How do you update a TDXImageList at runtime?

[masonwheeler]

I'm using UndelphiX for Delphi 7 on Delphi 2006.

Everything I've seen in any tuturial only talks about loading images into a TDXImageList at design time, and then using them. But what I really want to do is add images directly into the list at runtime, like I can do with the TImageList.add method.

Since TDXImageList doesn't *have* a handy "add" method, how can I do it? I don't care how kludgy or work-around-ish it is; I just want to be able to insert items into the list at runtime, at will.

Can anyone help me with this?

Mason

[AthenaOfDelphi]

It is possible and relatively straight forward.

The key thing is not rely on the auto initialisation of the other components such that you can initialise and deinitialise them at will.

Basically, what you do, is load the images you want to use into your TDXImageList, then initialise the TDXDraw component. Once you've done that, you link the image list to the TDXDraw and build the colour tables.

fDXDraw.initialize;

fTileSet:=fEngineState.game.tiles;
fTileSet.dxdraw:=fDXDraw;

fTileSet.items.MakeColorTable;

fDXDraw.DefColorTable:=fTileSet.items.colorTable;
fDXDraw.ColorTable:=fTileSet.items.colorTable;

The only problem with this is that making the colour tables can take time.

When you're done and you want to load other tiles, you just call the finalize method of the DXDraw, and unlink the TDXImageList... or the other way round, I can't remember (Sorry :-) ).

The obvious downside to this is the fact that DirectX will completely deinitialise and then have to reinitialise, so its not a quick load and go option.

Hope this helps :-)

[masonwheeler]

Thanks. I assume, from your example, that fTileSet is a TDXImageList object. And you've hit the mark spot-on; creating a tile set is exactly what I'm trying to do. But what is fEngineState.game.tiles? (Or to simplify, what is fEngineState?)

Also,

Basically, what you do, is load the images you want to use into your TDXImageList,

Yeah, that's what I'm trying to do. But how do I do it at run-time? The only way I know to do it is to set up the list in the object inspector at design-time.

Mason

[AthenaOfDelphi]

Sorry I don't have more time to explain, but heres a quick breakdown.

This code comes from my competition entry from last year. It basically had an editor and a play engine. The code I pasted earlier was from the play engine and yes, fEngineState.game.tiles is a TDXImageList that is loaded from a file stream linked to a data file containing the games base data (fEngineState is a big object that holds the entire state of the play engine... one of the sub-objects is 'game' which hold all the games base data... one component of that is the tile set 'tiles').

To populate a TDXImageList at runtime, heres some code... this is taken straight out of my game data editor (fTileImportBuffer is a TDXImageList)

[pascal]
function TfrmGameEditor.loadTilesFromFile(filename:string): boolean;
var
dib : TDib;
tile: TDib;
x : integer;
y : integer;
tilesX : integer;
tilesY : integer;
srcRect : TRect;
dstRect : TRect;
item : TPictureCollectionItem;


dim : integer;
begin
result:=false;

fTileImportBuffer:=TDXImageList.create(application );

dib:=TDib.create;

dim:=8+(cboSourceSize.itemIndex*;

try
dib.LoadFromFile(filename);

if (dib.Width mod dim<>0) or (dib.height mod dim<>0) then
begin
showMessage('Cannot load file - Not divisible by '+intToStr(dim));
exit;
end;

dstRect.top:=0;
dstRect.left:=0;
dstRect.bottom:=dib.height;
dstRect.right:=dib.width;

tilesX:=(dib.width div dim);
tilesY:=(dib.height div dim);

dstRect.top:=0;
dstRect.left:=0;
dstRect.right:=dim;
dstRect.bottom:=dim;

tile:=TDib.create;
tile.SetSize(dim,dim,24);

for y:=1 to tilesY do
for x:=1 to tilesX do
begin
srcRect.left:=(x-1)*dim;
srcRect.right:=srcRect.left+dim;
srcRect.top:=(y-1)*dim;
srcRect.bottom:=srcRect.top+dim;

tile.canvas.CopyRect(dstRect,dib.canvas,srcRect);

item:=TPictureCollectionItem(fTileImportBuffer.Ite ms.add);
item.Picture.Graphic:=tile;
item.transparent:=true;
item.transparentColor:=clBlack;
end;

result:=true;
finally
try
dib.free;
except
end;

try
tile.free;
except
end;
end;

reinitializeTilePreviewDX;
end;

{$warnings on}

[/pascal]

What this does is loads a bitmap into a device independent bitmap and then chops it up into tiles of 'dim x dim' size. dim is calculated based on a size specified in a combo box on the editor form. These tiles are then just dumped into a TDXImageList.

[masonwheeler]

Whee! That's precisely what I needed! (With a few minor modifications to fit my specific project, of course.) You mind if I use your code?

Mason

[masonwheeler]

One other question.

Trying to load up the file I'm using gave me this:

First chance exception at $7C812A5B. Exception class EInvalidGraphic with message 'DIB is invalid'.

I assume this is because the file I'm trying to open isn't in DIB format. (It's a PNG.) I've already got a routine written to open the file and convert it, from before I got your example.

   dlgOpen.Filter:='All images: '+BitmapLoaders.GetLoadFilter;
   if dlgOpen.Execute then
      filename := dlgOpen.FileName;
      with TLinearBitmap.Create do
      try
         imgLoaded.Picture:=nil;
         LoadFromFile(dlgOpen.FileName);
         AssignTo(imgLoaded.Picture.Bitmap);
      finally
         Free;
      end;
   //end if

(imgLoaded is a TImage control.) What would be the best way to merge this with your code, so the dib object gets its picture from the (now decoded) imgLoaded instead of trying to bring it in straight from the file? Or is there a better way?

Thanks for your patience,

Mason

[AthenaOfDelphi]

Hi mason,

I'm afraid (as far as I know), (un)DelphiX doesn't support PNG's directly. As you've said you've got a conversion routine, I guess whether or not its compatible depends on the output from the routine.

Maybe someone who has used DelphiX more extensively could chip in.

For what its worth, I've stopped using (un)DelphiX because I've never been overly impressed with the performance (even with hardware acceleration). Asphyre is pretty neat, so too is DanJetX and then of course OpenGL.

Anyhow, sorry I can't help more on the image format stuff.

[seiferalmasy]

Yes PNG is unsupported, I really wish one day it is added to delphix but for now, yo will have to make do with the rather crap transparent settings.

[ijcro]

Tool for PNG-conversion exists (with alphachannel) and it is under testing now. I release it next week with installation tool of (un)DelphiX 1.07f (I announcing support for Delphi 2007 and good work under Windows Vista; it is tested now too). As bonus I have prepared new tool for conversion animated GIF.

Regards for all