Enum cogs_gamedev::directions::Direction4

pub enum Direction4 {
    North,
    East,
    South,
    West,
}

Four-way directions.

These start at North and increment counter-clockwise, so you can convert them to integers with as and use them in rotational calculations if you need.

Variants

North

East

South

West

Implementations

impl Direction4

pub const DIRECTIONS: [Direction4; 4]

All the directions in order. This is used internally for rotations and flips. I made it public just in case it's helpful for you the programmer.

pub fn rotate(self, steps_clockwise: isize) -> Self

Get this direction, rotated by this many steps clockwise. Negative numbers go counter-clockwise.

use Direction4::*;
let north = North;
assert_eq!(north.rotate(1), East);
assert_eq!(north.rotate(2), South);
assert_eq!(north.rotate(-1), West);
assert_eq!(north.rotate(5).rotate(-11), South);

pub fn flip(self) -> Self

Flip this direction.

use Direction4::*;
assert_eq!(North.flip(), South);
assert_eq!(West.flip(), East);
assert_eq!(East.flip().flip(), East);

pub fn radians(self) -> f32

Get this direction in radians.

This uses trigonometric + graphical standard, where:

• 0 radians is to the right
• Positive radians increment clockwise. NOTE: this is opposite from normal trig, but makes sense in computer graphics where +Y is downwards.

If you need it in degrees just call .to_degrees on the result.

use Direction4::*;
use std::f32::consts::TAU;

let north_radians = North.radians();
assert!((north_radians - (TAU / 4.0 * 3.0)).abs() < 1e-10);

let west_radians = West.radians();
assert!((west_radians - (TAU / 4.0 * 2.0)).abs() < 1e-10);

pub fn deltas(self) -> ICoord

Get the deltas a step in this direction would result in, as a ICoord.

use Direction4::*;

assert_eq!(North.deltas(), ICoord {x: 0, y: -1});
assert_eq!(West.deltas(), ICoord {x: -1, y: 0});

Trait Implementations

impl Clone for Direction4

pub fn clone(&self) -> Direction4

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Copy for Direction4

impl Debug for Direction4

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

Formats the value using the given formatter.

impl Eq for Direction4

impl Ord for Direction4

pub fn cmp(&self, other: &Direction4) -> Ordering

This method returns an Ordering between self and other.

#[must_use]pub fn max(self, other: Self) -> Self

Compares and returns the maximum of two values.

#[must_use]pub fn min(self, other: Self) -> Self

Compares and returns the minimum of two values.

#[must_use]pub fn clamp(self, min: Self, max: Self) -> Self

Restrict a value to a certain interval.

impl PartialEq<Direction4> for Direction4

pub fn eq(&self, other: &Direction4) -> bool

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

#[must_use]pub fn ne(&self, other: &Rhs) -> bool

This method tests for !=.

impl PartialOrd<Direction4> for Direction4

pub fn partial_cmp(&self, other: &Direction4) -> Option<Ordering>

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

#[must_use]pub fn lt(&self, other: &Rhs) -> bool

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

#[must_use]pub 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]pub fn gt(&self, other: &Rhs) -> bool

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

#[must_use]pub 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 StructuralEq for Direction4

impl StructuralPartialEq for Direction4