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Re: [pygame] Smooth scaling using WMF drawings

Thanks, Atul. I had been blindly pursuing the WMF route, forgetting that this was a Windows-only solution. This seems to be on the right track. The only problem is that I "lost" my C / C++ compiler a few years ago!

I had a look at Cairo (http://cairographics.org) and it seems that there are already python bindings for it. However, there's no Windows binaries so I would need to compile unless anyone out there has already done so and can let me have the binaries?


> Since no one else has responded to this yet, I'll give it a try,
> although it's a bit of a long shot.
>
> If you're interested in working with vector graphics and you have some
> C/C++ experience, you may want to consider integrating a 2D vector
> graphics library with SDL/Pygame.  One such vector graphics library,
> the Anti-Grain Geometry project (http://www.antigrain.com), is a
> collection of algorithms that blit the rendering result to a
> framebuffer, which can have any of a variety of pixel formats.  It's
> not very difficult to "hook up" this rendering pipeline to SDL by
> pointing it to the "pixels" property of a SDL_Surface structure and
> telling it what pixel format the buffer uses.  The end result is that
> there's no conversion or copying of pixel information from one library
> to another: the 2D vector pipeline simply rasterizes its output
> directly to your screen (or any other SDL/Pygame surface you provide),
> which is extremely efficient.
>
> Thanks to Pygame's C API, it shouldn't be hard to write a Python
> extension module that works with Pygame to do all this.  It could even
> be a cool new extension to Pygame itself.
>
> AGG has built-in functionality for rendering SVG files, which it
> supposedly does very quickly.  Another library called Cairo
> (http://cairographics.org) may be a good alternative.  Both are
> works-in-progress; AGG uses a (IMHO) fairly complicated C++ API that
> relies on extensive use of templates, and isn't terribly
> well-documented, unfortunately, while Cairo seems to have a very
> straightforward C API.  I've only used AGG, so I can't really comment
> much on Cairo, except to say that it looks like it has promise:
> apparently both Mozilla and the GTK+ toolkit are planning to move to
> its rendering engine in the near future (see
> http://www.mozillazine.org/talkback.html?article=6498).
>
> I hope this is of some help.
>
> - Atul
>
> On 4/29/05, Ben Friman <ben@xxxxxxxxxxxxxxx> wrote:
> > Here's something for the weekend:
> >
> > I am planning an application in which all window contents will scale automatically to
> > the window size. I don't want to see the pixellation effects which you get with scaling
> > bitmaps, so I had a look at what can be done with .WMF drawings. Here's the result,
> > using PIL with Pygame.
> >
> > If anyone can see a more efficient way of doing it, please let me know, as eventually I
> > will be displaying up to 100 .WMF images in a window!  I did read that
> > image.frombuffer() is more efficient than image.fromstring(), but in Pygame 1.6 it
> > seems there is no "frombuffer" function. Is that right?
> >
> > Here's the code:
> > """
> >
> > wmf_show.py  ----- brf Apr 2005   ---------
> >
> > Just to find out how to use/display a WMF file in Pygame. It works. Of course,
> > it is a CONVERTED image that we are looking at. To scale smoothly, you need to
> > re-convert at each resolution, which is what this demo does.
> >
> > """
> >
> > import pygame, Image, WmfPlugin
> > from pygame.locals import *
> > import win32api
> >
> > # ------------------------------------------------------------------------------------
> > def main():
> >
> >     pygame.init()
> >
> >     SM_CXSCREEN = 0
> >     SM_CYSCREEN = 1
> >     x = win32api.GetSystemMetrics(SM_CXSCREEN)
> >     y = win32api.GetSystemMetrics(SM_CYSCREEN)
> >     width = x -50
> >     height = y -80
> >     print RESIZABLE
> >     screen = pygame.display.set_mode((width,height),RESIZABLE,32)
> >     pygame.display.set_caption\
> >         ("WMF Show - Resize the window to control drawing size")
> >
> >     scale = 250
> >     resized = 0
> >
> >     # Get loopin'
> >     for counter in range(10**5):
> >
> >         # Have we received an event to close the window?
> >         for e in pygame.event.get():
> >             if e.type in (QUIT,KEYDOWN):  return
> >
> >             if e.type == VIDEORESIZE:
> >
> >                scale = 250 * e.size[0] / width
> >                screen = pygame.display.set_mode(e.size,RESIZABLE,32)
> >                resized = 1
> >
> >         # For some reason, (e.g. the wmf is rendered behind the scenes) I need to
> >         # re-open file each time as even copying the im1 surface freezes the size.
> >
> >         # I found this wmf image in
> >         # http://www.worldofmusic.com.au/downloads_view.asp?id=24
> >         im1 = Image.open("logo.wmf")
> >
> >         if resized:
> >            im1.size = im1.size[0] * scale / 100, im1.size[1] * scale / 100
> >         else:
> >            # Back & forth scaling in a way that uses bigger increments when
> >            # the image is bigger.
> >            sc = abs(counter%200-(100)) + 10
> >            sc = max((sc * sc/10) * scale/200,10)
> >            im1.size = im1.size[0] * sc / 500, im1.size[1] * sc / 500
> >
> >         buf = im1.tostring("raw","RGB",0,0)
> >
> >         # rotating background colours, well, why not?
> >         image = pygame.image.fromstring(buf,im1.size,"RGB",0)
> >         fcolour = abs(counter % 511 - 255), abs((counter / 2) % 511 - 255), \
> >                  abs((counter / 3) % 511 - 255)
> >         screen.fill(fcolour)
> >
> >         # Centering
> >         ctr = screen.get_rect().center
> >         rsize = image.get_rect().center
> >
> >         offset = ctr[0] - rsize[0], ctr[1] - rsize[1]
> >         screen.blit(image,offset)
> >         pygame.display.flip()
> >
> > #
> > if __name__ == '__main__': main()
> >
> > # I thank you.
> > --
> > Regards
> > Ben Friman
> > t 0870 041 0935
> > w www.learntotype.com
> >
> >


--
Regards
Ben Friman
t 0870 041 0935
w www.learntotype.com