Alien Error!

[Peter]

Deleted.

[Charles Pegge]

Of course.

Assuming the function returns a pointer to the image surface, I think it should be:


dim image* as SDL_Surface
@image = SDL_LoadBMP "bmp/devil.bmp"


Then you have access to all the members of image, which should be easy to test.

[Charles Pegge]

Not a precise match. Have you tried accessing the pixels directly, Peter?

Code: C

1. typedef struct SDL_Surface {
2.         Uint32 flags;                           /**< Read-only */
3.         SDL_PixelFormat *format;                /**< Read-only */
4.         int w, h;                               /**< Read-only */
5.         Uint16 pitch;                           /**< Read-only */
6.         void *pixels;                           /**< Read-write */
7.         int offset;                             /**< Private */
8.  
9.         /** Hardware-specific surface info */
10.         struct private_hwdata *hwdata;
11.  
12.         /** clipping information */
13.         SDL_Rect clip_rect;                     /**< Read-only */
14.         Uint32 unused1;                         /**< for binary compatibility */
15.  
16.         /** Allow recursive locks */
17.         Uint32 locked;                          /**< Private */
18.  
19.         /** info for fast blit mapping to other surfaces */
20.         struct SDL_BlitMap *map;                /**< Private */
21.  
22.         /** format version, bumped at every change to invalidate blit maps */
23.         unsigned int format_version;            /**< Private */
24.  
25.         /** Reference count -- used when freeing surface */
26.         int refcount;                           /**< Read-mostly */
27. } SDL_Surface;
28.  

[Charles Pegge]

Here is a bare-bones SDL Header and test progs. Just add SDL.DLL to the folder.

I hope it resolves the pointer/address issues for you, Peter

Charles

[Charles Pegge]

Similar code after beauty-treatment.

The let syntax is a cleaner alternative for creating objects and it can be used with all those  SDL functions that return a pointered structure.

These three lines all do the same: (the return type of SDL_LoadBMP is SDL_Surface*)

let loadedImage = SDL_LoadBMP filename

SDL_Surface* loadedImage : @loadedImage =  SDL_LoadBMP filename

SDL_Surface loadedImage at ( SDL_LoadBMP filename )

Code: OxygenBasic

1.  
2.  
3.   'tutorials
4.  'http://www.lazyfoo.net/SDL_tutorials/lesson02/index.php
5.  
6.  
7.   extern cdecl lib "sdl.dll"
8.   include "MinSdl.inc"
9.   end extern
10.  
11.   function load_image( string filename ) as SDL_Surface*
12.   '=====================================================
13.  '
14.  let loadedImage = SDL_LoadBMP filename
15.   if @loadedImage
16.     let optimizedImage = SDL_DisplayFormat loadedImage
17.     SDL_FreeSurface loadedImage
18.     return optimizedImage
19.   end if
20.   end function
21.  
22.  
23.   function main() as int
24.   '=====================
25.  '
26.  SDL_Rect DestRect
27.   sys er
28.   er=SDL_Init SDL_INIT_EVERYTHING
29.   if er=-1
30.     return 1
31.   end if
32.   let screen = SDL_SetVideoMode 640,480,32, SDL_SWSURFACE
33.   if not @screen
34.       return 2  
35.   end if
36.   SDL_WM_SetCaption "Hello World", NULL
37.   '
38.  let angel = load_image "angel.bmp"
39.   DestRect<=100,100
40.   SDL_BlitSurface Angel, NULL, screen, DestRect
41.   '
42.  let bat = load_image "bat.bmp"
43.   DestRect<=280,240
44.   SDL_BlitSurface bat, NULL, screen, DestRect
45.   '
46.  if SDL_Flip( screen ) = -1
47.       return 3;    
48.   end if
49.   SDL_Delay 3000 'ms
50.  SDL_FreeSurface angel
51.   SDL_FreeSurface bat
52.   SDL_Quit
53.   return 0
54.   end function
55.  
56.  
57.   er=main
58.  
59.   if er then print er
60.  

[Charles Pegge]

What code are you using Peter? This error occurs when you try to direct-access a type like sdl_surface. As I try to explain: you must use "@" to access the pointer value.

Charles

[Charles Pegge]

Not sure which version you have.

This one is up to the minute

[attachment deleted by admin]

[Charles Pegge]

I have a consolidated header for SDL. It is very large because most of it seems to be equates for OpenGl. If this is excluded then including SDL headers in the standard package is quite feasible, and, for the sake of maintenance, I would try to keep as close to the original C headers as possible.

Users will have to download their own SDL.DLL however.

Charles