CODEWITHSUNDEEP
performancegraphicsbitmapdrawingallegro5
Robert Wegner
Robert Wegner

Reputation: 173

Fastest way to draw many primitives in Allegro 5

I want to draw a very large amount of triangles (up to 600000). What I did first was to:

al_init();
display = al_create_display();

and then loop through my triangles and

al_draw_triangle(); each one.

Finally I did

al_flip_display();

This was not very fast though. I read that it helps to draw to a bitmap on hold first and then draw that bitmap to the display. I tried to do this in the following fashion (sketched):

al_init();
display = al_create_display();
bitmap = al_create_bitmap();
al_set_target_bitmap(bitmap);
al_hold_bitmap_drawing(1);
for every triangle: 
    al_draw_triangle();
al_hold_bitmap_drawing(0);
al_set_target_bitmap(al_get_backbuffer(display));
al_draw_bitmap(bitmap, 0, 0, 0);
al_flip_display();

This is just as fast as the previous method though. How can I correctly buffer my triangles to reduce the amount of draws? What is the most efficient way to draw many primitives in Allegro 5?

Thanks for all answers

Upvotes: 1

Views: 519

Answers (1)

rcorre
rcorre

Reputation: 7218

al_hold_bitmap_drawing does nothing for primitives. This thread has some discussion on the topic, including a suggestion to buffer all of your primitives and make one call to al_draw_prim:

The difference is that I only call al_draw_prim once, after buffering possibly hundreds of primitives. The primitive drawing functions will kick off a batch every time.

Upvotes: 1

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