SmallintRaster

[Daniel]

Hello!

I am trying to rebuild the demo from:
/ Examples / Terrains / TerrainLOD /

But I get an error in this line:

  rasterLine := SmallintRaster[Y - YTop];
   for X := XLeft to XLeft + Size - 1 do
    rasterLine[X - XLeft] := map[X, Y] * 20;

Error is: unit1.pas(80,37) Error: Incompatible types: got "TSmallIntRaster" expected "PSmallIntArray"

Why would I get this error?

[Jerome.D (BeanzMaster)]

Hi Daniel just need add ^ because is a pointer the char is needed under Lazarus

procedure TfrmMain.GLCustomHDS1StartPreparingData(heightData: TGLHeightData);
var
  rasterLine: GLHeightData.PSmallIntArray;
  b: SmallInt;
  X, Y: Integer;
begin

  b := 128; // 128 = one unit

  heightData.DataState := hdsPreparing;
  with heightData do
  begin
    if (XLeft < 0) or (XLeft > cMapSize - 1) or (YTop < 0) or
      (YTop > cMapSize - 1) then
      heightData.DataState := hdsNone
    else
    begin
      Allocate(hdtSmallInt);
      for Y := YTop to YTop + Size - 1 do
      begin
        rasterLine := SmallIntRaster^[Y - YTop];
        for X := XLeft to XLeft + Size - 1 do
          rasterLine^[X - XLeft] := map[X, Y] * 20;
      end;
      DataState := hdsReady;
    end;
  end;
end;      

Replace also this code, is more fast

procedure TfrmMain.LoadMap;
var
  bmp: TBitmap;
  X, Y: Integer;
  PixPtr : PByte;
begin

  // Load the image. It should be cMapsize and preferably grayscale.
  bmp := TBitmap.Create;
  bmp.LoadFromFile('terrain.bmp');
  for Y := 0 to cMapSize - 1 do
  begin
    PixPtr := bmp.RawImage.GetLineStart(y);
    for X := 0 to cMapSize - 1 do
    begin
      map[X, Y] := PixPtr^;
      inc(PixPtr, 3);
    end;
  end;

  bmp.Free;
end;  

[Daniel]

Works great!
Thank you for taking the time to help me, Jerome!

Cheers

[Daniel]

Now I wonder how to update the terrain during runtime if I want to change the bmp?
I tried this, but it doesn't work...

procedure TForm1.Button1Click(Sender: TObject);
var
hds1: TGLCustomHDS;
begin
  myHds1.Free; //current HDS

  hds1 := TGLCustomHDS.Create(form1);
  hds1.MaxPoolSize := 8 * 1024 * 1024;
  hds1.name := 'myHds1';
  terrain.HeightDataSource := myHds1;                                   
  loadMap;
  terrain.StructureChanged;

end;               

[Daniel]

MarkDirty did the trick!
Cheers