FreeType 2.7 Bringing DirectWrite/ClearType-Like Rendering -- Much Better Looking Fonts On Linux

[carewolf]

Well, yes, but v40 is what's used by the native TrueType hinting interpreter. "slight" refers to the autohinter that does its' own thing regardless of what the hinting in the font says or doesn't. This means that full/medium and slight will look at lot more alike but not completely identical (depending on the font). See below.



The principal difference is that TrueType hinting is explicit and deliberate, while the autohinter is luck and clever guesswork. Aside, plenty of TrueType fonts snap stems to full pixels vertically (e.g. Source * Pro, Acumin, google it), while others and the autohinter snap the outer edge of a stem to the grid but drag the inner edge along to preserve the actual thickness. You can tell the former by looking for aliasing when displaying a text waterfall. So when using hintmedium/full, you will encouter fonts that seem to look sharper (and "harder-edged") and others that will look smoother. Using the autohinter ("slight"), all fonts will look smooth.

Okay, thanks. Is there a way we can detect at runtime that sub-pixel positioning is possible? Right now we just look at the requested hinting we pass from fontconfig to freetype, but with this, we need to know more about which version of freetype it is, and how it is configured. Please make sure we have such a method in 2.7. It was the same problem with stem darkening.

[mr_tawan]

This is not written with intention to troll at all.

One of the reasons i dropped Windows for Linux was this ClearType )or any for of anti-aliasing) that hurts my eyesight (that, and also any refresh rate bellow 100 Hz be in a LED or CRT monitor), funny enough i finally learned some months ago to get rid of all that crap in Windows (in Linux, i also still had some issues with Browsers but finally also managed to remove all that stuff time ago)...

So now, are you telling me that ClearType crap is gonna start to be (forcefully) implemented in LINUX distros ?!?

I might as well return to W7 if there will not be a EASY WAY TO DISABLE THAT CRAP THAT ALMOST PERMANENTLY DAMAGED MY EYESIGHT if i didn't solve it.

May bitmap fonts always with you ...

[omer666]

So now, are you telling me that ClearType crap is gonna start to be (forcefully) implemented in LINUX distros ?!?

No, we are not.

[stqn]

Windows renders fonts fine now.

Here's a comparison - your screenshot is on top, windows rendering on bottom.

http://i.imgur.com/DSVgjYL.png

The text on the top looks better, it is pixel perfect unlike the bottom that is slightly blurry. But yeah, different fonts anyway…

When I switched from Windows XP to Linux the fonts looked better on Linux to me (without using infinality). I’m currently using full hinting because the default font (déjà vu sans?) looks bad with slight hinting. Medium and full hinting both look the same.

[FuturePilot]

The only rendering-related patch that Ubuntu applies is to enable subpixel rendering that FreeType disables by default because it's still patented.

I thought those patents expired several years ago.

[mudig]

Okay, thanks. Is there a way we can detect at runtime that sub-pixel positioning is possible? Right now we just look at the requested hinting we pass from fontconfig to freetype, but with this, we need to know more about which version of freetype it is, and how it is configured. Please make sure we have such a method in 2.7. It was the same problem with stem darkening.

Subpixel positioning is done by the toolkit that uses FreeType. Do you mean subpixel hinting? Just test for v40. Note that it might not give you what you expect depending on the font. The compatibility mode and the way it looks depends on the font not being a "native ClearType" font. Fonts like Constantia and Corbel are native CT fonts that are left alone. They will look and behave differently from compatibility fonts. Tricky fonts like DF Kai SB rely on the native hinter to render correctly and are also exempt.

Medium and full hinting both look the same.

Because they are the same. There is no medium in FT.

I thought those patents expired several years ago.

Bytecode patents, yes. ClearType patents, no. I think they expire 2018 or something.

[stqn]

Because they are the same. There is no medium in FT.

Thanks for the information. I wonder why there is a medium setting in Xfce then.

[mudig]

Thanks for the information. I wonder why there is a medium setting in Xfce then.

An artifact from whoever decided to create hintslight, hintmedium and hintfull. It was originally conceived as a sharpness control but never mapped to the reality of how FreeType operates. An unfortunate accident of history. I'd like to get rid of it.

[carewolf]

Subpixel positioning is done by the toolkit that uses FreeType. Do you mean subpixel hinting? Just test for v40. Note that it might not give you what you expect depending on the font. The compatibility mode and the way it looks depends on the font not being a "native ClearType" font. Fonts like Constantia and Corbel are native CT fonts that are left alone. They will look and behave differently from compatibility fonts. Tricky fonts like DF Kai SB rely on the native hinter to render correctly and are also exempt.

Let's say I am working on a toolkit, and let's say Qt

Qt like Skia and others disable subpixel positioning when normal or full hinting is requested, because pixel-grid hinting doesn't combine with subpixel positioning. So we need to know if face loaded by FreeType is can support subpixel positioning. Note it has to be a runtime because a toolkit might be build against a different version of FreeType than it is run with.

[carewolf]

An artifact from whoever decided to create hintslight, hintmedium and hintfull. It was originally conceived as a sharpness control but never mapped to the reality of how FreeType operates. An unfortunate accident of history. I'd like to get rid of it.

I thought hintfull enabled subpixel rendering when available and lcd-filtering. Without subpixel rendering they are identical though.

Note: Chrome and Chromium doesn't support hintmedium and will fall down to hintslight when it is configured as default.