Perhaps a function to blit multiple surfaces at once would be more helpful?
On 03/14/2016 07:01 PM, Leif Theden wrote:
Thanks for the benchmark, but your example is not using the
SDL_LowerBlit. I did my own testing at home using SDL_LowerBlit and
got similar results, meaning there is little difference between
SDL_BlitSurface, and SDL_LowerBlit when all inputs are valid and
optimal. As my use case has checked all the boxes for requiring
optimized/lower-level blits (many small blits for small surfaces, all
valid parameters without need to check each time), I felt compelled to
test it. I will consider different approaches.
On Mon, Mar 14, 2016 at 5:19 PM, Peter Finlayson <frnkn...@iafrica.com
<mailto:frnkn...@iafrica.com>> wrote:
Well, if it gives you any satisfaction... I am not a pygame-team
developer, but Ubuntu makes building this stuff easy-ish.
I wrote a quick test script, using cProfile for timing
information. I stripped almost everything out of the blit call,
both in PySurface_Blit() and surf_blit() which calls it.
*Results with blit()*
372532 function calls (370644 primitive calls) in 13.809 seconds
ncalls tottime percall cumtime percall filename:lineno(function)
288000 8.232 0.000 8.232 0.000 {method 'blit' of
'pygame.Surface' objects}
600 5.080 0.008 5.080 0.008 {pygame.display.flip}
*Results with unsafe_blit()*
372532 function calls (370644 primitive calls) in 13.899 seconds
ncalls tottime percall cumtime percall filename:lineno(function)
288000 8.231 0.000 8.231 0.000 {method 'blit' of
'pygame.Surface' objects}
600 5.125 0.009 5.125 0.009 {pygame.display.flip}
Sorry, guys. There really wasn't much there to strip out. Just a
couple of if statements.
Here is are the C functions I used:
https://bitbucket.org/snippets/frnknstn/bKqAz
Here is the test Python code I used:
https://bitbucket.org/snippets/frnknstn/dKqAr
Regards,
Peter Finlayson
On 2016/03/14 08:55 PM, Leif Theden wrote:
Thanks for taking the time Peter to do this benchmark, but I
don't believe that
this is testing the overhead that exists in the pygame C
code. To clarify, your
benchmark is slightly contrived in that it is doubling the
python workload, when
I am interested in seeing the results of getting lower to SDL
blitting. I get
your message, I am absolutely clear that python is generally
the bottleneck. If
you can find a way to isolate and test the following parts of
the C extension
library, I would be happy to see the results.
https://bitbucket.org/pygame/pygame/src/d61ea8eabd56025fcb4ceb24d63f9a6a30fbe8d4/src/surface.c?at=default&fileviewer=file-view-default#surface.c-2988:3114
On Mon, Mar 14, 2016 at 12:06 PM, Peter Finlayson
<frnkn...@iafrica.com <mailto:frnkn...@iafrica.com>
<mailto:frnkn...@iafrica.com <mailto:frnkn...@iafrica.com>>>
wrote:
On 2016/03/14 04:35 PM, herve wrote:
before being a skilled pygame developer, there is a
newby developer and
_maybe_
giving him good performance for simple things will let
him stay and
growing to
skilled developer.
A newbie developer seeing a "faster" unchecked function,
trying to use it,
and then getting discouraged when it inevitably fails...
That is exactly why
unsafe_blit() is a bad fit for Pygame.
If you want a quick benchmark to show you are barking up
the wrong tree, you
can do one at home, with no C experience needed! Take some
game code you
wrote, and run it three ways:
1. Once unaltered
2. Once where you run the sprite update code twice (logic,
movement and physics)
3. Once where you draw every sprite twice
Record the FPS every time and see if that shows you where
the real
bottleneck lies. Here are the results I got from one of my
projects:
1. Base: 125 FPS
2. Double logic: 75 FPS
3. Double draw: 115 FPS
I had to take the game all the way up to 6x draw calls per
frame (4000+
blits!) before I got it down to the 75 FPS mark.
The point here is that if I was writing a game to have
even double the
sprites I do now, the game logic overhead would be the
problem. Even if the
unsafe_blit() magically doubled the speed of my draw
routines, it would have
little effect on my overall frame rate.
Regards,
Peter Finlayson
