Struct euclid::Scale

#[repr(C)]
pub struct Scale<T, Src, Dst>(pub T, _);

A scaling factor between two different units of measurement.

This is effectively a type-safe float, intended to be used in combination with other types like length::Length to enforce conversion between systems of measurement at compile time.

Src and Dst represent the units before and after multiplying a value by a Scale. They may be types without values, such as empty enums. For example:

use euclid::Scale;
use euclid::Length;
enum Mm {};
enum Inch {};

let mm_per_inch: Scale<f32, Inch, Mm> = Scale::new(25.4);

let one_foot: Length<f32, Inch> = Length::new(12.0);
let one_foot_in_mm: Length<f32, Mm> = one_foot * mm_per_inch;

Implementations

impl<T, Src, Dst> Scale<T, Src, Dst>

pub const fn new(x: T) -> Self

pub fn identity() -> Self where
    T: One, 

Creates an identity scale (1.0).

pub fn transform_point(self, point: Point2D<T, Src>) -> Point2D<T::Output, Dst> where
    T: Copy + Mul, 

Returns the given point transformed by this scale.

Example

use euclid::{Scale, point2};
enum Mm {};
enum Cm {};

let to_mm: Scale<i32, Cm, Mm> = Scale::new(10);

assert_eq!(to_mm.transform_point(point2(42, -42)), point2(420, -420));

pub fn transform_point3d(
    self,
    point: Point3D<T, Src>
) -> Point3D<T::Output, Dst> where
    T: Copy + Mul, 

Returns the given point transformed by this scale.

pub fn transform_vector(self, vec: Vector2D<T, Src>) -> Vector2D<T::Output, Dst> where
    T: Copy + Mul, 

Returns the given vector transformed by this scale.

Example

use euclid::{Scale, vec2};
enum Mm {};
enum Cm {};

let to_mm: Scale<i32, Cm, Mm> = Scale::new(10);

assert_eq!(to_mm.transform_vector(vec2(42, -42)), vec2(420, -420));

pub fn transform_size(self, size: Size2D<T, Src>) -> Size2D<T::Output, Dst> where
    T: Copy + Mul, 

Returns the given vector transformed by this scale.

Example

use euclid::{Scale, size2};
enum Mm {};
enum Cm {};

let to_mm: Scale<i32, Cm, Mm> = Scale::new(10);

assert_eq!(to_mm.transform_size(size2(42, -42)), size2(420, -420));

pub fn transform_rect(self, rect: &Rect<T, Src>) -> Rect<T::Output, Dst> where
    T: Copy + Mul, 

Returns the given rect transformed by this scale.

Example

use euclid::{Scale, rect};
enum Mm {};
enum Cm {};

let to_mm: Scale<i32, Cm, Mm> = Scale::new(10);

assert_eq!(to_mm.transform_rect(&rect(1, 2, 42, -42)), rect(10, 20, 420, -420));

pub fn transform_box2d(self, b: &Box2D<T, Src>) -> Box2D<T::Output, Dst> where
    T: Copy + Mul, 

Returns the given box transformed by this scale.

pub fn transform_box3d(self, b: &Box3D<T, Src>) -> Box3D<T::Output, Dst> where
    T: Copy + Mul, 

Returns the given box transformed by this scale.

pub fn is_identity(self) -> bool where
    T: PartialEq + One, 

Returns true if this scale has no effect.

Example

use euclid::Scale;
use euclid::num::One;
enum Mm {};
enum Cm {};

let cm_per_mm: Scale<f32, Mm, Cm> = Scale::new(0.1);
let mm_per_mm: Scale<f32, Mm, Mm> = Scale::new(1.0);

assert_eq!(cm_per_mm.is_identity(), false);
assert_eq!(mm_per_mm.is_identity(), true);
assert_eq!(mm_per_mm, Scale::one());

pub fn get(self) -> T

Returns the underlying scalar scale factor.

pub fn inverse(self) -> Scale<T::Output, Dst, Src> where
    T: One + Div, 

The inverse Scale (1.0 / self).

Example

use euclid::Scale;
enum Mm {};
enum Cm {};

let cm_per_mm: Scale<f32, Cm, Mm> = Scale::new(0.1);

assert_eq!(cm_per_mm.inverse(), Scale::new(10.0));

impl<T: NumCast, Src, Dst> Scale<T, Src, Dst>

pub fn cast<NewT: NumCast>(self) -> Scale<NewT, Src, Dst>

Cast from one numeric representation to another, preserving the units.

Panics

If the source value cannot be represented by the target type NewT, then method panics. Use try_cast if that must be case.

Example

use euclid::Scale;
enum Mm {};
enum Cm {};

let to_mm: Scale<i32, Cm, Mm> = Scale::new(10);

assert_eq!(to_mm.cast::<f32>(), Scale::new(10.0));

That conversion will panic, because i32 not enough to store such big numbers:

use euclid::Scale;
enum Mm {};// millimeter = 10^-2 meters
enum Em {};// exameter   = 10^18 meters

// Panics
let to_em: Scale<i32, Mm, Em> = Scale::new(10e20).cast();

pub fn try_cast<NewT: NumCast>(self) -> Option<Scale<NewT, Src, Dst>>

Fallible cast from one numeric representation to another, preserving the units. If the source value cannot be represented by the target type NewT, then None is returned.

Example

use euclid::Scale;
enum Mm {};
enum Cm {};
enum Em {};// Exameter = 10^18 meters

let to_mm: Scale<i32, Cm, Mm> = Scale::new(10);
let to_em: Scale<f32, Mm, Em> = Scale::new(10e20);

assert_eq!(to_mm.try_cast::<f32>(), Some(Scale::new(10.0)));
// Integer to small to store that number
assert_eq!(to_em.try_cast::<i32>(), None);

Trait Implementations

impl<T: Add, Src, Dst> Add<Scale<T, Src, Dst>> for Scale<T, Src, Dst>

type Output = Scale<T::Output, Src, Dst>

The resulting type after applying the + operator.

fn add(self, other: Scale<T, Src, Dst>) -> Self::Output

Performs the + operation.

impl<T: Clone, Src, Dst> Clone for Scale<T, Src, Dst>

fn clone(&self) -> Scale<T, Src, Dst>

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<T: Debug, Src, Dst> Debug for Scale<T, Src, Dst>

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

Formats the value using the given formatter.

impl<T: Default, Src, Dst> Default for Scale<T, Src, Dst>

fn default() -> Self

Returns the “default value” for a type.

impl<Src, Dst, T: Div> Div<Scale<T, Src, Dst>> for Length<T, Dst>

type Output = Length<T::Output, Src>

The resulting type after applying the / operator.

fn div(self, scale: Scale<T, Src, Dst>) -> Self::Output

Performs the / operation.

impl<T: Copy + Div, U1, U2> Div<Scale<T, U1, U2>> for Box2D<T, U2>

type Output = Box2D<T::Output, U1>

The resulting type after applying the / operator.

fn div(self, scale: Scale<T, U1, U2>) -> Self::Output

Performs the / operation.

impl<T: Copy + Div, U1, U2> Div<Scale<T, U1, U2>> for Box3D<T, U2>

type Output = Box3D<T::Output, U1>

The resulting type after applying the / operator.

fn div(self, scale: Scale<T, U1, U2>) -> Self::Output

Performs the / operation.

impl<T: Copy + Div, U1, U2> Div<Scale<T, U1, U2>> for Point2D<T, U2>

type Output = Point2D<T::Output, U1>

The resulting type after applying the / operator.

fn div(self, scale: Scale<T, U1, U2>) -> Self::Output

Performs the / operation.

impl<T: Copy + Div, U1, U2> Div<Scale<T, U1, U2>> for Point3D<T, U2>

type Output = Point3D<T::Output, U1>

The resulting type after applying the / operator.

fn div(self, scale: Scale<T, U1, U2>) -> Self::Output

Performs the / operation.

impl<T: Copy + Div, U1, U2> Div<Scale<T, U1, U2>> for Rect<T, U2>

type Output = Rect<T::Output, U1>

The resulting type after applying the / operator.

fn div(self, scale: Scale<T, U1, U2>) -> Self::Output

Performs the / operation.

impl<T: Copy + Div, U1, U2> Div<Scale<T, U1, U2>> for SideOffsets2D<T, U2>

type Output = SideOffsets2D<T::Output, U1>

The resulting type after applying the / operator.

fn div(self, scale: Scale<T, U1, U2>) -> Self::Output

Performs the / operation.

impl<T: Copy + Div, U1, U2> Div<Scale<T, U1, U2>> for Size2D<T, U2>

type Output = Size2D<T::Output, U1>

The resulting type after applying the / operator.

fn div(self, scale: Scale<T, U1, U2>) -> Self::Output

Performs the / operation.

impl<T: Copy + Div, U1, U2> Div<Scale<T, U1, U2>> for Size3D<T, U2>

type Output = Size3D<T::Output, U1>

The resulting type after applying the / operator.

fn div(self, scale: Scale<T, U1, U2>) -> Self::Output

Performs the / operation.

impl<T: Copy + Div, U1, U2> Div<Scale<T, U1, U2>> for Vector2D<T, U2>

type Output = Vector2D<T::Output, U1>

The resulting type after applying the / operator.

fn div(self, scale: Scale<T, U1, U2>) -> Self::Output

Performs the / operation.

impl<T: Copy + Div, U1, U2> Div<Scale<T, U1, U2>> for Vector3D<T, U2>

type Output = Vector3D<T::Output, U1>

The resulting type after applying the / operator.

fn div(self, scale: Scale<T, U1, U2>) -> Self::Output

Performs the / operation.

impl<T: Copy + DivAssign, U> DivAssign<Scale<T, U, U>> for Box2D<T, U>

fn div_assign(&mut self, scale: Scale<T, U, U>)

Performs the /= operation.

impl<T: Copy + DivAssign, U> DivAssign<Scale<T, U, U>> for Box3D<T, U>

fn div_assign(&mut self, scale: Scale<T, U, U>)

Performs the /= operation.

impl<T: Copy + DivAssign, U> DivAssign<Scale<T, U, U>> for Point2D<T, U>

fn div_assign(&mut self, scale: Scale<T, U, U>)

Performs the /= operation.

impl<T: Copy + DivAssign, U> DivAssign<Scale<T, U, U>> for Point3D<T, U>

fn div_assign(&mut self, scale: Scale<T, U, U>)

Performs the /= operation.

impl<T: Copy + DivAssign, U> DivAssign<Scale<T, U, U>> for Rect<T, U>

fn div_assign(&mut self, scale: Scale<T, U, U>)

Performs the /= operation.

impl<T: Copy + DivAssign, U> DivAssign<Scale<T, U, U>> for SideOffsets2D<T, U>

fn div_assign(&mut self, other: Scale<T, U, U>)

Performs the /= operation.

impl<T: Copy + DivAssign, U> DivAssign<Scale<T, U, U>> for Size2D<T, U>

fn div_assign(&mut self, other: Scale<T, U, U>)

Performs the /= operation.

impl<T: Copy + DivAssign, U> DivAssign<Scale<T, U, U>> for Size3D<T, U>

fn div_assign(&mut self, other: Scale<T, U, U>)

Performs the /= operation.

impl<T: Copy + DivAssign, U> DivAssign<Scale<T, U, U>> for Vector2D<T, U>

fn div_assign(&mut self, scale: Scale<T, U, U>)

Performs the /= operation.

impl<T: Copy + DivAssign, U> DivAssign<Scale<T, U, U>> for Vector3D<T, U>

fn div_assign(&mut self, scale: Scale<T, U, U>)

Performs the /= operation.

impl<T: Hash, Src, Dst> Hash for Scale<T, Src, Dst>

fn hash<H: Hasher>(&self, state: &mut H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H) where
    H: Hasher, 

Feeds a slice of this type into the given Hasher.

impl<T: Mul, A, B, C> Mul<Scale<T, B, C>> for Scale<T, A, B>

type Output = Scale<T::Output, A, C>

The resulting type after applying the * operator.

fn mul(self, other: Scale<T, B, C>) -> Self::Output

Performs the * operation.

impl<Src, Dst, T: Mul> Mul<Scale<T, Src, Dst>> for Length<T, Src>

type Output = Length<T::Output, Dst>

The resulting type after applying the * operator.

fn mul(self, scale: Scale<T, Src, Dst>) -> Self::Output

Performs the * operation.

impl<T: Copy + Mul, U1, U2> Mul<Scale<T, U1, U2>> for Box2D<T, U1>

type Output = Box2D<T::Output, U2>

The resulting type after applying the * operator.

fn mul(self, scale: Scale<T, U1, U2>) -> Self::Output

Performs the * operation.

impl<T: Copy + Mul, U1, U2> Mul<Scale<T, U1, U2>> for Box3D<T, U1>

type Output = Box3D<T::Output, U2>

The resulting type after applying the * operator.

fn mul(self, scale: Scale<T, U1, U2>) -> Self::Output

Performs the * operation.

impl<T: Copy + Mul, U1, U2> Mul<Scale<T, U1, U2>> for Point2D<T, U1>

type Output = Point2D<T::Output, U2>

The resulting type after applying the * operator.

fn mul(self, scale: Scale<T, U1, U2>) -> Self::Output

Performs the * operation.

impl<T: Copy + Mul, U1, U2> Mul<Scale<T, U1, U2>> for Point3D<T, U1>

type Output = Point3D<T::Output, U2>

The resulting type after applying the * operator.

fn mul(self, scale: Scale<T, U1, U2>) -> Self::Output

Performs the * operation.

impl<T: Copy + Mul, U1, U2> Mul<Scale<T, U1, U2>> for Rect<T, U1>

type Output = Rect<T::Output, U2>

The resulting type after applying the * operator.

fn mul(self, scale: Scale<T, U1, U2>) -> Self::Output

Performs the * operation.

impl<T: Copy + Mul, U1, U2> Mul<Scale<T, U1, U2>> for SideOffsets2D<T, U1>

type Output = SideOffsets2D<T::Output, U2>

The resulting type after applying the * operator.

fn mul(self, scale: Scale<T, U1, U2>) -> Self::Output

Performs the * operation.

impl<T: Copy + Mul, U1, U2> Mul<Scale<T, U1, U2>> for Size2D<T, U1>

type Output = Size2D<T::Output, U2>

The resulting type after applying the * operator.

fn mul(self, scale: Scale<T, U1, U2>) -> Self::Output

Performs the * operation.

impl<T: Copy + Mul, U1, U2> Mul<Scale<T, U1, U2>> for Size3D<T, U1>

type Output = Size3D<T::Output, U2>

The resulting type after applying the * operator.

fn mul(self, scale: Scale<T, U1, U2>) -> Self::Output

Performs the * operation.

impl<T: Copy + Mul, U1, U2> Mul<Scale<T, U1, U2>> for Vector2D<T, U1>

type Output = Vector2D<T::Output, U2>

The resulting type after applying the * operator.

fn mul(self, scale: Scale<T, U1, U2>) -> Self::Output

Performs the * operation.

impl<T: Copy + Mul, U1, U2> Mul<Scale<T, U1, U2>> for Vector3D<T, U1>

type Output = Vector3D<T::Output, U2>

The resulting type after applying the * operator.

fn mul(self, scale: Scale<T, U1, U2>) -> Self::Output

Performs the * operation.

impl<T: Copy + MulAssign, U> MulAssign<Scale<T, U, U>> for Box2D<T, U>

fn mul_assign(&mut self, scale: Scale<T, U, U>)

Performs the *= operation.

impl<T: Copy + MulAssign, U> MulAssign<Scale<T, U, U>> for Box3D<T, U>

fn mul_assign(&mut self, scale: Scale<T, U, U>)

Performs the *= operation.

impl<T: Copy + MulAssign, U> MulAssign<Scale<T, U, U>> for Point2D<T, U>

fn mul_assign(&mut self, scale: Scale<T, U, U>)

Performs the *= operation.

impl<T: Copy + MulAssign, U> MulAssign<Scale<T, U, U>> for Point3D<T, U>

fn mul_assign(&mut self, scale: Scale<T, U, U>)

Performs the *= operation.

impl<T: Copy + MulAssign, U> MulAssign<Scale<T, U, U>> for Rect<T, U>

fn mul_assign(&mut self, scale: Scale<T, U, U>)

Performs the *= operation.

impl<T: Copy + MulAssign, U> MulAssign<Scale<T, U, U>> for SideOffsets2D<T, U>

fn mul_assign(&mut self, other: Scale<T, U, U>)

Performs the *= operation.

impl<T: Copy + MulAssign, U> MulAssign<Scale<T, U, U>> for Size2D<T, U>

fn mul_assign(&mut self, other: Scale<T, U, U>)

Performs the *= operation.

impl<T: Copy + MulAssign, U> MulAssign<Scale<T, U, U>> for Size3D<T, U>

fn mul_assign(&mut self, other: Scale<T, U, U>)

Performs the *= operation.

impl<T: Copy + MulAssign, U> MulAssign<Scale<T, U, U>> for Vector2D<T, U>

fn mul_assign(&mut self, scale: Scale<T, U, U>)

Performs the *= operation.

impl<T: Copy + MulAssign, U> MulAssign<Scale<T, U, U>> for Vector3D<T, U>

fn mul_assign(&mut self, scale: Scale<T, U, U>)

Performs the *= operation.

impl<T: One, Src, Dst> One for Scale<T, Src, Dst>

fn one() -> Self

impl<T: Ord, Src, Dst> Ord for Scale<T, Src, Dst>

fn cmp(&self, other: &Self) -> Ordering

This method returns an Ordering between self and other.

#[must_use]

fn max(self, other: Self) -> Self

Compares and returns the maximum of two values.

#[must_use]

fn min(self, other: Self) -> Self

Compares and returns the minimum of two values.

#[must_use]

fn clamp(self, min: Self, max: Self) -> Self

Restrict a value to a certain interval.

impl<T: PartialEq, Src, Dst> PartialEq<Scale<T, Src, Dst>> for Scale<T, Src, Dst>

fn eq(&self, other: &Scale<T, Src, Dst>) -> bool

This method tests for self and other values to be equal, and is used by ==.

#[must_use]

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

This method tests for !=.

impl<T: PartialOrd, Src, Dst> PartialOrd<Scale<T, Src, Dst>> for Scale<T, Src, Dst>

fn partial_cmp(&self, other: &Self) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

#[must_use]

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

This method tests less than (for self and other) and is used by the < operator.

#[must_use]

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

This method tests less than or equal to (for self and other) and is used by the <= operator.

#[must_use]

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

This method tests greater than (for self and other) and is used by the > operator.

#[must_use]

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

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl<T: Sub, Src, Dst> Sub<Scale<T, Src, Dst>> for Scale<T, Src, Dst>

type Output = Scale<T::Output, Src, Dst>

The resulting type after applying the - operator.

fn sub(self, other: Scale<T, Src, Dst>) -> Self::Output

Performs the - operation.

impl<T: Copy, Src, Dst> Copy for Scale<T, Src, Dst>

impl<T: Eq, Src, Dst> Eq for Scale<T, Src, Dst>