Add options to embolden and transform font outlines to simulate bold and italic typefaces.

[bruvzg]

• Adds options to embolden and transform font outlines to simulate bold and italic typefaces.
• Adds bold, bold italics, and italics modified font versions to the default theme (for RichTextLabel style). With 1.2 embolden and Transform2D(1.0, 0.4, 0.0, 1.0, 0.0, 0.0) transform.

Normal
[b]Bold[/b]
[i]Italic[/i]

Fixes #58988

[bruvzg]

Screen.Recording.2022-03-11.at.12.05.55.mov

[akien-mga]

Playing a bit with dynamic updates to slant and embolden:

simplescreenrecorder-2022-03-11_11.42.13.mp4

It works well but seems to be fairly expensive, the above drops from 1670 FPS with just the RichTextEffects, to 20 FPS with both slant and embolden set dynamically in _process. Or down to 2-3 FPS if set in _physics_process.

If I double the font size from 48 to 96px, I get 5 FPS in _process.

Using this code:

var fd = get_theme_font("normal_font").get_data(0)

func _process(delta):
	fd.slant = sin(Time.get_ticks_msec() / 1000.0)
	fd.embolden = clamp(cos(Time.get_ticks_msec() / 500.0), 0.2, 0.8)

[bruvzg]

Changed slant to full Transform2D, now it's possible to do more stuff:

Screen.Recording.2022-03-11.at.13.06.12.mov

Original slant is equivalent to Transform2D(1.0, slant, 0.0, 1.0, 0.0, 0.0)

[akien-mga]

Changed slant to full Transform2D, now it's possible to do more stuff:

Heh I was suggesting this mostly in jest, I don't know if there's a real need for it.

It's nice to have the flexibility but at the same time I fear it might not be easy for users to edit the Transform2D directly if what they want is a simple slanting effect.

Maybe mention in the transform documentation that for italics-like slanting users should set the yx component?

I confirm that this still works fine from script (and doesn't seem slower than it was with slant):

var fd = get_theme_font("normal_font").get_data(0)

func _process(delta):
	fd.transform.x.y = sin(Time.get_ticks_msec() / 600.0)
	fd.embolden = abs(cos(Time.get_ticks_msec() / 800.0)) - 0.2

[bruvzg]

Maybe mention in the transform documentation that for italics-like slanting users should set the yx component?

Added slant an example to the documentation.

Also changed max. font texture cache size to 1024x1024 (2048x2048 for MSDF, it's slow anyway and usually have large size glyphs rendered), it should be faster with larger font.

[akien-mga]

Also changed max. font texture cache size to 1024x1024 (2048x2048 for MSDF, it's slow anyway and usually have large size glyphs rendered), it should be faster with larger font.

It doesn't seem to make much difference in my test project, still ~40 FPS with 64px font and 10 FPS with 65px font when changing embolden and transform every other _process call.

[bruvzg]

64px font and 10 FPS with 65px

This should be transition from 512 to 1024, so it's not changed.

[akien-mga]

Thanks!

[markdibarry]

It seems this causes all font outlines to be anti-aliased. Is that intentional?