Color Palette?

[HellfireXP]

I am trying to create a reusable color palette. What I have so far doesn't show any errors until runtime. Here is what I have:

struct COLORPALETTE {
 static const ALLEGRO_COLOR RED;
 static const ALLEGRO_COLOR BLACK;
 static const ALLEGRO_COLOR YELLOW;

 COLORPALETTE() {
  ALLEGRO_COLOR RED = al_map_rgb(255,0,0);
  ALLEGRO_COLOR BLACK = al_map_rgb(0,0,0);
  ALLEGRO_COLOR YELLOW = al_map_rgb(255,255,0);
 }
};

COLORPALETTE Color;

int main() {
  ALLEGRO_COLOR testClr = Color.RED;
  return 0;
}

The error I get is:
1>main.obj : error LNK2001: unresolved external symbol "public: static struct ALLEGRO_COLOR const COLORPALETTE::RED" (?RED@COLORPALETTE@@2UALLEGRO_COLOR@@B)

What am I doing wrong?

[Peter87]

Static class variables need to be defined outside the class body.

const COLORPALETTE::ALLEGRO_COLOR RED = al_map_rgb(255,0,0);
const COLORPALETTE::ALLEGRO_COLOR BLACK = al_map_rgb(0,0,0);
const COLORPALETTE::ALLEGRO_COLOR YELLOW = al_map_rgb(255,255,0);

This is unfortunately not a solution because you're not allowed to call Allegro functions before you have initialized the Allegro library.

[HellfireXP]

Thanks, this works. In another header (loaded before these colors) I have this, so allegro initialization is already taken care of:

#pragma once
#ifndef ALLEGRO_INITIALIZE_HEADER_H_
#define ALLEGRO_INITIALIZE_HEADER_H_

#include <iostream>
#include <exception>
#include <allegro5/allegro.h>
#include <allegro5/allegro_native_dialog.h>
#include <allegro5/allegro_ttf.h>
#include <allegro5/allegro_font.h>
#include <allegro5/allegro_primitives.h>
#include <allegro5/allegro_image.h>
#include <allegro5/allegro_windows.h>

bool initializeAllegro5() {
	try {

		if (!al_init()) throw ("Allegro failed to initialize.");
		al_init_font_addon();
		if (!al_init_ttf_addon()) throw ("Failed to initialize TTF font file support.");
		if (!al_init_primitives_addon()) throw ("Failed to initialize allegro primitives support.");
		if (!al_install_keyboard()) throw ("Failed to initialize allegro keyboard support");
		if (!al_install_mouse()) throw ("Failed to initialize allegro mouse support.");
		if (!al_init_image_addon()) throw ("Failed to initialize allegro image support.");		
		
	} catch (const char* e) {
		std::cout << e << std::endl;
		return false;

	} catch (const std::exception& e) {
		std::cout << "Unexpected initialization error: " << e.what() << std::endl;
		return false;

	}
	return true;
}


const static bool INITIALIZE_ALLEGRO = initializeAllegro5();

#endif

[newcoder1]

Hello!, I saw you helped someone with a battleship program a while back, is there any way you could help me with mine? I just posted on my profile the parameters, I could really use help

[cire]

Thanks, this works. In another header (loaded before these colors) I have this, so allegro initialization is already taken care of:

That is not really much of a solution either. You will be initializing the allegro library once per translation unit that includes that header, and you do not want to initialize the allegro library more than once.