[cairo] why cairo is so slow on Windows, is there any plan to improve cairo performance on Windows?

[Rainman Lee]

Hi everyone,
I use cairo on windows for a while. I found that cairo was so slow
whenever fill a surface to another with scaling, rotating, or even a
non-integer translaton. I compared it with GDI+, which is at least 7
times faster than cairo :(

It seems that if a source pixel can not map to a dest pixel which has
an integer coordinate, cairo will use a subpixel algorithm, and it
will terribly hurt the performance. I made a filling test, firstly by
a 0.5 pixel step horz translation transform, and a 1 pixel step horz
translation transform then, each of which looped 100 times. the first
case was extremely slow than the second one.

Is there any idea to speed up cairo in this case? I tryed to set
antialias with none, but it had no effect.

Thank you!

Rainman.