Struct Composite

pub struct Composite { /* private fields */ }

Object to style RawPixels.

Implementations

impl Composite

pub fn new_rgb(vmin: Vec<f64>, vmax: Vec<f64>) -> Self

Create a RGB Composite that maps 3 pixel values (from 3 different bands) into RGBA components.

Example

use map_engine::cmap::{Composite, HandleGet, viridis};
let comp = Composite::new_rgb(vec![0.0, 0.0, 0.0], vec![100.0, 100.0, 100.0]);
assert_eq!(comp.get(&[0.0, 50.0, 100.0], None), [0, 127, 255, 255]);

pub fn new_gradient( vmin: f64, vmax: f64, cmap_f: &'static dyn Fn(f64, f64) -> GradientLinearRGBA, ) -> Self

Create a Composite that maps 1 pixel value into RGBA using the provided function.

You can use one of the functions provided in the cmap module.

Example

use map_engine::cmap::{Composite, HandleGet, viridis};
let comp = Composite::new_gradient(0.0, 100.0, &viridis);
assert_eq!(comp.get(&[0.0], None), [68, 1, 84, 255]);

pub fn new_custom_gradient(vmin: f64, vmax: f64, colours: Vec<Colour>) -> Self

Create an equally-spaced Composite that maps 1 pixel value into RGBA using a sequence of Colour.

Example

use map_engine::{
    colour::Colour,
    cmap::{Composite, HandleGet},
};
let comp = Composite::new_custom_gradient(0.0, 100.0, vec![
    Colour::from((255, 0, 0, 255)), // red
    Colour::from((0, 0, 255, 255)), // blue
]);
assert_eq!(comp.get(&[50.0], None), [127, 0, 127, 255]); // purple

pub fn new_gradient_with_breaks(cols_and_breaks: Vec<(f64, Colour)>) -> Self

Create an Composite with custom breaks that maps 1 pixel value into RGBA.

Example

use map_engine::{
    colour::Colour,
    cmap::{Composite, HandleGet},
};
let comp = Composite::new_gradient_with_breaks(vec![
    (0.0, Colour::from((255, 0, 0, 255))), // red
    (25.0, Colour::from((127, 0, 127, 255))), // purple shifted to the red
    (100.0, Colour::from((0, 0, 255, 255))), // blue
]);
assert_eq!(comp.get(&[25.0], None), [127, 0, 127, 255]); // purple

pub fn new_discrete_palette(cols_and_breaks: Vec<(isize, Colour)>) -> Self

Create an discrete Composite that maps 1 pixel value into RGBA.

Example

use map_engine::{
    colour::Colour,
    cmap::{Composite, HandleGet},
};
let comp = Composite::new_discrete_palette(vec![
    (0, Colour::from((255, 0, 0, 255))), // red
    (1, Colour::from((0, 255, 0, 255))), // green
    (2, Colour::from((0, 0, 255, 255))), // blue
]);
assert_eq!(comp.get(&[0.0], None), [255, 0, 0, 255]); // red
assert_eq!(comp.get(&[3.0], None), [0, 0, 0, 0]); // transparent if not defined

pub fn n_bands(&self) -> usize

Number of bands supported by the Composite.

⚠ This will probably be deprecated once we enforce the number of bands using the type system ⚠

Trait Implementations

impl Clone for Composite

fn clone(&self) -> Composite

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Composite

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

Formats the value using the given formatter.

impl Default for Composite

fn default() -> Self

Returns the “default value” for a type.

impl Display for Composite

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

Formats the value using the given formatter.

impl HandleGet for Composite

fn get(&self, values: &[f64], no_data_values: Option<&[f64]>) -> [u8; 4]

Get a RGBA colour given a raw pixel value.