Client/ULandscape.pas

@@ -320,6 +320,8 @@ type
     Hue: Word;
   end;
 
+  TGhostTile = class(TStaticItem);
+
 operator enumerator(AScreenBuffer: TScreenBuffer): TScreenBufferItemEnumerator;
 
 implementation
@@ -996,6 +998,7 @@ var
   i, x, y: Integer;
   tempDrawList: TWorldItemList;
   staticTileData: TStaticTiledata;
+  blockInfo: PBlockInfo;
 begin
   ADrawList.Clear;
   tempDrawList := TWorldItemList.Create(False);;
@@ -1042,7 +1045,11 @@ begin
 
   tempDrawList.Sort(@CompareWorldItems);
   for i := 0 to tempDrawList.Count - 1 do
-    ADrawList.Add(TWorldItem(tempDrawList[i]));
+  begin
+    blockInfo := ADrawList.Add(TWorldItem(tempDrawList[i]));
+    if tempDrawList[i] is TGhostTile then
+      blockInfo^.State := ssGhost;
+  end;
   tempDrawList.Free;
 end;
 

Client/UUoaDesigns.pas

@@ -32,6 +32,19 @@ type
     constructor CreateFromStream(AStream: TStream);
   end;
 
+  TUoaDesign = class
+  private
+    FHeader: TUoaDesignHeader;
+    FTiles: TStaticItemList;
+
+    constructor Create(AHeader: TUoaDesignHeader; AData: TStream);
+  public
+    property Header: TUoaDesignHeader read FHeader;
+    property Tiles: TStaticItemList read Ftiles;
+
+    destructor Destroy; override;
+  end;
+
   { TUoaDesigns }
 
   TUoaDesigns = class
@@ -42,8 +55,7 @@ type
     constructor Create(AIdxFile, ABinFile: String);
     destructor Destroy; override;
 
-    function LoadTiles(AHeader: TUoaDesignHeader; AOffsetX, AOffsetY: Word;
+    function LoadDesign(AHeader: TUoaDesignHeader): TUoaDesign;
-      AOffsetZ: ShortInt): TStaticItemList;
   public
     property Headers: TUoaDesignHeaders read FHeaders;
   end;
@@ -65,6 +77,49 @@ begin
   end;
 end;
 
+{ TUoaDesign }
+
+constructor TUoaDesign.Create(AHeader: TUoaDesignHeader; AData: TStream);
+var
+  i: Integer;
+  tile: TStaticItem;
+  version: Int32;
+
+  function ReadInt: Int32;
+  begin
+    AData.Read(Result, SizeOf(Result));
+  end;
+
+begin
+  FHeader := AHeader;
+  FTiles := TStaticItemList.Create(True);
+  AData.Seek(FHeader.FilePosition, soFromBeginning);
+  for i := 0 to FHeader.TileCount - 1 do
+  begin
+    AData.Read(version, SizeOf(version));
+    if (version < 0) or (version > 1) then
+      raise Exception.Create('Unsupported binary version');
+
+    tile := TStaticItem.Create(nil);
+    tile.TileID := ReadInt;
+    tile.X := ReadInt;
+    tile.Y := ReadInt;
+    tile.Z := ReadInt;
+    ReadInt; // Level; unused
+
+    if version = 1 then
+      tile.Hue := ReadInt;
+
+    FTiles.Add(tile);
+  end;
+end;
+
+destructor TUoaDesign.Destroy;
+begin
+  FTiles.Free;
+  inherited Destroy;
+end;
+
 { TUoaDesignHeaders }
 
 constructor TUoaDesignHeaders.CreateFromStream(AStream: TStream);
@@ -120,39 +175,9 @@ begin
   Headers.Free;
 end;
 
-function TUoaDesigns.LoadTiles(AHeader: TUoaDesignHeader; AOffsetX,
+function TUoaDesigns.LoadDesign(AHeader: TUoaDesignHeader): TUoaDesign;
-  AOffsetY: Word; AOffsetZ: ShortInt): TStaticItemList;
-var
-  i: Integer;
-  tile: TStaticItem;
-  version: Int32;
-
-  function ReadInt: Int32;
 begin
-    FData.Read(Result, SizeOf(Result));
+  Result := TUoaDesign.Create(AHeader, FData);
-  end;
-
-begin
-  Result := TStaticItemList.Create(True);
-  FData.Seek(AHeader.FilePosition, soFromBeginning);
-  for i := 0 to AHeader.TileCount - 1 do
-  begin
-    FData.Read(version, SizeOf(version));
-    if (version < 0) or (version > 1) then
-      raise Exception.Create('Unsupported binary version');
-
-    tile := TStaticItem.Create(nil);
-    tile.TileID := ReadInt;
-    tile.X := AOffsetX + ReadInt;
-    tile.Y := AOffsetY + ReadInt;
-    tile.Z := AOffsetZ + ReadInt;
-    ReadInt; // TODO: Level??
-
-    if version = 1 then
-      tile.Hue := ReadInt;
-
-    Result.Add(tile);
-  end;
 end;
 
 end.

Client/UfrmMain.pas

@@ -47,7 +47,6 @@ type
 
   TBlockInfoList = specialize TFPGList<PBlockInfo>;
 
-  TGhostTile = class(TStaticItem);
   TPacketList = specialize TFPGObjectList<TPacket>;
   TAccessChangedListeners = specialize TFPGList<TAccessChangedListener>;
   TSelectionListeners = specialize TFPGList<TSelectionListener>;
@@ -360,10 +359,13 @@ type
     FUndoList: TPacketList;
     FGLFont: TGLFont;
     FSelectionListeners: TSelectionListeners;
+    FHoverListeners: TSelectionListeners;
     FTileHint: TTileHintInfo;
     FLightManager: TLightManager;
     FTileFilter: TTileDataFlags;
     FUoaDesigns: TUoaDesigns;
+    FCurrentUoaDesign: TUoaDesign;
+    FCurrentUoaDesignAnchor: TWorldItem;
     { Methods }
     procedure BuildTileList;
     function  ConfirmAction: Boolean;
@@ -381,6 +383,7 @@ type
     procedure PlaceUoaDesign(AWorldItem: TWorldItem);
     procedure PrepareMapCell(AMapCell: TMapCell);
     procedure PrepareScreenBlock(ABlockInfo: PBlockInfo);
+    procedure PreviewUoaDesign(AWorldItem: TWorldItem);
     procedure ProcessToolState;
     procedure ProcessAccessLevel;
     procedure RebuildScreenBuffer;
@@ -420,10 +423,12 @@ type
     procedure InvalidateFilter;
     procedure InvalidateScreenBuffer;
     procedure RegisterAccessChangedListener(AListener: TAccessChangedListener);
+    procedure RegisterHoverListener(AListener: TSelectionListener);
     procedure RegisterSelectionListener(AListener: TSelectionListener);
     procedure SetPos(AX, AY: Word);
     procedure SwitchToSelection;
     procedure UnregisterAccessChangedListener(AListener: TAccessChangedListener);
+    procedure UnregisterHoverListener(AListener: TSelectionListener);
     procedure UnregisterSelectionListener(AListener: TSelectionListener);
   end; 
 
@@ -1038,6 +1043,7 @@ begin
   pnlBottom.DoubleBuffered := True;
 
   FAccessChangedListeners := TAccessChangedListeners.Create;
+  FHoverListeners := TSelectionListeners.Create;
   FSelectionListeners := TSelectionListeners.Create;
   
   FLastDraw := Now;
@@ -1408,6 +1414,7 @@ begin
   FreeAndNil(FGLFont);
   FreeAndNil(FRandomPresetsDoc);
   FreeAndNil(FAccessChangedListeners);
+  FreeAndNil(FHoverListeners);
   FreeAndNil(FSelectionListeners);
   FreeAndNil(FUoaDesigns);
   
@@ -1989,8 +1996,24 @@ begin
 end;
 
 procedure TfrmMain.vstUoaDesignsDblClick(Sender: TObject);
+var
+  selectedNode: PVirtualNode;
 begin
+  // Make sure to reset the current view first.
+  PreviewUoaDesign(nil);
+
+  UnregisterSelectionListener(@PlaceUoaDesign);
+  UnregisterHoverListener(@PreviewUoaDesign);
+
+  selectedNode := vstUoaDesigns.GetFirstSelected();
+  if selectedNode = nil then
+    Exit;
+
+  FreeAndNil(FCurrentUoaDesign);
+  FCurrentUoaDesign := FUoaDesigns.LoadDesign(FUoaDesigns.Headers[selectedNode^.Index]);
+
   RegisterSelectionListener(@PlaceUoaDesign);
+  RegisterHoverListener(@PreviewUoaDesign);
 end;
 
 procedure TfrmMain.vstUoaDesignsGetText(Sender: TBaseVirtualTree;
@@ -2065,6 +2088,12 @@ begin
   FAccessChangedListeners.Add(AListener);
 end;
 
+procedure TfrmMain.RegisterHoverListener(AListener: TSelectionListener);
+begin
+  if FHoverListeners.IndexOf(AListener) = -1 then
+    FHoverListeners.Add(AListener);
+end;
+
 procedure TfrmMain.RegisterSelectionListener(AListener: TSelectionListener);
 begin
   if FSelectionListeners.IndexOf(AListener) = -1 then
@@ -2077,6 +2106,11 @@ begin
   FAccessChangedListeners.Remove(AListener);
 end;
 
+procedure TfrmMain.UnregisterHoverListener(AListener: TSelectionListener);
+begin
+  FHoverListeners.Remove(Alistener);
+end;
+
 procedure TfrmMain.UnregisterSelectionListener(AListener: TSelectionListener);
 begin
   FSelectionListeners.Remove(AListener);
@@ -2294,7 +2328,9 @@ begin
   if selectedNode = nil then
     Exit;
 
-  header := FUoaDesigns.Headers[selectedNode^.Index];
+  vstUoaDesigns.ClearSelection;
+
+  {header := FUoaDesigns.Headers[selectedNode^.Index];
   tiles := FUoaDesigns.LoadTiles(header, AWorldItem.X, AWorldItem.Y, AWorldItem.Z);
   try
     FUndoList.Clear;
@@ -2305,7 +2341,7 @@ begin
     end;
   finally
     tiles.Free;
-  end;
+  end;}
 end;
 
 procedure TfrmMain.PrepareMapCell(AMapCell: TMapCell);
@@ -2568,6 +2604,62 @@ begin
   end;
 end;
 
+procedure TfrmMain.PreviewUoaDesign(AWorldItem: TWorldItem);
+var
+  offsetX, offsetY, offsetZ: Integer;
+  newX, newY, newZ: Integer;
+  i: Integer;
+  designTile, virtualTile: TStaticItem;
+  blockInfo: PBlockInfo;
+begin
+  // If nothing has changed, we can keep this short.
+  if FCurrentUoaDesignAnchor = AWorldItem then
+    Exit;
+
+  // No design selected? Well then.
+  if FCurrentUoaDesign = nil then
+    Exit;
+
+  for i := FVirtualTiles.Count - 1 downto 0 do
+  begin
+    if FVirtualTiles[i] is TGhostTile then
+    begin
+      FScreenBuffer.Delete(FVirtualTiles[i]);
+      FVirtualTiles.Delete(i);
+    end;
+  end;
+
+  if AWorldItem = nil then
+    Exit;
+
+  offsetX := AWorldItem.X - FCurrentUoaDesign.Header.Width div 2;
+  offsetY := AWorldItem.Y - FCurrentUoaDesign.Header.Height div 2;
+  offsetZ := AWorldItem.Z;
+
+  for designTile in FCurrentUoaDesign.Tiles do
+  begin
+    newX := designTile.X + offsetX;
+    newY := designTile.Y + offsetY;
+    newZ := designTile.Z + offsetZ;
+
+    if (newX < 0) or (newX >= FLandscape.CellWidth) or
+      (newY < 0) or (newY >= FLandscape.CellHeight) or
+      (newZ < -128) or (newZ > 127) then
+      // We can't render this tile. Skip it.
+      continue;
+
+    virtualTile := TGhostTile.Create(nil, nil, 0, 0);
+    virtualTile.X := newX;
+    virtualTile.Y := newY;
+    virtualTile.Z := newZ;
+    virtualTile.TileID := designTile.TileID;
+    virtualTile.Hue := designTile.Hue;
+    FVirtualTiles.Add(virtualTile);
+  end;
+
+  InvalidateScreenBuffer;
+end;
+
 procedure TfrmMain.Render;
 var
   highlight: Boolean;
@@ -3060,6 +3152,7 @@ end;
 procedure TfrmMain.UpdateCurrentTile(AX, AY: Integer);
 var
   blockInfo: PBlockInfo;
+  listener: TSelectionListener;
 begin
   //Logger.EnterMethod([lcClient, lcDebug], 'UpdateCurrentTile');
   FOverlayUI.ActiveArrow := FOverlayUI.HitTest(AX, AY);
@@ -3077,6 +3170,9 @@ begin
   else
     CurrentTile := nil;
 
+  for listener in FHoverListeners do
+    listener(CurrentTile);
+
   //Logger.ExitMethod([lcClient, lcDebug], 'UpdateCurrentTile');
 end;