Struct ScaleFactor 

pub struct ScaleFactor(pub f64);

Scale factor for converting between logical and physical coordinates.

Common values:

• 1.0: Standard DPI (96 DPI on Windows, 72 DPI on macOS historically)
• 2.0: Retina/HiDPI displays
• 1.5, 1.25: Common Windows scaling factors

Safety

The scale factor must be positive (greater than 0). Methods like inverse() and coordinate conversions will produce infinity or NaN if the scale is 0. Use try_new() or is_valid() to validate scale factors from untrusted input.

Example

use astrelis_core::geometry::ScaleFactor;

let scale = ScaleFactor(2.0);
assert_eq!(scale.0, 2.0);
assert_eq!(scale.inverse().0, 0.5);

// Validate scale factors from user input
let scale = ScaleFactor::try_new(2.0).expect("Invalid scale");

Tuple Fields

0: f64

Implementations

impl ScaleFactor

pub const fn new(scale: f64) -> Self

Create a new scale factor.

Panics

In debug builds, panics if the scale is not positive (> 0) or is NaN. In release builds, invalid values may cause division by zero or NaN propagation.

pub fn try_new(scale: f64) -> Option<Self>

Try to create a new scale factor, returning None if invalid.

Returns None if:

• The scale is zero or negative
• The scale is NaN or infinity

Example

use astrelis_core::geometry::ScaleFactor;

assert!(ScaleFactor::try_new(2.0).is_some());
assert!(ScaleFactor::try_new(0.0).is_none());
assert!(ScaleFactor::try_new(-1.0).is_none());
assert!(ScaleFactor::try_new(f64::NAN).is_none());

pub fn is_valid(self) -> bool

Check if this scale factor is valid (positive and finite).

pub fn inverse(self) -> Self

Get the inverse scale factor (1.0 / scale).

Note

Returns infinity if the scale is 0. Use is_valid() to check first if the scale factor comes from untrusted input.

pub fn as_f32(self) -> f32

Get the scale as f32.

pub fn as_f64(self) -> f64

Get the scale as f64.

Trait Implementations

impl Clone for ScaleFactor

fn clone(&self) -> ScaleFactor

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for ScaleFactor

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

Formats the value using the given formatter.

impl Default for ScaleFactor

fn default() -> Self

Returns the “default value” for a type.

impl From<ScaleFactor> for f32

fn from(scale: ScaleFactor) -> Self

Converts to this type from the input type.

impl From<ScaleFactor> for f64

fn from(scale: ScaleFactor) -> Self

Converts to this type from the input type.

impl From<f32> for ScaleFactor

fn from(scale: f32) -> Self

Converts to this type from the input type.

impl From<f64> for ScaleFactor

fn from(scale: f64) -> Self

Converts to this type from the input type.

impl PartialEq for ScaleFactor

fn eq(&self, other: &ScaleFactor) -> 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 PartialOrd for ScaleFactor

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

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

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

Tests less than (for self and other) and is used by the < operator.

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

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

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

Tests greater than (for self and other) and is used by the > operator.

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

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

impl Copy for ScaleFactor

impl StructuralPartialEq for ScaleFactor