ReadonlycenterThe gradient's centre, in local space; finite (§85).
ReadonlykindDiscriminant (§58 "radial gradient").
Optional ReadonlyopacitySee SolidPaint.opacity; multiplies every stop's alpha.
ReadonlyradiusDistance at which offset 1 is reached; finite, positive (§85).
ReadonlystopsAt least two sorted stops (§85) — see GradientStop.
A §58 radial gradient: colour as a function of distance from
center, reaching offset 1 atradius, both in the shape's local space (see LinearGradientPaint for the space and the stop rules). Beyond the radius the gradient pads with the last stop's colour.