Enum ImageOrientation 

pub enum ImageOrientation {
    Normal,
    FlipHorizontal,
    Rotate180,
    FlipVertical,
    Transpose,
    Rotate90,
    Transverse,
    Rotate270,
}

How the stored pixel grid is turned to be displayed upright, with the semantics of the TIFF and EXIF Orientation tag.

The four quarter-turn cases (swaps_axes) swap the displayed width and height. Mapping a point back to a source pixel undoes the orientation, so a press on a turned picture still finds the pixel drawn under it.

Variants

Normal

1 — stored upright. The overwhelmingly common case.

FlipHorizontal

2 — mirrored left-to-right.

Rotate180

3 — rotated 180°.

FlipVertical

4 — mirrored top-to-bottom.

Transpose

5 — transposed (mirrored along the main diagonal).

Rotate90

6 — rotated 90° clockwise for display.

Transverse

7 — transversed (mirrored along the anti-diagonal).

Rotate270

8 — rotated 270° clockwise for display.

Implementations

impl ImageOrientation

pub const fn from_exif(value: u16) -> Option<ImageOrientation>

The orientation a TIFF or EXIF Orientation value names, or None outside 1..=8.

pub const fn from_tiff(value: u16) -> ImageOrientation

Map a raw TIFF Orientation value, leniently: anything outside 1..=8 — including the 0 some buggy encoders write — is treated as Normal, the only safe reading of a value that cannot be trusted. from_exif is the strict form.

pub const fn swaps_axes(self) -> bool

Whether displaying this orientation swaps width and height.

pub const fn is_identity(self) -> bool

Whether this is a no-op, so callers can skip work entirely.

pub const fn displayed_size(self, width: u32, height: u32) -> (u32, u32)

The displayed size of a width × height source.

Trait Implementations

impl Clone for ImageOrientation

fn clone(&self) -> ImageOrientation

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for ImageOrientation

impl Debug for ImageOrientation

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

Formats the value using the given formatter.

impl Default for ImageOrientation

fn default() -> ImageOrientation

Returns the “default value” for a type.

impl Eq for ImageOrientation

impl Hash for ImageOrientation

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

where __H: Hasher,

Feeds this value into the given Hasher.

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

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl PartialEq for ImageOrientation

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for ImageOrientation