Re: Make sure slurs actually avoid stafflines. (issue 15400049)

[Janek Warchoł]

Hi Keith,

I'm sorry for not replying earlier - i had to focus on other things,
and i didn't have time to spare on the slur stuff.  Thanks for all
your suggestions; i'll get back to this when i finish one thing i have
to do for Urs (hopefully after the weekend).

best,
JAenk

2013/11/12  <address@hidden>:
> I suggest making the minimal changes to the structure of the old code
> (plus whatever comments you like) that make the change we all want in in
> behavior.
>
>
> https://codereview.appspot.com/15400049/diff/120001/lily/slur-configuration.cc
> File lily/slur-configuration.cc (left):
>
> https://codereview.appspot.com/15400049/diff/120001/lily/slur-configuration.cc#oldcode45
> lily/slur-configuration.cc:45: {
>       Real t = ts[0];
>       Real y = bez.curve_point (t)[Y_AXIS];
>
>       Grob *staff = state.extremes_[LEFT].staff_;
>
>       Real p = 2 * (y - staff->relative_coordinate
> (state.common_[Y_AXIS], Y_AXIS))
>                / state.staff_space_;
>
>       Real const round = my_round (p);
>       Real const frac = p - round;
>       Real min_separation = 0.5 * state.thickness_
>         + (frac * state.dir_ > 0.0)
>           ? state.parameters_.min_gap_inside_
>           : state.parameters_.min_gap_outside_;
>
>       if (fabs (frac) < 2 * min_separation
>           && Staff_symbol_referencer::on_staff_line (staff, int
> (round)))
>         {
>           Direction resolution_dir = (frac > 0.0) ? UP : DOWN;
>
>           Real newp = round + resolution_dir * min (1.0, 2 *
> min_separation);
>
>           Real dy = (newp - p) * state.staff_space_ / 2.0;
>
>           bez.control_[1][Y_AXIS] += dy;
>           bez.control_[2][Y_AXIS] += dy;
>
>           // The horizontal part of the curve moves 3t-3t² as far
>           // as the middle control-points, so the remaining correction
> is:
>           dy -= dy * 3.0 * t * (1.0 - t);
>
>           bez.control_[0][Y_AXIS] += dy;
>           bez.control_[1][Y_AXIS] += dy;
>           bez.control_[2][Y_AXIS] += dy;
>           bez.control_[3][Y_AXIS] += dy;
>         }
>
> https://codereview.appspot.com/15400049/