.Args[nextpointtagargnum] = clone.Tag = General.Map.Map.GetNewTag();
+									}
+
+									t.Selected = false;
+									clone.Selected = true;
 								}
 
-								// Apply changes?
-								if(nextpointtagargnum != -1)
-								{
-									if(t.Tag == 0) t.Tag = General.Map.Map.GetNewTag();
-									t.Args[nextpointtagargnum] = clone.Tag = General.Map.Map.GetNewTag();
-								}
-
-								t.Selected = false;
-								clone.Selected = true;
+								// We'll want to skip creating additional Undo in DragThingsMode
+								thingscloned = true;
 							}
 						}
 
-						General.Editing.ChangeMode(new DragThingsMode(new ThingsMode(), mousedownmappos));
+						General.Editing.ChangeMode(new DragThingsMode(new ThingsMode(), mousedownmappos, !thingscloned));
 					}
 				}
 			}