Character widths
I need a second pair of eyes (or more) for a change I've done in
Font-java.
I think there are a number of bugs in the getCharWidth() method:
- The widths for special spaces were never returned as getWidth()
automatically replaced them with #.
- The value for em was taken from the width of the small m.
WikiPedia says to use the width of the big M, or rather, today, the
size of the font in use (like in the XSL-FO spec).
- A similar problem with en. It is defined by WikiPedia as em/2.
- I changed the widths of 200A and 200B to better match the description
in http://www.unicode.org/charts/PDF/U2000.pdf. I actually used half the
width of a thin space for hair space and set the width of the zwsp to
zero which surprisingly it wasn't.
Before I commit this change, can anyone tell me in case I got something
wrong here. Thanks.
Index: C:/Dev/FOP/main/xml-fop-patching/src/java/org/apache/fop/fonts/Font.java
===
--- C:/Dev/FOP/main/xml-fop-patching/src/java/org/apache/fop/fonts/Font.java
(revision 381073)
+++ C:/Dev/FOP/main/xml-fop-patching/src/java/org/apache/fop/fonts/Font.java
(working copy)
@@ -206,62 +206,46 @@
if ((c == '\n') || (c == '\r') || (c == '\t') || (c == '\u00A0')) {
width = getCharWidth(' ');
} else {
-width = getWidth(mapChar(c));
+if (hasChar(c)) {
+width = getWidth(mapChar(c));
+} else {
+width = -1;
+}
if (width = 0) {
// Estimate the width of spaces not represented in
// the font
-int em = getWidth(mapChar('m'));
-int en = getWidth(mapChar('n'));
-if (em = 0) {
-em = 500 * getFontSize();
-}
-if (en = 0) {
-en = em - 10;
-}
+int em = getFontSize();
//http://en.wikipedia.org/wiki/Em_(typography)
+int en = em / 2; //http://en.wikipedia.org/wiki/En_(typography)
if (c == ' ') {
width = em;
-}
-if (c == '\u2000') {
+} else if (c == '\u2000') {
width = en;
-}
-if (c == '\u2001') {
+} else if (c == '\u2001') {
width = em;
-}
-if (c == '\u2002') {
+} else if (c == '\u2002') {
width = em / 2;
-}
-if (c == '\u2003') {
+} else if (c == '\u2003') {
width = getFontSize();
-}
-if (c == '\u2004') {
+} else if (c == '\u2004') {
width = em / 3;
-}
-if (c == '\u2005') {
+} else if (c == '\u2005') {
width = em / 4;
-}
-if (c == '\u2006') {
+} else if (c == '\u2006') {
width = em / 6;
-}
-if (c == '\u2007') {
+} else if (c == '\u2007') {
width = getCharWidth(' ');
-}
-if (c == '\u2008') {
+} else if (c == '\u2008') {
width = getCharWidth('.');
-}
-if (c == '\u2009') {
+} else if (c == '\u2009') {
width = em / 5;
-}
-if (c == '\u200A') {
-width = 5;
-}
-if (c == '\u200B') {
-width = 100;
-}
-if (c == '\u202F') {
+} else if (c == '\u200A') {
+width = em / 10;
+} else if (c == '\u200B') {
+width = 0;
+} else if (c == '\u202F') {
width = getCharWidth(' ') / 2;
-}
-if (c == '\u3000') {
+} else if (c == '\u3000') {
width = getCharWidth(' ') * 2;
}
}
Jeremias Maerki
Re: Character widths
On Feb 27, 2006, at 18:57, Jeremias Maerki wrote: Hi Jeremias, I need a second pair of eyes (or more) for a change I've done in Font-java. snip / Before I commit this change, can anyone tell me in case I got something wrong here. Thanks. Your changes seem fine to me... Any doubts in particular? Cheers, Andreas
Re: Character widths
Well, it's just that this is code that's been in there for a long time and someone must have given it some thought. I simply want to make sure I did not miss anything obvious. Thanks for looking at it. On 27.02.2006 19:42:36 Andreas L Delmelle wrote: On Feb 27, 2006, at 18:57, Jeremias Maerki wrote: Hi Jeremias, I need a second pair of eyes (or more) for a change I've done in Font-java. snip / Before I commit this change, can anyone tell me in case I got something wrong here. Thanks. Your changes seem fine to me... Any doubts in particular? Jeremias Maerki
Re: Character widths
On Mon, Feb 27, 2006 at 06:57:02PM +0100, Jeremias Maerki wrote: I need a second pair of eyes (or more) for a change I've done in Font-java. I think there are a number of bugs in the getCharWidth() method: - The widths for special spaces were never returned as getWidth() automatically replaced them with #. - The value for em was taken from the width of the small m. WikiPedia says to use the width of the big M, or rather, today, the size of the font in use (like in the XSL-FO spec). - A similar problem with en. It is defined by WikiPedia as em/2. - I changed the widths of 200A and 200B to better match the description in http://www.unicode.org/charts/PDF/U2000.pdf. I actually used half the width of a thin space for hair space and set the width of the zwsp to zero which surprisingly it wasn't. Donald Knuth in The TeX Book, page 60, says this: em is the width of a quad in the current font. Each font defines its own em and ex values. In olden days an em was the width of an `M', but this is no longer true; ems are simply arbitrary units that come with a font, and so are exes. Indeed, Knuth's Computer Modern fonts contain a quantity called quad width. For en space he uses .5 em. Regards, Simon -- Simon Pepping home page: http://www.leverkruid.nl
