al_draw_polyline - Allegro 5 API

       Draw a series of line segments.

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

       • vertex_stride - the number of bytes between pairs of vertices (the stride)

       • 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

       • cap_style - Member of ALLEGRO_LINE_CAP(3alleg5) specifying how to render the end caps

       • color - Color of the line

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

       • miter_limit - Parameter for miter join style

       The stride is normally 2 * sizeof(float) but may be more if the vertex coordinates are  in  an  array  of
       some structure type, e.g.

              struct VertexInfo {
                 float x;
                 float y;
                 int id;
              };

              void my_draw(struct VertexInfo verts[], int vertex_count, ALLEGRO_COLOR c)
              {
                 al_draw_polyline((float *)verts, sizeof(VertexInfo), vertex_count,
                    ALLEGRO_LINE_JOIN_NONE, ALLEGRO_LINE_CAP_NONE, c, 1.0, 1.0);
              }

       The stride may also be negative if the vertices are stored in reverse order.

       al_draw_polyline - Allegro 5 API

al_draw_polygon(3alleg5), ALLEGRO_LINE_JOIN(3alleg5), ALLEGRO_LINE_CAP(3alleg5)

Allegro reference manual                                                               al_draw_polyline(3alleg5)

       5.1.0

              #include <allegro5/allegro_primitives.h>

              void al_draw_polyline(const float* vertices, int vertex_stride,
                 int vertex_count, int join_style, int cap_style,
                 ALLEGRO_COLOR color, float thickness, float miter_limit)