display-mm-height for MacOS?

display-mm-height for MacOS?

[David Kastrup]

People are trying out preview-latex, and it would appear that the
size calculations fail utterly.

preview-latex creates bitmaps to fit in well with the screen.  It uses
display-mm-height and display-pixel-height for calculating the
resolution of the screen, and then takes the point size of the default
font to make a guess how large the font is in reality.  This then gets
transformed into pixels, and the resulting images should match up
fine.

Or so is the theory, and the way stuff works under X.

On MacOS, it would appear that this results in awfully large images,
so one of the three above stated dimensions would seem to be quite
wrong.

-- 
David Kastrup, Kriemhildstr. 15, 44793 Bochum

Re: display-mm-height for MacOS?

[Hans-Peter Binder]

* David Kastrup <dak@gnu.org> writes:
> People are trying out preview-latex, and it would appear that the
> size calculations fail utterly.

Just for your information, here are some screenshots of the problem:

<URL:http://www.appledomain.de/emacs/screenshots/emacs-2.jpg>
<URL:http://www.appledomain.de/emacs/screenshots/emacs-3.jpg>


Regards/Gruesse
Hans-Peter Binder
-- 
(coffee-mode -1)

Re: display-mm-height for MacOS?

[David Kastrup]

Hans-Peter Binder <macosx.pb@gmx.de> writes:

> * David Kastrup <dak@gnu.org> writes:
> > People are trying out preview-latex, and it would appear that the
> > size calculations fail utterly.
> 
> Just for your information, here are some screenshots of the problem:
> 
> <URL:http://www.appledomain.de/emacs/screenshots/emacs-2.jpg>
> <URL:http://www.appledomain.de/emacs/screenshots/emacs-3.jpg>

And an update for developers: try C-x C-e behind the following
expressions:

(display-mm-height)                ;; 203 on my 13.3" display
(display-pixel-height)             ;; 768 here
(face-attribute 'default :height)  ;; 150 here

Note that the face attribute is specified in tenths of PostScript
points.

I use this data to calculate the pixel height of graphics supposed to
fit the size of the default font.

What output do you Carbonized hackers get?

-- 
David Kastrup, Kriemhildstr. 15, 44793 Bochum

Re: display-mm-height for MacOS?

[YAMAMOTO Mitsuharu]

>>>>> On 22 Mar 2004 13:08:11 +0100, David Kastrup <dak@gnu.org> said:

> On MacOS, it would appear that this results in awfully large images,
> so one of the three above stated dimensions would seem to be quite
> wrong.

Could you try this patch?

				     YAMAMOTO Mitsuharu
				mituharu@math.s.chiba-u.ac.jp

Index: src/macfns.c
===================================================================
RCS file: /cvsroot/emacs/emacs/src/macfns.c,v
retrieving revision 1.31
diff -c -r1.31 macfns.c
*** src/macfns.c	11 Mar 2004 22:43:18 -0000	1.31
--- src/macfns.c	23 Mar 2004 00:42:32 -0000
***************
*** 3025,3035 ****
    /* MAC_TODO: this is an approximation, and only of the main display */
  
    struct mac_display_info *dpyinfo = check_x_display_info (display);
-   short h, v;
  
!   ScreenRes (&h, &v);
! 
!   return make_number ((int) (v / 72.0 * 25.4));
  }
  
  DEFUN ("x-display-mm-width", Fx_display_mm_width, Sx_display_mm_width, 0, 1, 0,
--- 3025,3032 ----
    /* MAC_TODO: this is an approximation, and only of the main display */
  
    struct mac_display_info *dpyinfo = check_x_display_info (display);
  
!   return make_number ((int) (dpyinfo->height * 25.4 / dpyinfo->resy));
  }
  
  DEFUN ("x-display-mm-width", Fx_display_mm_width, Sx_display_mm_width, 0, 1, 0,
***************
*** 3043,3053 ****
    /* MAC_TODO: this is an approximation, and only of the main display */
  
    struct mac_display_info *dpyinfo = check_x_display_info (display);
-   short h, v;
- 
-   ScreenRes (&h, &v);
  
!   return make_number ((int) (h / 72.0 * 25.4));
  }
  
  DEFUN ("x-display-backing-store", Fx_display_backing_store,
--- 3040,3047 ----
    /* MAC_TODO: this is an approximation, and only of the main display */
  
    struct mac_display_info *dpyinfo = check_x_display_info (display);
  
!   return make_number ((int) (dpyinfo->width * 25.4 / dpyinfo->resx));
  }
  
  DEFUN ("x-display-backing-store", Fx_display_backing_store,

Re: display-mm-height for MacOS?

[Vincent LADEUIL]

>>>>> "David" == David Kastrup <dak@gnu.org> writes:

    David> And an update for developers: try C-x C-e behind the
    David> following expressions:

    David> (display-mm-height) ;; 203 on my 13.3" display
    David> (display-pixel-height) ;; 768 here 
    David> (face-attribute 'default :height) ;; 150 here

With the following patch applied, I obtain the following results :

(display-mm-height)                ;; 304 on my 17" 1444*900 LCD display
(display-pixel-height)             ;; 900 here
(face-attribute 'default :height)  ;; 135 here

Note that Mac OSX reports a  72 dpi resolution instead of 100 dpi
in my case.  But may be your calculus take this into account thru
the default font size ?

        Vincent

Index: src/macfns.c
===================================================================
RCS file: /cvsroot/emacs/emacs/src/macfns.c,v
retrieving revision 1.31
diff -u -r1.31 macfns.c
--- src/macfns.c	11 Mar 2004 22:43:18 -0000	1.31
+++ src/macfns.c	23 Mar 2004 08:58:48 -0000
@@ -3025,11 +3025,10 @@
   /* MAC_TODO: this is an approximation, and only of the main display */
 
   struct mac_display_info *dpyinfo = check_x_display_info (display);
-  short h, v;
 
-  ScreenRes (&h, &v);
-
-  return make_number ((int) (v / 72.0 * 25.4));
+    /*	Height  in   pixels  divided  by   vertical  resolution,
+     * converted from inches to mm */
+  return make_number ((int) ((dpyinfo->height * 25.4) / dpyinfo->resy));
 }
 
 DEFUN ("x-display-mm-width", Fx_display_mm_width, Sx_display_mm_width, 0, 1, 0,
@@ -3043,11 +3042,10 @@
   /* MAC_TODO: this is an approximation, and only of the main display */
 
   struct mac_display_info *dpyinfo = check_x_display_info (display);
-  short h, v;
-
-  ScreenRes (&h, &v);
 
-  return make_number ((int) (h / 72.0 * 25.4));
+    /*	Width  in   pixels  divided  by   horizontal  resolution,
+     * converted from inches to mm */
+  return make_number ((int) ((dpyinfo->width * 25.4) / dpyinfo->resx));
 }
 
 DEFUN ("x-display-backing-store", Fx_display_backing_store,