tearing is caused by interaction of CRT refresh with your drawing.
DOUBLEBUF means “use hardware page-flipping” and shouldn’t have any
significance with software surfaces
Does this mean there is no point in using
DOUBLEBUF unless you also use HWSURFACE?
That doesn’t seem to be the case here
though as the weird speed differences
attest.
I will try to convert the Python source
into C. For the moment here are the
image and the Python source. (I am
also sending them directly to your email
address as the newsgroup seems to have
rejected my earlier attachments).On 23 Mar 2001 03:50:22 -0800, “Mattias Engdeg?rd” wrote:
“Andy Sy” wrote in message
news:nohnbtsn2bi01h2jgicu3pfgk9153o1t81 at 4ax.com…
Does this mean there is no point in using
DOUBLEBUF unless you also use HWSURFACE?
HWSURFACE --> no back buffer; write directly to visible surface
SWSURFACE --> back buffer in system memory
HWSURFACE | DOUBLEBUF --> back buffer in video memory
What is ‘SWSURFACE | DOUBLEBUF’ supposed to mean?–
Rainer Deyke (root at rainerdeyke.com)
Shareware computer games - http://rainerdeyke.com
"In ihren Reihen zu stehen heisst unter Feinden zu kaempfen" - Abigor
“Andy Sy” wrote in message
news:nohnbtsn2bi01h2jgicu3pfgk9153o1t81 at 4ax.com…
Does this mean there is no point in using
DOUBLEBUF unless you also use HWSURFACE?
HWSURFACE --> no back buffer; write directly to visible surface
SWSURFACE --> back buffer in system memory
HWSURFACE | DOUBLEBUF --> back buffer in video memory
What is ‘SWSURFACE | DOUBLEBUF’ supposed to mean?
It’s not a valid combination. If you specify DOUBLEBUF, SDL will
add HWSURFACE implicitly.
See ya,
-Sam Lantinga, Lead Programmer, Loki Entertainment Software
HWSURFACE --> no back buffer; write directly to visible surface
SWSURFACE --> back buffer in system memory
HWSURFACE | DOUBLEBUF --> back buffer in video memory
What is ‘SWSURFACE | DOUBLEBUF’ supposed to mean?
Okay, so with SWSURFACE the back buffer
’shadows’ the video memory. But it (the
back buffer in system memory) has to be
blitted to the video memory sometime. And
this is probably done in sync with the
vertical refresh and that’s why you do not
get flicker.
Am I right in concluding that DOUBLEBUF
automatically enables hardware surfaces
(at least in DirectX)? This would explain
the nearly identical fps between DOUBLEBUF
and HWSURFACE|DOUBLEBUF.On Fri, 23 Mar 2001 16:02:27 -0700, “Rainer Deyke” wrote: