Initial description of font interface #1
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| Ascender float32 // Typographic ascender. | ||
| Descender float32 // Typographic descender. | ||
| LineGap float32 // Suggested line spacing gap. |
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just a drive-by comment: why float32?
shouldn't we use some fixed-point integer type (like x/image/math/fixed.Int26_6) instead ?
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Good point, thanks ! I've used float32 for simplicity, but x/image/math/fixed.Int26_6 will probably be required for integration and performances.
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perhaps this should be reflected in this PR? :)
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Actually, thinking of it a bit more, it is not obvious to me that x/image/math/fixed.Int26_6 is a better choice. From what I've read, the performance of float32 is similar on modern computers. I'm not sure about the integration point.
I've opened this issue to discuss the question.
| Kerx TableKernx | ||
| GSUB TableGSUB // An absent table has a nil slice of lookups | ||
| GPOS TableGPOS // An absent table has a nil slice of lookups | ||
| } |
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I know it's just a sketch, but: what about MATH TableMATH ?
https://docs.microsoft.com/en-us/typography/opentype/spec/math
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The reason is simply that Harfbuzz does not support layout using MATH, thus, for now, this field is not required by the shaper.
However we could expose this table (just as Harfbuzz does), so that other math shaper can consume it.
Co-authored-by: Sebastien Binet <binet@cern.ch>
Co-authored-by: Sebastien Binet <binet@cern.ch>
Co-authored-by: Sebastien Binet <binet@cern.ch>
This is a sketch of a possible font interface. The common interface may be implemented by the "simple" font formats like Type1 and bitmap. The opentype.FaceOpentype would be use by the shaper (Harfbuzz) for Opentype font files.
This package could also provide a way to render glyphs (it's the purpose of the FaceRenderer interface), but I've not thought about it yet.