[css-images-4] Gradients need more than piecewise-linear interpolation

[svgeesus]

@jrus wrote:

If you really want to make a more capable gradient capability, the most useful addition in terms of raw power/flexibility isn’t changing the color space where interpolation happens, but instead adding some facility for non-linear interpolation on each segment. For instance, allowing arbitrary cubic (or even just quadratic) polynomial segments would give the tool dramatically more flexibility for a given number of specified colors, comparable to the difference between polylines vs. Bézier splines for specifying 2D shapes.

[SelenIT]

Isn't this the same as #1332 (or am I missing something)?

[tabatkins]

Yeah, closing as a dupe of #1332.