Font rendering (was: Adding fonts to iACS)

Apologies for the very late response. Had to basically suspend mailing
list activity for a while.

On Wed, Jun 8, 2022 at 6:21 AM Patrik Schindler <poc@xxxxxxxxxx> wrote:

From the list presented, I'd say, the list is filtered to only show monospaced fonts. This makes sense, because fonts where a i is less wide than a m would most likely create a mess on the emulated screen.

The handling of proportional fonts varies from application to
application. Any application that gives its screen dimensions in terms
of rows and characters (such as 80x24, 80x25, or 132x27) is
intrinsically monospaced. I consider it a bug if such an application
allows selection of a proportional font. But some do anyway, with
varying degrees of intelligence. The "most" intelligent is to render
each character individually, horizontally centered in its "cell". I am
not sure I have ever seen that in person (it would be computationally
expensive and not easy to implement). I have seen naive monospaced
apps that accept proportional fonts, with of course horrific and
unusable results.

Lately I've been using the IBM Softcopy Reader, which is essentially a Java Application in Disguise. No matter which font I use, the display never looks pleasant. Example here: https://leela.pocnet.net/~poc/ibmscr.png I can't really put my finger on it, but in part it might be related to missing antialiasing of glyph edges, and the glyph placement looks somewhat irregular. Maybe this is what happens for iACS on Windows, too?

The image you linked to looks like Windows 95. That is before
Microsoft adopted ClearType. Prior to ClearType, Windows apps either
had no antialiasing at all (which seems to be the case in that image)
or used a much less sophisticated antialiasing system with decidedly
inferior results. Early versions of ACS did not have any antialiasing.

I am not completely sure what recent versions of ACS are doing, but
they at least do include some antialiasing. I am pretty confident that
it does *not* use ClearType on Windows. I would guess it's some kind
of scheme that is included with Java and rendered completely by the
JVM (not delegating to the operating system, at least on Windows).

John Y.