1924346 - Firefox Nightly switched to Chromium's DirectWrite font rendering on Windows; about:config flag to bring back GDI doesn't work

Status: RESOLVED WONTFIX

(Firefox :: Untriaged, defect)

Description

[motosegaman]

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:133.0) Gecko/20100101 Firefox/133.0

Steps to reproduce:

1. Update to the 2024-10-12 Nightly.
2. gfx.font_rendering.cleartype_params.rendering_mode should be set to default.

Actual results:

1. DirectWrite seems to be used for font rendering:
   https://i.postimg.cc/RZSCrB2J/2.png

2. gfx.font_rendering.cleartype_params.rendering_mode set to 2 doesn't properly bring back GDI:
   https://i.postimg.cc/t4BqpcHS/3.png

Expected results:

1. GDI is being used for font rendering, like on older Nightles:
   https://i.postimg.cc/RZSCrB2J/2.png

2. If this not a bug, but a conscious decision, then gfx.font_rendering.cleartype_params.rendering_mode set to 2 should properly enable GDI.

Comment 1

[motosegaman]

GDI is being used for font rendering, like on older Nightles:
I posted incorrect image and can't edit the link. Here is the correct one:
https://i.postimg.cc/gch284vj/1.png

Comment 2

[Robert Longson [:longsonr]]

This was a deliberate decision in bug 1920733. You could (temporarily) set

gfx.font_rendering.cleartype_params.force_gdi_classic_for_families=Arial,Consolas,Courier New,Microsoft Sans Serif,Segoe UI,Tahoma,Trebuchet MS,Verdana
and
gfx.font_rendering.cleartype_params.force_gdi_classic_max_size=15

but GDI rendering would seem to be on its way out so you'd be better off just getting used to ClearType.