Unicode key names and file content support (Or, ASCII font based cultural symbols)

[anytizer]

What can be done to allow unicode based key names here?
The file should be able to compile when saved with Unicode Byte Order mark.

lmms/src/gui/editors/PianoRoll.cpp

Lines 123 to 125 in d5f5d00

	static std::array<QString, 12> s_noteStrings {
	"C", "C\u266F / D\u266D", "D", "D\u266F / E\u266D", "E", "F", "F\u266F / G\u266D",
	"G", "G\u266F / A\u266D", "A", "A\u266F / B\u266D", "B"

#6162 Desiring unicode labels.

[michaelgregorius]

For me it also compiles and works if I simply replace the code with the symbols:

static std::array<QString, 12> s_noteStrings {
	"C", "C♯ / D♭", "D", "D♯ / E♭", "E", "F", "F♯ / G♭", 
	"G", "G♯ / A♭", "A", "A♯ / B♭", "B"
};

I am not sure if it depends on the system though. It also doesn't work with every character. If I replace one flat with an emoji (🤩) it does not work. I guess that's because the font used on my system doesn't have the emoji.

[irrenhaus3]

UTF-8 will be guaranteed to be accepted as an input by all C++23-compilant compilers as per https://wg21.link/P2295R6
Until then however, it's generally not portable to encode C++ source files as UTF-8, so putting non-ASCII characters in them might work or it might not. If we want to try, we could test it in our CI to see if any compiler stumbles upon them.

Edit:
I should note that all big-3 compilers (GCC, clang and MSVC) already accept UTF-8 encoded files, and have been doing so for years. GCC in particular did it 10 years ago already, so I don't expect many problems with this.

[anytizer]

Just a thought:

Can we "embed" a non-unicode font or SVG symbols for these keys? I had tried replacing with unicode texts in the source file, but I got square blocks instead, when executing the LMMS binary. It may be due to that the machines I used did not have proper unicode fonts.

If we could implement an embedded font file, these symbols would be ASCII like characters from that font, available to all machines; at the additional cost of new font file's disk size.

[Veratil]

Yes, we can add custom fonts via

QFontDatabase::addApplicationFont("/path/to/font.ttf");

[anytizer]

Just borrowed some glyphs from Tillana font | @itfoundry/tillana . I reordered the symbols into characters: A, B, C, D, E, F, G, H, I, J, K, L - as the 12 keys. Resized the numerals into smaller font size to mark the octave numbers. 0 , 1, 2, 3, 4, 5, 6, 7, 8, 9, *, . and a - sign. If it works with these symbols, it can work for any other language. :-)

Expanded set of fonts:
culture-keys-for-lmms.zip

Notes: Font preview removed. Added more fonts.

[anytizer]

Yes, we can add custom fonts via

QFontDatabase::addApplicationFont("/path/to/font.ttf");

Font based system worked under Ubuntu. But here are new challenges:

• All fonts intended to use use should be packed in the binary exe, that would include symbols from other languages/cultures.
• QFontDatabase did not throw error when font is missing. The paths to the font should be absolute or relative? Is CMake helping us to decide where to place the fonts as resource?
• There needs to be a new feature/mechanism to choose which symbols (from which culture) to paint on screen.
• Somebody should at least design these glyphs in minimum:
  • Minus sign ( - )
  • 0 - 9
  • A - L (custom keys) where:

Keys → Culture ↓	C	C#	D	D#	E	F	F#	G	G#	A	A#	B	Notes
English	C	C#	D	D#	E	F	F#	G	G#	A	A#	B	Currently in use
Using Flats	C	D♭	D	E♭	E	F	G♭	G	A♭	A	B♭	B	The word "komal" from classical systems represent flats
Classical	सा	.रे	रे	.ग	ग	म	म'	प	.ध	ध	ऩि	नि	Dots to be replaced with underlines
Short form	S	r	R	g	G	m	M	P	d	D	n	N	Best selected, as all notes may be in ASCII range.
In Proposed Font	A	B	C	D	E	F	G	H	I	J	K	L	All capitals, Binary Character Table - Character set
ASCII in Font	65	66	67	68	69	70	71	72	73	74	75	76	All cultures' symbol should appear in these ASCII characters (replacement)

There are at least 3 places that need new font information, and sharing keys:

1. Under combo box "No Key" -
2. On the piano labels -
3. At the actual note names in the roll -

Important bookmarks:

• Draw Note Name
• PaintEvent

[michaelgregorius]

This could be implemented with an interface that replaces s_noteStrings. It would have the following functionality:

1. Provide the font to use for a given QPaintDevice.
2. Map the index 0-11 to the string that should be painted with that font.

The currently used "English" implementation would simply return the font of the QPaintDevice and map the indices to the values that are currently in s_noteStrings.

The other implementations will return the font that was registered for them via QFontDatabase::addApplicationFont and return the appropriate strings for the indices, e.g. 0 -> "A", 1 -> "B", 2 -> "C", etc.

[anytizer]

Thank you @michaelgregorius. I am making a font for at least 3 notation names (cultures). For predefined single culture, it works. But to add more cultures, we might need an option to pick which system to display/use.

Meanwhile, is it necessary to check a minimum height?

lmms/src/gui/editors/PianoRoll.cpp

Line 1026 in d5f5d00

if (noteTextHeight > 6)

I had to put the value "4" instead of "6" here, so that notation name got printed on the green note in the roll.

Also, this picture is great to know related to this thread. :-)

[michaelgregorius]

Thank you @michaelgregorius. I am making a font for at least 3 notation names (cultures). For predefined single culture, it works. But to add more cultures, we might need an option to pick which system to display/use.

IMO the option should then be moved from the main menu into the preferences/settings. An additional combo box could be added which lets the users select the notation system that they want to use.

Meanwhile, is it necessary to check a minimum height?

lmms/src/gui/editors/PianoRoll.cpp

Line 1026 in d5f5d00

if (noteTextHeight > 6)

I had to put the value "4" instead of "6" here, so that notation name got printed on the green note in the roll.

The check was added so that we do not render text that gets too tiny. See the commit message of 0dc2843. If you keep it as is then the text should get rendered if you increase the vertical zooming of the piano roll.

[Veratil]

I haven't checked, but does any of MuseScore's fonts contain the glyphs we're wanting? If so we may be able to use that.

[anytizer]

Just checked: Leland and Edwin - they are huge collection of symbols. I am looking for text based glyphs for readable notes.

My current plan is to build limited font files, per culture for testing purpose. If it works, we can replace with higher quality glyphs from these fonts; even assuming symbols as a culture. Here is the glyph preview list:

devanagari-keys-for-lmms.ttf

doremi-keys-for-lmms.ttf
(in progress)

nashville-keys-for-lmms.ttf (not sure if it is correct)

sargam-keys-for-lmms.ttf

solfege-keys-for-lmms.ttf

Here are the .birdfont files if anyone might be interested in improving these glyphs.
keys-for-lmms.zip

[anytizer]

Updates:

Here is a proof that that it now works for the defined culture name (sargam in this case). It is based on embeddable font, and not unicode dependencies to have the missing glyphs.

Some questions are about managing the file structure of these fonts and notation system, as well modifying the various parts of PianoRoll.cpp.

• How should we organize the file names that uniquely represent the notes group (I call: culture)? Here are the variations available now:
  • devanagari
  • sargam
  • solfege
  • doremi
  • nashvile (number system)
• How to ship the fonts with LMMS? Somewhere adjust CMAKE to always include these font files?
• Qt Font Database does not warn about missing .ttf fonts. In that case, a wrong letter/symbol would display. @Veratil.
• Font size might matter. Somewhere we have 80% of the line height for the font size. It looks we have to adjust text height based on font file. Otherwise, a bigger zoom is necessary to see the letters clearly.

  lmms/src/gui/editors/PianoRoll.cpp

  Line 1025 in 20102c4

  int const noteTextHeight = static_cast<int>(noteHeight * 0.8);

• How to display the flats or sharps in one culture?
• New settings/combo box should be provided to determine which culture to pick by default, or let the user choose them.

[Veratil]

• How should we organize the file names

It should be a single file, allowing us to utilize the tr() translation function.

• Qt Font Database does not warn about missing .ttf fonts. In that case, a wrong letter/symbol would display

If it's shipped with LMMS, then we just can check if the file exists in the place we expect and warn if missing.

• Font size might matter. Somewhere we have 80% of the line height for the font size

This can be adjusted to set the size of the font based on the size we want through QFontMetrics probably.

• How to display the flats or sharps in one culture?

Translations should take care of that.

• or let the user choose them

This is the way: translations.