allegro 5 multi display drawing problems

allegro 5 multi display drawing problems

dhia hassen

Member #16,240

March 2016

i am using allegro 5.0.10 , and i am trying to create a sub display , a normal display that my classes treats as a sub window of a parent one , the problem is all drawing operation made on that child window are not visible until i move it (shake it , move it 2 times go and back) . i am wondering , what are the correct flags and options i need to use to let the sub window draws correctly

Edgar Reynaldo

Major Reynaldo

May 2007

All you should need to do is set the current display and then flip it.

ALLEGRO_DISPLAY* d1 = al_create_display(400,300);
ALLEGRO_DISPLAY* d2 = al_create_display(200,150);

al_set_target_backbuffer(d1);
al_clear_to_color(al_map_rgb(255,0,0));
al_flip_display();

al_set_target_backbuffer(d2);
al_clear_to_color(al_map_rgb(0,255,0));
al_flip_display();

al_rest(5.0);

You'll note that al_flip_display() doesn't take any parameters, like a display. This means it is operating on globally stored data, in this case, the currently active display. al_set_target_backbuffer(display); will change the currently active display.

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King Piccolo will make it so Then I could just flip it with some sweet, sweet matrix math. In either case, I’ll ride this wagon until the wheels fall off. Thanks to those that keep it running

dhia hassen

Member #16,240

March 2016

thanks the problem is solved , it is not about allegro it self it is my using al_store_state(&state,ALLEGRO_TARGET_BITMAP) with no need