monitoring the contents of the screen -- bug#14648

Nathaniel Smith njs at
Sat Aug 16 20:18:53 PDT 2008

On Sat, Aug 16, 2008 at 7:34 PM, Keith Packard <keithp at> wrote:
> On Sat, 2008-08-16 at 19:19 -0700, Nathaniel Smith wrote:
>> The fix is just to dike out a few lines of code from the damage
>> extension, but it also changes the extension's semantics, probably
>> needs a version number bump so apps can tell whether the new
>> functionality is usable, etc.  So I can write the patch to change the
>> behavior in a few minutes, but I'm not sure how to approach the rest
>> of it.  Thoughts?
> Write some code that does what you want and post that here; ideally,
> you'll extend the current damage sematics so you end up asking for the
> new behaviour.

To clarify -- are you asking for an example of code that *uses*
Damage, so you can see whether I'm asking for something sensible, or
an example of implementing what I want inside Damage itself?  And re:
extending the semantics, basically what you're suggesting is to
preserve backwards compatibility by adding a new DamageReportLevel
like DamageReportDeltaRectanglesExceptNotBroken (except presumably
with a more, umm, politic, name)?

(FWIW, I spent some time spelunking through google codesearch, and as
far as I can tell all the clients that would be affected by this fall
into two classes: those which have switched to
DamageReportRawRectangles as a workaround for the current semantics
and are therefore unaffected, and those whose authors assumed the
semantics that I propose and are therefore currently broken.  But I
can understand if you want to prioritize backwards compatibility too.)

-- Nathaniel

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