rest() + save_bitmap() clashes?

rest() + save_bitmap() clashes?

Dark Nation

Member #1,642

November 2001

My game calls the rest command to reduce CPU usage. However, after calling save_bitmap (called by a specific keypress to take snapshots), trouble begins. About 10 seconds after making the call to save_bitmap, my palette goes all wonky. I haven't studied it very closely, but I think it may be reverting to the system palette. Any ideas why? If I don't call save_bitmap (just return from the snapshot code) or remove the call to rest, everything is fine.

Billybob

Member #3,136

January 2003

Sounds like memory problems. Accessing memory haven't allocated, broken pointers, dangling pointers, etc.

Dark Nation

Member #1,642

November 2001

I've whittled down the code to about 100 lines (including several blank lines) and am still getting the error. Can anyone take a look and see if they get the same problem?

1#include <allegro.h>
2 
3bool quit=false;
4int d_nbmenu_proc(int msg,DIALOG *d,int c);
5 
6 
7int onExit()
8{
9  exit(0);
10}
11 
12static MENU the_menu[] =
13{
14  { "&Exit",          onExit,            NULL },
15  { NULL }
16};
17 
18int onSnapshot()
19{
20  BITMAP *screen2 = create_bitmap_ex(8,320,240);
21  char buf[20];
22  int num=0;
23  do
24  {
25    sprintf(buf, "test%03d.bmp", ++num);
26  } while(num<999 && exists(buf));
27 
28  blit(screen,screen2,0,0,0,0,320,240);
29  PALETTE temppal;
30  get_palette(temppal);
31  save_bitmap(buf,screen2,temppal);
32  destroy_bitmap(screen2);
33  return D_O_K;
34}
35 
36static DIALOG dialogs[] =
37{
38  { d_nbmenu_proc,     0,    0,    0,    13,    0,    0,    0,       D_USER,  0,        0,       (void *) the_menu },
39  { d_keyboard_proc,   0,    0,    0,    0,    0,    0,    'z',     0,       0,        0,       (void *) onSnapshot },
40  { d_keyboard_proc,   0,    0,    0,    0,    0,    0,    27,      0,       0,        0,       (void *) onExit },//
41  { NULL,              0,    0,    0,    0,    0,    0,    0,       0,       0,        0,       NULL }
42};
43 
44int main(int argc,char **argv)
45{
46  allegro_init();
47 
48  if(install_timer() < 0)
49  {
50    al_trace(allegro_error);
51    exit(1);
52  }
53 
54  if(install_keyboard() < 0)
55  {
56    al_trace(allegro_error);
57    exit(1);
58  }
59 
60  if(install_mouse() < 0)
61  {
62    al_trace(allegro_error);
63    exit(1);
64  }
65 
66  set_color_depth(8);
67  if(set_gfx_mode(GFX_AUTODETECT_FULLSCREEN,320,240,0,0)!=0)
68  {
69    al_trace(allegro_error);
70    exit(1);
71  }
72  else
73  {
74    al_trace("OK\n");
75  }
76  DIALOG_PLAYER *player=init_dialog(dialogs,-1);
77  show_mouse(screen);
78  quit=!update_dialog(player);
79  while(!quit)
80  {
81    quit = !update_dialog(player);
82  }
83  return 0;
84}
85 
86END_OF_MAIN()
87 
88int d_nbmenu_proc(int msg,DIALOG *d,int c)
89{
90  rest (1);
91  return d_menu_proc(msg,d,c);
92}
93 
94/* end */

I compiled it with:

g++ -o test.exe test.cpp -lalleg

When you run it, hit the Z key on the keyboard. After about 5 to 10 seconds, the mouse will change colors. I have a strange feeling that it's because I have a rest command inside of a dialog procedure. Is that the problem? Is there a way to make it work? I've even tried replacing the nbmenu_proc with rest_proc, which I defined as:

int d_rest_proc(int msg,DIALOG *d,int c)
{
  rest (1);
  return D_O_K;
}

This still gives me the same bug.

Kauhiz

Member #4,798

July 2004

This may be completely irrelevant, but

do
{
    sprintf(buf, "test%03d.bmp", ++num);
} while(num<999 && exists(buf));

What is this supposed to do?

---
It's Ridge Racer! RIIIIIDGE RAAAAACER!

Dark Nation

Member #1,642

November 2001

It finds the first unused testXXX.bmp filename.

I even tried taking that part out and just using a static filename. Same bug.

I even copied the update_dialog function into my code and whittled it down as much as possible while still keeping the bug. I even took out the keyboard_proc and replaced it with specific functions. After doing that and a little more whittling, here is the current incarnation:

1#include <allegro.h>
2 
3bool quit=false;
4int d_rest_proc(int msg,DIALOG *d,int c);
5 
6 
7int onExit()
8{
9  exit(0);
10}
11 
12int onSnapshot()
13{
14  PALETTE temppal;
15  get_palette(temppal);
16  save_bitmap("test.bmp",screen,temppal);
17  return D_O_K;
18}
19 
20int d_exit_proc(int msg, DIALOG *d, int c)
21{
22  if (msg==MSG_KEY) exit(0);
23  return D_O_K;
24}
25 
26int d_snapshot_proc(int msg, DIALOG *d, int c)
27{
28  if (msg==MSG_KEY)
29  {
30    PALETTE temppal;
31    get_palette(temppal);
32    save_bitmap("test.bmp",screen,temppal);
33  }
34  return D_O_K;
35}
36 
37static DIALOG dialogs[] =
38{
39  { d_rest_proc,     0,    0,    0,    13,    0,    0,    0,       D_USER,  0,        0,       NULL },
40  { d_snapshot_proc,   0,    0,    0,    0,    0,    0,    'z',     0,       0,        0,       NULL },
41  { d_exit_proc,   0,    0,    0,    0,    0,    0,    'x',      0,       0,        0,       NULL },
42  { NULL,              0,    0,    0,    0,    0,    0,    0,       0,       0,        0,       NULL }
43};
44 
45int update_dialog2(DIALOG_PLAYER *player)
46{
47   int c, cascii, cscan, ccombo, r, ret;
48 
49   /* deal with keyboard input */
50   if (keypressed())
51   {
52     cascii = readkey()&0xFF;
53 
54      /* keyboard shortcut? */
55      for (c=0; player->dialog[c].proc; c++)
56      {
57        if (utolower(player->dialog[c].key) == utolower(cascii))
58        {
59          object_message(player->dialog+c, MSG_KEY, cascii);
60          goto getout;
61        }
62      }
63   }
64 
65   /* send idle messages */
66   player->res |= dialog_message(player->dialog, MSG_IDLE, 0, &player->obj);
67 
68   getout:
69 
70   return 1;
71}
72 
73 
74int main(int argc,char **argv)
75{
76  allegro_init();
77 
78  if(install_timer() < 0)
79  {
80    al_trace(allegro_error);
81    exit(1);
82  }
83 
84  if(install_keyboard() < 0)
85  {
86    al_trace(allegro_error);
87    exit(1);
88  }
89 
90  if(install_mouse() < 0)
91  {
92    al_trace(allegro_error);
93    exit(1);
94  }
95 
96  set_color_depth(8);
97  if(set_gfx_mode(GFX_AUTODETECT_FULLSCREEN,320,240,0,0)!=0)
98  {
99    al_trace(allegro_error);
100    exit(1);
101  }
102  else
103  {
104    al_trace("OK\n");
105  }
106  DIALOG_PLAYER *player=init_dialog(dialogs,-1);
107  show_mouse(screen);
108  quit=!update_dialog2(player);
109  while(!quit)
110  {
111    quit = !update_dialog2(player);
112  }
113  return 0;
114}
115 
116END_OF_MAIN()
117 
118int d_rest_proc(int msg,DIALOG *d,int c)
119{
120  rest (1);
121  return D_O_K;
122}
123 
124/* end */

Thoughts? The bug seems to have something to do with MSG_IDLE messages. When I take out this line from update_dialog2:

player->res |= dialog_message(player->dialog, MSG_IDLE, 0, &player->obj);

...the bug goes away.

Edit: I just ran my original code and put a graphical display of the current palette on the screen. All of the colors change to what seems to be the default palette. What's worse, when I do a set_palette from a master palette I set up, the last 10 palette entries won't change. Odder still is the fact that if I output (through al_trace) the palette entries before and after the odd palette change, the values are the same. But, for some reason, the wrong colors are being displayed on the screen.