It’s useful to sometimes take the longer path when interpolating hue. For example, hue in the default cubehelix ramp goes through 540°. But this need extends beyond cubehelix—it seems reasonable to allow “long” hue interpolation in other cylindrical colorspaces, such as HCL and HSL, too.
This means: 1. Color instances in those spaces must be capable of representing hues outside of [0°,360°). Having hue default to that range when converting from another colorspace seems reasonable, though. 2. We need both “short” and “long” forms of interpolation for cylindrical colorspaces. It seems reasonable to default to short.
(I suppose it would also be possible to default to “long” if the change in hue is greater than or equal to 360°. But… that seems a little brittle, since you definitely might want to use “long” hue interpolation when the hue delta is in [180°,360°), too. So probably best to always make it explicit.)
It’s useful to sometimes take the longer path when interpolating hue. For example, hue in the default cubehelix ramp goes through 540°. But this need extends beyond cubehelix—it seems reasonable to allow “long” hue interpolation in other cylindrical colorspaces, such as HCL and HSL, too.
This means: 1. Color instances in those spaces must be capable of representing hues outside of [0°,360°). Having hue default to that range when converting from another colorspace seems reasonable, though. 2. We need both “short” and “long” forms of interpolation for cylindrical colorspaces. It seems reasonable to default to short.
(I suppose it would also be possible to default to “long” if the change in hue is greater than or equal to 360°. But… that seems a little brittle, since you definitely might want to use “long” hue interpolation when the hue delta is in [180°,360°), too. So probably best to always make it explicit.)