diff options
Diffstat (limited to 'vendor/exr/src/image/read/specific_channels.rs')
| -rw-r--r-- | vendor/exr/src/image/read/specific_channels.rs | 463 |
1 files changed, 463 insertions, 0 deletions
diff --git a/vendor/exr/src/image/read/specific_channels.rs b/vendor/exr/src/image/read/specific_channels.rs new file mode 100644 index 0000000..375691c --- /dev/null +++ b/vendor/exr/src/image/read/specific_channels.rs @@ -0,0 +1,463 @@ +//! How to read arbitrary but specific selection of arbitrary channels. +//! This is not a zero-cost abstraction. + +use crate::image::recursive::*; +use crate::block::samples::*; +use crate::image::*; +use crate::math::*; +use crate::meta::header::*; +use crate::error::*; +use crate::block::UncompressedBlock; +use crate::image::read::layers::{ChannelsReader, ReadChannels}; +use crate::block::chunk::TileCoordinates; + +use std::marker::PhantomData; +use crate::io::Read; + + +/// Can be attached one more channel reader. +/// Call `required` or `optional` on this object to declare another channel to be read from the file. +/// Call `collect_pixels` at last to define how the previously declared pixels should be stored. +pub trait ReadSpecificChannel: Sized + CheckDuplicates { + + /// A separate internal reader for the pixels. Will be of type `Recursive<_, SampleReader<_>>`, + /// depending on the pixels of the specific channel combination. + type RecursivePixelReader: RecursivePixelReader; + + /// Create a separate internal reader for the pixels of the specific channel combination. + fn create_recursive_reader(&self, channels: &ChannelList) -> Result<Self::RecursivePixelReader>; + + /// 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 required<Sample>(self, channel_name: impl Into<Text>) -> ReadRequiredChannel<Self, Sample> { + let channel_name = channel_name.into(); + assert!(self.already_contains(&channel_name).not(), "a channel with the name `{}` is already defined", channel_name); + ReadRequiredChannel { channel_name, previous_channels: self, px: Default::default() } + } + + /// 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 optional<Sample>(self, channel_name: impl Into<Text>, default_sample: Sample) + -> ReadOptionalChannel<Self, Sample> + { + let channel_name = channel_name.into(); + assert!(self.already_contains(&channel_name).not(), "a channel with the name `{}` is already defined", channel_name); + ReadOptionalChannel { channel_name, previous_channels: self, default_sample } + } + + /// 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. + 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), + { + CollectPixels { read_channels: self, set_pixel, create_pixels, px: Default::default() } + } +} + +/// A reader containing sub-readers for reading the pixel content of an image. +pub trait RecursivePixelReader { + + /// The channel descriptions from the image. + /// Will be converted to a tuple before being stored in `SpecificChannels<_, ChannelDescriptions>`. + type RecursiveChannelDescriptions; + + /// Returns the channel descriptions based on the channels in the file. + fn get_descriptions(&self) -> Self::RecursiveChannelDescriptions; + + /// The pixel type. Will be converted to a tuple at the end of the process. + type RecursivePixel: Copy + Default + 'static; + + /// Read the line of pixels. + fn read_pixels<'s, FullPixel>( + &self, bytes: &'s[u8], pixels: &mut [FullPixel], + get_pixel: impl Fn(&mut FullPixel) -> &mut Self::RecursivePixel + ); +} + +// does not use the generic `Recursive` struct to reduce the number of angle brackets in the public api +/// Used to read another specific channel from an image. +/// Contains the previous `ReadChannels` objects. +#[derive(Clone, Debug)] +pub struct ReadOptionalChannel<ReadChannels, Sample> { + previous_channels: ReadChannels, + channel_name: Text, + default_sample: Sample, +} + +// does not use the generic `Recursive` struct to reduce the number of angle brackets in the public api +/// Used to read another specific channel from an image. +/// Contains the previous `ReadChannels` objects. +#[derive(Clone, Debug)] +pub struct ReadRequiredChannel<ReadChannels, Sample> { + previous_channels: ReadChannels, + channel_name: Text, + px: PhantomData<Sample>, +} + +/// Specifies how to collect all the specified channels into a number of individual pixels. +#[derive(Copy, Clone, Debug)] +pub struct CollectPixels<ReadChannels, Pixel, PixelStorage, CreatePixels, SetPixel> { + read_channels: ReadChannels, + create_pixels: CreatePixels, + set_pixel: SetPixel, + px: PhantomData<(Pixel, PixelStorage)>, +} + +impl<Inner: CheckDuplicates, Sample> CheckDuplicates for ReadRequiredChannel<Inner, Sample> { + fn already_contains(&self, name: &Text) -> bool { + &self.channel_name == name || self.previous_channels.already_contains(name) + } +} + +impl<Inner: CheckDuplicates, Sample> CheckDuplicates for ReadOptionalChannel<Inner, Sample> { + fn already_contains(&self, name: &Text) -> bool { + &self.channel_name == name || self.previous_channels.already_contains(name) + } +} + +impl<'s, InnerChannels, Pixel, PixelStorage, CreatePixels, SetPixel: 's> +ReadChannels<'s> for CollectPixels<InnerChannels, Pixel, PixelStorage, CreatePixels, SetPixel> + where + InnerChannels: ReadSpecificChannel, + <InnerChannels::RecursivePixelReader as RecursivePixelReader>::RecursivePixel: IntoTuple<Pixel>, + <InnerChannels::RecursivePixelReader as RecursivePixelReader>::RecursiveChannelDescriptions: IntoNonRecursive, + CreatePixels: Fn(Vec2<usize>, &<<InnerChannels::RecursivePixelReader as RecursivePixelReader>::RecursiveChannelDescriptions as IntoNonRecursive>::NonRecursive) -> PixelStorage, + SetPixel: Fn(&mut PixelStorage, Vec2<usize>, Pixel), +{ + type Reader = SpecificChannelsReader< + PixelStorage, &'s SetPixel, + InnerChannels::RecursivePixelReader, + Pixel, + >; + + fn create_channels_reader(&'s self, header: &Header) -> Result<Self::Reader> { + if header.deep { return Err(Error::invalid("`SpecificChannels` does not support deep data yet")) } + + let pixel_reader = self.read_channels.create_recursive_reader(&header.channels)?; + let channel_descriptions = pixel_reader.get_descriptions().into_non_recursive();// TODO not call this twice + + let create = &self.create_pixels; + let pixel_storage = create(header.layer_size, &channel_descriptions); + + Ok(SpecificChannelsReader { + set_pixel: &self.set_pixel, + pixel_storage, + pixel_reader, + px: Default::default() + }) + } +} + +/// The reader that holds the temporary data that is required to read some specified channels. +#[derive(Copy, Clone, Debug)] +pub struct SpecificChannelsReader<PixelStorage, SetPixel, PixelReader, Pixel> { + set_pixel: SetPixel, + pixel_storage: PixelStorage, + pixel_reader: PixelReader, + px: PhantomData<Pixel> +} + +impl<PixelStorage, SetPixel, PxReader, Pixel> +ChannelsReader for SpecificChannelsReader<PixelStorage, SetPixel, PxReader, Pixel> + where PxReader: RecursivePixelReader, + PxReader::RecursivePixel: IntoTuple<Pixel>, + PxReader::RecursiveChannelDescriptions: IntoNonRecursive, + SetPixel: Fn(&mut PixelStorage, Vec2<usize>, Pixel), +{ + type Channels = SpecificChannels<PixelStorage, <PxReader::RecursiveChannelDescriptions as IntoNonRecursive>::NonRecursive>; + + fn filter_block(&self, tile: TileCoordinates) -> bool { tile.is_largest_resolution_level() } // TODO all levels + + fn read_block(&mut self, header: &Header, block: UncompressedBlock) -> UnitResult { + let mut pixels = vec![PxReader::RecursivePixel::default(); block.index.pixel_size.width()]; // TODO allocate once in self + + let byte_lines = block.data.chunks_exact(header.channels.bytes_per_pixel * block.index.pixel_size.width()); + debug_assert_eq!(byte_lines.len(), block.index.pixel_size.height(), "invalid block lines split"); + + for (y_offset, line_bytes) in byte_lines.enumerate() { // TODO sampling + // this two-step copy method should be very cache friendly in theory, and also reduce sample_type lookup count + self.pixel_reader.read_pixels(line_bytes, &mut pixels, |px| px); + + for (x_offset, pixel) in pixels.iter().enumerate() { + let set_pixel = &self.set_pixel; + set_pixel(&mut self.pixel_storage, block.index.pixel_position + Vec2(x_offset, y_offset), pixel.into_tuple()); + } + } + + Ok(()) + } + + fn into_channels(self) -> Self::Channels { + SpecificChannels { channels: self.pixel_reader.get_descriptions().into_non_recursive(), pixels: self.pixel_storage } + } +} + + +/// Read zero channels from an image. Call `with_named_channel` on this object +/// to read as many channels as desired. +pub type ReadZeroChannels = NoneMore; + +impl ReadSpecificChannel for NoneMore { + type RecursivePixelReader = NoneMore; + fn create_recursive_reader(&self, _: &ChannelList) -> Result<Self::RecursivePixelReader> { Ok(NoneMore) } +} + +impl<DefaultSample, ReadChannels> ReadSpecificChannel for ReadOptionalChannel<ReadChannels, DefaultSample> + where ReadChannels: ReadSpecificChannel, DefaultSample: FromNativeSample + 'static, +{ + type RecursivePixelReader = Recursive<ReadChannels::RecursivePixelReader, OptionalSampleReader<DefaultSample>>; + + fn create_recursive_reader(&self, channels: &ChannelList) -> Result<Self::RecursivePixelReader> { + debug_assert!(self.previous_channels.already_contains(&self.channel_name).not(), "duplicate channel name: {}", self.channel_name); + + let inner_samples_reader = self.previous_channels.create_recursive_reader(channels)?; + let reader = channels.channels_with_byte_offset() + .find(|(_, channel)| channel.name == self.channel_name) + .map(|(channel_byte_offset, channel)| SampleReader { + channel_byte_offset, channel: channel.clone(), + px: Default::default() + }); + + Ok(Recursive::new(inner_samples_reader, OptionalSampleReader { + reader, default_sample: self.default_sample, + })) + } +} + +impl<Sample, ReadChannels> ReadSpecificChannel for ReadRequiredChannel<ReadChannels, Sample> + where ReadChannels: ReadSpecificChannel, Sample: FromNativeSample + 'static +{ + type RecursivePixelReader = Recursive<ReadChannels::RecursivePixelReader, SampleReader<Sample>>; + + fn create_recursive_reader(&self, channels: &ChannelList) -> Result<Self::RecursivePixelReader> { + let previous_samples_reader = self.previous_channels.create_recursive_reader(channels)?; + let (channel_byte_offset, channel) = channels.channels_with_byte_offset() + .find(|(_, channel)| channel.name == self.channel_name) + .ok_or_else(|| Error::invalid(format!( + "layer does not contain all of your specified channels (`{}` is missing)", + self.channel_name + )))?; + + Ok(Recursive::new(previous_samples_reader, SampleReader { channel_byte_offset, channel: channel.clone(), px: Default::default() })) + } +} + +/// Reader for a single channel. Generic over the concrete sample type (f16, f32, u32). +#[derive(Clone, Debug)] +pub struct SampleReader<Sample> { + + /// to be multiplied with line width! + channel_byte_offset: usize, + + channel: ChannelDescription, + px: PhantomData<Sample> +} + +/// Reader for a single channel. Generic over the concrete sample type (f16, f32, u32). +/// Can also skip reading a channel if it could not be found in the image. +#[derive(Clone, Debug)] +pub struct OptionalSampleReader<DefaultSample> { + reader: Option<SampleReader<DefaultSample>>, + default_sample: DefaultSample, +} + +impl<Sample: FromNativeSample> SampleReader<Sample> { + fn read_own_samples<'s, FullPixel>( + &self, bytes: &'s[u8], pixels: &mut [FullPixel], + get_sample: impl Fn(&mut FullPixel) -> &mut Sample + ){ + let start_index = pixels.len() * self.channel_byte_offset; + let byte_count = pixels.len() * self.channel.sample_type.bytes_per_sample(); + let mut own_bytes_reader = &mut &bytes[start_index .. start_index + byte_count]; // TODO check block size somewhere + let mut samples_out = pixels.iter_mut().map(|pixel| get_sample(pixel)); + + // match the type once for the whole line, not on every single sample + match self.channel.sample_type { + SampleType::F16 => read_and_convert_all_samples_batched( + &mut own_bytes_reader, &mut samples_out, + Sample::from_f16s + ), + + SampleType::F32 => read_and_convert_all_samples_batched( + &mut own_bytes_reader, &mut samples_out, + Sample::from_f32s + ), + + SampleType::U32 => read_and_convert_all_samples_batched( + &mut own_bytes_reader, &mut samples_out, + Sample::from_u32s + ), + } + + debug_assert!(samples_out.next().is_none(), "not all samples have been converted"); + debug_assert!(own_bytes_reader.is_empty(), "bytes left after reading all samples"); + } +} + + +/// Does the same as `convert_batch(in_bytes.chunks().map(From::from_bytes))`, but vectorized. +/// Reads the samples for one line, using the sample type specified in the file, +/// and then converts those to the desired sample types. +/// Uses batches to allow vectorization, converting multiple values with one instruction. +fn read_and_convert_all_samples_batched<'t, From, To>( + mut in_bytes: impl Read, + out_samples: &mut impl ExactSizeIterator<Item=&'t mut To>, + convert_batch: fn(&[From], &mut [To]) +) where From: Data + Default + Copy, To: 't + Default + Copy +{ + // this is not a global! why is this warning triggered? + #[allow(non_upper_case_globals)] + const batch_size: usize = 16; + + let total_sample_count = out_samples.len(); + let batch_count = total_sample_count / batch_size; + let remaining_samples_count = total_sample_count % batch_size; + + let len_error_msg = "sample count was miscalculated"; + let byte_error_msg = "error when reading from in-memory slice"; + + // write samples from a given slice to the output iterator. should be inlined. + let output_n_samples = &mut move |samples: &[To]| { + for converted_sample in samples { + *out_samples.next().expect(len_error_msg) = *converted_sample; + } + }; + + // read samples from the byte source into a given slice. should be inlined. + // todo: use #[inline] when available + // error[E0658]: attributes on expressions are experimental, + // see issue #15701 <https://github.com/rust-lang/rust/issues/15701> for more information + let read_n_samples = &mut move |samples: &mut [From]| { + Data::read_slice(&mut in_bytes, samples).expect(byte_error_msg); + }; + + // temporary arrays with fixed size, operations should be vectorized within these arrays + let mut source_samples_batch: [From; batch_size] = Default::default(); + let mut desired_samples_batch: [To; batch_size] = Default::default(); + + // first convert all whole batches, size statically known to be 16 element arrays + for _ in 0 .. batch_count { + read_n_samples(&mut source_samples_batch); + convert_batch(source_samples_batch.as_slice(), desired_samples_batch.as_mut_slice()); + output_n_samples(&desired_samples_batch); + } + + // then convert a partial remaining batch, size known only at runtime + if remaining_samples_count != 0 { + let source_samples_batch = &mut source_samples_batch[..remaining_samples_count]; + let desired_samples_batch = &mut desired_samples_batch[..remaining_samples_count]; + + read_n_samples(source_samples_batch); + convert_batch(source_samples_batch, desired_samples_batch); + output_n_samples(desired_samples_batch); + } +} + +#[cfg(test)] +mod test { + use super::*; + + #[test] + fn equals_naive_f32(){ + for total_array_size in [3, 7, 30, 41, 120, 10_423] { + let input_f32s = (0..total_array_size).map(|_| rand::random::<f32>()).collect::<Vec<f32>>(); + let in_f32s_bytes = input_f32s.iter().cloned().flat_map(f32::to_le_bytes).collect::<Vec<u8>>(); + + let mut out_f16_samples_batched = vec![ + f16::from_f32(rand::random::<f32>()); + total_array_size + ]; + + read_and_convert_all_samples_batched( + &mut in_f32s_bytes.as_slice(), + &mut out_f16_samples_batched.iter_mut(), + f16::from_f32s + ); + + let out_f16_samples_naive = input_f32s.iter() + .cloned().map(f16::from_f32); + + assert!(out_f16_samples_naive.eq(out_f16_samples_batched)); + } + } +} + + +impl RecursivePixelReader for NoneMore { + type RecursiveChannelDescriptions = NoneMore; + fn get_descriptions(&self) -> Self::RecursiveChannelDescriptions { NoneMore } + + type RecursivePixel = NoneMore; + + fn read_pixels<'s, FullPixel>( + &self, _: &'s[u8], _: &mut [FullPixel], + _: impl Fn(&mut FullPixel) -> &mut NoneMore + ){} +} + +impl<Sample, InnerReader: RecursivePixelReader> + RecursivePixelReader + for Recursive<InnerReader, SampleReader<Sample>> + where Sample: FromNativeSample + 'static +{ + type RecursiveChannelDescriptions = Recursive<InnerReader::RecursiveChannelDescriptions, ChannelDescription>; + fn get_descriptions(&self) -> Self::RecursiveChannelDescriptions { Recursive::new(self.inner.get_descriptions(), self.value.channel.clone()) } + + type RecursivePixel = Recursive<InnerReader::RecursivePixel, Sample>; + + fn read_pixels<'s, FullPixel>( + &self, bytes: &'s[u8], pixels: &mut [FullPixel], + get_pixel: impl Fn(&mut FullPixel) -> &mut Self::RecursivePixel + ) { + self.value.read_own_samples(bytes, pixels, |px| &mut get_pixel(px).value); + self.inner.read_pixels(bytes, pixels, |px| &mut get_pixel(px).inner); + } +} + +impl<Sample, InnerReader: RecursivePixelReader> +RecursivePixelReader +for Recursive<InnerReader, OptionalSampleReader<Sample>> + where Sample: FromNativeSample + 'static +{ + type RecursiveChannelDescriptions = Recursive<InnerReader::RecursiveChannelDescriptions, Option<ChannelDescription>>; + fn get_descriptions(&self) -> Self::RecursiveChannelDescriptions { Recursive::new( + self.inner.get_descriptions(), self.value.reader.as_ref().map(|reader| reader.channel.clone()) + ) } + + type RecursivePixel = Recursive<InnerReader::RecursivePixel, Sample>; + + fn read_pixels<'s, FullPixel>( + &self, bytes: &'s[u8], pixels: &mut [FullPixel], + get_pixel: impl Fn(&mut FullPixel) -> &mut Self::RecursivePixel + ) { + if let Some(reader) = &self.value.reader { + reader.read_own_samples(bytes, pixels, |px| &mut get_pixel(px).value); + } + else { + // if this channel is optional and was not found in the file, fill the default sample + for pixel in pixels.iter_mut() { + get_pixel(pixel).value = self.value.default_sample; + } + } + + self.inner.read_pixels(bytes, pixels, |px| &mut get_pixel(px).inner); + } +} + + |