Our 2012 Ideas List

Below is a list of projects that we suggested for GSoC 2012 students. Although the application period is over, we decided to keep this webpage online as an inspiration for anyone who is interested in developing LilyPond. Some members of the development team are willing to help people who would like to tackle these projects.

Of course, there are many more things to improve in LilyPond, including very small ones. A full list of all known issues can be found here.

Grace notes

Fix problems with synchronization of grace notes, together with all underlying architecture (see issue 34 in our tracker). Grace notes are confusing to LilyPond’s timing because they’re like going back in time. This causes weird effects, especially when one staff has a grace note and the other doesn’t.

难度：中等

Requirements: C++, MIDI

Recommended: familiarity with LilyPond internals

Mentor(s): Mike Solomon, Carl Sorensen

MusicXML

Adding comprehensive MusicXML export and improving import, together with tests checking that it works. Depending on time available, implement some or all of the following:

The goal will be considered achieved when a (previously chosen) score could be imported from MusicXML and exported back with no unintentional loss of data.

难度：中等

Requirements: MusicXML, Python, basic LilyPond knowledge

Mentor(s): Reinhold Kainhofer, Mike Solomon

Familiarity with other scorewriters (for cross-testing) would be a nice bonus.

Improve slurs and ties

The default shape of slur and tie curves is often unsatisfactory. Ties on enharmonic notes { cis'~ des' } are not supported, ties "broken" by clef or staff change aren’t supported well. The project includes collecting and sorting examples of bad output, deciding on the intended output and writing the actual code.

难度：hard

Requirements: C++, experience with writing heuristics

Recommended knowledge: LilyPond knowledge, aesthetic sense

Mentor(s): Mike Solomon

Adding special variant of font glyphs

Adding on-staff-line, between-staff-line, shorter and narrower variants of some glyphs, for example accidentals, together with a generic infrastructure to support them. An example is ancient notation breve notehead coming in two variants, with smaller and bigger hole.

难度：easy

Requirements: MetaFont, C++, good eye for details

Recommended knowledge: basic LilyPond knowledge

Mentor(s): Werner Lemberg

Improve beaming

Default positioning of regular, cross-staff, broken and kneed beams should be improved. Beaming should depend on context and neighbor notes (see section 2.2 here). If possible, reduce beaming computation time.

难度：中等

Requirements: C++, experience with writing heuristics

Recommended knowledge: aesthetic sense

Mentor(s): Mike Solomon, Carl Sorensen

Clean up various compilation warnings

Clean up compiler warnings, static code analysis, and valgrind warnings. Automatic code analysis tools (warnings in g++ and clang) and analysis tools like valgrind memory leak detection and callgrind code profilers provide valuable information about possible flaws in C++ code. Cleaning these warnings would allow us to automatically reject any patch which introduced extra warnings.

难度：中等

Requirements: C++

Mentor(s): Joe Neeman, Reinhold Kainhofer