[Spice-devel] [PATCH 1/1] canvas: Better coordinate rounding in scaling

[Yonit Halperin]

On 08/27/2010 05:53 PM, alexl at redhat.com wrote:
> From: Alexander Larsson<alexl at redhat.com>
>
> When scaling in pixman you give the source coordinates in transformed
> space rather than in the source coordinates. This is a bit problematic
> when both source and destination coordinates are at integer positions, but
> the scaling factor is not an exact 16.16 fixed point value. We used
> to calculate the transformed source based on the floating point
> transformation, which gave the wrong answer sometimes. Now we do the
> calculations based on the fixed point transform that we give pixman.
>
> However, even with this patch I can still sometimes see issues related
> to this, although they are less bad.
> ---

Ack