center of the start circle
radius of the start circle
center of the end circle
radius of the end circle
Note: The coordinates here are in pattern space. For a new pattern, pattern space is identical to user space, but the relationship between the spaces can be changed with Pattern.setMatrix().
Creates a new radial gradient pattern between the two circles defined by (c0, radius0) and (c1, radius1). Before using the gradient pattern, a number of color stops should be defined using Pattern.addColorStopRGB() or Pattern.addColorStopRGBA().