Enum RequestedSize 

pub enum RequestedSize {
    Full,
    Reduced {
        width: u32,
        height: u32,
    },
    NoSamples,
}

The resolution an image was decoded at.

Full and a Reduced size are distinct keys: an image cached reduced cannot serve a full-resolution request, while a full-resolution one can serve anything.

Variants

Full

Every sample the image has.

Reduced

At most this many pixels in each direction.

Fields

width: u32

Requested width.

height: u32

Requested height.

NoSamples

No samples at all. A build for text extraction, which never reads an image, asks for this, and the image object is not emitted — the same outcome as a codec refusing it. Never a key the cache holds: on the corpus’s image documents the decode was 87% of a text run.

Implementations

impl RequestedSize

pub fn for_device(width: f64, height: f64) -> Self

The request a device box of width by height float pixels makes.

The box is the render device’s whole extent, not an image’s destination rectangle, so a 5000x5000 image on a 612x792 page is reduced by four however small the cm that draws it is. Dimensions truncate, and a box under one pixel on either axis names Self::Full rather than a zero reduction.

pub fn levels(self, width: u32, height: u32) -> u8

How many resolution levels to skip to satisfy this request for an image of width by height.

Integer division, then the smaller of the two, then a floored base-two logarithm — so an image four times too large skips two levels and one three times too large skips one.

pub fn satisfies( self, wanted: Self, cached_width: u32, cached_height: u32, ) -> bool

Whether an image cached at self can serve a request for wanted.

Trait Implementations

impl Clone for RequestedSize

fn clone(&self) -> RequestedSize

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for RequestedSize

impl Debug for RequestedSize

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

Formats the value using the given formatter.

impl Default for RequestedSize

fn default() -> RequestedSize

Returns the “default value” for a type.

impl Eq for RequestedSize

impl Hash for RequestedSize

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, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl PartialEq for RequestedSize

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for RequestedSize