Shadow in SVG is displaying in wrong location when the object is rotated

[jtweku]

the SVG generated from shadow for the rotated object is not in the same position as the in canvas. I am assuming that the x and y position of the shadow does not accounted for the angle in the object's shadow.

http://jsfiddle.net/1fgk6qoo/

[asturur]

Omg, i never noticed this. In the canvas the shadow is managed like a shadow, while in svg we emulate it with a filter that makes a copy of the shadow displaced.
We have to change the shadow offset when exporting to svg to take in account of current rotation.

[asturur]

Not a simple fix. i tried couple of hours thinking that rotating shadow offset would help me, but is not that easy. Rotation repeats every 90 degrees and i cannot guess easily the algorithm behind canvas shadow.

[jtweku]

I think this should fix it, calculating the rotation modifying the area for the filter to accounted for the rotation.

http://jsfiddle.net/3hnghy3d/

[asturur]

Yes it does.
I did same thing, just i did not do "360 - angle"
how did you get to that conclusion? why not just angle?

( when angle was not working i then lost myself in terrible calculation searching for some complicated solution including angle of shadow itself and so on...)

[asturur]

i will make a pr later, so we merge this.

[jtweku]

thanks @asturur
I just playing around and notice that after rotating it the value of offset X and offset Y was the opposite. so I figure it must be in the wrong quadrant.

[asturur]

no it is totally right, i m stupid.

if i rotate the object of x, i have to rotate back the shadow of -x to leave it in its original position.

that's all :)

[asturur]

closed with latests commit