[A5] al_load_bitmap_f fails

no-reply@allegro.cc (kakadas) — Sun, 23 Feb 2014 19:38:48 +0000

I have a problem loading a bitmap from memory with al_load_bitmap_f. Here's the situation: The bitmap data is in class1, and I get it from class2, which is derived class. Here's my code extract:

#SelectExpand
  1al_file_Data = al_open_memfile(class1::Image_Data, class1::Image_Size, "r");
  2
  3if (!al_file_Data)
  4  printf("memfile loading didn't work :( ");
  5
  6al_bmp_ScreenShot = al_load_bitmap_f(al_file_Data, ".bmp");
  7
  8if (!al_bmp_ScreenShot)
  9  printf("loading bitmap from data didn't work :( ");

To me the code seems legit and should work fine. I wrote class1::Image_Data to disk and confirmed that the image is valid.

Could Anyone tell me any reasons for al_load_bitmap_f failing?

no-reply@allegro.cc (ph03nix) — Sun, 23 Feb 2014 21:08:30 +0000

Do you call al_init and al_init_image_addon before this? Also, is your bitmap data of a bmp file, as you specified in al_load_bitmap_f?

no-reply@allegro.cc (SiegeLord) — Sun, 23 Feb 2014 22:12:33 +0000

This code works for me:

#SelectExpand
  1#include 
  2#include 
  3#include 
  4#include 
  5
  6int main()
  7{
al_init();
al_init_image_addon();
ALLEGRO_DISPLAY* display = al_create_display(800, 600);

ALLEGRO_BITMAP* bitmap = al_load_bitmap("test.bmp");
assert(bitmap);

ALLEGRO_FILE* file = al_fopen("test.bmp", "rb");
assert(file);

int64_t size = al_fsize(file);
assert(size > 0);

void* data = malloc(size);
al_fread(file, data, size);

ALLEGRO_FILE* memfile = al_open_memfile(data, size, "rb");

ALLEGRO_BITMAP* bitmap2 = al_load_bitmap_f(memfile, ".bmp");
assert(bitmap2);

ALLEGRO_EVENT_QUEUE* queue = al_create_event_queue();
al_register_event_source(queue, al_get_display_event_source(display));

bool quit = false;
while(!quit)
{
  ALLEGRO_EVENT event;
  if(al_get_next_event(queue, &event))
  {
    if(event.type == ALLEGRO_EVENT_DISPLAY_CLOSE)
      quit = true;
  }
  al_draw_bitmap(bitmap, 0, 0, 0);
  al_draw_bitmap(bitmap2, 100, 100, 0);
  al_flip_display();
}

return 0;
 47}

Check to see that the class1::ImageSize is right and if that is fine, then post the bitmap here... Allegro has trouble with some bitmap files (we suggest you use png/tga for that reason).

no-reply@allegro.cc (kakadas) — Sun, 23 Feb 2014 22:28:59 +0000

ph03nix said:

Do you call al_init and al_init_image_addon before this? Also, is your bitmap data of a bmp file, as you specified in al_load_bitmap_f?

Wow, such a terrible mistake I made... I think I need to take a little break...

Anyway, thanks for the reply.