Struct Reader 

pub struct Reader<Data: AsRef<[u8]>> { /* private fields */ }

Parses and validates a KTX2 texture container from an in-memory buffer.

All validation (magic bytes, bounds checks, DFD integrity, level index) is performed eagerly in Reader::new. Subsequent accessors are infallible.

Data can be any type that derefs to [u8] — &[u8], Vec<u8>, Arc<[u8]>, etc.

Implementations

impl<Data: AsRef<[u8]>> Reader<Data>

pub fn new(input: Data) -> Result<Self, ParseError>

Parse and validate a KTX2 buffer.

Validates the header magic, all section bounds, the DFD, and the level index. Returns ParseError on any structural problem.

pub fn data(&self) -> &[u8]

The raw KTX2 file bytes backing this reader.

pub fn header(&self) -> Header

Container-level metadata (dimensions, format, compression, etc.).

pub fn color_primaries(&self) -> Option<ColorPrimaries>

The color primaries used by this image (e.g. BT.709, BT.2020, etc.).

Shorthand for dfd::Basic::color_primaries. Returns None if there is no basic DFD block.

pub fn transfer_function(&self) -> Option<TransferFunction>

The transfer function used by this image (e.g. Linear, sRGB, PQ, etc.).

Shorthand for dfd::Basic::transfer_function. Returns None if there is no basic DFD block.

pub fn color_model(&self) -> Option<ColorModel>

The color model used by this image (e.g. RGB, YUV, etc.). Note that compressed formats will have a dedicated color model (e.g. BC1, ASTC) rather than RGB, even if the uncompressed data would be RGB.

Shorthand for dfd::Basic::color_model. Returns None if there is no basic DFD block.

pub fn is_alpha_premultiplied(&self) -> Option<bool>

The alpha premuliplication state of the image. true if the RGB channels are premultiplied by alpha, false if not.

Shorthand for dfd::Basic::flags’s dfd::DataFormatFlags::ALPHA_PREMULTIPLIED flag. Returns None if there is no basic DFD block.

pub fn writer(&self) -> Option<&str>

The program used to write this file, if specified by this file.

Shorthand for retrieving the KTXwriter key from the key/value data.

Returns None if:

• The file doesn’t contain a KTXwriter key.
• The KTXwriter value is not valid UTF-8.

pub fn levels(&self) -> impl ExactSizeIterator<Item = Level<'_>> + '_

Iterator over the texture’s mip levels, ordered largest to smallest (level 0 first, level N-1 last). Each Level contains the raw (possibly supercompressed) bytes for that level.

pub fn supercompression_global_data(&self) -> &[u8]

Supercompression Global Data (SGD) section. Currently only used by BasisLZ (scheme 1) for codebooks and image descriptors. Empty for other schemes.

pub fn dfd_blocks(&self) -> &[Block]

The Data Format Descriptor blocks. Most KTX2 files contain exactly one dfd::Block::Basic block. Use this to inspect color model, transfer function, primaries, and per-sample layout.

pub fn basic_dfd(&self) -> Option<&Basic>

The first dfd::Basic block, if present.

Nearly all KTX2 files contain exactly one basic DFD block. Returns None only for files that exclusively use non-standard descriptor blocks.

pub fn key_value_data(&self) -> KeyValueDataIterator<'_>

Iterator over key/value metadata pairs. Keys are UTF-8 strings; values are raw bytes (often NUL-terminated UTF-8, but not always).

Standard Keys

The KTX specification defines a number of standard keys. Most commonly, the KTXwriter key is used to indicate the tool that wrote the file.

For a full list of standard keys, see the KTX specification.