[Xcb] 7.7 katamari Release Notes draft & RC1 content list

Josh Triplett josh at joshtriplett.org
Sun Apr 1 16:06:42 PDT 2012

On Sat, Mar 31, 2012 at 07:53:24PM -0700, Alan Coopersmith wrote:
>         </p><div class="sect4" title="Changed behavior caused by DDC."><div class="titlepage"><div><div><h5 class="title"><a id="Changed_behavior_caused_by_DDC."></a>Changed behavior caused by DDC.</h5></div></div></div><p>
>             Several drivers use DDC information to set the screen size and
>             pitch.  This can be overridden by explicitly resetting it to
>             the and non-DDC default value 75 with the <code class="option">-dpi 75</code>
> 	    command line option for the X
>             server, or by specifying appropriate screen dimensions with the
>             "DisplaySize" keyword in the "Monitor" section of the config
>             file.

As nice as it would be to have X go back to automatically having
readable fonts on modern high-DPI displays, this paragraph no longer
describes the current behavior of the X server.  X now gathers display
size information from DDC at startup, prints it to the server log, then
discards it and uses hard-coded incorrect values.

Suggested replacement text:

The X server previously used DDC information to detect screen size and
pitch, and compute DPI automatically, allowing fonts and other UI
elements to automatically scale to appropriate sizes.  This mechanism
worked reasonably well for many single-monitor cases, but did not
compute accurate DPI values for multi-monitor cases or less common
single-display setups.  Thus, this autodetection has been removed, and
the X server no longer tries to compute an appropriate DPI value.  All
users wanting fonts, physical measurement units, and other UI elements
scaled appropriately for their display (including users for whom
autodetection previously worked) must now set DPI or some other scaling
factor explicitly, either via the X server's -dpi option, a DPI setting
in their graphical enironment, or an alternate scaling mechanism
provided by their environment.

- Josh Triplett

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