15d82b5b9c
Highlight appearances written by other editors are a transparency group whose content is filled with `/BM /Multiply`. Every `/Group` form got a layer of its own, so the Multiply blended with that layer's transparent backdrop and the layer then covered the page as an opaque block. Vendored hayro-interpret patch (28): a group that is neither isolated nor knockout composites its elements with the backdrop (ISO 32000-2 §11.4.7), so when it is entered at full opacity with no soft mask and Normal blending there is nothing for a layer to add, and its content is drawn straight onto the page. `/I` and `/K` are read from the group dictionary. An isolated group keeps its blank backdrop; a knockout group or one entered at partial opacity, under a soft mask or with a blend mode keeps its layer. Test: `raster::tests::a_multiply_highlight_inside_a_transparency_group_keeps_the_text` (the appearance drawn as an annotation and from page content, with `/I false /K false` spelled out and with no group at all; an isolated group as a control; a group entered at half opacity still composited as one). It fails before the fix with the text pixel yellow instead of black. parity: view.render-transparency cites it and says what is still approximated. Claude-Session: https://claude.ai/code/session_01RUNQSPVXx3dDBabRZHAnjz Co-authored-by: Claude Fable 5.1 <noreply@anthropic.com> Co-authored-by: Brandon Thomas <echelon@gmail.com>
hayro-interpret
A crate for interpreting PDF files.
This crate provides an abstraction to interpret the content of a PDF file and render them
into an abstract [Device], which clients can implement as needed. This allows you, for
example, to render PDF files to bitmaps (which is what the hayro crate does), or other formats
such as SVG.
It should be noted that this crate is still very much in development. Therefore it currently lacks pretty much any documentation on how to use it. It's current API also only really makes it useful for rendering to PNG or SVG, though this will be improved upon in the future.
Examples
See the examples folder on the GitHub repository. Apart from that, you can also consult
the implementation of hayro and hayro-svg to get an idea on how to use this crate.
Safety
This crate forbids unsafe code via a crate-level attribute.
Cargo features
This crate has one optional feature:
embed-fonts: PDF processors are required to support 14 predefined fonts that do not need to be embedded into a PDF file. If you enable this feature, hayro will embed a (permissively-licensed) substitute for each font, so that you don't have to implement your custom font loading logic. This will add around ~240KB to your binary.
License
Licensed under either of
- Apache License, Version 2.0 (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
- MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)
at your option.
PdfCraft function limits
The PdfCraft patch rejects function construction after 64 nested functions or 10,000 total
function nodes, including repeated references, and detects cycles on the current path. Shared
children in different branches remain valid. Stitching functions reject empty or unresolved
child lists instead of silently truncating them. Calculator functions have a shared limit of 64
procedure levels and 10,000 parsed tokens (operators and procedure openings); evaluation has
its own 10,000-operator limit across selected branches. These are implementation resource
limits rather than PDF format limits. Rejection returns the existing None, and the optional
logging feature reports the reason and limit; no new interface warning is introduced.
Calculator integer division without an integer result is also rejected. Bit shifting discards bits beyond the 32-bit word and fills with zeroes, including logical right shifts of negative words; rotation accepts the full signed shift range without negating the minimum integer. Fixed-size operand and procedure-stack overflow errors propagate instead of truncating work. Normal function signatures and supported color/transfer-function behavior remain unchanged.