[lilypond.git] / TODO

-*-outline-layout:(2 (-1 -1 0 :) 0);outline-stylish-prefixes:nil -*-

* GNU LilyPond TODO
Features you cannot find in the documentation as working, should be
mentioned here.  This is an assorted collection of stuff that will be
done, might be done, or is an idea that we want to think about.
m
Most of the items are marked in the code as well
Grep -i for TODO, FIXME and ugh/ugr/urg.  

.* TODO
. * use Rhythmic_head::position_i () for all Staff_referenced 
. * Depracate Wordwrap
. * rerun profile
. * Break_req handling is silly (break_forbid () + \break fucks up.)
. * script engraver
. * HaraKiriStaffContext removes bar lines and doesn't remove
    staff margin text on removed staff lines.
. * Chords:
.  * Bass/inversion pitch when not part of Chord
Sometimes a series of changing chords will be blocked out over a static tone
in the bass, usually this was referred to as a pedal tone (and it's been
continued to be used, even in contemporary music).  Another less frequently
used practice is putting a non-chordal tone in the bass (that is not acting
as a pedal tone) in order to create tension or make a more colorful sound.
There are examples of this in the classsical literature, but its use is much
more prevalent today.  For example, the chord sequence Dm7 - Dm7/G is such a
sequence, and the Dm7/G defies easy classification.  Is it a G7(no 3rd)add
9/11?  Or is it a G7(no 3rd)add2/4?  Or perhaps Dm7 add11?  It's a heck of a
lot easier to read to just leave it as Dm7/G!
.  * Diminished does not mean 5-
When speaking of a chord, dimished can mean one of two things:  A diminished
triad or a dimished seventh chord (which is distinctly different from what's
known as the 'half-diminished' chord).  The triad is a root with a flat
third and flat fifth, and is notated (at least in America, someone else will
have to fill me in on other countries) as (using C as the root) Cdim, or Co.
The diminished seventh has a root with a flat third, flat fifth, and a
doubly flatted seventh (which is enharmonically equivalent to a sixth, and
from which comes tons of confusion).  It is usually notated as (again, using
C as the root) Cdim7 or Co7.

. * Mondrup:

- I would like the possibility of forcing clef- and key- changes to be
printed _after_ the new bar line

- I would like an option to define the number of systems on which the
score must be distributed. As it is now it seems that I may only
influence that indirectly through the gourlay_maxmeasures property.

- if I change the property minVerticalAlign in a multi staff score with
lyrics the change affects the lyrics too. I would like the change to
_only_ affect staves.

- I would like to be able to influence the sloping of xtuplet brackets

- for one of my test scores containing a modern edition of an early
17'th century composition I have a leading measure containing the
orginal clefs and note values of the original composition. I use the
"harmonic" and "diamond" note head styles for that measure and would
like to have the stems of these notes _centered_ on the notehead as in
the mensural music notation.

- after the leading measure in the above mentioned score I want a double
bar line fully drawn across the staves and after that keep to the
ChoirStaff bar line types in the rest of the scores

- autoBeamMelisma: if I explicitly beam notes in a staff with auto
beaming disabled I would like to have these beams also to be
melismatic.

. * make all Feta (including dynamics) available to the user in
    textual scripts. Examples: "D.S. al \coda", "\mf espress.".
 
. * ?  -Q, --find-old-relative show all changes in relative syntax
What's old about absolute to relative conversion?  Could maybe use for
abc2ly, midi2ly?

.* Cleanups needed
. * \$ and $ identifier syntax in examples.
. * Junk ghost positioning objects eg, Script leans on  Staffside
    leans on Staff.
. * bracket ps code.
. * mudela-book
.  * center option (??)
.  * make mudela-book understand usepackage{geometry}
. * Key_engraver, Local_key_item
. * Think of comprehensive solution for "if (grace_b == self_grace_b_)"
. * String[String.length] doesn't trap.
. * Beam
. * Stem
. * Rhythmic_column and interaction stem/rhythmic_column/note_head/dots.
. * Duration
. * clef engraver 
. * parser
. * Lookup::text -> needs  to be TeX independent.
. * junk Music_iterator::first_b_
. * Bezier

.* BUGS
. * [c8. c16 c16 c16] in 6/8 timesig. 
. * staffside spanner (crescendo!) along with staffswitch.
. * --- 2, margin notes don't work correctly for the pianostaff (in the
following example, i expect the "piano" string to be centered
vertically between the two staves):

\score {
  \notes \context PianoStaff <
    \property PianoStaff.instrument = "Piano"
    \context Staff = treble {
        a b c
    }
    \context Staff = bass {
        \clef bass;
        a, b, c,
    }
  >
  \paper {
    \translator { \StaffContext \consists "Staff_margin_engraver"; }
    \translator { \PianoStaffContext \consists "Staff_margin_engraver"; }
  }
}
. * 
> \context Staff <
>   {\voiceone''4. r8}
>  \voicetwo c,4 r4}
> >
. * sort out breve shapes.
. * \time forces keysig?

.* STUFF
. * We need feta-din*.mf files for more sizes than 10.
. *
- The syntax for chords looks clumsy with two different meanings of 
  '-' and different syntax for separating modifiers from the tonic
  and from other modifiers. Why not use for example ':' between
  tonic and modifier and between the different modifiers?

- Rests and beams don't work too well together. Example:
   [ r8 g''16 des'] [r8 c16 a] 

- The stemLength property should affect also beamed stems.

. * align left edge of broken tuplet-spanner (have a test case?)
. * fix dynamics decently, ie. use kerning & ligatures.
. * key restorations & repeats
. * paperXX.ly \quartwidth, font setting not up to date. (Should read from AFM?)
. * * auto melismaBusy for beams.
. *In Caro Mio Ben, bar 8, there's a syllable that starts on a note, and
ends on a pair of grace notes.  Standard practice is to mark this with
a slur starting on the main note and ending on the grace note, so a
singer knows where to break the words.

In bar 27, there's a crescendo that's supposed to start at the start
of the grace notes and extend to the note after the grace notes.
. * 5. Sometimes lyrics extend past the right end of the staff. I guess that
this is a similar problem (if not another symptom of the same problem) as
one of the spacing bugs mentioned in the TODO.
. * 4.  Lyrics and grace sections don't go too well together.
        The words are aligned with the main note, not the start of the
        grace note.  This is usually wrong, but is sometimes right.
. * decimal point in \paper {}
. * tie-direction
. * repeats and partial measures.
. * rhythmic staff & accidentals.
. * use melismaBusy in Lyric context to typeset melismata correctly.  
. * ly2dvi/lilypond logfile.
. * hang Item on Spanner
. * do --safe for PS output?
. * msgfmt -o check?
. * collision of lyrics with span_bars. See star-spangled.
. * Auto_beam debugging output (waarom/wanneer heb jij die weggehaald?)
. * It is impossible to typeset two textual scripts that are stacked
  on top of eachother and avoids note collisions and at the same
  time are typeset with different textStyle. I tried to move around
  the text_engraver and other engravers between Voice and Thread 
  but the granularity is not fine enough, the scripts have to 
  share the same engraver in order to be get correct vertical 
  position but than they cannot have different style.
  In my opinion, all scripts that share the same staff, should
  be stacked vertically, avoiding collisions with the notes
  in all voices.

. * break priority setting from SCM.
. * Matanya's tips: 
.  * don't  shorten stems/staffs closer to each other.
.  * accidentals closer to note head
.  * to space the staffs/staffgroups contained in the score.  
.  * heavier beams?

. * tuplets that are written as "number : note", for example
   "3 : [image of a half note here]".  possible?
. * a note with a circle after it, meaning:

   note + circle = note + 1/4 of its length

   the circle is like a dot that's not filled in.  for example, on
   page three, the c-sharp on the second line should be a quarter with 
   a circle, not a quarter tied to a sixteenth.  is this at all
   possible with lily?
. * scm-ify \property values.
. * make dependencies () a virtual function.
. * deprecate hangOnClef.
. * Abstraction for engravers:
.  * make "in-between" engraver (Tie)
.  * make wide_spanner_engraver (line_group_spanner, staff_symbol)
. * store req -> element, element -> element causes for warnings
. * compulsory hshift
. *  My wish list for lyrics. I dream of a time when I will have enough time to
become familiar enough with the source code to be able to implement some of
these myself, but I don't know when that will be, so I thought I'd "publish"
my suggestions in case someone else is in a position to give them some
priority. Otherwise, perhaps they could go on the todo list?

If any of these are already implemented, please let me what the syntax is to
use them!

1. Stanza numbering. Numbering at the beginning of a song with the number
set to the left of the first note. It would also be nice (but not as
important) to be able to have some form of automatic numbering at the
beginning of each new line. This would make it easier to follow songs with a
large number of stanzas.

3. Notes centred above/below lyrics rather than left-aligned.

4. It would be very nice to be able to build some kind of phrasing into the
lyrics of hymns, etc, so that the first words of a phrase are left aligned
with each other, the last words are right aligned, and the words in between
are centred.

5. In a song, with (say) four stanzas and a chorus, it would be nice to be
able to vertically align the chorus midway between the staves.

6. It would be nice to be able to put vertical brackets either side of a
repeated section with different words for each repeat.
. * Give # lines in linebreaking.  
. * arrows on slurs.
. * rewrite context defs using Scheme
. * junk TeX specifics from internal code.
. * \selectmusic to cut pieces from music. 
. * formatting of input stuff. 
.  * deps for ly2dvi
. * TODO: merge atom & molecule; make  tree from molecule.
. * Align_element::padding  ?
. * typo checks on property names?
. * use streambufs and iostream
to provide IO handling for TeX stream, mudela stream, data-file.
. * seriously buffer TeX output (do profile of writing .5 mb TeX file.)
. * strip EXEs before installing
. * zip target for binary windows dist (JBR)
. * fix partial measures in meaningful way.
. * uniformise recent feta contributions.
.  * bigger and fatter 4/4 C
. * relative mode for midi2ly
. * junking \skip req in lyrics
. * midi2ly empty staffs.
. * use Fourier transformation for rhythmic quantisation.
. * horizontal centering of dynamics 
. * $DEPENDENCIES_OUTPUT support
. * turn slope-damping on/off
. * sort out directory stuff.
.  * --prefix option?
.  * -I option per filetype?
.  * kpathsea?
. * fix vertical alignment and stafflines
. * declaring Performers
. * text-items clash with stems/beams
. * --include, -I option for ly2dvi (pass on to lily)
. * fix placement of beam-less abbrev
. * \meter 3/4;
        <{\voiceone cis4. cis8 cis4 | cis4 cis cis | r1 }
         {\voicetwo cis,4 r r | r2. | r1 }> |
        }
. * Musical_pitch (analogous to Duration and Rhythmic_req)
          think about, analogous to pitch: 
           * { a4 a16 } c <-- duration of c?
           * < a4 b8 > c <-- duration of c?
. * \tempo 4. = 90;
. * make sure all ex's have a mudela-version
. * do rest-collisions for Multi_measure_rests as well.
. * split error/warning in error/warning/non_fatal_error
. * add a Duration_convert member to Duration_iter to set parameters.
        Junk global duration settings. 
. * en-,discouraged linebreaking: 
.  * handle DISALLOW < penalty > FORCE
.  * discourage breaking of slurs
. * fix variable define/lookup parser global<->paper
. * fix title/instrument placements; see input/test/title.ly
. * <\voiceone c4. \voicetwo c4>
. *  I'd like to change the \repetitions command to Jan's suggested
  syntax: \repeat "repeatsymbol" 2 {...}, but I'm not sure that
  I understand the implementation of repeats well enough.
. * add full cello suites to web site (kom op, Maarten!)
. * rename 'staff_line_leading' (who is being lead where?) to
staff_space, interline; (or other meaningful name) and use throughout
lily

[-> leading are the lead strips between the sticks (lines) of
typeface. ie. leading is vertical space  --hwn]
. * add mudela-book-doc source to webstie.
. * Rethink Time_description
\cadenza , \meter,  should all be \properties
. * fix singleStaffBracket
. * rename
.  * partial -> anacrouse
. * move paper vars into engraver properties
. * add new glyphs to font.ly
. * check for groff / troff/ nroff et
. * more intelligent file searching
. * disable spaces in TeX stuff
. * handle ^C for tmp/file creation.
. * make LilyPond RPM fully relocatable
. * better hshift (dots, distance, head dependent)
. * didot / big point.
. * clefs (AG): The "8" should appear closer to the actual clef,
touching it.
. * put errorlevel in Input class
. * junk nesting slurs
. * distinguish between unset and empty properties. 

.* FONT
. * the bracket is ugly (wings are too parabolic, should be more circular)
. * versioning for Feta
. * rewrite dynamic signs.  They're kind of spaghetti now. 
. * The `3' in the meter key is a one or two pixels too thin (at 600dpi)
        in the middle:
. * design macro for penstroke with rounded endings
. * timesig C: fat yet less curved.  Check out relations. 
. * design decent macro for bulbed endings
. * printer dependencies.
. * versioning  
. * lo-res fixes.
. * work out sizes of character fonts.
. * more symbols
.  * piano pedals: Ped/*
.  * maxima notehead
.  * coda signs: Segno, O+
.  * glissando, arpeggio
.  * lengthened trill
. * include important spacing dims in fetalog 
. * scalability: use blot_diameter everywhere, make font chubbier for
    small sizes.

.* 3RD PARTY BUGS
. * UMR: Uninitialized memory read
      This is occurring while in:
            qst            [qsort.c]
            qsort          [libc.so.1]
            Keyword_table::Keyword_table(Keyword_ent*) [keyword.cc:28]
            My_lily_lexer::My_lily_lexer() [my-lily-lexer.cc:78]
            My_lily_parser::parse_file(String,String) [my-lily-parser.cc:54]
            do_one_file(String,String) [scores.cc:124]
      Reading 4 bytes from 0xefffeca8 on the stack.
      Address 0xefffeca8 is 728 bytes below frame pointer in function 
. *  Array<Axis [2] > axeses;

  for (int i=0; i < loose_elems.size (); i++)
    {
      Score_element* elt = loose_elems[i];
      /*
            with which axes do we have to meddle?
      */
      int j =0;
      Axis as [2];
      for (int a = X_AXIS; a < NO_AXES; ++a)
        if (elt->parent_l (Axis (a)) == this)
          as[j++] = Axis (a);
      if (j == 1)
        as[j++] = as[0];

      axeses.push (as);
    }
. * GNU diff 2.7: diff -rN does not see a new directory with empty file
. * patch: don't touch timestamp if all patches fail.
. * MetaPost: should not generate setgray for unfill
. * mfplain.ini not in tetex 0.9
. * mf-to-table -> add space 'before ; in AFM output.  (-> check AFM
spec. Is this a bug in afm2tfm?)
. * check out GCC signatures?
. * glibc 2.0:
          f = fopen ("/dev/null", "r")
          assert (feof (f))
. * tetex: mfplain.mem

.* PROJECTS
. * Scripts:
.  * stack scripts in chords:
          % fingering:        footing:
            < a-4 c-2 g-1 >   < c-\ltoe e-\lheel >
.  * script-spacing
.  * slur parts as a script
.  * stack parameterised scripts for fingering and footing:

. * convert-mudela:
.  * automatically add  a \version if not present.
.  * better parsing
.  * make smarter
.  * convert-mudela -e empty.ly

. * emacs mudela-mode
.  *  should handle block comments too.
.  *  handle lexer modes (\header, \melodic, \lyric) etc.
.  *  indentation
.  *  notenames?
.  *  fontlock: \melodic \melodic

. * use properties for:
.  * default tempo.
.  * cadenza mode? 

. * page handling:
.  * PS output
.  * optimal pagebreaking.

. * internationalisation for input.
.  * Unicode support? -> man 7 unicode
.  * (The explanation below is mostly intended for Han-Wen and Jan)
> Before, the font was changed with macros declared separately for 
> pure TeX and LaTeX, but now all the fonts are declared directly in
> the generated code using the low-level TeX commands. This circumvents
> the fontencoding mechanism of LaTeX and is a potential source of
> problems also for us users of the Latin-1 character set. 
> I think it still works since the inputencoding latin1 is 
> declared by ly2dvi, but it still means that e.g. an o with
> umlaut is typeset as a combination of the two symbols 'o' and
> 'umlaut' instead of as a single character, as would be the case
> if fontencoding OT1 had been used. This shouldn't give any 
> difference in layout, though. One of the main argument for using
> fontencoding OT1 is for the hyphenation mechanism to work, an 
> argument that's clearly irrelevant in our application. Yet we
> see the problem for August.

. * \header
.  * output header info to MIDI too.

. * a musical dictionary. See Documentation/vocabulary-*, other
languages:
.  * explanations
.  * italian
.  * german
.  * dutch
.  * swedish
         .. ?

. * chords
.  * guitar chords (fret diagrams)
.  * other chord name styles (american(?) style)
.  * basso continuo
.  * MIDI output?

. * Debug logs:
.  * derive lily_stream, Dstream, texstream from ostream?
.  * indentable stream as baseclass for TeX stream, lily stream, Dstream.
.  * use dstream feature in midi2ly
.  * integrate IO checking into stream class

. * input converters
.  * NIFF?
.  * ABC? 
.  * SMDL?

. * add to MIDI output:
.  * sharp / flat on trills (in MIDI ??)
.  * ornaments (and trills?)
.  * slurs
.  * accents
.  * dynamics
> Would it be hard to add support for proper dynamics in MIDI output?  I
> would really like to have this feature...

Concretely spoken, for dynamics you have to write a performer
(Dynamics_performer), that will take the input requests. If I
understand correctly, every MIDI note played must have its dynamic
strength set separately.  That means the the Dynamics_performer must
set the strength of every Audio_note it finds.  This means that one
has to modify existing Audio items.  The best way of doing this is
with a broadcast/acknowledge process.

So the best way of handling this, is

  1 supporting dynamic settings in Audio_note

  2 Write a Dynamics_performer that will modify
  any notes it finds to set appropriate strengths.

I'd say that the work involved is not hard, but you have to be fluent
with C++ and need some insight into the working of Notation Contexts
and friends.  I guess I could do it in a day or so, but if you are not
so fluent with the inner workings of LilyPond, it could take you some
more time (A few more days?).

Please note, that I am *not* going to code this myself: my days are
valuable, and I think I have more interesting things to do than fixing
the MIDI output (I don't even have a soundcard).  But I *do* want to help
you or other people with implementing this, so if you need help, don't
hesitate to ask.
.  * account for rhythmic position in measure
.  * etc.


. * Output class, handles : (smallish)
.  * help text /(c) notice?
.  * version line
.  * warning /errors/progress
.  * abort on error/warning; exit status
.  * quiet/ignore-version options
.  * logfile output

. * PS 
.  * speed up PS code.
.  * PS lines to .eps files
.  * write custom prolog

. * SGML input

. * Documentation
.  * remove links to non-free SW.
.  * internal documentation
.  * a general paper. 
.  * \properties
.   * left/rightbeamcount
.   * various other new properties.
.  * introduction?
.  * info?
.  * LaTeX?
.  * more manpages?
.  * Doc (C) stuff of sheet music
.  * a better format?  SGML?  TeX?  Info?
.  * a better tutorial

. * more spanners (smallish)
.  * Glissando
.  * trill

. * Rewrite Stem, Beam (hairy)
.  * general shaving on Beam and Stem
.  * use plet grouping
.  * beams over bars

. * lines:
.  * Ledger lines, should be separate item: Ledger_lines
.  * set different line sizes / thicknesses
.  * beam stem showthrough, inter beam sizes (french vs german style)

. * Collisions
.  * left/right note balls should be handled by Collision:
        < \multi 2; { \stem 1; <b c> } { <f as b> } >

. * Keys:
.  * merge key{item} & localkey{item}?
.  * spacing, national styles?

. * Support for TAB
.  * redo Notehead to allow digits as heads
.  * add a \tablature {} lexer mode for easy entering

. * should adjust stemlength for flag number.

. * breaking:
.  * caching breakpoints
.  * saving them
.  * specify number of lines

.* INPUTLANGUAGE
. * convention for slurs vs. phrasing marks.
. * Language:
.  * \translator -> ?
.  * fix \partial 
.  * \bla {} vs \bla ; 
.  * mix engraver hacking with music ?
.  * \once\property  KEY = VAL
.  * input property
.  * abstract grammar.
. * Figure out semicolons.
. * <c f a>4 ?
. * Viola mode?

                @c c g e g 
        for
                c g es g, 

                @A c g e g
        for
                cis gis e gis
. * configure pitch_byte
. * rest name configurable


.* SMALLISH PROJECTS

. * fix confusing naming in Engraver vs Engraver_group_engraver (context)

. * A range for context errors (eg. mark both { and }. )

. * lyric in staff  (sharpsharp in staff, text below)

. * write Dynamic_line (to group dynamics horizontally)

. * use Real for all y positions.

. * half-sharps, half-flats

. * adaptive accidental spacing.

. * handle EOF graciously in error messages.

. * midi esp.: use I32 iso int where 32 bits are needed (or assumed...)

. * lily \tempo

. *   % toe to bheel   four to five
            %   ^_u            4_5  
            %     -                           
            %  --|x--         --|x--
            %  --|---         --|---
            %  --|---         --|---
          (where "to" is a tiny bow)

. * auxilliary file for caching info.
. * Text_crescendo

.* IDEAS
. * Output data structures of Mudela in XML/SGML.
. * create libmudela, or liblily_frontend
. * move MIDI stuff (including Quantization) to a ANSI C libmidi library.
. * Spacing_request for manually adjusting spacing
. * caching breakpoints
. * used fixedpoint arithmetic for min. energy.

* OUTLINE SETUP
.* .EMACS
;;; from outline.el
(defvar outline-font-lock-keywords
  '(;; Highlight headings according to the level.
    ;; must change this to allout node layout
    ;;("^\\(\\*+\\)[ \t]*\\(.+\\)?[ \t]*$"
    ("^\\([.]*[ ]*[*]\\)[ \t]*\\(.*\\)$"
     (1 font-lock-string-face)
     (2 (let ((len (- (match-end 1) (match-beginning 1))))
          (or (cdr (assq len '((1 . font-lock-function-name-face)
                               (2 . font-lock-keyword-face)
                               (3 . font-lock-comment-face))))
              font-lock-variable-name-face))
        nil t))
    ;; Highlight citations of the form [1] and [Mar94].
    ("\\[\\([A-Z][A-Za-z]+\\)*[0-9]+\\]" . font-lock-type-face))
  "Additional expressions to highlight in Outline mode.")

(add-hook 'outline-mode-hook
          '(lambda ()
            (setq font-lock-maximum-decoration t)
            (setq font-lock-maximum-decoration t)
            (make-local-variable 'font-lock-defaults)
            (setq font-lock-defaults '(outline-font-lock-keywords t))
            (font-lock-mode global-font-lock-mode)
        ))
 
(require 'allout)
(outline-init 't)