do_arc(3)                       Allegro manual                       do_arc(3)



NAME
       do_arc - Calculates all the points in a circular arc. Allegro game
       programming library.

SYNOPSIS
       #include <allegro.h>


       void do_arc(BITMAP *bmp, int x, int y, fixed a1, fixed a2, int r, int
       d, void (*proc)(BITMAP *bmp, int x, int y, int d));

DESCRIPTION
       Calculates all the points in a circular arc around point (x, y) with
       radius r, calling the supplied function for each one. This will be
       passed a copy of the bmp parameter, the x and y position, and a copy of
       the d parameter, so it is suitable for use with putpixel(). The arc
       will be plotted in an anticlockwise direction starting from the angle
       a1 and ending when it reaches a2. These values are specified in 16.16
       fixed point format, with 256 equal to a full circle, 64 a right angle,
       etc.  Zero is to the right of the centre point, and larger values
       rotate anticlockwise from there. Example:

          void draw_explosion_ring(BITMAP *bmp, int x, int y, int d)
          {
             ...
          }
             do_arc(screen, SCREEN_W/2, SCREEN_H/2,
                 itofix(-21), itofix(43), 50, flame_color,
                 draw_explosion_ring);


SEE ALSO
       do_circle(3), do_ellipse(3), do_line(3), arc(3)



Allegro                          version 4.2.3                       do_arc(3)
