Any faster code?

[justnewbie]

I need to create 1000 TImages runtime.
My simple code works well, but very very slow.

Code: Pascal  [Select][+][-]

1. for iC := 1 to 50 do
2.     for iiC := 1 to 20 do
3.     begin
4.       pix[iC, iiC] := TImage.Create(Self);
5.       pix[iC, iiC].Parent := Panel1;
6.       pix[iC, iiC].Width := 15;
7.       pix[iC, iiC].Height := 15;
8.       pix[iC, iiC].Left := (iiC - 1) * 15;
9.       pix[iC, iiC].Top := (iC - 1) * 15;
10.       pix[iC, iiC].Visible := True;
11.       pix[iC, iiC].Enabled := True;
12.     end;

Is it possible to make it (much) faster? 

[Awkward]

not to make 1000 TImage?
Or make it when it needs only coz i thinkm you can't show all of them at same time

[wp]

What else are you doing? I put your code into the OnCreate method of a form, added time measuring steps and found that the 1000 images are created within 0.008 sec. Even with assigning the appliation icon to each image it only takes 0.1 sec. That not "very, very, slow".

Code: Pascal  [Select][+][-]

1. procedure TForm1.FormCreate(Sender: TObject);
2. var
3.   ic, iic: Integer;
4.   t: TDateTime;
5. begin
6.   t := Now();
7.   for iC := 1 to 50 do
8.       for iiC := 1 to 20 do
9.       begin
10.         pix[iC, iiC] := TImage.Create(Self);
11.         pix[iC, iiC].Parent := Panel1;
12.         pix[iC, iiC].Width := 15;
13.         pix[iC, iiC].Height := 15;
14.         pix[iC, iiC].Left := (iiC - 1) * 15;
15.         pix[iC, iiC].Top := (iC - 1) * 15;
16.         pix[iC, iiC].Visible := True;
17.         pix[iC, iiC].Enabled := True;
18.         pix[iC, iiC].Picture.Assign(Application.Icon);
19.       end;
20.   t := Now() - t;
21.   Caption := FormatDateTime('s.zzz"s"', t);
22. end;  

On the other hand, when this code is run in the OnClick event handler of a button, when the form is already show, it becomes much slower: 8 seconds. The reason is - probably - that the panel is repainted after adding each new image. An easy (and cross-platform) way to prevent this is to hide the panel before, and to re-show it after inserting the images. (there are certainly more sophisticated and better solutions..., but i did not want to spend too much thinking...)

[MarkMLl]

Start off by finding out where the bottleneck is. For example, is it the visible/enabled?

MarkMLl

[justnewbie]

@Awkward: I need all of them at the same time.
@wp: it's strange, for me it takes 6.7 seconds.

[jamie]

you are approaching this at the wrong angle..
use a TImageList or use a single image at the sum of the X and Y then in code simply mark it off..

you can display all of them at once because its a single image.

Use a TpaintBox to paint the image and draw on the paint box any bounding boxes etc..

EDIT:

 There are also other alternatives like using the beginFormUpdate, etc...

[justnewbie]

@wp: yes, the "panel hide/show trick" is not a bad idea, now it is 0.8 sec.
@jamie: I'm not sure what you mean, but the single image is surely not good. It is a puzzle game, and I need to move the images.

[wp]

@wp: yes, the "panel hide/show trick" is not a bad idea, now it is 0.8 sec.

I could imagine one issue with "show/hide": When other controls are anchored to the panel they may jump to other locations while the panel is hidden. As a workaround you can place the panel into another equally sized panel which remains visible, and to which you can anchor these controls.

[jamie]

@wp: yes, the "panel hide/show trick" is not a bad idea, now it is 0.8 sec.
@jamie: I'm not sure what you mean, but the single image is surely not good. It is a puzzle game, and I need to move the images.

Use a TDrawGrid and custom draw your cells

[Awkward]

@Awkward: I need all of them at the same time.
@wp: it's strange, for me it takes 6.7 seconds.

TImage? not TPicture?

[Handoko]

@justnewbie

Are you writing a computer game?

If yes then don't use TImage. It is okay for very simple games, like Tetris or Tic-Tac-Toe but soon you will know it is slow. You can check the wiki or search the forum for better graphics libraries.

Maybe you haven't know, let me tell you a little secret that all game programmers should already know. It usually has better performance if you draw all the graphics at once to the screen. That means you should a buffer or some call it virtual screen. Doing it also will fix flickering effect that may happen if there are too many items need to be drawn.
You can read more here:

https://forum.lazarus.freepascal.org/index.php/topic,38136.msg263143.html#msg263143

[justnewbie]

Use a TDrawGrid and custom draw your cells

I need to move the images with the mouse.

[justnewbie]

@justnewbie

Are you writing a computer game?

If yes then don't use TImage. It is okay for very simple games, like Tetris or Tic-Tac-Toe but soon you will know it is slow. You can check the wiki or search the forum for better graphics libraries.

Maybe you haven't know, let me tell you a little secret that all game programmers should already know. It usually has better performance if you draw all the graphics at once to the screen. That means you should a buffer or some call it virtual screen. Doing it also will fix flickering effect that may happen if there are too many items need to be drawn.
You can read more here:

https://forum.lazarus.freepascal.org/index.php/topic,38136.msg263143.html#msg263143

Thank you Handoko, I will check it out.

[Handoko]

It's strange. This code below should give a random list without repeated items. But, it gives repeated values. Why?

Are you sure? How did test it?

By using this code below, I can see there were no repeating number:

Code: Pascal  [Select][+][-]

1.   S := '';
2.   for iC := 0 to resolution-1 do
3.     S := S + randX[iC].ToString + LineEnding;
4.   ShowMessage(S);

[justnewbie]

It's strange. This code below should give a random list without repeated items. But, it gives repeated values. Why?

Are you sure? How did test it?

By using this code below, I can see there were no repeating number:

Code: Pascal  [Select][+][-]

1.   S := '';
2.   for iC := 0 to resolution-1 do
3.     S := S + randX[iC].ToString + LineEnding;
4.   ShowMessage(S);

Yes, the code was good, the silly post removed. Thanks Handoko for the feedback!