[pygame] Re: Drawing/Surface performance

["Stuart Axon" <stu.axon+pygame@xxxxxxxxx>]

I simplified my create_surface... by keeping copies of the indexed
(greyscale) image and it's palette; but still slow...
I'm wondering -
  Would locking surfaces help
  Is the pygame 1.8 buffer object relevant here?
  Would surarray be quicker?
  The palette manipulation seems like it could def be quicker; but my
python knowledge isn't good enough here.

For performance reference I'm using a 1.5ghz centrino core 2 thingy.

Simplified create_surface:

    def create_surface(self, colour):
        # Check cache
        #p_colour = utils.pack_colour(colour)
        #if p_colour in Block.surface_cache:
        #    return Block.surface_cache[p_colour]

        pal_image = Block.indexed_image.copy()
        # Manipulate the palette
        pal_image.set_palette(self.colourise_palette(Block.indexed_palette,
colour))

        image = pygame.Surface((Block.width, Block.height), pygame.SRCALPHA, 32)
        image.blit(pal_image, (0, 0), image.get_rect())

        # Apply the alpha to our newly colourised image
        pygame.surfarray.pixels_alpha(image)[...] = Block.alpha_channel

        # Add to cache; eviction policy might be nice ;)
        #Block.surface_cache[p_colour] = image

        return image

On 31/01/2008, Stuart Axon <stu.axon+pygame@xxxxxxxxx> wrote:
> Hello,
>   I'm combining a paletted surface and an alpha surface so I can
> manipulate the colours. As I'm quite new to python + pygame so
> slowness is probably down to me :)
>
> At the moment I cache the surfaces, but if it was realtime it would be
> simpler and not use shedloads of memory.
>
> Both methods seem too slow - especially the palette manipulation
> (commenting that out speeds things up quite a bit).  The rest of the
> code still seems to be slower than I'd expect without the palette code
> enabled; I thought pygame 1.8 might hardware accelerate this, but it
> doesn't seem to make a difference (so I'm using 1.7.1 as 1.8 isn't
> finished).
>
> The game (in progress):                                  (python ballbreaker.py)
> stuartaxon.com/ballbreaker/pygame.zip          - shows the performance
> stuartaxon.com/ballbreaker                             - build with caching
>
>
> Cheers :)
>
> ---------------------------------------------------------------
> These are the relevant two methods from block.py
>
>     ##
>     # Return a surface to represent the block
>     #
>     def create_surface(self, colour):
>         # Check cache
>         #p_colour = utils.pack_colour(colour)
>         #if p_colour in Block.surface_cache:
>         #    return Block.surface_cache[p_colour]
>
>         # Create 8 bit surface and copy our image there
>         pal_image = pygame.Surface((Block.width, Block.height), 0, 8)
>         pal_image.set_palette(Block.indexed_image.get_palette())
>         pal_image.blit(Block.indexed_image, (0, 0))
>
>         palette = Block.indexed_image.get_palette()
>
>         # Manipulate the palette
>         pal_image.set_palette(self.colourise_palette(palette, colour))
>
>         # Create our image palette
>         image = pygame.Surface((Block.width, Block.height), pygame.SRCALPHA, 32)
>         image.blit(pal_image, (0, 0), image.get_rect())
>
>         # Get the alpha channel from our alpha image
>         alpha_channel = pygame.surfarray.array_alpha(Block.alpha_image)
>
>         # Apply the alpha to our newly colourised image
>         pygame.surfarray.pixels_alpha(image)[...] = alpha_channel
>
>         # Add to cache; eviction policy might be nice ;)
>         # Block.surface_cache[p_colour] = image
>
>         return image
>
>     def colourise_palette(self, palette, colour):
>         hls_colour = colorsys.rgb_to_hls(*utils.normalize_colour(colour))
>
>         ##
>         # Function for actually altering the colour
>         def alter_colour(colour):
>             h, l, s = colorsys.rgb_to_hls(*utils.normalize_colour(colour))
>             h = hls_colour[0]
>             l = (hls_colour[1] + l) / 2.0
>             s = 0.95
>             return utils.reformat_colour( colorsys.hls_to_rgb(h, l, s) )
>
>         return map(alter_colour, palette)
>