Removing horizontal space in latex fragments

Removing horizontal space in latex fragments

[Matt Huszagh]

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I've modified the behavior of `org-create-formula-image' so that
`\definecolor' etc do not create unnecessary whitespace in the output PDF.
Here's the relevant change:

```
...
        ;; remove tex \par at end of line
        (if (string= (substring string -1 nil) "\n")
            (aset string (- (length string) 1) ?%)
          (setq string (concat string "%")))
        (with-temp-file texfile
          (insert latex-header)
          (insert "\n\\begin{document}\n"
         "\\definecolor{fg}{rgb}{" fg "}%\n"
         "\\definecolor{bg}{rgb}{" bg "}%\n"
         "\n\\pagecolor{bg}%\n"
         "\n{\\color{fg}\n"
         string
         "\n}\n"
         "\n\\end{document}\n"))
...
```

This is useful if you (like me) have replaced the default document class
with standalone and are using dvisvgm. The change removes leading left and
right space, which is especially useful when using inline math mixed with
normal text. It shouldn't make a difference if using Imagemagick's convert
as a backend since that can get rid of whitespace boundaries.

Is anyone else interested in this modification? Should I submit it as a
patch?

Matt

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Re: Removing horizontal space in latex fragments

[Fraga, Eric]

On Thursday,  5 Dec 2019 at 11:03, Matt Huszagh wrote:
> Is anyone else interested in this modification? Should I submit it as a
> patch?

I think so.  And I am not sure all those \n's are necessary.  Without
them, you can probably also remove many of the %s.
-- 
Eric S Fraga via Emacs 27.0.50, Org release_9.2.6-544-gd215c3

Re: Removing horizontal space in latex fragments

[Matt Huszagh]

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Thanks for the reply Eric. The thing I like about the newlines is that the
generated tex files are slightly easier to read. However, this is really
minor. I've created 2 separate patches: one keeping the newlines and the
other without. I'm happy to defer to you or anyone else in regard to which
is preferable.

On Thu, Dec 5, 2019 at 2:24 PM Fraga, Eric <e.fraga@ucl.ac.uk> wrote:

> On Thursday,  5 Dec 2019 at 11:03, Matt Huszagh wrote:
> > Is anyone else interested in this modification? Should I submit it as a
> > patch?
>
> I think so.  And I am not sure all those \n's are necessary.  Without
> them, you can probably also remove many of the %s.
> --
> Eric S Fraga via Emacs 27.0.50, Org release_9.2.6-544-gd215c3
>

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From baf9812cb050c804d4d12bf3e2819bd4a5987722 Mon Sep 17 00:00:00 2001
From: Matt Huszagh <huszaghmatt@gmail.com>
Date: Thu, 5 Dec 2019 23:16:39 -0800
Subject: [PATCH] org.el: Remove leading/trailing whitespace from latex
 fragment

* lisp/org.el (org-create-formula-image): Ensure user input ends
with a % character to remove trailing whitespace. Also, remove
newlines from macro calls.
---
 lisp/org.el | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/lisp/org.el b/lisp/org.el
index 9b84592ba..4e3dbe4c3 100644
--- a/lisp/org.el
+++ b/lisp/org.el
@@ -16554,13 +16554,18 @@ a HTML file."
 	(setq bg (org-latex-color :background))
       (setq bg (org-latex-color-format
 		(if (string= bg "Transparent") "white" bg))))
+    ;; remove tex \par at end of snippet to avoid trailing
+    ;; whitespace
+    (if (string= (substring string -1 nil) "\n")
+        (aset string (- (length string) 1) ?%)
+      (setq string (concat string "%")))
     (with-temp-file texfile
       (insert latex-header)
       (insert "\n\\begin{document}\n"
-	      "\\definecolor{fg}{rgb}{" fg "}\n"
-	      "\\definecolor{bg}{rgb}{" bg "}\n"
-	      "\n\\pagecolor{bg}\n"
-	      "\n{\\color{fg}\n"
+	      "\\definecolor{fg}{rgb}{" fg "}"
+	      "\\definecolor{bg}{rgb}{" bg "}"
+	      "\\pagecolor{bg}"
+	      "{\\color{fg}\n"
 	      string
 	      "\n}\n"
 	      "\n\\end{document}\n"))
-- 
2.24.0


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From bdb93a13a43d90ad6e66449797111e836a67a219 Mon Sep 17 00:00:00 2001
From: Matt Huszagh <huszaghmatt@gmail.com>
Date: Thu, 5 Dec 2019 23:25:32 -0800
Subject: [PATCH] org.el: Remove leading/trailing whitespace from latex
 fragment

* lisp/org.el (org-create-formula-image): Ensure user input ends
with a % character to remove trailing whitespace. Also, add %
characters between macros and newlines purely visual.
---
 lisp/org.el | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/lisp/org.el b/lisp/org.el
index 9b84592ba..ae686e330 100644
--- a/lisp/org.el
+++ b/lisp/org.el
@@ -16554,12 +16554,17 @@ a HTML file."
 	(setq bg (org-latex-color :background))
       (setq bg (org-latex-color-format
 		(if (string= bg "Transparent") "white" bg))))
+    ;; remove tex \par at end of snippet to avoid trailing
+    ;; whitespace
+    (if (string= (substring string -1 nil) "\n")
+        (aset string (- (length string) 1) ?%)
+      (setq string (concat string "%")))
     (with-temp-file texfile
       (insert latex-header)
       (insert "\n\\begin{document}\n"
-	      "\\definecolor{fg}{rgb}{" fg "}\n"
-	      "\\definecolor{bg}{rgb}{" bg "}\n"
-	      "\n\\pagecolor{bg}\n"
+	      "\\definecolor{fg}{rgb}{" fg "}%\n"
+	      "\\definecolor{bg}{rgb}{" bg "}%\n"
+	      "\n\\pagecolor{bg}%\n"
 	      "\n{\\color{fg}\n"
 	      string
 	      "\n}\n"
-- 
2.24.0

Re: Removing horizontal space in latex fragments

[Fraga, Eric]

Not really worried about which alternative is chosen.  I was just
exhibiting my inner compulsive nature... ;-)

-- 
Eric S Fraga via Emacs 27.0.50, Org release_9.2.6-544-gd215c3

Re: Removing horizontal space in latex fragments

[Nicolas Goaziou]

Hello,

Matt Huszagh <huszaghmatt@gmail.com> writes:

> Thanks for the reply Eric. The thing I like about the newlines is that the
> generated tex files are slightly easier to read. However, this is really
> minor. I've created 2 separate patches: one keeping the newlines and the
> other without. I'm happy to defer to you or anyone else in regard to which
> is preferable.

So, has anyone settled on which one to apply?

> +    ;; remove tex \par at end of snippet to avoid trailing
> +    ;; whitespace

  Remove TeX \par at end of... trailing space.

> +    (if (string= (substring string -1 nil) "\n")

Minor nitpick: 

  (if (string-suffix-p string "\n") ...)

is slightly less low-level.

Thank you.

Regards,

-- 
Nicolas Goaziou

Re: Removing horizontal space in latex fragments

[Matt Huszagh]

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Nicolas Goaziou <mail@nicolasgoaziou.fr> writes:

> So, has anyone settled on which one to apply?

My vote goes for keeping the newlines to improve readability in the
generated tex file. But, again, I'm more than happy to be overuled.

> Minor nitpick:
>
>   (if (string-suffix-p string "\n") ...)
>
> is slightly less low-level.

Appreciate the nitpick; your version is better!

I've attached an updated patch.

Best,
Matt


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From bdb93a13a43d90ad6e66449797111e836a67a219 Mon Sep 17 00:00:00 2001
From: Matt Huszagh <huszaghmatt@gmail.com>
Date: Thu, 5 Dec 2019 23:25:32 -0800
Subject: [PATCH] org.el: Remove leading/trailing whitespace from latex
 fragment

* lisp/org.el (org-create-formula-image): Ensure user input ends
with a % character to remove trailing whitespace. Also, add %
characters between macros and newlines purely visual.
---
 lisp/org.el | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/lisp/org.el b/lisp/org.el
index 9b84592ba..ae686e330 100644
--- a/lisp/org.el
+++ b/lisp/org.el
@@ -16554,12 +16554,17 @@ a HTML file."
 	(setq bg (org-latex-color :background))
       (setq bg (org-latex-color-format
 		(if (string= bg "Transparent") "white" bg))))
+    ;; remove tex \par at end of snippet to avoid trailing
+    ;; whitespace
+    (if (string-suffix-p string "\n")
+        (aset string (- (length string) 1) ?%)
+      (setq string (concat string "%")))
     (with-temp-file texfile
       (insert latex-header)
       (insert "\n\\begin{document}\n"
-	      "\\definecolor{fg}{rgb}{" fg "}\n"
-	      "\\definecolor{bg}{rgb}{" bg "}\n"
-	      "\n\\pagecolor{bg}\n"
+	      "\\definecolor{fg}{rgb}{" fg "}%\n"
+	      "\\definecolor{bg}{rgb}{" bg "}%\n"
+	      "\n\\pagecolor{bg}%\n"
 	      "\n{\\color{fg}\n"
 	      string
 	      "\n}\n"
--
2.24.0

Re: Removing horizontal space in latex fragments

[Nicolas Goaziou]

Hello,

Matt Huszagh <huszaghmatt@gmail.com> writes:

> My vote goes for keeping the newlines to improve readability in the
> generated tex file. But, again, I'm more than happy to be overuled.

[...]

> I've attached an updated patch.

Applied. Thank you.

I added TINYCHANGE at the end of the commit message since I don't know
if you have signed the FSF papers. If you did, please let me know.

Regards,

-- 
Nicolas Goaziou