[cairo] Pycairo + Pygame

[Steve Chaplin]

On Wed, 2005-10-12 at 00:34 -0700, Vladimir Vukicevic wrote:
> > So I presume now with this change we can do:
> >
> > import cairo
> > import pygame
> >
> > surface = cairo.ImageSurface(cairo.FORMAT_ARGB32, 100, 100)
> > import StringIO
> > buffer = StringIO.StringIO()
> > image = pygame.image.frombuffer(buffer)
> 
> I'm assuming there's some kind of write_to_png(buffer) call right
> before the pygame.image.frombuffer?
> 
> Ideally, you really want pycairo to allocate its own buffer for the
> cairo image surface, and let you access it, to pass it to pygame
> directly as a 32-bbp ARGB image.  Otherwise, you waste lots of CPU
> doing png encoding/decoding for no reason, especially if you do this
> often...
> 
>     - Vlad
You can already do that with something like this:

import array
import cairo
width, height = 30*16, 30*9
data = array.array('c', 'a' * width * height * 4)
stride = width * 4
surface = cairo.ImageSurface.create_for_data (data, cairo.FORMAT_ARGB32,
                                              width, height, stride);

'data' is a Python array object which supports the read/write buffer
protocol. It holds the cairo surface pixel-data in premultiplied ARGB32
format, can Pygame read that format?

Steve

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