static void
relocate_arcpoint(F_arc *arc, int x, int y, int movedpoint_num)
{
float xx, yy;
F_pos p[3];
p[0] = arc->point[0];
p[1] = arc->point[1];
p[2] = arc->point[2];
p[movedpoint_num].x = x;
p[movedpoint_num].y = y;
if (compute_arccenter(p[0], p[1], p[2], &xx, &yy)) {
arc->point[movedpoint_num].x = x;
arc->point[movedpoint_num].y = y;
arc->center.x = xx;
arc->center.y = yy;
arc->direction = compute_direction(p[0], p[1], p[2]);
}
}
int
compute_arcradius(int x1, int y1, int x2, int y2, int x3, int y3, float *r)
{
F_pos p1, p2, p3;
float cx, cy, dx, dy;
p1.x = x1; p1.y = y1;
p2.x = x2; p2.y = y2;
p3.x = x3; p3.y = y3;
if (!compute_arccenter(p1, p2, p3, &cx, &cy))
return 0;
dx = x2 - cx;
dy = y2 - cy;
if (dx == 0.0 && dy == 0.0) {
*r = 0.0;
return 0;
}
else {
*r = sqrt(dx * dx + dy * dy);
return 1;
}
}
