Incorrect subpixel font rendering in Unity Panel when using Radiance

[Michael Titke]

This bug has been there for at least three years.

The font anti aliasing in the menu bar is completely off when the user chooses the Radiance theme. The attached screen shot shows a Firefox menu on top of an Emacs session. You see the unity menu bar at the top with the distorted anti aliasing. Under it in the pop-up menu you see a font rendered normally which looks much better.

In addition to the distorted anti aliasing the menu bar does not seem to respect the user settings in "~/.fonts.conf".

Please fix this and alter the name of Radiance to "Bright". Stop the menu bar from radiating with Radiance.

[Michael Titke (michael-tiedtke-i)]

Found it. Solved it.

Just apply the patch to "/usr/share/themes/Radiance/gtk-2.0/gtkrc".

It somehow works instantly, i.e. it changes the appearance of the menu bar instantly. Don't know why ...

Caveats:

1) It's still called Radiance and not Bright.

2) One might still perceive some kind of embossed or glossy effect: maybe that's a perceptive interference with the background gradient but it doesn't show up in the pixel values.
 (This might even depend on the type of display - not all liquid crystal display show a static image: some try to interpolate unrepresentable colors of RGB24 by alternating rapidly between two colors in 6 bit color channels bla bla etc.)

[Ubuntu Foundations Team Bug Bot (crichton)]

The attachment "Patch (created with diff -u): set RGBA to false in gtkrc" seems to be a patch. If it isn't, please remove the "patch" flag from the attachment, remove the "patch" tag, and if you are a member of the ~ubuntu-reviewers, unsubscribe the team.

[This is an automated message performed by a Launchpad user owned by ~brian-murray, for any issues please contact him.]

[Michael Titke (michael-tiedtke-i)]

Imagination is everything! The RGBA patch didn't seem to change anything - no matter what (with Xrdb, fonts.conf) font rendering always stays on rgb.

The radiance problem was text shadows. Please see attached screenshot of screenshots: it's color enhanced. The upper part is a menu bar item with text-shadow the lower one without.

Here is an overview of the changes:

/usr/share/themes/Radiance$ grep -iR text-shadow *gtk-3.0/gtk-widgets.css.orig: text-shadow: 0 1px shade (@bg_color, 1.04);
gtk-3.0/gtk-widgets.css.orig: text-shadow: 0 1px alpha (shade (@button_bg_color, 1.25), 0.4);
gtk-3.0/gtk-widgets.css.orig: text-shadow: 0 1px alpha (shade (@button_bg_color, 1.25), 0.2);
gtk-3.0/gtk-widgets.css.orig: text-shadow: 0 1px alpha (shade (@button_bg_color, 1.25), 0.4);
gtk-3.0/gtk-widgets.css.orig: text-shadow: 0 1px alpha (shade (@button_bg_color, 1.25), 0.2);
gtk-3.0/gtk-widgets.css.orig: text-shadow: 0 1px alpha (shade (@bg_color, 1.25), 0.4);
gtk-3.0/gtk-widgets.css.orig: text-shadow: 0 -1px shade (@dark_bg_color, 0.6);
gtk-3.0/gtk-widgets.css.orig: text-shadow: 0 -1px shade (@dark_bg_color, 0.8);
gtk-3.0/gtk-widgets.css.orig: text-shadow: 0 -1px shade (@dark_bg_color, 0.7);
gtk-3.0/gtk-widgets.css.orig: text-shadow: none;
gtk-3.0/gtk-widgets.css.orig: text-shadow: 0 -1px shade (@selected_bg_color, 0.7);
gtk-3.0/gtk-widgets.css.orig: text-shadow: 0 -1px shade (@dark_bg_color, 0.6);
gtk-3.0/gtk-widgets.css.orig: text-shadow: 0 1px shade (@bg_color, 1.14);
gtk-3.0/gtk-widgets.css.orig: text-shadow: 0 -1px shade (@dark_bg_color, 0.7);
gtk-3.0/gtk-widgets.css.orig: text-shadow: 0 1px shade (@selected_bg_color, 0.7);
gtk-3.0/gtk-widgets.css.orig: text-shadow: 0 1px alpha (shade (@bg_color, 1.25), 0.5);
gtk-3.0/gtk-widgets.css.orig: text-shadow: 0 1px shade (@selected_bg_color, 0.7);
gtk-3.0/gtk-widgets.css.orig: text-shadow: 0 1px alpha (shade (@bg_color, 1.25), 0.5);
gtk-3.0/gtk-widgets.css.orig: text-shadow: 0 1px alpha (shade (@button_bg_color, 1.25), 0.4);
gtk-3.0/gtk-widgets.css.orig: text-shadow: 0 1px alpha (shade (@button_bg_color, 1.25), 0.2);
gtk-3.0/gtk-widgets.css.orig: text-shadow: none;
gtk-3.0/gtk-widgets.css.orig: text-shadow: 0 -1px shade (@dark_bg_color, 0.7);
gtk-3.0/gtk-widgets.css.orig: text-shadow: 0 -1px shade (@dark_bg_color, 0.7);
gtk-3.0/gtk-widgets.css.orig: text-shadow: 0 -1px shade (@dark_bg_color, 0.7);
gtk-3.0/gtk-widgets.css.orig: text-shadow: 0 -1px shade (@dark_bg_color, 0.9);
gtk-3.0/gtk-widgets.css.orig: text-shadow: 0 -1px shade (@dark_bg_color, 0.6);
gtk-3.0/gtk-widgets.css.orig: text-shadow: none;
gtk-3.0/gtk-widgets.css.orig: text-shadow: none;
gtk-3.0/gtk-widgets.css.orig: text-shadow: none;
gtk-3.0/gtk-widgets.css.orig: text-shadow: none;
gtk-3.0/gtk-widgets.css.orig: text-shadow: 0 1px alpha (shade (@bg_color, 1.25), 0.5);
gtk-3.0/gtk-widgets.css: text-shadow: none;
gtk-3.0/gtk-widgets.css: text-shadow: none;
gtk-3.0/gtk-widgets.css: text-shadow: none;
gtk-3.0/gtk-widgets.css: text-shadow: none;
gtk-3.0/gtk-widgets.css: text-shadow: none;
gtk-3.0/gtk-widgets.css: text-shadow: none;
gtk-3.0/gtk-wi...

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.