Files
63363ec438 M3: rasters reach egui without a copy on the UI thread (#555)
* M3: rasters reach egui without a copy on the UI thread

Every page, tile and thumbnail raster was copied pixel by pixel on the UI
thread (`ColorImage::from_rgba_premultiplied`), because egui's `Color32` is
4-byte aligned and a `Vec<u8>` isn't. That is 0.5 ms per 1024² tile, 5.4 ms
for a 33 MB page and 36 ms for a 197 MB page, against a 16.7 ms frame.

hayro, vendored patch 7: `render_size` and `render_into` render into a buffer
the caller allocates. `render` is `render_into` on a new pixmap, so its output
is unchanged. pdfcraft-render renders straight into `Pixels`, the same
premultiplied RGBA bytes kept in one 4-byte word per pixel. `Pixels`
dereferences to `[u8]`, so every reader of `RenderedPage::rgba` compiles
unchanged. The canvas reinterprets the words as `Color32`s and hands them to
egui as they are.

Pixels are identical: all 33 renders of #260's test file hash the same. The
UI-thread copy is gone, and rendering a 6182×8000 page takes 67 ms instead of
71–76 ms.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* M3: render_into leaves a buffer of the wrong length untouched instead of reaching vello's assert

* M3: regression test for render_into with a wrong-length buffer

---------

Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>
Co-authored-by: Brandon Thomas <echelon@gmail.com>
2026-10-09 12:28:46 -04:00
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hayro

Crates.io Documentation

A crate for rendering PDF files.

This crate allows you to render pages of a PDF file into bitmaps. It is supposed to be relatively lightweight, since we do not have any dependencies on the GPU. All the rendering happens on the CPU.

The ultimate goal of this crate is to be a feature-complete and performant PDF rasterizer. With that said, we are currently still very far away from reaching that goal: So far, no effort has been put into performance optimizations, as we are still working on implementing missing features. However, this crate is currently the most comprehensive and feature-complete implementation of a PDF rasterizer in pure Rust. This claim is supported by the fact that we currently include over 1000 PDF files in our regression test suite. The majority of those have been scraped from the pdf.js and PDFBOX test suites and therefore represent a very large and diverse sample of PDF files.

As mentioned, there are still some serious limitations, including lack of support for encrypted/password-protected PDF files, blending and isolation, knockout groups as well as a range of smaller features such as color key masking. But you should be able to render the vast majority of PDF files without too many issues.

Safety

This crate forbids unsafe code via a crate-level attribute.

Examples

For usage examples, see the example in the GitHub repository.

Cargo features

This crate has one optional feature:

  • embed-fonts: See the description of hayro-interpret for more information.

License

Licensed under either of

at your option.