From divanov at aha.ru  Sun Jan 18 13:47:18 2009
From: divanov at aha.ru (Dmitriy Ivanov)
Date: Sun, 18 Jan 2009 16:47:18 +0300
Subject: [cl-typesetting-devel] *use-exact-char-boxes*
References: <04bc01c677f6$7b246240$1402a8c0@marcx2>
	<000f01c67815$03bb7120$8100a8c0@digo>
	<005001c67817$ac57bd50$1402a8c0@marcx2>
	<001001c6782b$9c1c8740$8100a8c0@digo>
	<013501c67831$5071be40$1402a8c0@marcx2>
Message-ID: <006201c97973$4aef81a0$8100a8c0@digo>

Marc Battyani wrote on Mon, 15 May 2006 17:07:42 +0200 18:07:

| In fact, the only bug is the character descent missing in the first
| table.
| 
| In make-char-box:
| :dy *leading* :baseline *font-size*
| should be replaced by something like:
| :dy *leading* :baseline (- *font-size* *descender*)
| With *descender* being the maximum descender for the font.
| Or better by adddding *base-line*:
| :dy *leading* :baseline *base-line*

I have found quite a simple solution working when
*use-exact-char-boxes* is nil.

The descender slot is already present in every pdf::font-metrics instance.
It
holds a minumum descender (as descenders are non-positive norlmally) among
the characters of the font. So we can add the same slot to the font class
definition (see cl-pdf/font.lisp):

(defclass font ()
((name :accessor name :initform "helvetica" :initarg :name)
  ...
  ;; minimum descender among chars
  (descender :accessor descender :initform 0)))

are simply copy it on initializing:

(defmethod initialize-instance :after ((font font) &key encoding
                                                &allow-other-keys)
  (let ((font-metrics (gethash (name font) *font-metrics*)))
    ...
    (setf (font-metrics font) font-metrics
          (descender font) (descender font-metrics))
  ...)))

In cl-typesetting, we are using the value of the font descender in
make-char-box and make-white-char-box.

My gut feeling is that the font ascender should be used similarly somewhere
but I cannot figure out where.

I will provide a patch as soon as I resolve troubles with
updating/committing from/to the repository.
--
Sincerely,
Dmitriy Ivanov
lisp.ystok.ru



From marc.battyani at fractalconcept.com  Mon Jan 19 02:22:04 2009
From: marc.battyani at fractalconcept.com (Marc Battyani)
Date: Sun, 18 Jan 2009 21:22:04 -0500
Subject: [cl-typesetting-devel] *use-exact-char-boxes*
In-Reply-To: <006201c97973$4aef81a0$8100a8c0@digo>
References: <04bc01c677f6$7b246240$1402a8c0@marcx2>
	<000f01c67815$03bb7120$8100a8c0@digo>
	<005001c67817$ac57bd50$1402a8c0@marcx2>
	<001001c6782b$9c1c8740$8100a8c0@digo>
	<013501c67831$5071be40$1402a8c0@marcx2>
	<006201c97973$4aef81a0$8100a8c0@digo>
Message-ID: <4973E3CC.2020005@fractalconcept.com>

Dmitriy Ivanov wrote:
> Marc Battyani wrote on Mon, 15 May 2006 17:07:42 +0200 18:07:
>
> | In fact, the only bug is the character descent missing in the first
> | table.
> | 
> | In make-char-box:
> | :dy *leading* :baseline *font-size*
> | should be replaced by something like:
> | :dy *leading* :baseline (- *font-size* *descender*)
> | With *descender* being the maximum descender for the font.
> | Or better by adddding *base-line*:
> | :dy *leading* :baseline *base-line*
>
> I have found quite a simple solution working when
> *use-exact-char-boxes* is nil.
>
> The descender slot is already present in every pdf::font-metrics instance.
> It
> holds a minumum descender (as descenders are non-positive norlmally) among
> the characters of the font. So we can add the same slot to the font class
> definition (see cl-pdf/font.lisp):
>
> (defclass font ()
> ((name :accessor name :initform "helvetica" :initarg :name)
>   ...
>   ;; minimum descender among chars
>   (descender :accessor descender :initform 0)))
>
> are simply copy it on initializing:
>
> (defmethod initialize-instance :after ((font font) &key encoding
>                                                 &allow-other-keys)
>   (let ((font-metrics (gethash (name font) *font-metrics*)))
>     ...
>     (setf (font-metrics font) font-metrics
>           (descender font) (descender font-metrics))
>   ...)))
>
> In cl-typesetting, we are using the value of the font descender in
> make-char-box and make-white-char-box.
>
> My gut feeling is that the font ascender should be used similarly somewhere
> but I cannot figure out where.
>
> I will provide a patch as soon as I resolve troubles with
> updating/committing from/to the repository.
>   
Seems reasonable to me. Just check that the examples still work before
committing. ;-)

The repository should work at
http://www.fractalconcept.com/public/open-source
or http://www.fractalconcept.com:8000/public/open-source

Marc



From divanov at aha.ru  Tue Jan 20 09:04:57 2009
From: divanov at aha.ru (Dmitriy Ivanov)
Date: Tue, 20 Jan 2009 12:04:57 +0300
Subject: [cl-typesetting-devel] *use-exact-char-boxes*
References: <04bc01c677f6$7b246240$1402a8c0@marcx2>
	<000f01c67815$03bb7120$8100a8c0@digo>
	<005001c67817$ac57bd50$1402a8c0@marcx2>
	<001001c6782b$9c1c8740$8100a8c0@digo>
	<013501c67831$5071be40$1402a8c0@marcx2>
	<006201c97973$4aef81a0$8100a8c0@digo>
	<4973E3CC.2020005@fractalconcept.com>
Message-ID: <00f301c97adf$55e3d4e0$8100a8c0@digo>

Marc Battyani wrote on Sun, 18 Jan 2009 21:22:04 -0500 05:22:

|> In cl-typesetting, we are using the value of the font descender in
|> make-char-box and make-white-char-box.
|
| Seems reasonable to me. Just check that the examples still work before
| committing. ;-)

The patch has committed. The full-example works for me, nevertheless. please
update carefully :-)

The net effect is shifting text up a bit. Maybe the top-margin should be
enlarged for paragraphs.
--
Sincerely,
Dmitriy Ivanov
lisp.ystok.ru