al_draw_triangle - Allegro 5 API
  
  - 
    #include <allegro5/allegro_primitives.h>
void al_draw_triangle(float x1, float y1, float x2, float y2,
 float x3, float y3, ALLEGRO_COLOR color, float thickness)
 
Draws an outlined triangle.
Parameters:
  - x1, y1, x2, y2, x3, y3 - Three points of the triangle
- color - Color of the triangle
- thickness - Thickness of the lines, pass <= 0
      to draw hairline lines
al_draw_filled_triangle(3), al_draw_soft_triangle(3)