RE: [pygame] Pygame subsurface inherit surface flags? <-- RLE encoding

[Lin Parkh]

OK I didn’t recognize the acronym “RLE encoding” but decompressed I do ;-)
I see how that would save memory but wouldn’t that slow graphical
performance because presumably it would need to be decompressed to blit? I’m
not worried about memory efficiency but FPS.

  Please advise.

 

From: owner-pygame-us...@seul.org [mailto:owner-pygame-us...@seul.org] On
Behalf Of Lin Parkh
Sent: Thursday, September 19, 2013 9:03 AM
To: pygame-users@seul.org
Subject: RE: [pygame] Pygame subsurface inherit surface flags?

 

Thank you. I suspect you are right about HWSURFACE. For example I used to be
able to generate these and now I can’t at all with the same code! I suspect
just doing a driver update to my video card squelched it.  Color depth is
good advice except I would have to drop my display color depth wouldn’t I or
I would have slow downs due to mismatch?  And that would be annoying to any
user.

  I’ll look into “RLE encoding.” Don’t know about that.

 

From: owner-pygame-us...@seul.org [mailto:owner-pygame-us...@seul.org] On
Behalf Of René Dudfield
Sent: Thursday, September 19, 2013 12:28 AM
To: pygame-users@seul.org
Subject: Re: [pygame] Pygame subsurface inherit surface flags?

 

Yeah, they should inherit the flags.

 

However... you should generally avoid HWSURFACE surfaces.  There are cases
on some hardware and drivers where they actually get accelerated... but
often they don't.

 

If your sprites don't have many colours, dropping the colour depth will give
you a speedup (less memory bandwidth used).  Also RLE encoding can speed up
drawing for some sprites.

 

All the best,

 

 

 

On Wed, Sep 18, 2013 at 9:11 PM, Lin Parkh <lpa...@comcast.net> wrote:

Hi,

 I've read the documentation but am still hazy. If have defined a surface
with specific flags (in particular pygame.HWSURFACE) should a subsurface of
that surface inherit the flags (i.e. is also a hardware accelerated
surface(i.e. in video card memory) or do I need to do an explicit 'convert'
with the flags called again? My impression when I call 'get_flags' on the
subsurface is that it is NOT getting the parent flags... but wanted to
confirm this is expected and therefore I have to do an explicit convert. 

  Thanks

p.s. my overall context is I have loaded a texture atlas from file. I have
given hardware acceleration flag (HWSURFACE) I now want sprite imagery
derived from the atlas (subsurface seem the simplest and most efficient way
to achieve this) but I want it to retain the same flags (e.g. HWSURFACE).