Dylan M. Taylor
473fe09862
* Add craft-kra: Krita archives, maindoc.xml and tiled pixel files, from PhotoCraft The format half of PhotoCraft's Krita import (crates/io/src/kra.rs and kra/tiles.rs at abeb16c96): the archive and its mimetype, maindoc.xml as a tree of nodes with the attributes Krita writes, the tiled pixel files and their LZF compression. The mapping onto a document (blend modes, surfaces, warnings) stays in the app. maindoc.xml is read with craft-xml and the archive with the zip crate. * craft-kra: a default pixel is read under a one-pixel limit The .defaultpixel member (1 to 8 bytes) was inflated under the 1 GiB layer-file limit before its size was checked. Ported from storytold/photocraft#11138. * craft-kra: the tile table is not reserved from the declared count A tiled file may declare one record per eight bytes of its size. Reserving that many up front is 3 GiB for a 1 GiB member that holds none of them. Reserve 65,536 records at first and grow as records are read, never past the declared count. Ported from storytold/photocraft#13309.
craft-kra
Krita documents (.kra, .krz), read. Written from files Krita writes; no Krita code is used.
A Krita document is a ZIP whose first, stored entry is mimetype = application/x-krita. It
holds maindoc.xml (the node tree), one tiled pixel file per paint layer and mask under
<image name>/layers/, the ICC profile in <image name>/annotations/icc, and Krita's rendering
of the whole image in mergedimage.png.
is_kra,zip_mimetype: recognise an archive by its first entry, without unzipping.Archive::open: checks the mimetype and readsmaindoc.xmlinto anImageofNodes. Every node kind is kept with the attributes the file has (nodetype,compositeop,opacity, offsets,colorspacename,filename, masks, ...). No pixel is read.Archive::layer_file,default_pixel,icc_profile,merged_image: the other entries, each with a size limit.tiles::TileFile: a tiled pixel file's header and tile table;decodegives one tile's interleaved pixels.tiles::lzf_decompressis the LZF inside.tiles::Space: the pixel layouts read (RGBA,RGBA16,GRAYA,GRAYAU16, and one-byte masks), withrgbaandsamplesto turn Krita's B, G, R, A little-endian pixels into channel order.
What a node kind, a composite operation or a colour space means to an application is not decided here. There is no writer.
Limits
| Limit | Value |
|---|---|
| Canvas side | 300,000 px (MAX_SIDE); offsets and tile positions up to four times that |
| Canvas area | 1 GiB at 8 bytes per pixel (MAX_PIXEL_BYTES) |
<layer> nodes |
8192 (MAX_NODES) |
maindoc.xml |
32 MiB, 512 levels of nesting, no internal DTD subset |
| A pixel file, inflated | 1 GiB (MAX_LAYER_FILE) |
| ICC profile | 16 MiB |
| Tile | 1024 × 1024 px, 64 bytes per pixel, header lines of 256 bytes |
A pixel file is decoded one tile at a time into a buffer the caller owns, so the memory a document takes is the caller's to budget.
ZIP
The archive is read with the zip crate directly. zip_mimetype (the leading stored mimetype
entry) and the bounded entry read are the same in every mimetype-first ZIP format and belong in a
shared ZIP crate once there is one.