How do I access data memory in Lazarus?

[TBMan]

I'm trying to learn Lazarus/Free Pascal and I'm a Borland Pascal programmer. Years ago I created a sprite class that could have different sizes. I would access  memory using getmem, mem, seg and ofs and freemem in my routines. However, in this new (to me) Pascal the memory accessing abilities are different. Here's my code. Any help would be appreciated.  In this example there is no error checking for opening the sprite file. The loadsprite function used to use the "searchrec" type from the old DOS unit of Turbo/Borland pascal, but that will be something else I have to learn.

Code: Pascal  [Select][+][-]

1.  
2.  
3.  
4. TYPE
5.   rt_spritetop = RECORD
6.     version,
7.     width,depth:BYTE;
8.   END;
9.  
10.   rt_spriteclass = RECORD
11.     loaded:BOOLEAN;
12.     description:rt_spritetop;
13.     s_segment,s_offset:WORD;
14.     data:POINTER;
15.   END;
16.  
17.  
18. FUNCTION loadsprite(s:STRING;VAR sprite:rt_spriteclass):INTEGER;
19.     VAR
20.      f:FILE;
21.      w,D:BYTE;
22.  
23.     BEGIN
24.         Assign(f,s);
25.         Reset(f,1);
26.  
27.         BlockRead(f,sprite.description,SizeOf(rt_SPRITEtop));
28.         w := sprite.description.width;
29.         D := sprite.description.depth;
30.  
31.         GetMem(sprite.data,w*D);
32.  
33.           Sprite.s_segment := Seg(sprite.data^);
34.           Sprite.s_offset  := Ofs(sprite.data^);
35.           BlockRead(f,sprite.data^,w*D);
36.           sprite.loaded := TRUE;
37.           Close(F);
38.           loadsprite := 0;
39.     END;
40.  
41. PROCEDURE killsprite(VAR n:rt_spriteclass);
42. BEGIN
43.   IF n.loaded THEN
44.   BEGIN
45.     n.loaded := FALSE;
46.     FreeMem(n.data,n.description.width*n.description.depth);
47.   END;
48. END;
49.  
50.  
51.  
52.  PROCEDURE displaysprite(n:rt_spriteclass;X,Y:INTEGER);
53. VAR
54.  xx,
55.  w,D,
56.  r,c:INTEGER;
57. BEGIN
58.   w := n.description.width-1;
59.   D := n.description.depth-1;
60.   FOR r := 0 TO D DO
61.   BEGIN
62.     xx :=X;
63.     FOR c := 0 TO w DO
64.     BEGIN
65.       PutPixel(xx,Y,mem[n.s_segment:n.s_offset+(r*(w+1)+c)]);
66.       Inc(xx);
67.     END;
68.     Inc(Y);
69.   END;
70. END;                    

[jamie]

That code is no longer valid unless you have an old 16-bit box around.

Today we use TBitmaps for images and TImageList to store a series of images.

use the Canvas to paint them.

 Maybe you should look into the OpenGL, there are samples that comes with the install.

[TBMan]

That code is no longer valid unless you have an old 16-bit box around.

Today we use TBitmaps for images and TImageList to store a series of images.

use the Canvas to paint them.

 Maybe you should look into the OpenGL, there are samples that comes with the install.

Thanks, there's a lot to learn there. I'm making progress with the Lazarus package. It's nice to be able to code in a windows app instead of DOSBOX. I'm working with the Graph unit in Lazarus right now which is fun.