do_arc(3) Allegro manual do_arc(3)NAMEdo_arc - Calculates all the points in a circular arc. Allegro game pro‐
gramming 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 ALSOdo_circle(3), do_ellipse(3), do_line(3), arc(3)Allegro version 4.4.2 do_arc(3)
