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w3c / musicxml

MusicXML specification
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Documentation - default-x and default-y origin points for glyphs (articulations, dynamics, etc) #193

Open webern opened 7 years ago

webern commented 7 years ago

I asked the following question on the mailing list:

When we have a glyph, say an accent mark or a staccato, how do we know the point on this glyph that default-x and default-y are originating from. We know that the default-x is relative to the left of the note, and default-y is relative to the top staff line, but I don't know how these are relative to the glyph. Bottom left of the bounding box? Center of the bounding box? Something else?

And received this answer:

Currently, these relationships are all font-dependent. It all depends on where the font designer has placed the origin for that particular glyph.

If this is correct, it should be documented in the specification. Namely that glyphs are measured from the origin point as specified by the font.

mdgood commented 7 years ago

That is how most applications handle it at the moment, but I think it might be best to leave this application-dependent for now. In the future we may want to move to using how SMuFL handles this alignment - see for instance #5. It might be easier to go from unspecified to more tightly specified than to change the meaning from one type of alignment to another.