Struct Gradient 

pub struct Gradient { /* private fields */ }

A box’s gradient: see the module’s notes. Built by Gradient::to, Gradient::angle or Gradient::radial, or read from plain data by parse_with.

Implementations

impl Gradient

pub fn to<S>(side: Side, stops: impl IntoIterator<Item = S>) -> Gradient

where S: Into<Stop>,

A linear gradient towards a side or a corner of the box. To a corner the half-way line runs through the other two corners at any aspect, which is CSS’s to bottom right.

pub fn angle<S>(turns: f32, stops: impl IntoIterator<Item = S>) -> Gradient

where S: Into<Stop>,

A linear gradient along turns, clockwise from east (0.25 is downwards), measured in the box’s unit square — so an eighth of a turn runs corner to corner whatever the box’s aspect, which CSS’s 45deg, measured in pixels, does not.

pub fn radial<S>(stops: impl IntoIterator<Item = S>) -> Gradient

where S: Into<Stop>,

A radial gradient from the middle of the box out to its corners.

pub fn radial_at<S>(at: Vec2, stops: impl IntoIterator<Item = S>) -> Gradient

where S: Into<Stop>,

A radial gradient from at — fractions of the box, (0.5, 0) the middle of its top edge — out to the corner farthest from it.

pub fn is_drawable(&self) -> bool

Whether there is anything to paint: two stops or more, and a shape made of numbers.

pub fn key(&self) -> u64

The key its raster is held under: equal for equal gradients, whatever box draws them.

pub fn stops(&self) -> &[(Color, f32)]

The stops as resolved: a colour and its position, in order.

pub fn raster_size(&self) -> (u32, u32)

The raster’s size in texels: a strip along the axis the gradient runs on, or the square.

pub fn slot_size(&self) -> (u32, u32)

The texels its slot takes: Self::raster_size and a gutter of one all round.

pub fn rasterize(&self) -> Vec<u8>

The raster: Self::slot_size texels of straight RGBA, row after row, each the gradient at its texel’s centre. The quad draws the inner Self::raster_size of them; the gutter is the gradient carried on a texel past each edge, because the quad is stretched and sampled linearly, and at the box’s edge the sampler reads half a texel past the rect it was given — a strip one texel high would otherwise fade into whatever the atlas holds above and below it.

pub fn color_in(&self, x: f32, y: f32) -> Color

The colour at a point of the box, as fractions of it: (0, 0) its top left, (1, 1) its bottom right. What the raster samples, and what a test of the stretched raster compares it with.

pub fn color_at(&self, t: f32) -> Color

The colour t of the way along: the stops either side mixed in straight sRGB with the alpha premultiplied, as CSS mixes them, so a fade to transparent does not pass through grey. Before the first stop it is the first, past the last the last.

Trait Implementations

impl Clone for Gradient

fn clone(&self) -> Gradient

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Gradient

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.

impl PartialEq for Gradient

fn eq(&self, other: &Gradient) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl StructuralPartialEq for Gradient