🔒 Locked

problem loading .dat data

Started by raptorstrike Aug 27, 2004 at 9:20 AM 18 replies 2.3k views

Original Post

Aug 27, 2004 at 9:20 AM

ok in allegro im trying to use this function void drawAll() { blit( ( BITMAP* )data[ building ].dat, buffer, 0, 0, 0, 0, SCREEN_W, SCREEN_H ); acquire_screen(); blit( buffer, screen, 0, 0, 0, 0, SCREEN_W, SCREEN_H ); release_screen(); } if my understanding of this function is right the filename[ spacific file ].datatype but my compiler says that data is undefined do i need to inclose this statement in () if i put it in "" i get a critical error error: `data' undeclared (first use this function)

raevin

Aug 27, 2004 at 9:39 AM

Quote:
Original post by raptorstrike
ok in allegro im trying to use this function
void drawAll()
{
blit( ( BITMAP* )data[ building ].dat, buffer,
0, 0, 0, 0, SCREEN_W, SCREEN_H );
acquire_screen();
blit( buffer, screen, 0, 0, 0, 0, SCREEN_W, SCREEN_H );
release_screen();
}

if my understanding of this function is right the
filename[ spacific file ].datatype
but my compiler says that data is undefined do i need to inclose this statement in () if i put it in "" i get a critical error

error: `data' undeclared (first use this function)

Well, for one, isn't it not safe to do "data[ building ].dat"?? *the spaces are what I'm refering to*.

raptorstrike

Aug 27, 2004 at 9:47 AM

yeah i guesss your right but thats not the problem

catlettc

Aug 27, 2004 at 9:58 AM

Where are you declaring data?

GameCreator

Aug 27, 2004 at 10:05 AM

Well, here's the source for the datafile example...

/* *    Example program for the Allegro library, by Shawn Hargreaves. * *    This program demonstrates how to access the contents of an *    Allegro datafile (created by the grabber utility). */#include "allegro.h"/* the grabber produces this header, which contains defines for the names * of all the objects in the datafile (BIG_FONT, SILLY_BITMAP, etc). */#include "example.h"int main(int argc, char *argv[]){   DATAFILE *datafile;   char buf[256];   allegro_init();   install_keyboard();    if (set_gfx_mode(GFX_SAFE, 320, 200, 0, 0) != 0) {      set_gfx_mode(GFX_TEXT, 0, 0, 0, 0);      allegro_message("Unable to set any graphic mode\n%s\n", allegro_error);      return 1;   }   /* we still don't have a palette => Don't let Allegro twist colors */   set_color_conversion(COLORCONV_NONE);   /* load the datafile into memory */   replace_filename(buf, argv[0], "example.dat", sizeof(buf));   datafile = load_datafile(buf);   if (!datafile) {      set_gfx_mode(GFX_TEXT, 0, 0, 0, 0);      allegro_message("Error loading %s!\n", buf);      return 1;   }   /* select the palette which was loaded from the datafile */   set_palette(datafile[THE_PALETTE].dat);   /* aha, set a palette and let Allegro convert colors when blitting */   set_color_conversion(COLORCONV_TOTAL);      /* display the bitmap from the datafile */   textout(screen, font, "This is the bitmap:", 32, 16, makecol(255, 255, 255));   blit(datafile[SILLY_BITMAP].dat, screen, 0, 0, 64, 32, 64, 64);   /* and use the font from the datafile */   textout(screen, datafile[BIG_FONT].dat, "And this is a big font!", 32, 128,	   makecol(0, 255, 0));   readkey();   /* unload the datafile when we are finished with it */   unload_datafile(datafile);   return 0;}END_OF_MAIN();

As you can see you first need to declare your datafile:
DATAFILE *data;
(in your case it's data instead of datafile)

It seems to me that you didn't do that globally (meaning declared outside of the main function).

The next step after that is to load the actual file into the variable. That's done with
data = load_datafile("yourfilename.dat");
where you replace yourfilename.dat with whatever your filename is. Do this before you call that drawAll() function.

raptorstrike

Aug 27, 2004 at 2:51 PM

well i think i got that problem fixed but there is one error left that says there is an invalid convertion from BITMAP* to void

error: invalid conversion from void*' to BITMAP*'

23yrold3yrold

Aug 27, 2004 at 4:02 PM

If you're casting properly, that shouldn't happen.

draw_sprite(screen, (BITMAP *)data[THE_IMAGE].dat, x, y);

raptorstrike

Aug 28, 2004 at 11:51 AM

#include "main.h"#include "allegro.h"int main(int argc, char *argv[]){   DATAFILE *datafile;   char buf[256];   allegro_init();   install_keyboard();    if (set_gfx_mode(GFX_SAFE, 320, 200, 0, 0) != 0) {      set_gfx_mode(GFX_TEXT, 0, 0, 0, 0);      allegro_message("Unable to set any graphic mode\n%s\n", allegro_error);      return 1;   }   /* we still don't have a palette => Don't let Allegro twist colors */   set_color_conversion(COLORCONV_NONE);   /* load the datafile into memory */   replace_filename(buf, argv[0], "datafile.dat", sizeof(buf));   datafile = load_datafile(buf);   if (!datafile) {      set_gfx_mode(GFX_TEXT, 0, 0, 0, 0);      allegro_message("Error loading %s!\n", buf);      return 1;   }   /* select the palette which was loaded from the datafile */  // set_palette(datafile[THE_PALETTE].dat);   /* aha, set a palette and let Allegro convert colors when blitting */   set_color_conversion(COLORCONV_TOTAL);      /* display the bitmap from the datafile */   textout(screen, font, "This is the bitmap:", 32, 16, makecol(255, 255, 255));   blit(datafile[building_red].dat, screen, 0, 0, 64, 32, 64, 64);   /* and use the font from the datafile */  // textout(screen, datafile[BIG_FONT].dat, "And this is a big font!", 32, 128,//	   makecol(0, 255, 0));   readkey();   /* unload the datafile when we are finished with it */   unload_datafile(datafile);   return 0;}END_OF_MAIN();

heres the file thats having the problems i think it SHOULD compile fine but its not (is this a problem with dev-cpp im useing 4.9.9.0)

Auron

Aug 28, 2004 at 12:04 PM

Just as 23 said, you've got to cast the data object to a BITMAP*, like this:

// This doesn't work because you haven't cast the pointerblit(datafile[building_red].dat, screen, 0, 0, 64, 32, 64, 64);// This will workblit((BITMAP *)datafile[building_red].dat, screen, 0, 0, 64, 32, 64, 64);

If you already did that, then tell us your error message. Your code looks fine otherwise...

-Auron

raptorstrike

Aug 28, 2004 at 12:19 PM

yeah it worked i should have know i forgot that when you use a .dat file all the pointers are void and you need to declare them thanks

raptorstrike

Aug 28, 2004 at 12:21 PM

ok now it runs but my bit map comes out as a red square like thing do i need to change the grahics or lower the bit on the map

raptorstrike

Aug 28, 2004 at 12:23 PM

never mind what i was seeing was just a fraction of the building i just need to scale it down

23yrold3yrold

Aug 28, 2004 at 12:29 PM

// worksblit((BITMAP*)datafile[building_red].dat, screen, 0, 0, 64, 32, ((BITMAP*)datafile[building_red].dat)->w, ((BITMAP*)datafile[building_red].dat)->h);// neaterBITMAP* bmp = (BITMAP*)datafile[building_red].dat;blit(bmp, screen, 0, 0, 64, 32, bmp->w, bmp->h);

raptorstrike

Aug 28, 2004 at 12:31 PM

um is there anyway to scale your bitmaps or am i just going to have to draw it smaller??

23yrold3yrold

Aug 28, 2004 at 12:51 PM

stretch_blit()

Or you can just use smaller bitmaps.

raptorstrike

Aug 28, 2004 at 1:02 PM

one final question what function do you use to set what the invisible color is or if you could just tell me where i can find a dictonary of all the allegro functions and peramaters that would work too thanks

23yrold3yrold

Aug 28, 2004 at 1:04 PM

The "invisible color" is always 0 for 8-bit (the first palette entry) and pink (RGB(255, 0, 255)) for truecolor modes. You can't change it, though that might change in later versions of Allegro.

The "dictionary" is otherwise known as the API docs and comes with Allegro in several forms. HTML, TXT, you name it. Check the docs folder.

raptorstrike

Aug 29, 2004 at 1:50 PM

so dose it support 24 bit? and what do you mean 0 for 8 bit (black?)

23yrold3yrold

Aug 29, 2004 at 2:12 PM

By "truecolor", I mean 16bpp, 24bpp, and 32bpp. All three use pink as the transparent color. As for 8 bit, it's always color 0, which means the first color in the palette (palette[0]). It might be (and usually is) black, but doesn't have to be.

Topic Locked

This topic has been locked by a moderator. New replies are not allowed.