color information for the gradient
X coordinate of the first circle's center
Y coordinate of the first circle's center
radius of the first circle
X coordinate of the second circle's center
Y coordinate of the second circle's center
radius of the second circle
the data accompanying the paint functions in Font.paintGlyph
the user data pointer passed to PaintFuncs.setRadialGradientFunc
A callback to paint a radial gradient everywhere within the current clip. The coordinates of the points are interpreted according to the current transform; see the OpenType spec COLR section for details on how the points define the direction of the gradient, and how to interpret the
colorLine.