Allegro 5 api
#include <allegro5/allegro_primitives.h> void al_draw_rectangle(float x1, float y1, float x2, float y2, ALLEGRO_COLOR color, float thickness)
Draws an outlined rectangle.
Parameters:
x1, y1, x2, y2 - Upper left and lower right points of the rectangle
color - Color of the rectangle
thickness - Thickness of the lines, pass <= 0 to draw hairline lines
al_draw_filled_rectangle(3alleg5), al_draw_rounded_rectangle(3alleg5)