//! Describes all meta data possible in an exr file. //! Contains functionality to read and write meta data from bytes. //! Browse the `exr::image` module to get started with the high-level interface. pub mod attribute; pub mod header; use crate::io::*; use ::smallvec::SmallVec; use self::attribute::*; use crate::block::chunk::{TileCoordinates, CompressedBlock}; use crate::error::*; use std::fs::File; use std::io::{BufReader}; use crate::math::*; use std::collections::{HashSet}; use std::convert::TryFrom; use crate::meta::header::{Header}; use crate::block::{BlockIndex, UncompressedBlock}; // TODO rename MetaData to ImageInfo? /// Contains the complete meta data of an exr image. /// Defines how the image is split up in the file, /// the number and type of images and channels, /// and various other attributes. /// The usage of custom attributes is encouraged. #[derive(Debug, Clone, PartialEq)] pub struct MetaData { /// Some flags summarizing the features that must be supported to decode the file. pub requirements: Requirements, /// One header to describe each layer in this file. // TODO rename to layer descriptions? pub headers: Headers, } /// List of `Header`s. pub type Headers = SmallVec<[Header; 3]>; /// List of `OffsetTable`s. pub type OffsetTables = SmallVec<[OffsetTable; 3]>; /// The offset table is an ordered list of indices referencing pixel data in the exr file. /// For each pixel tile in the image, an index exists, which points to the byte-location /// of the corresponding pixel data in the file. That index can be used to load specific /// portions of an image without processing all bytes in a file. For each header, /// an offset table exists with its indices ordered by `LineOrder::Increasing`. // If the multipart bit is unset and the chunkCount attribute is not present, // the number of entries in the chunk table is computed using the // dataWindow, tileDesc, and compression attribute. // // If the multipart bit is set, the header must contain a // chunkCount attribute, that contains the length of the offset table. pub type OffsetTable = Vec; /// A summary of requirements that must be met to read this exr file. /// Used to determine whether this file can be read by a given reader. /// It includes the OpenEXR version number. This library aims to support version `2.0`. #[derive(Clone, Copy, Eq, PartialEq, Debug, Hash)] pub struct Requirements { /// This library supports reading version 1 and 2, and writing version 2. // TODO write version 1 for simple images pub file_format_version: u8, /// If true, this image has tiled blocks and contains only a single layer. /// If false and not deep and not multilayer, this image is a single layer image with scan line blocks. pub is_single_layer_and_tiled: bool, // in c or bad c++ this might have been relevant (omg is he allowed to say that) /// Whether this file has strings with a length greater than 31. /// Strings can never be longer than 255. pub has_long_names: bool, /// This image contains at least one layer with deep data. pub has_deep_data: bool, /// Whether this file contains multiple layers. pub has_multiple_layers: bool, } /// Locates a rectangular section of pixels in an image. #[derive(Copy, Clone, Debug, Hash, Eq, PartialEq)] pub struct TileIndices { /// Index of the tile. pub location: TileCoordinates, /// Pixel size of the tile. pub size: Vec2, } /// How the image pixels are split up into separate blocks. #[derive(Copy, Clone, Debug, PartialEq, Eq, Hash)] pub enum BlockDescription { /// The image is divided into scan line blocks. /// The number of scan lines in a block depends on the compression method. ScanLines, /// The image is divided into tile blocks. /// Also specifies the size of each tile in the image /// and whether this image contains multiple resolution levels. Tiles(TileDescription) } /*impl TileIndices { pub fn cmp(&self, other: &Self) -> Ordering { match self.location.level_index.1.cmp(&other.location.level_index.1) { Ordering::Equal => { match self.location.level_index.0.cmp(&other.location.level_index.0) { Ordering::Equal => { match self.location.tile_index.1.cmp(&other.location.tile_index.1) { Ordering::Equal => { self.location.tile_index.0.cmp(&other.location.tile_index.0) }, other => other, } }, other => other } }, other => other } } }*/ impl BlockDescription { /// Whether this image is tiled. If false, this image is divided into scan line blocks. pub fn has_tiles(&self) -> bool { match self { BlockDescription::Tiles { .. } => true, _ => false } } } /// The first four bytes of each exr file. /// Used to abort reading non-exr files. pub mod magic_number { use super::*; /// The first four bytes of each exr file. pub const BYTES: [u8; 4] = [0x76, 0x2f, 0x31, 0x01]; /// Without validation, write this instance to the byte stream. pub fn write(write: &mut impl Write) -> Result<()> { u8::write_slice(write, &self::BYTES) } /// Consumes four bytes from the reader and returns whether the file may be an exr file. // TODO check if exr before allocating BufRead pub fn is_exr(read: &mut impl Read) -> Result { let mut magic_num = [0; 4]; u8::read_slice(read, &mut magic_num)?; Ok(magic_num == self::BYTES) } /// Validate this image. If it is an exr file, return `Ok(())`. pub fn validate_exr(read: &mut impl Read) -> UnitResult { if self::is_exr(read)? { Ok(()) } else { Err(Error::invalid("file identifier missing")) } } } /// A `0_u8` at the end of a sequence. pub mod sequence_end { use super::*; /// Number of bytes this would consume in an exr file. pub fn byte_size() -> usize { 1 } /// Without validation, write this instance to the byte stream. pub fn write(write: &mut W) -> UnitResult { 0_u8.write(write) } /// Peeks the next byte. If it is zero, consumes the byte and returns true. pub fn has_come(read: &mut PeekRead) -> Result { Ok(read.skip_if_eq(0)?) } } fn missing_attribute(name: &str) -> Error { Error::invalid(format!("missing or invalid {} attribute", name)) } /// Compute the number of tiles required to contain all values. pub fn compute_block_count(full_res: usize, tile_size: usize) -> usize { // round up, because if the image is not evenly divisible by the tiles, // we add another tile at the end (which is only partially used) RoundingMode::Up.divide(full_res, tile_size) } /// Compute the start position and size of a block inside a dimension. #[inline] pub fn calculate_block_position_and_size(total_size: usize, block_size: usize, block_index: usize) -> Result<(usize, usize)> { let block_position = block_size * block_index; Ok(( block_position, calculate_block_size(total_size, block_size, block_position)? )) } /// Calculate the size of a single block. If this is the last block, /// this only returns the required size, which is always smaller than the default block size. // TODO use this method everywhere instead of convoluted formulas #[inline] pub fn calculate_block_size(total_size: usize, block_size: usize, block_position: usize) -> Result { if block_position >= total_size { return Err(Error::invalid("block index")) } if block_position + block_size <= total_size { Ok(block_size) } else { Ok(total_size - block_position) } } /// Calculate number of mip levels in a given resolution. // TODO this should be cached? log2 may be very expensive pub fn compute_level_count(round: RoundingMode, full_res: usize) -> usize { usize::try_from(round.log2(u32::try_from(full_res).unwrap())).unwrap() + 1 } /// Calculate the size of a single mip level by index. // TODO this should be cached? log2 may be very expensive pub fn compute_level_size(round: RoundingMode, full_res: usize, level_index: usize) -> usize { assert!(level_index < std::mem::size_of::() * 8, "largest level size exceeds maximum integer value"); round.divide(full_res, 1 << level_index).max(1) } /// Iterates over all rip map level resolutions of a given size, including the indices of each level. /// The order of iteration conforms to `LineOrder::Increasing`. // TODO cache these? // TODO compute these directly instead of summing up an iterator? pub fn rip_map_levels(round: RoundingMode, max_resolution: Vec2) -> impl Iterator, Vec2)> { rip_map_indices(round, max_resolution).map(move |level_indices|{ // TODO progressively divide instead?? let width = compute_level_size(round, max_resolution.width(), level_indices.x()); let height = compute_level_size(round, max_resolution.height(), level_indices.y()); (level_indices, Vec2(width, height)) }) } /// Iterates over all mip map level resolutions of a given size, including the indices of each level. /// The order of iteration conforms to `LineOrder::Increasing`. // TODO cache all these level values when computing table offset size?? // TODO compute these directly instead of summing up an iterator? pub fn mip_map_levels(round: RoundingMode, max_resolution: Vec2) -> impl Iterator)> { mip_map_indices(round, max_resolution) .map(move |level_index|{ // TODO progressively divide instead?? let width = compute_level_size(round, max_resolution.width(), level_index); let height = compute_level_size(round, max_resolution.height(), level_index); (level_index, Vec2(width, height)) }) } /// Iterates over all rip map level indices of a given size. /// The order of iteration conforms to `LineOrder::Increasing`. pub fn rip_map_indices(round: RoundingMode, max_resolution: Vec2) -> impl Iterator> { let (width, height) = ( compute_level_count(round, max_resolution.width()), compute_level_count(round, max_resolution.height()) ); (0..height).flat_map(move |y_level|{ (0..width).map(move |x_level|{ Vec2(x_level, y_level) }) }) } /// Iterates over all mip map level indices of a given size. /// The order of iteration conforms to `LineOrder::Increasing`. pub fn mip_map_indices(round: RoundingMode, max_resolution: Vec2) -> impl Iterator { 0..compute_level_count(round, max_resolution.width().max(max_resolution.height())) } /// Compute the number of chunks that an image is divided into. May be an expensive operation. // If not multilayer and chunkCount not present, // the number of entries in the chunk table is computed // using the dataWindow and tileDesc attributes and the compression format pub fn compute_chunk_count(compression: Compression, data_size: Vec2, blocks: BlockDescription) -> usize { if let BlockDescription::Tiles(tiles) = blocks { let round = tiles.rounding_mode; let Vec2(tile_width, tile_height) = tiles.tile_size; // TODO cache all these level values?? use crate::meta::attribute::LevelMode::*; match tiles.level_mode { Singular => { let tiles_x = compute_block_count(data_size.width(), tile_width); let tiles_y = compute_block_count(data_size.height(), tile_height); tiles_x * tiles_y } MipMap => { mip_map_levels(round, data_size).map(|(_, Vec2(level_width, level_height))| { compute_block_count(level_width, tile_width) * compute_block_count(level_height, tile_height) }).sum() }, RipMap => { rip_map_levels(round, data_size).map(|(_, Vec2(level_width, level_height))| { compute_block_count(level_width, tile_width) * compute_block_count(level_height, tile_height) }).sum() } } } // scan line blocks never have mip maps else { compute_block_count(data_size.height(), compression.scan_lines_per_block()) } } impl MetaData { /// Read the exr meta data from a file. /// Use `read_from_unbuffered` instead if you do not have a file. /// Does not validate the meta data. #[must_use] pub fn read_from_file(path: impl AsRef<::std::path::Path>, pedantic: bool) -> Result { Self::read_from_unbuffered(File::open(path)?, pedantic) } /// Buffer the reader and then read the exr meta data from it. /// Use `read_from_buffered` if your reader is an in-memory reader. /// Use `read_from_file` if you have a file path. /// Does not validate the meta data. #[must_use] pub fn read_from_unbuffered(unbuffered: impl Read, pedantic: bool) -> Result { Self::read_from_buffered(BufReader::new(unbuffered), pedantic) } /// Read the exr meta data from a reader. /// Use `read_from_file` if you have a file path. /// Use `read_from_unbuffered` if this is not an in-memory reader. /// Does not validate the meta data. #[must_use] pub fn read_from_buffered(buffered: impl Read, pedantic: bool) -> Result { let mut read = PeekRead::new(buffered); MetaData::read_unvalidated_from_buffered_peekable(&mut read, pedantic) } /// Does __not validate__ the meta data completely. #[must_use] pub(crate) fn read_unvalidated_from_buffered_peekable(read: &mut PeekRead, pedantic: bool) -> Result { magic_number::validate_exr(read)?; let requirements = Requirements::read(read)?; // do this check now in order to fast-fail for newer versions and features than version 2 requirements.validate()?; let headers = Header::read_all(read, &requirements, pedantic)?; // TODO check if supporting requirements 2 always implies supporting requirements 1 Ok(MetaData { requirements, headers }) } /// Validates the meta data. #[must_use] pub(crate) fn read_validated_from_buffered_peekable( read: &mut PeekRead, pedantic: bool ) -> Result { let meta_data = Self::read_unvalidated_from_buffered_peekable(read, !pedantic)?; MetaData::validate(meta_data.headers.as_slice(), pedantic)?; Ok(meta_data) } /// Validates the meta data and writes it to the stream. /// If pedantic, throws errors for files that may produce errors in other exr readers. /// Returns the automatically detected minimum requirement flags. pub(crate) fn write_validating_to_buffered(write: &mut impl Write, headers: &[Header], pedantic: bool) -> Result { // pedantic validation to not allow slightly invalid files // that still could be read correctly in theory let minimal_requirements = Self::validate(headers, pedantic)?; magic_number::write(write)?; minimal_requirements.write(write)?; Header::write_all(headers, write, minimal_requirements.has_multiple_layers)?; Ok(minimal_requirements) } /// Read one offset table from the reader for each header. pub fn read_offset_tables(read: &mut PeekRead, headers: &Headers) -> Result { headers.iter() .map(|header| u64::read_vec(read, header.chunk_count, u16::MAX as usize, None, "offset table size")) .collect() } /// Skip the offset tables by advancing the reader by the required byte count. // TODO use seek for large (probably all) tables! pub fn skip_offset_tables(read: &mut PeekRead, headers: &Headers) -> Result { let chunk_count: usize = headers.iter().map(|header| header.chunk_count).sum(); crate::io::skip_bytes(read, chunk_count * u64::BYTE_SIZE)?; // TODO this should seek for large tables Ok(chunk_count) } /// This iterator tells you the block indices of all blocks that must be in the image. /// The order of the blocks depends on the `LineOrder` attribute /// (unspecified line order is treated the same as increasing line order). /// The blocks written to the file must be exactly in this order, /// except for when the `LineOrder` is unspecified. /// The index represents the block index, in increasing line order, within the header. pub fn enumerate_ordered_header_block_indices(&self) -> impl '_ + Iterator { crate::block::enumerate_ordered_header_block_indices(&self.headers) } /// Go through all the block indices in the correct order and call the specified closure for each of these blocks. /// That way, the blocks indices are filled with real block data and returned as an iterator. /// The closure returns the an `UncompressedBlock` for each block index. pub fn collect_ordered_blocks<'s>(&'s self, mut get_block: impl 's + FnMut(BlockIndex) -> UncompressedBlock) -> impl 's + Iterator { self.enumerate_ordered_header_block_indices().map(move |(index_in_header, block_index)|{ (index_in_header, get_block(block_index)) }) } /// Go through all the block indices in the correct order and call the specified closure for each of these blocks. /// That way, the blocks indices are filled with real block data and returned as an iterator. /// The closure returns the byte data for each block index. pub fn collect_ordered_block_data<'s>(&'s self, mut get_block_data: impl 's + FnMut(BlockIndex) -> Vec) -> impl 's + Iterator { self.collect_ordered_blocks(move |block_index| UncompressedBlock { index: block_index, data: get_block_data(block_index) } ) } /// Validates this meta data. Returns the minimal possible requirements. pub fn validate(headers: &[Header], pedantic: bool) -> Result { if headers.len() == 0 { return Err(Error::invalid("at least one layer is required")); } let deep = false; // TODO deep data let is_multilayer = headers.len() > 1; let first_header_has_tiles = headers.iter().next() .map_or(false, |header| header.blocks.has_tiles()); let mut minimal_requirements = Requirements { // according to the spec, version 2 should only be necessary if `is_multilayer || deep`. // but the current open exr library does not support images with version 1, so always use version 2. file_format_version: 2, // start as low as possible, later increasing if required has_long_names: false, is_single_layer_and_tiled: !is_multilayer && first_header_has_tiles, has_multiple_layers: is_multilayer, has_deep_data: deep, }; for header in headers { if header.deep { // TODO deep data (and then remove this check) return Err(Error::unsupported("deep data not supported yet")); } header.validate(is_multilayer, &mut minimal_requirements.has_long_names, pedantic)?; } // TODO validation fn! /*if let Some(max) = max_pixel_bytes { let byte_size: usize = headers.iter() .map(|header| header.total_pixel_bytes()) .sum(); if byte_size > max { return Err(Error::invalid("image larger than specified maximum")); } }*/ if pedantic { // check for duplicate header names let mut header_names = HashSet::with_capacity(headers.len()); for header in headers { if !header_names.insert(&header.own_attributes.layer_name) { return Err(Error::invalid(format!( "duplicate layer name: `{}`", header.own_attributes.layer_name.as_ref().expect("header validation bug") ))); } } } if pedantic { let must_share = headers.iter().flat_map(|header| header.own_attributes.other.iter()) .any(|(_, value)| value.to_chromaticities().is_ok() || value.to_time_code().is_ok()); if must_share { return Err(Error::invalid("chromaticities and time code attributes must must not exist in own attributes but shared instead")); } } if pedantic && headers.len() > 1 { // check for attributes that should not differ in between headers let first_header = headers.first().expect("header count validation bug"); let first_header_attributes = &first_header.shared_attributes; for header in &headers[1..] { if &header.shared_attributes != first_header_attributes { return Err(Error::invalid("display window, pixel aspect, chromaticities, and time code attributes must be equal for all headers")) } } } debug_assert!(minimal_requirements.validate().is_ok(), "inferred requirements are invalid"); Ok(minimal_requirements) } } impl Requirements { // this is actually used for control flow, as the number of headers may be 1 in a multilayer file /// Is this file declared to contain multiple layers? pub fn is_multilayer(&self) -> bool { self.has_multiple_layers } /// Read the value without validating. pub fn read(read: &mut R) -> Result { use ::bit_field::BitField; let version_and_flags = u32::read(read)?; // take the 8 least significant bits, they contain the file format version number let version = (version_and_flags & 0x000F) as u8; // the 24 most significant bits are treated as a set of boolean flags let is_single_tile = version_and_flags.get_bit(9); let has_long_names = version_and_flags.get_bit(10); let has_deep_data = version_and_flags.get_bit(11); let has_multiple_layers = version_and_flags.get_bit(12); // all remaining bits except 9, 10, 11 and 12 are reserved and should be 0 // if a file has any of these bits set to 1, it means this file contains // a feature that we don't support let unknown_flags = version_and_flags >> 13; // all flags excluding the 12 bits we already parsed if unknown_flags != 0 { // TODO test if this correctly detects unsupported files return Err(Error::unsupported("too new file feature flags")); } let version = Requirements { file_format_version: version, is_single_layer_and_tiled: is_single_tile, has_long_names, has_deep_data, has_multiple_layers, }; Ok(version) } /// Without validation, write this instance to the byte stream. pub fn write(self, write: &mut W) -> UnitResult { use ::bit_field::BitField; // the 8 least significant bits contain the file format version number // and the flags are set to 0 let mut version_and_flags = self.file_format_version as u32; // the 24 most significant bits are treated as a set of boolean flags version_and_flags.set_bit(9, self.is_single_layer_and_tiled); version_and_flags.set_bit(10, self.has_long_names); version_and_flags.set_bit(11, self.has_deep_data); version_and_flags.set_bit(12, self.has_multiple_layers); // all remaining bits except 9, 10, 11 and 12 are reserved and should be 0 version_and_flags.write(write)?; Ok(()) } /// Validate this instance. pub fn validate(&self) -> UnitResult { if self.file_format_version == 2 { match ( self.is_single_layer_and_tiled, self.has_deep_data, self.has_multiple_layers, self.file_format_version ) { // Single-part scan line. One normal scan line image. (false, false, false, 1..=2) => Ok(()), // Single-part tile. One normal tiled image. (true, false, false, 1..=2) => Ok(()), // Multi-part (new in 2.0). // Multiple normal images (scan line and/or tiled). (false, false, true, 2) => Ok(()), // Single-part deep data (new in 2.0). // One deep tile or deep scan line part (false, true, false, 2) => Ok(()), // Multi-part deep data (new in 2.0). // Multiple parts (any combination of: // tiles, scan lines, deep tiles and/or deep scan lines). (false, true, true, 2) => Ok(()), _ => Err(Error::invalid("file feature flags")) } } else { Err(Error::unsupported("file versions other than 2.0 are not supported")) } } } #[cfg(test)] mod test { use super::*; use crate::meta::header::{ImageAttributes, LayerAttributes}; #[test] fn round_trip_requirements() { let requirements = Requirements { file_format_version: 2, is_single_layer_and_tiled: true, has_long_names: false, has_deep_data: true, has_multiple_layers: false }; let mut data: Vec = Vec::new(); requirements.write(&mut data).unwrap(); let read = Requirements::read(&mut data.as_slice()).unwrap(); assert_eq!(requirements, read); } #[test] fn round_trip(){ let header = Header { channels: ChannelList::new(smallvec![ ChannelDescription { name: Text::from("main"), sample_type: SampleType::U32, quantize_linearly: false, sampling: Vec2(1, 1) } ], ), compression: Compression::Uncompressed, line_order: LineOrder::Increasing, deep_data_version: Some(1), chunk_count: compute_chunk_count(Compression::Uncompressed, Vec2(2000, 333), BlockDescription::ScanLines), max_samples_per_pixel: Some(4), shared_attributes: ImageAttributes { pixel_aspect: 3.0, .. ImageAttributes::new(IntegerBounds { position: Vec2(2,1), size: Vec2(11, 9) }) }, blocks: BlockDescription::ScanLines, deep: false, layer_size: Vec2(2000, 333), own_attributes: LayerAttributes { layer_name: Some(Text::from("test name lol")), layer_position: Vec2(3, -5), screen_window_center: Vec2(0.3, 99.0), screen_window_width: 0.19, .. Default::default() } }; let meta = MetaData { requirements: Requirements { file_format_version: 2, is_single_layer_and_tiled: false, has_long_names: false, has_deep_data: false, has_multiple_layers: false }, headers: smallvec![ header ], }; let mut data: Vec = Vec::new(); MetaData::write_validating_to_buffered(&mut data, meta.headers.as_slice(), true).unwrap(); let meta2 = MetaData::read_from_buffered(data.as_slice(), false).unwrap(); MetaData::validate(meta2.headers.as_slice(), true).unwrap(); assert_eq!(meta, meta2); } #[test] fn infer_low_requirements() { let header_version_1_short_names = Header { channels: ChannelList::new(smallvec![ ChannelDescription { name: Text::from("main"), sample_type: SampleType::U32, quantize_linearly: false, sampling: Vec2(1, 1) } ], ), compression: Compression::Uncompressed, line_order: LineOrder::Increasing, deep_data_version: Some(1), chunk_count: compute_chunk_count(Compression::Uncompressed, Vec2(2000, 333), BlockDescription::ScanLines), max_samples_per_pixel: Some(4), shared_attributes: ImageAttributes { pixel_aspect: 3.0, .. ImageAttributes::new(IntegerBounds { position: Vec2(2,1), size: Vec2(11, 9) }) }, blocks: BlockDescription::ScanLines, deep: false, layer_size: Vec2(2000, 333), own_attributes: LayerAttributes { other: vec![ (Text::try_from("x").unwrap(), AttributeValue::F32(3.0)), (Text::try_from("y").unwrap(), AttributeValue::F32(-1.0)), ].into_iter().collect(), .. Default::default() } }; let low_requirements = MetaData::validate( &[header_version_1_short_names], true ).unwrap(); assert_eq!(low_requirements.has_long_names, false); assert_eq!(low_requirements.file_format_version, 2); // always have version 2 assert_eq!(low_requirements.has_deep_data, false); assert_eq!(low_requirements.has_multiple_layers, false); } #[test] fn infer_high_requirements() { let header_version_2_long_names = Header { channels: ChannelList::new( smallvec![ ChannelDescription { name: Text::new_or_panic("main"), sample_type: SampleType::U32, quantize_linearly: false, sampling: Vec2(1, 1) } ], ), compression: Compression::Uncompressed, line_order: LineOrder::Increasing, deep_data_version: Some(1), chunk_count: compute_chunk_count(Compression::Uncompressed, Vec2(2000, 333), BlockDescription::ScanLines), max_samples_per_pixel: Some(4), shared_attributes: ImageAttributes { pixel_aspect: 3.0, .. ImageAttributes::new(IntegerBounds { position: Vec2(2,1), size: Vec2(11, 9) }) }, blocks: BlockDescription::ScanLines, deep: false, layer_size: Vec2(2000, 333), own_attributes: LayerAttributes { layer_name: Some(Text::new_or_panic("oasdasoidfj")), other: vec![ (Text::new_or_panic("xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"), AttributeValue::F32(3.0)), (Text::new_or_panic("y"), AttributeValue::F32(-1.0)), ].into_iter().collect(), .. Default::default() } }; let mut layer_2 = header_version_2_long_names.clone(); layer_2.own_attributes.layer_name = Some(Text::new_or_panic("anythingelse")); let low_requirements = MetaData::validate( &[header_version_2_long_names, layer_2], true ).unwrap(); assert_eq!(low_requirements.has_long_names, true); assert_eq!(low_requirements.file_format_version, 2); assert_eq!(low_requirements.has_deep_data, false); assert_eq!(low_requirements.has_multiple_layers, true); } }