diff options
Diffstat (limited to 'muse2/share/scoreglyphs/feta-original/parmesan-macros.mf')
| -rw-r--r-- | muse2/share/scoreglyphs/feta-original/parmesan-macros.mf | 215 |
1 files changed, 215 insertions, 0 deletions
diff --git a/muse2/share/scoreglyphs/feta-original/parmesan-macros.mf b/muse2/share/scoreglyphs/feta-original/parmesan-macros.mf new file mode 100644 index 00000000..94d728a3 --- /dev/null +++ b/muse2/share/scoreglyphs/feta-original/parmesan-macros.mf @@ -0,0 +1,215 @@ +% -%-Fundamental-%- -*-Metafont-*- +% parmesan-macros.mf -- macros for parmesan font +% +% source file of LilyPond's pretty-but-neat music font +% +% (c) 2001--2009 Juergen Reuter <reuter@ipd.uka.de> +% + + +% +% Find point on `curve' which gives the tangent between point `p' +% and `curve'. To guide the search, two auxiliary points must be +% specified, `p_in' and `p_out'. The line between `p' and `p_in' +% must intersect `curve', while the line between `p' and `p_out' +% must not. +% +def find_tangent (expr p, curve, p_in, p_out) = + begingroup; + save mid, t, t_good, in, out; + pair mid, in, out; + + in := p_in; + out := p_out; + + forever: + mid := 0.5 [in, out]; + exitif abs (out - mid) <= eps; + t := xpart (curve intersectiontimes (p -- mid)); + if t > 0: + in := mid; + t_good := t; + else: + out := mid; + fi; + endfor; + + point t_good of curve + endgroup +enddef; + + +% +% Shift `curve' along the line given by the auxiliary points `p_in' +% and `p_out' until `line' is a tangent, and return the shift. +% If `curve' is shifted to position `p_in', it must intersect +% `line', while shifted to `p_out' it must not. +% +def find_tangent_shift (expr line, curve, p_in, p_out) = + begingroup; + save mid, t, in, out; + pair mid, in, out; + + in := p_in; + out := p_out; + + forever: + mid := 0.5 [in, out]; + exitif abs (out - mid) <= eps; + t := xpart ((curve shifted mid) intersectiontimes line); + if t > 0: + in := mid; + else: + out := mid; + fi; + endfor; + + mid + endgroup +enddef; + + +% +% Get subpath specified by `dir_in' and `dir_out' of `curve' +% which is then shifted by `offset'. Assure that result has +% the same orientation as `curve'. +% +def get_subpath (expr curve, dir_in, dir_out, offset) = + begingroup; + save t_in, t_out; + + t_in := directiontime dir_in of curve; + t_out := directiontime dir_out of curve; + + if t_in > t_out: + t_out := t_out + length curve; + fi; + + (subpath (t_in, t_out) of curve) shifted offset + endgroup +enddef; + + +% +% Get point specified by `dir_' of `curve' which is then +% shifted by `offset'. +% +def get_subpoint (expr curve, dir_, offset) = + (directionpoint dir_ of curve) shifted offset +enddef; + + +% +% This is the same as `get_subpath', except that the time values +% used to construct the resulting subpath are rounded to integers. +% +def get_subpath_i (expr curve, dir_in, dir_out, offset) = + begingroup; + save t_in, t_out; + + t_in := directiontime dir_in of curve; + t_out := directiontime dir_out of curve; + + if t_in > t_out: + t_out := t_out + length curve; + fi; + + (subpath (floor (t_in + 0.5), floor (t_out + 0.5)) of curve) + shifted offset + endgroup +enddef; + + +% +% Find envelope cusp created by `object' moved along `curve', using +% step value `s' for initial intermediate points. `s' must be small +% enough so that this macro finds at least one point on the envelope +% between the `entrance' and `exit' points of the cusp which has +% a significantly different direction vector. +% +% This function returns a time value on `curve'; if there is no +% cusp, it returns -1. +% +def find_envelope_cusp (expr object, curve, s) = + begingroup; + save mid, p, t, t_good, delta, start, stop, do_exit; + pair p[]; + boolean do_exit; + + p0 := (directionpoint (direction 0 of curve) of object) + shifted (point 0 of curve); + p1 := (directionpoint (direction s of curve) of object) + shifted (point s of curve); + + t := s; + + forever: + t := t + s; + exitif t >= length curve; + + p2 := (directionpoint (direction t of curve) of object) + shifted (point t of curve); + if p2 <> p1: + delta := angle (p2 - p1) - angle (p1 - p0); + if delta > 180: + delta := delta - 360; + fi; + + % we check for a direction change by more than + % than 45 degrees + if abs (delta) >= 45: + do_exit := true; + else: + do_exit := false; + fi; + + p0 := p1; + p1 := p2; + fi; + + % having `exitif' within an if-clause doesn't work + exitif do_exit; + endfor; + + if t >= length curve: + t_good := -1; + else: + % the wanted point lies between `t - s' and `t' + start := t - s; + stop := t; + t_good := start; + + forever: + mid := 0.5 [start, stop]; + exitif abs (stop - mid) <= eps; + + p0 := (directionpoint (direction start of curve) + of object) shifted (point start of curve); + p1 := (directionpoint (direction mid of curve) + of object) shifted (point mid of curve); + p2 := (directionpoint (direction stop of curve) + of object) shifted (point stop of curve); + + exitif (length (p1 - p0) = 0) + or (length (p2 - p1) = 0); + + delta := angle (p2 - p1) - angle (p1 - p0); + if delta > 180: + delta := delta - 360; + fi; + + if abs (delta) >= 45: + stop := mid; + t_good := mid; + else: + start := mid; + t_good := stop; + fi; + endfor; + fi; + + t_good + endgroup +enddef; + +% EOF |