Gameboy Development Forum

Hello!

I just started watching GamingMonsters tutorial videos, and I am already getting an error just trying to display a sprite.

I use the newest GBDK and GB Tile Designer. My understanding that the only difference is that the new one adds "const" to the variables.

Anyway, GBTD gives you a .c and a .h file. The tutorial only uses the .c file. I have seen GBDK examples where they use both the .c and the .h file for one sprite, and then only a .c file for another (which seems very confusing and inconsistent. The example in question is "colorbar". It is part of the GDBK package)

Here is the code:

    // MyX.c
    const unsigned char MyX[] =
    {
      0x00,0x81,0x00,0x42,0x00,0x24,0x00,0x10,
      0x00,0x08,0x00,0x24,0x00,0x42,0x00,0x81,
      0x81,0x81,0x42,0x42,0x24,0x24,0x08,0x08,
      0x10,0x10,0x24,0x24,0x42,0x42,0x81,0x81
    };

    // MyX.h
    #ifndef __MyX_h_INCLUDE
    #define __MyX_h_INCLUDE

    #define MyXBank 0

    extern const unsigned char MyX[];

    #endif

    // main.c
    #include <gb/gb.h>
    #include "MyX.c"

    void main(void)
    {

        set_sprite_data(0, 2, MyX);
        set_sprite_tile(0, 0);
        move_sprite(0, 88, 78);
        SHOW_SPRITES;

        while(1) {
            wait_vbl_done();
        }
    }

When I include only the .c file, I get this error:

    Multiple definition of _MyY
    make: *** [Makefile:29: MyGame.gb] Error 1

When I include only the .h file, everything WORKS FINE

When I include both the .c and .h files, I get the same error if .c is included after .h. Otherwise, if .c is included before .h, then there are some dangerous errors.

When I just paste the contents of the .c file before the main loop, I get the error, but if I change the name of the variable in the declaration and in set_sprite_data(), it magically works fine.

My compilation command is: `"../gbdk/"bin/lcc  -o MyGame.gb main.c MyX.c `. This is what the console says. It appears that it automatically processes the .c file, despite me not including it in my final version where I paste the contents in the mail file :curious

_____________________________________

So now that you have all the facts, can you tell me why there are a .c and a .h file, when most tutorials only include the .c file?
Why does including the .h file work, and including the .c file doesn't?
What should I do if I want to include sprites this way? Should I just inline it and have everything in one file?
Any other advice you would give a beginner?

Thank you!