[cairo] Problem with scaling on win32

J.A. Magallón jamagallon at ono.com
Thu Jul 2 17:44:09 PDT 2009


Hi all...

I am using GTK+Cairo to build an application that runs both in linux and
win32.

I face several problems with cairo, that will try to describe here...

In short, I want to paint an image (about 2000x2000 pixels), and draw things
on top. I want to pan and zoom over the image, and I need to zoom very close,
so as an image pixel is 512 pixels wide in the screen.

First I did things byt hand (gtk dwawing area), but faced some problems.
The I read about limits in coordinates, and that GooCanvas solved some of
them, and as it offers so extra goodies I began to use GooCanvas. I have
the same problems, so I think it is a problem of Win32 backend in Cairo.

In short: use GooCanvas to add an ImageModel, zoom on it, and in Linux
I can zoom till infinte without problems, I set GooCanvas scale to
1024 and my pixels are there. In windows, as zoom gets bigger
that 32/64, I get just a big white window, no image is drawn.

Any clues ?

There are more problems, like lines dissapearing or moving when
I pan at high zoom rates, but lets begin with the image...

-- 
J.A. Magallon <jamagallon()ono!com>     \               Software is like sex:
                                         \         It's better when it's free
Mandriva Linux release 2010.0 (Cooker) for x86_64
Linux 2.6.29.3-desktop-1mnb (gcc 4.3.2 (GCC) #1 Wed May


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