color information for the gradient
X coordinate of the first point
Y coordinate of the first point
X coordinate of the second point
Y coordinate of the second point
X coordinate of the third point
Y coordinate of the third point
the data accompanying the paint functions in Font.paintGlyph
the user data pointer passed to PaintFuncs.setLinearGradientFunc
A callback to paint a linear 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.