kenh@hscfsas1.harvard.edu (Ken Hancock) (10/17/90)
I recently downloaded a Type 1 Shareware font called Zirkle and have noticed a few problems. The lower-case 'e' is designed as a single outline (like a rubber tube wrapped around). Where the outlines meet, there is a bit of an overlap. ATM inverts the overlap, and printing the font to any QuickDraw printer shows the overlap inverted as well. The Personal NT prints the font as one would expect it -- without overlap. This raises a few of my questions: 1) Is this just another example of a font which has been incorrectly designed (as is often the case with PD/SW fonts)? 2) Related to (1) are overlapping areas allowed, or should they be removed and a clockwise outer path and a counterclockwise inner path substituted? 3) The Personal NT supposedly as the ATM font generation built into the Postscript ROMs, yet ATM 2.0 and the output doesn't match. Explanation? Hopefully someone from Adobe or another informed party can answer this... Thanks in advance -- Ken -- Ken Hancock | INTERNET: kenh@hscfsas1.harvard.edu Isle Systems | Disclaimer: My opinions are mine, Macintosh Consulting | your opinions are yours. Simple, isn't it?
larry@csccat.cs.com (Larry Spence) (10/18/90)
In article <4447@husc6.harvard.edu> kenh@hscfsas1.harvard.edu (Ken Hancock) writes: >I recently downloaded a Type 1 Shareware font called Zirkle and have >noticed a few problems. The lower-case 'e' is designed as a single >outline (like a rubber tube wrapped around). Where the outlines meet, >there is a bit of an overlap. > >ATM inverts the overlap, and printing the font to any QuickDraw >printer shows the overlap inverted as well. The Type 1 spec says that self-intersections are not allowed in Type 1 outlines. -- Larry Spence larry@csccat.cs.com ...{uunet,texsun,cs.utexas.edu,decwrl}!csccat!larry
kevina@apple.com (This space for rent) (10/18/90)
In article <4447@husc6.harvard.edu> kenh@hscfsas1.harvard.edu (Ken Hancock) writes: > I recently downloaded a Type 1 Shareware font called Zirkle and have > noticed a few problems. The lower-case 'e' is designed as a single > outline (like a rubber tube wrapped around). Where the outlines meet, > there is a bit of an overlap. > > ATM inverts the overlap, and printing the font to any QuickDraw > printer shows the overlap inverted as well. > > The Personal NT prints the font as one would expect it -- without > overlap. This raises a few of my questions: > > 1) Is this just another example of a font which has been incorrectly > designed (as is often the case with PD/SW fonts)? Yep. > 2) Related to (1) are overlapping areas allowed, or should they > be removed and a clockwise outer path and a counterclockwise > inner path substituted? According to the infamous Black Book (section 3.6), "a single closed outline should not intersect itself". They use a stroked outline as an example of why this is a bad thing, but it also messes up on even-odd fills. However, you should replace it with a counterclockwise outer path and a clockwise inner path. (According to section 3.5, "A subpath that is to be filled must be defined in a counterclockwise orientation in character space. A subpath that is to be left unfilled must be defined in a clockwise orientation.") > 3) The Personal NT supposedly as the ATM font generation built > into the Postscript ROMs, yet ATM 2.0 and the output doesn't > match. Explanation? ATM 1.x and most (if not all) Level 1 PostScript interpreters use a winding-number fill (like the PostScript fill operator). Rumor has it that ATM 2.0 uses a faster even-odd fill (like the PostScript eofill operator). Since the Personal LaserWriter NT came out several months before ATM 2.0 was released, it's safe to assume that ATM 1.x technology is what was included. Disclaimer: This is not an official Apple claim about ATM in the Personal LaserWriter NT. --Kevin Andresen [kevina@apple.com] "Orange whip? Orange whip? Three orange whips."