Initialization source file

Initialization source file

AceBlkwell

Member #13,038

July 2011

All,

I'm creating a framework for my first A5 program. If I put all my allegro setup / inits in a separate source file, are the pointers global or will they need to be passed in order to be used.

Some items are just activated and working.
al_init(); / al_install_keyboard(); / al_init_image_addon(); etc.

However, some are pointers. In order to use timer or queue outside of the init source file, will I need to pass the pointer to all functions needing it.

ALLEGRO_TIMER* timer = al_create_timer(1.0 / 30.0);
ALLEGRO_EVENT_QUEUE* queue = al_create_event_queue();

Meaning, if I create queue in alleg_init.cpp will I have to pass it to main.cpp or will it just be available.

I'm a ways off from having anything compilable so I can't test my question out on my own yet. Was trying to get a head of the curve. Thanks

DanielH

Member #934

January 2001

You can DECLARE your pointers for other files to see using extern.

// myheader.h
// declare in your header file
extern ALLEGRO_BITMAP* bitmap;

// source1.h
// define only once
#include "myheader.h"
ALLEGRO_BITMAP* bitmap;

// source2.h
#include "myheader.h"

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AceBlkwell

Member #13,038

July 2011

Thanks Daniel. I thought about a header file last night. I had forgotten about extern. I haven't used it a lot in the past. Either way would be easier than trying to pass a pointer back and forth.

I watch part of your framework video. Not bad. I'm not a VC guy but the concept is still the same. As I work through my framework, I may check it out again to see how you handled certain difficulties. Thanks again.

DanielH

Member #934

January 2001

You don't actually need a header file. You can always just put the extern declaration in your other source files. As long as you only define it once.

// source1.cpp
ALLEGRO_BITMAP* bitmap = nullptr;

//source2.cpp
extern ALLEGRO_BITMAP* bitmap;

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AceBlkwell

Member #13,038

July 2011

Thanks Daniel. I have decided to start a lot smaller. Based on tutorials and other code, I was trying to create a framework for all setups and initiations needed for an entire game. At this point I don’t have enough experience with A5 to develop an initiation “black box”. I’m going take my previous approach, which works for me. I’m going to start writing code to learn a specific aspect of the library and expand from there. Once I have that, I’ll then start working on grouping like actions together.