effectcraft/crates/pdf

effectcraft-pdf

Vector footage from PDF files, PDF-compatible Adobe Illustrator files (.ai, which are PDF documents) and Encapsulated PostScript (.eps). Files parse into the same render tree as SVG (effectcraft_svg::Doc), so they rasterise at any scale (Continuously Rasterize), convert to shape layers (Layer ▸ Create ▸ Create Shapes from Vector Layer) and import as compositions with one layer per file layer (File ▸ Import ▸ Composition).

Specifications used: ISO 32000-1:2008 (PDF 1.7; the public Adobe edition) for the file structure, filters, content streams, graphics state, colour spaces, functions, shadings, text, fonts, images, patterns, transparency (blend modes, soft masks) and optional content; Adobe Technical Note #5176 (The Compact Font Format Specification) and #5177 (The Type 2 Charstring Format) for CFF font programs; Adobe Type 1 Font Format (version 1.1) for Type 1 font programs; the PostScript Language Reference, third edition and the Encapsulated PostScript File Format Specification 3.0 for EPS; ITU-T T.4 (07/2003) and ITU-T T.6 (11/1988) for CCITT fax images. TrueType font programs are read through skrifa and JPEG (DCT) images through zune-jpeg (both permissively licensed, pure Rust). PDF document/object loading uses the shared craft-pdf parser described below. The retained drawing, PostScript, font and filter implementations were developed from the public specifications without copying third-party implementations. Test files (including the CFF and Type 1 fonts and the CCITT data) are generated in code (write and the tests). One CCITT fixture was produced once by libtiff's tiffcp (an external encoder used only as a fixture generator, like ffmpeg elsewhere) to check the code tables against an independent implementation.

What is read

• Structure: craft-pdf resolves cross-reference tables/streams and indirect objects into the app's existing object model. References retain object and generation numbers. A bounded compatibility repair recovers referenced objects from object streams when damaged xrefs omit them; every recovery or unresolved reference is reported in Doc::skipped (up to 64 messages). The existing page tree preserves inherited resources, MediaBox / CropBox and /Rotate. Content/image filters remain app-owned: Flate (with PNG predictors), LZW, ASCIIHex, ASCII85, RunLength and CCITTFax. Encrypted files remain refused; page_count returns zero when the reader refuses a document.

• Content: q/Q, cm, line width / cap / join / miter / dash, ExtGState (CA, ca, LW, LC, LJ, ML, D), all path construction and painting operators (non-zero and even-odd), clipping (W, W*) as clipping groups, colour in DeviceGray / RGB / CMYK, ICCBased (by component count), CalGray / CalRGB, Lab, Indexed, Separation and DeviceN (tint transforms of function types 0, 2 and 3), axial and radial shadings as pattern fills and through sh, form XObjects (matrix, bounding-box clip, nested resources).

• Layers: top-level optional-content marked sequences (/OC … BDC, Illustrator's layers) become the document's layers, named after their OCG; content outside them is gathered into layers "Layer N".

• EPS: a PostScript interpreter for the subset exported vector EPS uses: operand and dictionary stacks, procedures and def/bind/load/where, arithmetic, comparisons, if/ifelse/for/repeat/loop/forall, arrays and strings, gsave/grestore, save/restore, matrices (concat, translate, scale, rotate, transform …), path construction including arc/arcn and relative operators, fill/eofill/stroke, clip/eoclip, rectfill/rectstroke/rectclip, gray / RGB / CMYK / HSB colour. DOS EPS binary headers and %%HiResBoundingBox / %%BoundingBox are honoured; %%BeginData / %%BeginBinary / preview sections are skipped. Text: findfont / findresource, scalefont, makefont, selectfont, setfont, currentfont, definefont (re-encoded copies made with forall and a new /Encoding), StandardEncoding / ISOLatin1Encoding, show, ashow, widthshow, awidthshow, xshow / yshow / xyshow, kshow / cshow (the procedure is not run), glyphshow, charpath (glyph outlines join the path, e.g. for clipping) and stringwidth. Fonts embedded in the file — Type 1 programs (… currentfile eexec … cleartomark, binary or hexadecimal) and CFF font sets (StartData) — are found by name before the program runs; other fonts are drawn with the bundled fonts as for PDF. Each show becomes one compound shape named "Text: …".

• Text (§9): text objects and state (Tc, Tw, Tz, TL, Ts, Tr, Tf, Td, TD, Tm, T*), Tj, TJ (with kerning), ' and "; render modes fill / stroke / fill-and-stroke / invisible and the clipping modes (glyph outlines clip until Q). Glyphs become outlines (one compound shape per show operator, named "Text: …" after the string through ToUnicode or the glyph names). Fonts: simple fonts with /Widths, base encodings (Standard, WinAnsi, MacRoman), /Differences and built-in encodings; composite (Type 0) fonts with Identity-H / Identity-V and embedded CMaps (cidrange / cidchar, /WMode), /W and /DW widths, vertical metrics (/W2, /DW2: the vertical displacement and the position vector from the horizontal to the vertical origin) and CIDToGIDMap. Embedded programs: TrueType (FontFile2, cmap (3,1) / (3,0) / (1,0) and post names), CFF (FontFile3 /Type1C, /CIDFontType0C, /OpenType; name-keyed and CID-keyed with FDArray / FDSelect, flex, hint masks, seac), Type 1 (FontFile, eexec, /Subrs, flex and hint replacement through othersubrs, seac) and Type 3 glyph procedures. Fonts that are not embedded (the standard 14 and others) are drawn with the bundled OFL fonts by name: Inter (sans serif, Regular / Italic / SemiBold / Bold), Noto Serif (Times and other serif names) and JetBrains Mono (Courier), with their own advances when the PDF gives no widths.

• Images (§8.9): image XObjects and inline images (BI … ID … EI, abbreviated keys); 1, 2, 4, 8 and 16 bits per component with /Decode; any colour space above (Indexed through its palette, ICCBased through its /Alternate space); DCT (JPEG, through zune-jpeg; Adobe inverted CMYK) and the general filters; stencil masks (/ImageMask) in the fill colour; soft masks (/SMask images) and colour-key and explicit /Masks. Images become image nodes of the render tree (bilinear, box-filtered when minified).

• Transparency: blend modes (/BM, all 16 PDF modes) and soft masks in the graphics state (/SMask with /S /Luminosity and /BC backdrops, or /S /Alpha) as groups of the render tree, open until the state changes or Q: what is painted while a soft mask is set is rendered to an offscreen buffer and the mask applies to that combined result. Transparency group XObjects (§11.6.6) composite as one object: the current alpha, blend mode and soft mask apply to the group's result, and its contents start from the initial alpha. Isolated groups (/I true) composite over a transparent backdrop; non-isolated groups over the page, with the backdrop's contribution removed again (§11.4.8) so group alpha and masks apply only to the group; knockout groups (/K true) composite each child with the group's initial backdrop. Clipping groups are not transparency groups: blend modes inside them reach the backdrop.

• Patterns: tiling patterns (coloured and uncoloured, XStep / YStep, the cell clipped to /BBox, at most 4096 tiles per fill) for fills; strokes with a tiling pattern use its colour (uncoloured) or grey.

• Shadings (§8.7.4.5): axial and radial shadings become gradients. Function-based shadings (type 1, Domain and Matrix) and the mesh shadings — free-form (type 4, edge flags 0–2) and lattice-form (type 5) Gouraud-shaded triangle meshes, Coons patch meshes (type 6) and tensor-product patch meshes (type 7, flags 0–3 sharing the previous patch's edges) with BitsPerCoordinate / BitsPerComponent / BitsPerFlag / Decode and an optional parametric Function — are rasterised into an image node in page space (up to 4 pixels per point, at most 1024 pixels a side, 2×2 supersampled): patches are tessellated into triangles (up to 48×48 cells), colours (or t) interpolated across each triangle. They paint through sh (their own extent only) and as shading-pattern fills (clipped to the path).

• Functions: sampled (one or several inputs, multilinear interpolation), exponential, stitching and PostScript calculator (type 4) functions.

• Pages: any page ([parse_page], [page_count]); File ▸ Import takes page (from 1) and the Import dialog asks for it; footage remembers its page (Footage::page).

Limitations

• JPX and JBIG2 images, predefined CJK CMaps other than Identity-H / Identity-V, and transfer functions (/TR) are not read. JBIG2 is deferred. Predefined CMaps (UniGB-UCS2-H, 90ms-RKSJ-H …) need the CMap data, and there is no permissively licensed pure-Rust source of it (Adobe's CMap resources are Adobe assets, which this project does not ship); text in such fonts is reported in Doc::skipped. Mesh shadings are raster images in the render tree (sharp to about 4× the document size). Knockout uses each child's coverage as its shape (a child with constant opacity knocks out fully where it covers). What a document skipped is listed in Doc::skipped.
• Illustrator EPS files whose drawing depends on Adobe's procedure-set resources (defined in the file through constructs beyond this subset) and Level 3 shfill gradients in EPS draw only what the subset understands; save such artwork as PDF-compatible .ai or PDF instead. EPS images are skipped; Type 3 (procedure) fonts defined in EPS files draw nothing (reported).
• Create Shapes from Vector Layer: clips that enclose the whole page become layer masks (the first clip Add, later ones Intersect). Nested clipping groups become Merge Paths: each closed shape inside them is a group with its geometry merged into one compound path, the clip paths, and Merge Paths ▸ Intersect before its fill and stroke, so fills match exactly and strokes follow the clipped outline; open stroked paths inside clips stay unclipped. Blend modes become the groups' Blend Mode. Images become footage layers: each is written as <file> Image <n>.png next to the source and imported, placed by its matrix (anchor at its top-left corner; position, rotation and scale — a skew is reported) and parented to the shape layer; the shapes drawn between images go to shape layers of their own (<name> Outlines <n>), so the layer stack keeps the document's paint order. Soft masks, and the clips and masks of images, are not converted (the command's skipped list says so).

Shared parser setup and bounds

The workspace pins craft-pdf to craft-libs Git revision 89dcbb3060377a26c99a6d80caa16084366704c4, with default-features = false and only the explicit read feature. This excludes the backend's bundled fonts and Adobe CMaps and preserves EffectCraft's font and asset policies. The shared parser does not change the supported drawing operators, image codecs, continuously rasterized SVG tree, editable shapes, or EPS interpreter.

The root Cargo patch pins Hayro-syntax to the same storytold/craft-libs revision. cargo xtask pdf-deps checks this graph and refuses an enabled Hayro interpreter, rasterizer or CMap dependency. The shared revision must be published before a fresh app checkout can resolve it; no sibling checkout is required.

Input is limited to 512 MiB. The object adapter admits at most 100,000 document/referenced objects, 1,000,000 converted values and 64 inline nesting levels, with a 512 MiB retained object-data budget. References are queued once rather than recursively expanded. Native unwinding panics during shared loading or lazy object conversion become an error and discard partial state. These limits are not an overall process-memory or execution-time guarantee; WASM aborts and process-wide allocation failures cannot be caught. Missing or repaired objects are reported rather than silently presented as a complete import.

The shared parser receives EffectCraft's existing ordinary object/xref stream limit at open: 256 MiB on 64-bit targets and 64 MiB on 32-bit targets, including WASM. Immutable document limits apply during normal parsing, initial xrefs, fallback and repair. Malformed object-stream compatibility recovery also obeys that limit and the adapter's remaining retained-data budget. Content/image filter decoding still uses EffectCraft's existing bounded filter chain; the retained-data cap is not a bound on every parser cache or temporary allocation.