Creates a mask filter that takes the shape being drawn and blurs it.
This is commonly used to approximate shadows.
The style
argument controls the kind of effect to draw; see BlurStyle.
The sigma
argument controls the size of the effect. It is the standard
deviation of the Gaussian blur to apply. The value must be greater than
zero. The sigma corresponds to very roughly half the radius of the effect
in pixels.
A blur is an expensive operation and should therefore be used sparingly.
Source
MaskFilter.blur(BlurStyle style, double sigma) { assert(style != null); _constructor(style.index, sigma); }