Python: font.generate not outputting glyph data to BDF

[projectitis]

I am loading a TTF font, generating bitmap strikes, then saving as BDF.
The resulting BDF file has the header data, but does not contain any glyphs.
I assume I am using the generate command incorrectly, but the docs there are extremely light.

This is a cut-down snippet of my script:

font = fontforge.open('KiwiSoda.ttf')
font.bitmapSizes = ((output_size,),)
font.regenBitmaps((output_size,))
font.generate('KiwiSoda.bdf', bitmap_type='bdf', bitmap_resolution=72)

If required, the original TTF and the generated BDF are attached: kiwisoda_ttf_to_bdf.zip

• Windows 11
• FontForge 20220308
• ffpython

[projectitis]

ok, immediately found the cause: The font has to have a selection. The selected glyphs are included in the generated BDF.

font = fontforge.open('KiwiSoda.ttf')
font.selection.select(('ranges',None)," ","~")
font.bitmapSizes = ((output_size,),)
font.regenBitmaps((output_size,))
font.generate('KiwiSoda.bdf', bitmap_type='bdf', bitmap_resolution=72)

Will close this issue, and leave the solution for posterity!

[ctrlcctrlv]

Reopening as it's not documented in font.regenBitmaps that the selection is taken into account.

[projectitis]

Note: I'm not sure if it's font.regenBitmaps or font.generate that requires the selection.

[ctrlcctrlv]

Don't worry, I'm sure enough for both of us.

The call tree looks like font.regenBitmaps → PyFFFont_regenBitmaps (python.c) → bitmapper (python.c) → BitmapControl (fontforge/bitmapcontrol.c) → BitmapsDoIt (fontforge/bitmapcontrol.c) → FVRegenBitmaps (fontforge/bitmapcontrol.c), which checks selection status:

fontforge/fontforge/bitmapcontrol.c

Line 262 in 566b261

if ( fv->selected[i] || bd->which == bd_all ) {

[ctrlcctrlv]

I removed [docs] tag as this is just a bug, the selection reliance does not look intentional.

[clort81]

• I open a bitmap font. I want to add a glyph to an empty code point.
• I click on a source glyph and copy (ctrl-c).
• I click on the destination code point in the table that I want to create a new glyph for.
• I paste (ctrl-v).
• I double click the new glyph and can edit. It inherits all the correct properties from the source glyph, so far, so good.
• I finish editing, close the window.
• The new glyph still has a faint 'x' in it, like unedited/empty glyphs do.
• The new glyph isn't exported to a .bdf file when i generate a font.
  

Why?
If I create a new glyph, I logically expect Fontforge to understand that I want the font to include this glyph.
I logically want the font I export to include the new content I added.
Is this a bug?? Or a feature request?
[EDIT] it's only happening with this font. It might be a different problem.
Blapinus4Medium.zip