README
¶
Prepared KTX2 texture profile
Inspect accepts Karty's runtime profile of KTX 2.0: UASTC LDR 4x4, one RGBA
sample (or RGB with implicit alpha 1), Zstandard supercompression, straight alpha, 2D array layers and a complete
mip chain. It bounds the whole encoded resource to 64 MiB, individual dimensions
to 8192 and layers to 256. The aggregate inflated block bytes and the complete
RGBA fallback bytes are each bounded to the shared 256 MiB texture budget before
either allocation. Texture owners impose their stricter semantic bounds.
DFD color model 166, channel type 0 or 3, linear/sRGB transfer and no premultiplication
are required. The transfer applies to RGB; alpha remains linear. Both the current
16-byte plane declaration and the historical unsized plane declaration are
accepted. Sample layout, 4x4 block dimensions, exact mip sizes, disjoint sections,
zero padding and complete file consumption are checked. KTXwriter and
KTXwriterScParams are informational; only rd orientation and identity rgba
swizzle are accepted. Alternate shader channel interpretations are rejected.
Every mip must contain exactly one dictionary-free Zstandard frame with its declared content size matching the UASTC array block count. Window size and block framing are bounded. Inspection does not inflate compressed blocks, validate their decoded content, verify a frame checksum or validate the UASTC bitstream. Consumers must perform complete bounded inflation and transcoding before publication; structural inspection alone is not decoder validation.
The SDK retains immutable caller bytes and owns only small descriptor slices. It does not select a GPU, implement a transcoder or regenerate mipmaps.
References: KTX 2.0 specification, Khronos texture guidance.
InspectRGBA8 admits a separate lossless, linear RGBA8_UNORM + Zstandard array
profile for independently resident cell lighting. It requires exactly one mip,
explicit unsigned 8-bit RGBA samples and straight linear alpha. It returns the
exact decoded allocation size. Consumers must completely decompress and verify
the bounded frame before publication; inspection does not claim to validate the
compressed pixel payload or its checksum.
Documentation
¶
Overview ¶
Package ktx2 inspects Karty's bounded UASTC LDR 4x4 + Zstandard profile. It does not decode pixels or transcode GPU blocks.
Index ¶
Constants ¶
const ( HeaderSize = 80 MaxLevels = 14 MaxLayers = 256 MaxEncodedBytes = asset.MaxSourceAssetBytes )
Variables ¶
var (
ErrInvalid = errors.New("KTX2 UASTC texture is invalid")
)
Functions ¶
This section is empty.
Types ¶
type Info ¶
type Info struct {
Width, Height, Layers uint32
SRGB bool
HasAlpha bool // False means the fourth component is implicitly 1.
Levels []Level
InflatedBytes, RGBABytes uint64
}
Info describes a validated container and preflight allocation costs. RGBABytes is the full fallback texture size; InflatedBytes is the UASTC block size or the exact RGBA byte size for the separate lossless profile. Alpha is straight and linear even when RGB uses the sRGB transfer function.
func Inspect ¶
Inspect validates all ranges, the complete mip chain, DFD, supported metadata and Zstandard frame boundaries before any inflated or GPU allocation. It cannot validate compressed block contents: consumers must fully decompress and transcode before publishing a texture. Returned slices are newly owned.
func InspectRGBA8 ¶
InspectRGBA8 validates the separate lossless, linear RGBA8_UNORM + Zstandard array profile. It has exactly one level, straight alpha and no pixel transforms. Consumers must completely decompress and verify the frame before publication.
func InspectRGBA8Array ¶
InspectRGBA8Array validates prepared lossless RGBA8 arrays with linear or sRGB RGB transfer and explicit mip levels. Every level already contains all layers in GPU order; consumers only decompress complete validated frames.
Source Files