Composite Quesiton

[Huang, FrankR]

Morton,

	I want to know if the black region after SRC is the CLEAR operation?
	If that is so, I want to modify the driver to do the CLEAR outside the 20x20 mask region to make the driver does the right SRC operation.


Thanks,
Frank 

-----Original Message-----
From: Jonathan Morton [mailto:jonathan.morton at movial.com] 
Sent: 2010年5月18日 21:12
To: Huang, FrankR
Cc: xorg-devel at lists.x.org
Subject: RE: Composite Quesiton

On Tue, 2010-05-18 at 11:10 +0800, Huang, FrankR wrote:
> I have used OVER operation to produce what I want on RS690 platform.
> But in the geode driver, I found that it can not do the SRC and OVER
> rendering correctly.

That would be a fairly serious bug.  Does it work with Option "NoAccel"
set?

> I am now firstly focusing the SRC operation. From your explanation, a
> (1,0,1,0) to (0,0,0,0) transfer is done outside the 20x20 mask region.
> Is it done by Xserver or driver? I think it is done by driver, is it
> correct?

It's an inherent part of the XRender spec.  Whether the driver, hardware
or xserver does any particular operation depends on whether the driver
claims to be able to accelerate it.

> Any reference code to see how the driver to handle it? I want to fix
> the bug in the geode driver.

My advice is to obtain the Rendercheck program.  It runs an insane
number of very small tests to (almost) exhaustively exercise XRender.
When a test fails, it displays the inputs, expected output and actual
output.  Run it on an unaccelerated driver first, to prove to yourself
that it works.

-- 
------
From: Jonathan Morton
      jonathan.morton at movial.com