Struct exr::image::read::specific_channels::ReadOptionalChannel

pub struct ReadOptionalChannel<ReadChannels, Sample> { /* fields omitted */ }

Used to read another specific channel from an image. Contains the previous ReadChannels objects.

Trait Implementations

impl<Inner: CheckDuplicates, Sample> CheckDuplicates for ReadOptionalChannel<Inner, Sample>

fn already_contains(&self, name: &Text) -> bool

Check for duplicate channel names.

impl<ReadChannels: Clone, Sample: Clone> Clone for ReadOptionalChannel<ReadChannels, Sample>

fn clone(&self) -> ReadOptionalChannel<ReadChannels, Sample>

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<ReadChannels: Debug, Sample: Debug> Debug for ReadOptionalChannel<ReadChannels, Sample>

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

Formats the value using the given formatter.

impl<DefaultSample, ReadChannels> ReadSpecificChannel for ReadOptionalChannel<ReadChannels, DefaultSample> where
    ReadChannels: ReadSpecificChannel,
    DefaultSample: FromNativeSample + 'static, 

type RecursivePixelReader = Recursive<ReadChannels::RecursivePixelReader, OptionalSampleReader<DefaultSample>>

A separate internal reader for the pixels. Will be of type Recursive<_, SampleReader<_>>, depending on the pixels of the specific channel combination.

fn create_recursive_reader(
    &self,
    channels: &ChannelList
) -> Result<Self::RecursivePixelReader>

Create a separate internal reader for the pixels of the specific channel combination.

fn required<Sample>(
    self,
    channel_name: impl Into<Text>
) -> ReadRequiredChannel<Self, Sample>

Plan to read an additional channel from the image, with the specified name. If the channel cannot be found in the image when the image is read, the image will not be loaded. The generic parameter can usually be inferred from the closure in collect_pixels.

fn optional<Sample>(
    self,
    channel_name: impl Into<Text>,
    default_sample: Sample
) -> ReadOptionalChannel<Self, Sample>

Plan to read an additional channel from the image, with the specified name. If the file does not contain this channel, the specified default sample will be returned instead. You can check whether the channel has been loaded by checking the presence of the optional channel description before instantiating your own image. The generic parameter can usually be inferred from the closure in collect_pixels.

fn collect_pixels<Pixel, PixelStorage, CreatePixels, SetPixel>(
    self,
    create_pixels: CreatePixels,
    set_pixel: SetPixel
) -> CollectPixels<Self, Pixel, PixelStorage, CreatePixels, SetPixel> where
    <Self::RecursivePixelReader as RecursivePixelReader>::RecursivePixel: IntoTuple<Pixel>,
    <Self::RecursivePixelReader as RecursivePixelReader>::RecursiveChannelDescriptions: IntoNonRecursive,
    CreatePixels: Fn(Vec2<usize>, &<<Self::RecursivePixelReader as RecursivePixelReader>::RecursiveChannelDescriptions as IntoNonRecursive>::NonRecursive) -> PixelStorage,
    SetPixel: Fn(&mut PixelStorage, Vec2<usize>, Pixel), 

Using two closures, define how to store the pixels. The first closure creates an image, and the second closure inserts a single pixel. The type of the pixel can be defined by the second closure; it must be a tuple containing f16, f32, u32 or Sample values. See the examples for more information.