- From: Walter Ian Kaye <walter@natural-innovations.com>
- Date: Wed, 2 Aug 2000 07:58:04 -0700
- To: www-style@w3.org
At 06:09a -0700 07/27/2000, Rowland Shaw didst inscribe upon an
electronic papyrus:
> > > Because your UA was assuming a screen resolution of 96dpi, which is used
> > > when the "large fonts" option is selected by the user in the Display
> > > Properties on the windows client.
> >
> > No it's not. See http://richinstyle.com/small.png for a disproof.
>
>Woo... seems your graphics card drivers are better than mine :)
>
> > > AFAIK, UAs rely on the same setting that wysiwyg text editors (eg. Word)
>use
> > > for computing font sizes,
> >
> > On which subject, Word is broken: see, for example,
> > http://www.freetype.org/docs/glyphs/index.html (section IV, part 4), an
> > excellent document that I recommend reading anyway.
>
>Found it quite interesting, as I coming from a software development role
>more than a DTP background...
Then you'll also enjoy the following, from the Microsoft KnowledgeBase:
Q62911 - Video Resolution Standards
http://support.microsoft.com/support/kb/articles/q62/9/11.asp
The following table summarizes the different standards for monochrome,
CGA, EGA, and VGA video displays:
Standard Resolution Pixels Total Colors Colors/Screen
-------- ----------------- ------------ -------------
Hercules MDA 720 x 348 N/A N/A
CGA 640 x 200 16 4
EGA 640 x 350 64 16
PGA 640 x 480 4096 256
MCGA
CGA Mode 640 x 200 4096 256
Text Mode 640 x 480 16 2
VGA
CGA Mode 640 x 200 4096 256
Text Mode 720 x 400 16 2
320 x 200 262,144 256
640 x 480 262,144 16
Super VGA 800 x 600 256 16
(also called 262,144 256 (depends
extended VGA on
or VGA Plus) display
memory)
IBM 8514/A 1024 x 768 16 million 16
(interlaced) 256 (depends
on
display
memory)
TI TIGA 1024 x 768 16 million 16
(Compaq, NEC) (noninterlaced) 256 (depends
on display
1280 x 1024 16 million 16 memory)
Windows NT Raster Fonts
http://msdn.microsoft.com/library/winresource/dnwinnt/S83E0.HTM
Table 7.2 Raster Font Sizes
Font set and output device Horiz. res. Vert. res. Aspect ratio H:V
E = VGA display 96 dpi 96 dpi 1:1
F = 8514 display 120 dpi 120 dpi 1:1
[[[Note: I used to have a file which listed A-D and other aspect ratios,
but it's gone missing over the years. --wik]]]
Chapter 17 -- Text and Fonts: Background on Fonts
http://msdn.microsoft.com/library/partbook/winprog/ch17-02.htm
The Logical Inch Problem
[...] Windows 98 defines the system font as being a 10-point font with
a 12-point line spacing. Depending on whether you choose Small Fonts or
Large Fonts from the Display Properties dialog, this font could have a
tmHeight value of 16 pixels or 20 pixels and a tmHeight minus
tmInternalLeading value of 13 pixels or 16 pixels. Thus, the choice of
the font implies a resolution of the device in dots per inch, namely
96 dpi when Small Fonts are selected and 120 dpi for Large Fonts.
You can obtain this implied resolution of the device by calling
GetDeviceCaps with the LOGPIXELSX or LOGPIXELSY arguments. Thus, the
metrical distance occupied by 96 or 120 pixels on the screen can be
said to be a "logical inch." If you start measuring your screen with
a ruler and counting pixels, you'll probably find that a logical inch
is larger than an actual inch. Why is this?
[...] When people read print on paper, the distance between the eyes
and the text is generally about a foot, but a video display is commonly
viewed from a distance of two feet.
The logical inch in effect provides a magnification of the screen,
allowing the display of legible fonts in a size as small as 8 points.
Also, having 96 dots per logical inch makes the 640-pixel minimum
display size equal to about 6.5 inches. This is precisely the width of
text that prints on 8.5-inch-wide paper when you use the standard
margins of an inch on each side. Thus, the logical inch also takes
advantage of the width of the screen to allow text to be displayed as
large as possible.
Basic hinting philosophies
http://www.microsoft.com/OpenType/hinting/hinttut3.htm
The ultimate goal of hinting is to best represent the font at all the
resolutions at which it will be displayed. PCs use several different
resolutions and aspect ratios11. The most common are the VGA at 96 dots
per inch, SVGA at 120 dpi and the Macintosh at 72 dpi. All these devices
have a 1:1 aspect ratio. When a font is hinted, the type engineer
determines the lowest pixel per em size to which they will hint and
retain satisfactory results. Commonly the lowest ppem size hinted is 9.
This is the equivalent of 7 point on a VGA screen, 5.5 point on an SVGA
and 9 point on a Macintosh.
Q101171 - Determining Video Resolution with Windows Paintbrush
http://support.microsoft.com/support/kb/articles/Q101/1/71.asp
Common video resolution standards for Windows are EGA, VGA, SVGA, and
8514 Large and Small fonts. The following are examples of these common
video resolution standards:
EGA 72 dpi
VGA 96 dpi
SVGA 96 dpi
8514 Large 120 dpi
8514 Small 96 dpi
Received on Wednesday, 2 August 2000 11:00:31 UTC