Struct Transform 

pub struct Transform { /* private fields */ }

A one-dimensional coordinate transform for a series or reference line.

For normal data coordinates, the transform is a value converter that runs before the plot’s axis scale. For example, Transform::affine(2.0, -1.0) draws raw * 2 - 1, then lets the x/y axis scale map that value into plot space.

Transform::axes() is different: it treats the input as a normalized position inside the plot area. 0.4 means 40% from the low edge, so the position stays fixed while the user pans or zooms.

Implementations

impl Transform

pub const fn identity() -> Self

Leave a data value unchanged before the axis scale is applied.

pub const fn axes() -> Self

Interpret values as normalized positions inside the plot area.

0.0 is the low edge of the axis and 1.0 is the high edge. A point using PositionTransform::axes() therefore remains fixed in the plot area during pan and zoom.

pub const fn affine(scale: f64, translate: f64) -> Self

Convert a data value with value * scale + translate before axis scaling.

pub const fn log(base: f64) -> Self

Convert a data value with log_base(value) before axis scaling.

pub const fn exp(base: f64) -> Self

Convert a data value with base.powf(value) before axis scaling.

pub fn coordinate_system(&self) -> CoordinateSystem

Return the transform’s source coordinate system.

pub fn then(self, next: Transform) -> Self

Run this value conversion, then run another one.

The returned transform applies self first, then next. The source coordinate system of self is retained.

pub fn transform_value(&self, value: f64) -> Option<f64>

Convert a raw value using only this transform’s operation.

pub fn inverted(&self) -> Option<Self>

Create the inverse operation, if it is representable.

pub fn transform_data(&self, pos: f64, axis_scale: AxisScale) -> Option<f64>

Convert a data-coordinate value into plot-space.

This applies the transform first, then the axis scale. Transform::axes() needs the current axis range, which is only available internally during rendering.

pub fn transform_position( &self, pos: f64, axis_scale: AxisScale, axis_range: [f64; 2], ) -> Option<f64>

Convert a value into a normalized [0, 1] position along an axis.

Data-coordinate transforms use axis_range as raw data coordinates. Axes-coordinate transforms already store normalized positions.

Trait Implementations

impl Clone for Transform

fn clone(&self) -> Transform

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Transform

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

Formats the value using the given formatter.

impl Default for Transform

fn default() -> Transform

Returns the “default value” for a type.

impl From<AxisScale> for Transform

fn from(scale: AxisScale) -> Self

Converts to this type from the input type.

impl PartialEq for Transform

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

Tests for self and other values to be equal, and is used by ==.

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

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl StructuralPartialEq for Transform