Struct Header 

pub struct Header {
    pub format: Option<Format>,
    pub type_size: u32,
    pub pixel_width: u32,
    pub pixel_height: u32,
    pub pixel_depth: u32,
    pub layer_count: u32,
    pub face_count: u32,
    pub level_count: u32,
    pub supercompression_scheme: Option<SupercompressionScheme>,
    pub index: Index,
}

Container-level metadata (dimensions, format, layout) from the 80-byte KTX2 file header.

Fields

format: Option<Format>

Vulkan VkFormat enum value. None means VK_FORMAT_UNDEFINED, used for supercompressed universal formats (e.g. Basis Universal) where the actual format is determined at transcode time.

type_size: u32

Size in bytes of the data type used for GPU upload, for endian conversion on big-endian systems (all image data in KTX2 is little-endian).

Must be 1 when format is None (VK_FORMAT_UNDEFINED) or for block-compressed formats (_BLOCK suffix). For packed formats (_PACKxx), equals the byte size of the packed unit xx / 8 (e.g. 4 for _PACK32). For unpacked formats, equals the byte size of a single component (e.g. 2 for R16G16B16_UNORM). For combined depth/stencil: 2 for D16_UNORM_S8_UINT, 4 for all others.

pixel_width: u32

Texture width in texels. Always non-zero.

pixel_height: u32

Texture height in texels. 0 for 1D textures.

pixel_depth: u32

Texture depth in texels. 0 for non-3D textures.

layer_count: u32

Number of array layers. 0 means a non-array texture (1 implicit layer). Use layer_count.max(1) when allocating storage.

face_count: u32

Number of cubemap faces. 6 for cubemaps, 1 otherwise.

level_count: u32

Number of mip levels. 0 means the full mip chain should be generated from level 0 by the application if needed. Use level_count.max(1) when iterating stored levels.

supercompression_scheme: Option<SupercompressionScheme>

Compression applied to mip level data. None means uncompressed. When set, each Level::data must be decompressed before use.

index: Index

Raw byte offsets/lengths for the DFD, KVD, and SGD sections. For most use cases, prefer Reader::dfd_blocks, Reader::key_value_data, and Reader::supercompression_global_data instead.

Implementations

impl Header

pub const LENGTH: usize = 80

Size of the KTX2 header in bytes (12-byte magic + 68-byte fields).

pub fn from_bytes(data: &[u8; 80]) -> Result<Self, ParseError>

Decode a header from exactly 80 bytes. Validates the magic bytes and rejects zero pixel_width or zero face_count.

pub fn as_bytes(&self) -> [u8; 80]

Serialize this header back to 80 bytes (including magic).

Trait Implementations

impl Clone for Header

fn clone(&self) -> Header

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Header

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

Formats the value using the given formatter.

impl PartialEq for Header

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

Tests for self and other values to be equal, and is used by ==.

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

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Copy for Header

impl Eq for Header

impl StructuralPartialEq for Header