Codec.Ktx2.Read

Block-by-block extraction of data from a KTX2 file.

• Acquire a Context. Header data is available without reading the rest of the source.
• Read levels index. An memory allocation information is available.
• Consult supercompressionScheme and copy level data to decompression staging buffer or GPU memory directly.

Extra information is available when needed:

• Image metadata.
• Data Format Descriptor. Khronos Basic descriptor block is usually present, but a file may contain more.
• Supercompression data shared between all the levels.

Documentation

data Context a

A bundle of source data and header information used by reader functions.

Constructors

Context

Fields

• context :: a
• header :: Header

Instances

Show (Context Handle)

Defined in Codec.Ktx2.Read

Methods

showsPrec :: Int -> Context Handle -> ShowS

show :: Context Handle -> String

showList :: [Context Handle] -> ShowS

Show (Context ByteString)

Defined in Codec.Ktx2.Read

Methods

showsPrec :: Int -> Context ByteString -> ShowS

show :: Context ByteString -> String

showList :: [Context ByteString] -> ShowS

type FileContext = Context Handle

Context for reading from a file. The file has to be seekable.

open :: MonadIO io => FilePath -> io FileContext

close :: MonadIO io => FileContext -> io ()

type BytesContext = Context ByteString

Context for reading from memory. Useful when the data is embedded in a module or otherwise already available in full.

bytes :: MonadIO io => ByteString -> io BytesContext

Reading blocks

Image data

levels :: (ReadChunk src, MonadIO io) => Context src -> io (Vector Level)

Read the level index.

levelToPtr :: (ReadLevel src, MonadIO io) => Context src -> Level -> Ptr () -> io Bool

Copy level data into a provided pointer.

The buffer must be large enough for the byteLength of the Level being accessed.

levelData :: (ReadChunk src, MonadIO io) => Context src -> Level -> io ByteString

Copy level data into a managed buffer.

Supplemental information

dataFormatDescriptor :: (ReadChunk src, MonadIO io) => Context src -> io DFD

Read DFD block data.

Further processing is performed according to descriptor vendortypeversion. E.g. Codec.Ktx2.DFD.Khronos.BasicV2.

keyValueData :: (ReadChunk src, MonadIO io) => Context src -> io KeyValueData

Read and parse Key-Value Data block.

supercompressionGlobalData :: (ReadChunk src, MonadIO io) => Context src -> io ByteString

Get a copy of global supercompression data.

Decoding internals

class ReadChunk a where

Methods

readChunkAt :: MonadIO io => a -> Int -> Int -> io ByteString

Get a chunk of data.

The context handle must have enough information to check whether requested region is safe to access. Throw ChunkError when it isn't possible to fullfill the request.

Instances

ReadChunk Handle

Defined in Codec.Ktx2.Read

Methods

readChunkAt :: MonadIO io => Handle -> Int -> Int -> io ByteString

ReadChunk ByteString

Defined in Codec.Ktx2.Read

Methods

readChunkAt :: MonadIO io => ByteString -> Int -> Int -> io ByteString

newtype ChunkError

Constructors

ChunkError Text

Instances

Exception ChunkError

Defined in Codec.Ktx2.Read

Methods

toException :: ChunkError -> SomeException

fromException :: SomeException -> Maybe ChunkError

displayException :: ChunkError -> String

Show ChunkError

Defined in Codec.Ktx2.Read

Methods

showsPrec :: Int -> ChunkError -> ShowS

show :: ChunkError -> String

showList :: [ChunkError] -> ShowS

Eq ChunkError

Defined in Codec.Ktx2.Read

Methods

(==) :: ChunkError -> ChunkError -> Bool

(/=) :: ChunkError -> ChunkError -> Bool

decodeAt :: forall a src io. (ReadChunk src, Show a, Typeable a, MonadIO io) => src -> Int -> Int -> Get a -> io a

Get a chunk of data and run a decoder on it.

data DecodeError

Constructors

DecodeError ByteOffset Text

Instances

Exception DecodeError

Defined in Codec.Ktx2.Read

Methods

toException :: DecodeError -> SomeException

fromException :: SomeException -> Maybe DecodeError

displayException :: DecodeError -> String

Show DecodeError

Defined in Codec.Ktx2.Read

Methods

showsPrec :: Int -> DecodeError -> ShowS

show :: DecodeError -> String

showList :: [DecodeError] -> ShowS

Eq DecodeError

Defined in Codec.Ktx2.Read

Methods

(==) :: DecodeError -> DecodeError -> Bool

(/=) :: DecodeError -> DecodeError -> Bool

class ReadLevel a where

Methods

readLevelTo :: MonadIO io => a -> Level -> Ptr () -> io Bool

Instances

ReadLevel Handle

Defined in Codec.Ktx2.Read

Methods

readLevelTo :: MonadIO io => Handle -> Level -> Ptr () -> io Bool

ReadLevel ByteString

Defined in Codec.Ktx2.Read

Methods

readLevelTo :: MonadIO io => ByteString -> Level -> Ptr () -> io Bool