Preserve the tip position when growing

[jeffchannell]

Preserve the tip position when growing

[jeffchannell]

It really depends on the cursor icon and the "xhot/yhot" values that can be read from the shell...

https://github.com/jeffchannell/jiggle/blob/master/effects/ScalingEffect.js#L80

[HifeFish]

Unfortunately, I do not completely understand the code, but if it helps, here are some calculations that might save you at least a little bit of time:

Original cursor:
(x0,y0) = position of top left corner
(xhot,yhot) = coordinates of tip counted from top left corner

Scaled cursor:
(x0',y0') = position of top left corner
(xhot',yhot') = coordinates of tip counted from top left corner

Then for the tips to coincide, we need:
x0'+xhot' = x0+xhot

So we should take:
x0' = x0+xhot-xhot'

If our scaling factor is r, then:
x0' = x0+ (1-r)*xhot

(Same for y0.)

There seems to be some conversion between center and corner position in your code, but I did not quite understand when you need which, but the conversion should follow from:
w,h = width, height
(xc,yc) = (x0+w/2,y0+h/2) = center of cursor image

[jeffchannell]

I've made some adjustments in the master branch for cursor positioning as I was revamping the animations to remove Tweener. Adding some modifiers to the X and Y offsets seems to get the fake cursor incredibly close for each supported size.

Feel free to make local and test the changes!