There are several reasons why I "re-wrote" the Glide effect:
* it doesn't work correctly because of some issues with perspective
projection;
* window close animation is not quite intuitive: if the close button is
located at the top and I click it, I would expect that window is
rotated around the bottom edge, not the top; (IMHO)
* it's too much distracting when working on something for quite good
amount of time: e.g. when editing photos, which involves a big number
of different dialogs;
* its code doesn't follow common coding style in KWin.
So, the "new" Glide effect is more subtle, it's possible to have
different rotation edges for window open/close animations, the code is
more simpler and readable. Yet, there are some issues with QTimeLine,
which are common to all effects in KWin anyway.
### Demos
{F5889803}
//Window Open Animation//
{F5889804}
//Window Close Animation//
{F5889805, layout=center, size=full}
//KCM//