The performance of the previous implementation was simply horrible,
when drawing an arc with a small span angle. The size of the corresponding full circle
is huge and the previous implementation always created an image/texture with
that size.
However the final implementation is supposed to create vertex lists
- like what the box renderer does. So this code will also not stay forever.
* add QskArcNode and QskArcRenderer
* IOT example: Use QskArcNode instead of own arc node
* move some functionality to the arc renderer
* add QskArcMetrics
* add methods to QskSkinlet
* remove circular bar graph node
We can now use updateArcNode() and don't need our own method.
* support linear gradients in the arc renderer
* clean up
* incorporate Uwe's changes
* add overloads for updateArcNode() when the angles are set dynamically
The angles don't always come from the style, so we need overloads
in QskSkinlet to set them dynamically.
Uwe Rathmann
Peter Hartmann