[Feature Request] Gradient interpolation types
Please see: https://bugs.launchpad.net/inkscape/+bug/1782844 and maybe: #479 (comment 413051142) (not sure if it's said this can not be done or they refer to another matter).
I'm using the gradient tool to generate height maps. When I do a radial gradient, the default interpolation is linear, which results in a conic heightmap, instead of the desired semi-spherical one.
I tried creating stops (10) and used the following formula I deducted from this website https://www.khanacademy.org/math/geometry/xff63fac4:hs-geo-conic-sections/hs-geo-circle-standard-equation/e/graphing_circles to interpolate each stop over the curve of a circle quarter: y=SQRT(r^2-x^2), where y is the (0-1) value to be interpolated (luminance in my case), r^2 is always 1 because our interpolation goes all the way through to the last stop, and x is each stop offset, which are 0-1. Then I'd multiply the result by 255 to get the scaled value to set the luminance to.
This kinda works visually in Inskcape:
See, as opposed to radially shaped gradient with linear interpolation, which results in a conic heightmap:
However 10 stops aren't just enough stops to make for a compelling heightmap and even if it seems visually ok-ish it results on a rather uneven heightmap.
So I'd like to request at least this sine or whatever-you-name-it interpolation be implemented if it's even possible. I would even give this a try myself but only with the go of a seasoned Inkscape contributor who assures me this is theoretically possible for svg and Inkscape.
Thanks