Allegro Throws errors when trying to draw lines - c++

Question

For some reason allegro (C++ Game Engine), throws errors when i try to run... So first this code works fine ! :
#include <allegro5/allegro.h>
#include <allegro5/allegro_primitives.h>
int main(void)
{
int width = 640, height = 480;
ALLEGRO_DISPLAY *display = NULL;
if (!al_init())
return -1;
display = al_create_display(width, height);
if (!display)
return -1;
al_flip_display();
//al_draw_line(100, 100, width - 100, 100, al_map_rgb(255, 0, 0), 1);
al_rest(3);
al_destroy_display(display);
return 0;
}
But all the sudden when i try to uncomment that line above i get this "error".
More Closer Up:
As you can see above this is some type of assertion failling... Im Confused?! Help would be appreciated!

Answer 1

Before you can use the primitives add-on you need to initialize it by calling al_init_primitives_addon.
#include <allegro5/allegro.h>
#include <allegro5/allegro_primitives.h>
int main(void)
{
int width = 640, height = 480;
ALLEGRO_DISPLAY *display = NULL;
if (!al_init())
return -1;
display = al_create_display(width, height);
if (!display)
return -1;
al_init_primitives_addon();
if (!al_init_primitives_addon())
return -1;
al_draw_line(0, 50, 300, 100, al_map_rgb(255, 0, 4), 1.0f);
al_flip_display();
al_rest(13);
al_shutdown_primitives_addon();
al_destroy_display(display);
return 0;
}
The full documentation can be found here: https://www.allegro.cc/manual/5/al_init_primitives_addon.
Don't forget to call al_shutdown_primitives_addon when you're done.