[SOLVED]Resizing TImage from middle?

[osman.schltz]

Hi there!
I'm trying to make a 2D car game. But I'm stuck at one point. How can I resize the TImage from the middle. I mean, if i want to resize the TImage, I use

Code: Pascal  [Select][+][-]

1. TImage.Width

Code: Pascal  [Select][+][-]

1. TImage.Height

But that resizes the TImage to one side, how can I resize the TImage to both sides at the same time? 

[balazsszekely]

By moving the Left, Top in oposite direction? See attached project.

[Segator]

Hi osman.schltz, you must to set the Strech and autosize to false of the TImage:

Code: Pascal  [Select][+][-]

1. TImage.Strech:=false;
2. TImage.Autosize:=false;
3. TImage.Width:=your_size;
4. TImage.Height:=your_size;
5.  

[Segator]

Code: Pascal  [Select][+][-]

1. const
2.        isize=100;
3. begin
4.   TImage.Strech:=false;
5.   TImage.Autosize:=false;
6.   TImage.Width:=isize;
7.   TImage.Heoght:=isize;
8.   TImage.Top:=isize div 2;
9.   TImage.Left:=isize div 2;
10. end;
11.  

[Handoko]

Try my code, it works:

Code: Pascal  [Select][+][-]

1. unit Unit1;
2.  
3. {$mode objfpc}{$H+}
4.  
5. interface
6.  
7. uses
8.   Classes, Forms, Controls, Graphics, ExtCtrls,
9.   ComCtrls;
10.  
11. type
12.  
13.   { TForm1 }
14.  
15.   TForm1 = class(TForm)
16.     Image1: TImage;
17.     TrackBar1: TTrackBar;
18.     procedure FormCreate(Sender: TObject);
19.     procedure TrackBar1Change(Sender: TObject);
20.   private
21.     CenterX, CenterY, SizeX, SizeY: Integer;
22.   end;
23.  
24. var
25.   Form1: TForm1;
26.  
27. implementation
28.  
29. {$R *.lfm}
30.  
31. { TForm1 }
32.  
33. procedure TForm1.TrackBar1Change(Sender: TObject);
34. var
35.   NewSizeX, NewSizeY: Integer;
36. begin
37.   // TrackBar.Position = percentage of the original size
38.  
39.   NewSizeX      := Round(TrackBar1.Position / 100 * SizeX);
40.   NewSizeY      := Round(TrackBar1.Position / 100 * SizeY);
41.   Image1.Left   := CenterX - (NewSizeX div 2);
42.   Image1.Top    := CenterY - (NewSizeY div 2);
43.   Image1.Width  := NewSizeX;
44.   Image1.Height := NewSizeY;
45. end;
46.  
47. procedure TForm1.FormCreate(Sender: TObject);
48. begin
49.   Image1.Stretch := True;
50.  
51.   SizeX   := Image1.Width;
52.   SizeY   := Image1.Height;
53.   CenterX := Image1.Left + (SizeX div 2);
54.   CenterY := Image1.Top  + (SizeY div 2);
55. end;
56.  
57. end.

[Handoko]

Just tested GetMem's code. It did not work correctly at least on my Lazarus 1.8.4 Linux GTK2.

-edit-
Actually, it works. But not proportionally on the size of both sides.

[osman.schltz]

Try my code, it works:

Code: Pascal  [Select][+][-]

1. unit Unit1;
2.  
3. {$mode objfpc}{$H+}
4.  
5. interface
6.  
7. uses
8.   Classes, Forms, Controls, Graphics, ExtCtrls,
9.   ComCtrls;
10.  
11. type
12.  
13.   { TForm1 }
14.  
15.   TForm1 = class(TForm)
16.     Image1: TImage;
17.     TrackBar1: TTrackBar;
18.     procedure FormCreate(Sender: TObject);
19.     procedure TrackBar1Change(Sender: TObject);
20.   private
21.     CenterX, CenterY, SizeX, SizeY: Integer;
22.   end;
23.  
24. var
25.   Form1: TForm1;
26.  
27. implementation
28.  
29. {$R *.lfm}
30.  
31. { TForm1 }
32.  
33. procedure TForm1.TrackBar1Change(Sender: TObject);
34. var
35.   NewSizeX, NewSizeY: Integer;
36. begin
37.   // TrackBar.Position = percentage of the original size
38.  
39.   NewSizeX      := Round(TrackBar1.Position / 100 * SizeX);
40.   NewSizeY      := Round(TrackBar1.Position / 100 * SizeY);
41.   Image1.Left   := CenterX - (NewSizeX div 2);
42.   Image1.Top    := CenterY - (NewSizeY div 2);
43.   Image1.Width  := NewSizeX;
44.   Image1.Height := NewSizeY;
45. end;
46.  
47. procedure TForm1.FormCreate(Sender: TObject);
48. begin
49.   Image1.Stretch := True;
50.  
51.   SizeX   := Image1.Width;
52.   SizeY   := Image1.Height;
53.   CenterX := Image1.Left + (SizeX div 2);
54.   CenterY := Image1.Top  + (SizeY div 2);
55. end;
56.  
57. end.

Thanks y'all for help! I'll use Handoko's and Segator's examples because GetMem's code is not cross-platform and I'll come back with results as soon as possible 

[osman.schltz]

Try my code, it works:

Code: Pascal  [Select][+][-]

1. unit Unit1;
2.  
3. {$mode objfpc}{$H+}
4.  
5. interface
6.  
7. uses
8.   Classes, Forms, Controls, Graphics, ExtCtrls,
9.   ComCtrls;
10.  
11. type
12.  
13.   { TForm1 }
14.  
15.   TForm1 = class(TForm)
16.     Image1: TImage;
17.     TrackBar1: TTrackBar;
18.     procedure FormCreate(Sender: TObject);
19.     procedure TrackBar1Change(Sender: TObject);
20.   private
21.     CenterX, CenterY, SizeX, SizeY: Integer;
22.   end;
23.  
24. var
25.   Form1: TForm1;
26.  
27. implementation
28.  
29. {$R *.lfm}
30.  
31. { TForm1 }
32.  
33. procedure TForm1.TrackBar1Change(Sender: TObject);
34. var
35.   NewSizeX, NewSizeY: Integer;
36. begin
37.   // TrackBar.Position = percentage of the original size
38.  
39.   NewSizeX      := Round(TrackBar1.Position / 100 * SizeX);
40.   NewSizeY      := Round(TrackBar1.Position / 100 * SizeY);
41.   Image1.Left   := CenterX - (NewSizeX div 2);
42.   Image1.Top    := CenterY - (NewSizeY div 2);
43.   Image1.Width  := NewSizeX;
44.   Image1.Height := NewSizeY;
45. end;
46.  
47. procedure TForm1.FormCreate(Sender: TObject);
48. begin
49.   Image1.Stretch := True;
50.  
51.   SizeX   := Image1.Width;
52.   SizeY   := Image1.Height;
53.   CenterX := Image1.Left + (SizeX div 2);
54.   CenterY := Image1.Top  + (SizeY div 2);
55. end;
56.  
57. end.

Thanks everyone for help! Handoko's code works well.