Struct piet::RadialGradient

pub struct RadialGradient {
    center: UnitPoint,
    origin: UnitPoint,
    radius: f64,
    stops: ArrayVec<[GradientStop; 3]>,
    scale_mode: ScaleMode,
}

A description of a radial gradient in the unit rect, which can be resolved to a fixed gradient.

The center and origin are given in UnitPoint coordinates.

The center parameter specifies the center of the circle, so that points of distance radius from the center map to 1.0 in the gradient stops. The origin parameter specifies the point that maps to 0.0 in the gradient stops. Using the same origin and center gives a radially symmetric gradient; using different points is useful for simulating lighting effects. See configuring a radial gradient for a fuller explanation.

By default, origin and center are both at the center (0.5, 0.5) point. This can be changed during construction with the with_center and with_origin builder methods.

The ScaleMode describes how the gradient is mapped to a non-square rectangle; by default this will expand on the longest axis, but this can be changed with the with_scale_mode builder method.

Fields

center: UnitPoint

origin: UnitPoint

radius: f64

stops: ArrayVec<[GradientStop; 3]>

scale_mode: ScaleMode

Methods

impl RadialGradient

pub fn new(radius: f64, stops: impl GradientStops) -> Self

Creates a simple RadialGradient. This gradient has origin and center set to (0.5, 0.5), and uses the Fill ScaleMode. These attributes can be modified with the with_center, with_origin, and with_scale_mode builder methods.

pub fn with_center(self, center: UnitPoint) -> Self

A builder-style method for changing the center of the gradient. This does not change the origin; in the common case, you will want to change both values.

See the main RadialGradient docs for an explanation of center vs. origin.

pub fn with_origin(self, origin: UnitPoint) -> Self

A builder-style method for changing the origin of the gradient.

See the main RadialGradient docs for an explanation of center vs. origin.

pub fn with_scale_mode(self, scale_mode: ScaleMode) -> Self

A builder-style method for changing the ScaleMode of the gradient.

fn resolve(&self, rect: Rect) -> FixedRadialGradient

Generate a FixedRadialGradient by mapping points in the unit square onto points in rect.

Trait Implementations

impl Clone for RadialGradient

fn clone(&self) -> RadialGradient

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.