[mythtv-users] program guide font size

[Michael T. Dean]

Todd wrote:

> Although the FAQ is technically correct; think of the use-case.  
> "Monitor Size" for X is generally with your face 2 feet from the 
> screen.  What is the "Monitor Size" when you are 30 feet away (to your 
> eye)?
>
> Here is what the "Monitor" section of my XFree86-4 looks like:
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> # Little Text
> # DisplaySize     400 300
> # DisplaySize     360 270
> # DisplaySize     320 240
> # DisplaySize     280 210
> # DisplaySize     240 180
> DisplaySize     200 150
> # DisplaySize     160 120
> # DisplaySize     120 90
> # DisplaySize     80 60
> # DisplaySize     40 30
> # HUGE Text
>
> I just uncomment out different lines until it is "just right".  Each 
> TV in my house used a different line to be just right.  It is a 
> balancing act, I would be amazed at any system that work at 
> 40x30!...be somewhere between both ends will be just right for you.

Note that when you do this, it is completely impossible for your 
text/graphics to line up properly when using a theme that was created 
correctly.

Normally, a program calculates the appropriate position of graphic 
elements (in pixels = dots) relative to fonts (specified in points = 
1/72 inch) based on the DPI (Dots Per Inch) specified by the windowing 
system.  However, this requires run-time calculations.  Myth's "theming 
engine" allows the creation of themes that combine text and graphical 
elements, but since the themes are simple XML (text) files, there is no 
ability to do calculations.  Therefore, all themes are supposed to be 
created to use  a fixed DPI--100 DPI--so that graphics and fonts line up 
appropriately on any /properly-configured/ Myth system.

Now you know why the "technically correct" FAQ is completely 
correct--it's correct by specification--and using DisplaySize (which is 
used by X to calculate DPI) to adjust font sizes is incorrect.  And, now 
you know why the little arrows in your playback box, etc. are in the 
wrong places...

If you were to adjust your DisplaySize and then adjust all your themes 
for the resulting DPI, it would be just as "correct" as using 100DPI 
with the provided themes.  However, that approach takes much more time 
and is likely to result in much bigger font problems when re-displaying 
Myth screens (i.e. mythtv-setup) on other systems on your network (which 
may not be using 100DPI, but are likely to be close enough to 100DPI 
that it will still be readable--especially on a monitor 2 feet in front 
of your eyes).

So, please don't tell people to simply adjust their DisplaySize to fix 
font size problems.  The /only/ correct way to adjust font size is to 
edit the font names and font sizes in the theme.  (Editing font names is 
required when the specified font is not installed on your system.  If 
Myth requests a non-existant font, X font substitution will select 
another font as a replacement and often the font metrics are very 
different from the requested font, so to take the unknown element out of 
the system, you must ensure the theme requests an installed font.)

Mike