al_draw_polygon - Allegro 5 API

       Draw    an    unfilled   polygon.    This   is   the   same   as   passing   ALLEGRO_LINE_CAP_CLOSED   to
       al_draw_polyline(3alleg5).

       • vertex - Interleaved array of (x, y) vertex coordinates

       • vertex_count - Number of vertices in the array

       • join_style - Member of ALLEGRO_LINE_JOIN(3alleg5) specifying how  to  render  the  joins  between  line
         segments

       • color - Color of the line

       • thickness - Thickness of the line, pass <= 0 to draw hairline lines

       • miter_limit - Parameter for miter join style

       al_draw_polygon - Allegro 5 API

al_draw_filled_polygon(3alleg5), al_draw_polyline(3alleg5), ALLEGRO_LINE_JOIN(3alleg5)

Allegro reference manual                                                                al_draw_polygon(3alleg5)

       5.1.0

              #include <allegro5/allegro_primitives.h>

              void al_draw_polygon(const float *vertices, int vertex_count,
                 int join_style, ALLEGRO_COLOR color, float thickness, float miter_limit)