* PDF interpret: a glyph shown in a clipping mode clips even with no outline
A glyph shown in a clipping render mode (`4 Tr` to `7 Tr`) adds its outline to
the clipping path, and that clip applies to everything painted after `ET` until
the enclosing `Q`. When the glyphs shown have no outline -- a space, say -- the
clip they contribute is empty, and an empty clip admits nothing.
`interpret_window` applied a clip only once a glyph had contributed an outline,
so such a text object applied *no* clip and what followed painted unmasked.
A text object that shows no glyph at all is a different case and is left alone:
the clipping path is unchanged there, as readers leave it, and a glyph whose
outline is unavailable (Type 3) leaves the real clip unknown, so both stay
unclipped. pdf.js draws the same line in `endText`: it builds the clip from the
glyphs shown, empty outlines and all, and applies none when none were shown.
Measured on a page filled red behind the text object, Preview (CoreGraphics)
and Firefox (pdf.js) agreeing on the case this changes:
a space shown in 7 Tr before: the fill paints after: nothing paints
no glyph shown in 7 Tr unchanged: the fill paints
Companion to storytold/pdfcraft#3451.
The first push of this branch also carried 803 build-artifact files from
`crates/pdf/read-only-contract/target/`, which `.gitignore` did not cover: its
`/target` is anchored to the repository root, so a sub-crate's own build
directory is not ignored. Recommitted without them, and `target/` added so the
next one cannot slip in either (#185 review).
* pdf: test visible glyphs in a clipping mode, and what each clip leaves on the page
---------
Co-authored-by: Hamza <mail.hamzanaveed@gmail.com>
`path_as_rect` in the vendored hayro-interpret took any five-element path whose
points reached all four corners of its bounding box for that box. An open
polyline of one MoveTo and four LineTo passes that test when its ends sit on
the corners, so it was drawn as a closed rectangle and a clip of that shape was
dropped. VectorCraft #2920: an open zigzag in an .ai file opened as its
bounding box.
Port PdfCraft #3327 (hayro-interpret patch 35): a path is a rectangle only when
its four points are distinct, each step runs along one axis, and the last point
returns exactly to the first, closed with ClosePath or a fourth line.
Tests: `rectangles` in crates/pdf/tests/interpretation.rs (4 of its 5 tests
fail without the change) and `context::path_as_rect_tests` in the vendored
crate. SOURCE.json and the reader ledger record the change.
Hamza NaveedandHamza
Don Omondi
skylar taylor-barrick