3 ms·

OpenType can contain vector outlines, hinting instructions to align those outlines to pixel boundaries at low resolutions, and also pre-rendered bitmaps for sys

OpenType can contain vector outlines, hinting instructions to align those outlines to pixel boundaries at low resolutions, and also pre-rendered bitmaps for systems that don't want to run the hinting VM for each glyph. Some tools will let you make an OpenType font with only pre-rendered bitmaps, but I think there's still systems that don't render such a font correctly, and also I don't think you can store multiple sizes of pre-rendered bitmaps, so you still only get one size. The technique used here (turning each source pixel into a vector square) renders just as crisply at the right size, and is more compatible.

weinzierl 3y ago
Not an OpenType expert but there seem to be two ways to store bitmap data: EBDT and sbits. From what I understand, both can store different sizes. For the latter the Microsoft documentation is pretty clear: "A font can also include different bitmap data for different sizes (“strikes”)" https://learn.microsoft.com/en-us/typography/opentype/spec/sbix https://learn.microsoft.com/en-us/typography/opentype/spec/s...
- thristian 3y ago
  I was hoping that would be the case! Unfortunately, the bitmap font manipulation tools I'm using (monobit¹ and BitsNPicas²) do not support putting more than one strike into an OpenType wrapper. If there's some other tool that can do that assembly, I'd like to hear about it. ¹: https://github.com/robhagemans/monobit/ https://github.com/robhagemans/monobit/ ²: https://github.com/kreativekorp/bitsnpicas/ https://github.com/kreativekorp/bitsnpicas/
  - weinzierl 3y ago
    I have not tried it, but what I read from Fontforge's documentation sounds a lot like it could do it. https://fontforge.org/docs/tutorial/editexample8.html https://fontforge.org/docs/tutorial/editexample8.html Also Glyphs 3 seems to support it. "Each glyph contains a single image file. However, images can be provided for different pixel sizes.". It's been years since I last worked with Glyphs and back then it was more of a creation tool than an editor. I don't know if that has changed.

weinzierl 3y ago

Not an OpenType expert but there seem to be two ways to store bitmap data: EBDT and sbits. From what I understand, both can store different sizes. For the latter the Microsoft documentation is pretty clear: "A font can also include different bitmap data for different sizes (“strikes”)" https://learn.microsoft.com/en-us/typography/opentype/spec/sbix https://learn.microsoft.com/en-us/typography/opentype/spec/s...

thristian 3y ago
I was hoping that would be the case! Unfortunately, the bitmap font manipulation tools I'm using (monobit¹ and BitsNPicas²) do not support putting more than one strike into an OpenType wrapper. If there's some other tool that can do that assembly, I'd like to hear about it. ¹: https://github.com/robhagemans/monobit/ https://github.com/robhagemans/monobit/ ²: https://github.com/kreativekorp/bitsnpicas/ https://github.com/kreativekorp/bitsnpicas/
- weinzierl 3y ago
  I have not tried it, but what I read from Fontforge's documentation sounds a lot like it could do it. https://fontforge.org/docs/tutorial/editexample8.html https://fontforge.org/docs/tutorial/editexample8.html Also Glyphs 3 seems to support it. "Each glyph contains a single image file. However, images can be provided for different pixel sizes.". It's been years since I last worked with Glyphs and back then it was more of a creation tool than an editor. I don't know if that has changed.