The remaining flags under crates/engine/src/cmd that read a boolean with
get(..).and_then(Value::as_bool).unwrap_or(..) now go through switch_or,
so a value such as "false" or 1 is an error instead of the default.
Omitting a flag or giving null keeps the old behavior.
- effect.move: copy
- aligned on the appearance.*, stroke.set, transparency.set and effect.*
commands, checked before any early return
- transparency.viewOpacityMask: on
- view.printTiling: on
- plugin.install: replace and allowHeavy, checked for every plug-in
- edit.clear: guides, and path.deleteAnchors' read of it
- text.create and text.createInPath: vertical (already refused by
check_switches, so their behavior is unchanged)
Loading a variable library deleted every variable of the document with its
bindings, including a text variable of the same name that the library
declares. Text made dynamic and then given a library's variable name lost its
binding, so selecting the library's data sets changed nothing. Such a
variable now stays bound, and the library's data sets change its text; other
variables are deleted as before.
The area an Intertwine member is drawn over another in was exactly the
overlap face, so its edge lay on the edge of the member below. Both edges
were anti-aliased, and the member below showed through as a thin line along
them. The area now reaches 2 pt past the face into the parts where only the
raised member paints (where drawing it again changes nothing), so its edge
lies inside that member.
Direct Selection kept only one picked point of a blend's spine. Shift-click
now adds a point of the same spine or takes it away, and dragging any picked
point moves them all. object.blend.spine.moveAnchor takes `with`, the other
points to move by as much, with the key objects on them, in one undo step.
The Join tool drew a segment between the open ends of two crossing paths
instead of trimming what overhangs the crossing. path.joinScrub now looks for
two crossing open subpaths whose overhanging ends the scrub runs over, cuts
both at the crossing and joins the kept parts there with a corner, in one undo
step. Without a crossing the endpoint join is unchanged.
The reader measured a symbol's definition only to find the page art an
instance covered, so every file with a placed symbol instance opened
with that instance as drawn art, or as its page.
- Each `%AI14_BeginSymbol` definition is read by a reader of its own into
a symbol of the document, with its art (in the symbol's space, y down),
the registration point its dictionary gives
(`AI13PatternRegistrationType`, 1 to 9 from the top left) and the
instances of other symbols in its art. A definition whose art isn't
read whole isn't kept: type, placed files, non-native art, pattern
fills, a gradient or an image the reader can't read or place, and
anything else the reader doesn't read. Its instances come in as the
page draws them, within the box of the art that is read. A definition
that holds an instance of a symbol the file doesn't have isn't kept
either, nor is a definition holding an instance of one of those, and
their instances aren't read. A definition after the first layer isn't
read.
- `%AI24_BeginSymbolList` orders the symbols as the Symbols panel lists
them. A name read twice is numbered ("Dot 2"), and instances name the
first symbol with the file's name.
- `/SymbolInstance` with `/SymbolRef` and `/RTransformMatrix` comes in as
a live instance, with the hide and lock set before it and the opacity,
blending mode, isolation and knockout of the `Xy` after it, as a
group's. An instance with appearance changes of its own
(`AI19SymbolAppearanceMap`), of a symbol that isn't read, or placed
only by `/Matrix` or `/Transform`, comes in as the page draws it.
- Symbol art takes the gradients and art styles read before it, and an
object in it linked to a listed graphic style keeps the link.
- In a symbol's art, the matrices of instances, gradients and images are
read in the canvas's space, y up, about the canvas point of the ruler
origin. Without `%AI3_TemplateBox` an image can't be placed, so the
symbol isn't kept.
- At most 4,096 definitions are read, and a symbol list names at most
16,384 symbols.
Tests: reader tests for each case above, and fuzz cases for damaged and
hostile symbol data.
links.findFiles hashes files up to MAX_HASHED (1 << 30 bytes) and compares larger ones by size only. The params text, the module doc comment and docs/mcp.md said 1 GB; they now say 1 GiB.
An art style with a Distort & Transform effect opened every object but
type as its drawn look. Objects other than type now open as themselves
with these effects live:
- Any object takes a Tweak that moves nothing and Pucker & Bloat at 0,
beside the effects it already took.
- A path, compound path or group takes Transform without copies, or a
Free Distort whose corners make a parallelogram, when it is the only
effect. Neither the style nor anything in the object may paint with a
gradient or pattern. Everything in the object must be a path, compound
path or group without a clip, an opacity mask or effects of its own.
When Transform scales, rotates or reflects, nothing in the object may
be stroked.
- An unstroked path or compound path whose segments are all straight
takes Twist when it is the only effect.
Other objects keep the drawn look, as do Zig Zag, Pucker & Bloat of
another amount, a Free Distort with other corners and Transform copies.
Docs: docs/file-format-parity.md, docs/target-app-parity.md.
Hovering looks up the bounds of every selected object, and each lookup
went through the memo key check, which compares the whole selection. That
made a hover quadratic in the selection: 1.5 s at 50,000 selected paths.
The walk now checks the key once and shares it across its lookups.
Part of #1280.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
A .ai or EPS graphic style library holds graphic styles and their list
in its editing data but no layers, so it came in as its PDF part or
page with the default styles, and Other Library listed those. A file
read as its PDF part or page, because it has no layers or its layers
can't be used, now gets the styles of its list, in list order, as a
file read from its layers does: File > Open shows them in the Graphic
Styles panel and Other Library lists them in a library panel.
Style stroke weights and effects are scaled by the Large Canvas factor
of an EPS, and for a .ai whose editing data is in the units of its
pages by the pages' UserUnit or the declared Large Canvas scale.
Part of #3349
links.findFiles' params text and docs/mcp.md now say that the saved path's
parent-folder steps (.., or the empty components of a classic Mac :: run)
are resolved and that . components in a slash path are skipped before
folder names are compared.
A library colour kept only its values, so a spot colour came back as a
process colour once its document was closed or in a new one. The library
now keeps a spot colour's ink name and tint (in the .vclibrary file too);
library.use links the paint to the document's spot swatch of that name,
adding it when the document has none of that colour, in one undo step.
A spot swatch dropped on the Libraries panel brings its name and tint.
A saved link path such as `Disk:Projects:Art::photo.png` (classic Mac OS)
or `/old/Projects/Art/../photo.png` names a file in `Projects`. Ranking
the files found compared `Art` first, so a file under a folder named
`Art` came before one under `Projects`. The `::` runs and `..` components
are now resolved before the folder names are compared.
Drawing a new Pencil or Paintbrush stroke kept the earlier selection: the engine's
`insert_look` selects the new path only when `keepSelected` is on, and with it off left the
selection as it was. Illustrator starts such a stroke by dropping the selection, and the new
stroke is not selected with Keep selected off, so the command now clears the selection after
inserting a new path.
What stays as before: with Keep selected on a stroke selects only the path it draws (the
earlier selection is replaced); a stroke that continues or redraws a selected path with Keep
selected off deselects that path and keeps the rest of the selection. The Blob Brush keeps its
own Keep selected and Merge only with selection options.
`path.freehand`'s documentation, the engine test
`pencil_with_keep_selected_off_leaves_nothing_selected` and the Tool Options test
`the_new_path_is_selected_only_with_keep_selected_on` cover the three cases. Docs: roadmap,
target-app-parity and ui-parity carry the change.
- Extend vectorcraft-geom::shapes with clean-room open/pie/chord/arc ellipse and rectangle builders, per-corner radii, polygon/star corner rounding and deterministic vertex randomization, logarithmic/Archimedean spiral divergence and inner radius, and perspective/isometric 3D box face builders.
- Isolate 3D Box and customizable shape parameters as a VectorCraft add-on under crates/*/src/**/addons/:
- crates/tools/src/addons/box3d.rs (Box3dTool and CustomShape extras stored under Node::extras["vc-shape-tools"])
- crates/engine/src/cmd/addons/shapes.rs (addon.shapes.rectangle, addon.shapes.ellipse, addon.shapes.polygon, addon.shapes.star, addon.shapes.spiral, addon.shapes.box3d, and addon.shapes.configure)
- crates/ui-egui/src/addons/shapes.rs (Object > Plug-ins > 3D Box > 3D Box Tool and context-sensitive Control bar options)
- Keep crates/engine/src/cmd/create.rs, crates/tools/src/shape.rs, and crates/tools/src/draw2/family.rs byte-for-byte identical to main.
- Add translations for "3D Box" and "3D Box Tool" across all 26 .tsv catalogs in crates/ui-egui/src/i18n/.
A linked 1-bit image mask from a .ai file keeps its fill color as a
colorize paint, so the image takes the color once its file is relinked.
Until then the image shows the missing-link placeholder, and the canvas
and PDF export colorized that placeholder too: its light tile turned
nearly transparent and its red cross took the fill color.
ImageBlob::takes_colorize is false for a preview whose pixels are not
grayscale. While it is false, the canvas draws the image and PDF export
writes it as it is, printed separations separate it as an uncolorized
image, and transparency flattening (EPS, PDF 1.3 and PDF/X-1a export,
Flatten Transparency) does not count its paint as transparency. The
paint stays on the image, and a grayscale preview is still colorized.
SVG and EPS export already write only grayscale images colorized.
A tab definition in type of the legacy format (`numDots numTabs Xb`, a
`leader decimal tabType tabPosition Xe` for each stop, then `XB`) was
skipped, so every paragraph opened with only the default stops every
36 pt. The stops it describes now become the paragraph's tab stops
(left, center, right or decimal, at their positions), and they last
into the next paragraphs and text objects like the other paragraph
attributes. A definition with no stops, or whose descriptions were all
skipped, leaves the default ones. A description with an unknown type or
a position outside 0 to 100000 pt is skipped, and so is one past the
first 1024 of a definition. A text object's `To` ends a definition that
an earlier object left open.
Docs: docs/file-format-parity.md.
VectorCraft now reads `CropAreaActive`, an `/Int` in the dictionary of
the editing data that holds the `ArtboardArray`, as the index of the
active artboard in that array. The reader ignored it before, and every
file opened on its first artboard.
The opened document starts with that artboard active, so the view the
document opens at and the Artboards panel use it. The index counts
every entry of the array, so an artboard that is left out (one with no
area) does not shift it. When the entry is missing, is not an `/Int`,
or names an artboard that does not open, the first artboard is active,
as before. A file that comes in as its PDF part, with its pages placed
where its artboards are, opens on the page of the active artboard, also
when the reading stops before the artboards. The same reader serves the
editing data of EPS and PDF files.
The active artboard is kept on the opened document only; native files
do not save it.
A linked image read from a version 7 `.ai` file can keep its path in
the classic Mac OS form, with colons between folders
(`Macintosh HD:Images:photo.tif`). The link's name was the whole path,
so the Links panel showed it as one long name, and Relink to Folder,
the search of the document's folder and Find Linked Files looked for a
file with that whole string as its name.
A path with a colon and no `/` or `\` is now read as a classic Mac OS
path. Its name is the part after the last colon, and `links.info` gives
the rest as `location`. Relink to Folder, the document-folder search and
`links.findFiles` look for that name, and Find Linked Files compares the
path's folders with the folders of the files it finds. The link keeps
the path as stored. Paths with a `/` or `\` keep those as separators,
so a file name may still hold a colon (`/Users/a/x:y.png`).
Docs: docs/mcp.md (Links), docs/file-format-parity.md (version 7
linked images).
As asked in review: the reference app has no such commands, so they ship
in the Color Effects add-on. paint.fillToStroke / paint.strokeToFill are
now addon.color.fillToStroke / addon.color.strokeToFill in
cmd/addons/color.rs, listed in Object > Plug-ins > Color Effects instead
of the Color panel menu, with catalog rows in all 26 catalogs.
Two fixes from CodeRabbit's review:
- A graph's series marks and labels give the graph the copied paint in
the same undo step (capture_series_paints / capture_label_styles, as
paint.setFill does), so drawing the graph again keeps it. Targets go
through graph::paint_targets, so a series group stands for its marks.
- A copy that would leave the effective paint as it is skips the object,
so None copied onto a missing fill or stroke adds no item and records
no undo step.
paint.fillToStroke and paint.strokeToFill copy each target's own top fill onto its top stroke, or the other way, so a mixed selection keeps each object's colour. They aim and undo like Swap Fill and Stroke: groups and compound paths by their members, each text run with its own paint, and only the characters the Type tool has selected. A stroke given paint at width 0 gets 1 pt, skipNone leaves objects whose source paint is None alone, and the defaults for new art change the same way. Both are in the Color panel menu after Invert and Complement.
In the legacy format, `Tr` sets the rendering mode of the type that
follows. Section 5.7 of the version 7 specification says that modes 4 to
7 make the text object a mask: 4, 5 and 6 also fill, stroke, or fill and
stroke it, and 7 paints nothing. Sections 15.3.2 and 15.4.5.1 add that
these modes are used in pattern definitions, and the reader does not
read type in a pattern. The reader painted 4 to 6 like 0 to 2 and never
clipped, so the art a text mask clips showed whole.
A text object with characters in modes 4 to 7 is now a clipping path of
its clipping group (`q` ... `Q`, or the layer), as a path painted with
`W` is, and the whole object is the mask. Beside other clipping paths it
nests as they do, and the mode lasts into later text objects. Area type
with linked areas (threaded frames, also when the reader's limits keep
one frame), and type in wraparound text or in a compound path, a group
inside them included, doesn't clip, with a warning.
A `Tr` operand that is not a whole number from 0 to 9 now leaves the
mode as it was; before, 4.5 read as 4 and -4 hid the type.
The new warning and the reader's warning about linked type areas left
out get rows in every catalog.
The Adobe Illustrator File Format Specification 7.0, section 4 (p. 51),
says the name shown for a global object is the part of its name in the
file before the newline
(https://13thmonkey.org/documentation/fonts/AI7FileFormat.pdf). The
legacy reader kept the whole name, so swatches and patterns came in
named "Sky\n1". The reader now applies this rule to the files of every
version it reads.
- Gradient swatches, gradient fills, pattern definitions, pattern fills,
palette cells and art-style pattern fills use the part before the
newline. Lookups inside the reader still use the whole name.
- When that name is taken, the first free "Sky 2", "Sky 3" is used.
Taken names are None and Registration, the palette's own swatch and
group names, the default swatches when no palette replaces them,
named colors (color operators, gradient stops, version 7 pattern
strings, the header's and an EPS program's custom colors), the names
of gradients and patterns that have no newline, and the names given
to earlier gradients and patterns. Only content the reader reads
counts: not the alternates of versioned content, the prolog, skipped
sections or what follows the trailer.
- A name with nothing before the newline comes in as "Gradient" or
"Pattern". Names without a newline do not change.
- docs/file-format-parity.md lists the rule.
In the legacy format, `TZ` makes a re-encoded font from an existing one
and can give it encoding pairs of its own, which change only that font's
encoding. Its `useDefault` operand says whether the file's `TE` encoding
also applies to the font (Adobe Illustrator File Format Specification
7.0, section 3.3.1,
https://13thmonkey.org/documentation/fonts/AI7FileFormat.pdf). The
reader skipped the body of `%AI3_BeginEncoding` sections and ignored
`TZ`, so every string was decoded with `TE`'s encoding.
Strings in a re-encoded font are now decoded with its own pairs, then
with `TE`'s encoding when `useDefault` is 1, and as Windows-1252 for the
codes left. Strings in other fonts keep `TE`'s encoding. The reader
reads `TZ` in the body of an `%AI3_BeginEncoding` section and wherever
else it appears in the script, with or without the direction operand
and the Multiple Master weight vector. The font names are the last two
names, and only numbers and the weight vector may follow them; the
reader does not use a `TZ` of another shape. The first `TZ` for a font
is used.
`TZ`'s font names also map the re-encoded font to the font it was made
from, as the `%AI3_BeginEncoding` comment does. Type in a re-encoded
font that no such comment names now opens in the font `TZ` names; when
both name the font, the first one read is used.
The version 7 and version 3 file format specifications list three text
operators the editing-data reader did not dispatch, so a file whose type
used any of them on a visible layer did not open from its editing data:
- `(text) justified TS` (special characters): the reader adds its
characters to the story, as it does for `Tx` and `Tj`.
- `Te` (end render) is read and ignored. The reader accepts it with any
number of operands.
- `TM` (pop text matrix) is read and ignored.
Tests cover each operator in a text object, `TS` without a string and
outside a text object, and `Te` inside a tab definition. The import fuzz
tests add the operators to the legacy type tokens.
The version 7 file format specification gives `XI` and `XF` an
ImageMask operand: 0 is an opaque image, 1 is an image that is
transparent and can be colorized (sections 8.1, 8.2 and the 1-bit
examples in 8.4,
https://13thmonkey.org/documentation/fonts/AI7FileFormat.pdf). The
reader ignored the operand, so a 1-bit image mask opened as an opaque
black-and-white image.
A 1-bit gray image with ImageMask 1 now opens with the fill color set
before it as the color that colorizes it. A spot or global color keeps
its swatch and tint. When the fill is a pattern, a gradient or none,
the image is colorized black. VectorCraft's own rule is that the pixels
that open black with ImageMask 0 take the color and the others are
transparent. A linked image (`XF`) keeps the same color for when its
file is relinked. 8-bit gray, RGB and CMYK images, and images with
ImageMask 0, open as before.
In `.ai` and EPS editing-data import, a clipping group, layer or opacity
mask's art that holds more than one clipping path (`W`) now clips to the
intersection of the paths, as each `W` intersects the current clip (AI7
spec section 5.6.2,
https://13thmonkey.org/documentation/fonts/AI7FileFormat.pdf). Before,
the paths were joined into one compound path, which clipped to their
union, and kept a stroke only when every path had the same one.
Each clipping path after the first clips a clipping group nested inside
the one before it, and keeps its own stroke, opacity and blend mode. The
innermost clipping group holds the art in the order written; as before,
every object in the group is clipped by all of its clipping paths. A
clipping path's painted fill stays at its path's level. A compound path
of clipping paths (`*u` ... `*U`) is still one clipping path. Clipping
paths that would nest the art past the document's 32 levels stop the
editing data from being read.
The editing copy of a PDF-compatible .ai wrote every image as its outline
filled with its average color. Embedded images are now written with their
pixels, and linked images as placed files with a preview:
- Embedded images are rasters in the form of the version 7 specification
(section 8, https://13thmonkey.org/documentation/fonts/AI7FileFormat.pdf):
%AI5_BeginRaster, the color space, the image matrix and the XI operands
of current files, then the samples in binary in a %%BeginData section.
Gray, RGB and CMYK images keep their samples (CMYK images their ink
amounts), and see-through images their alpha channel after the color
samples. The matrix is written to ten decimals.
- Linked images are placed files (section 16): the matrix, the box of the
file's pixels and its path, %%IncludeFile, the folder relative to the
document's (when the relative path ends in the path's file name), and a
preview of at most 256 pixels a side.
- Images that can't be decoded or have more than 33,554,432 pixels (the
most the reader reads) are written as their outlines filled mid gray,
images of 16 bits a channel (CMYK TIFFs included) at 8 bits, and linked
images in opacity masks and pattern tiles as embedded images, each with
a warning.
Each of these is written in the form VectorCraft's .ai reader reads, and
the tests read the written data back through that reader.
The reader now gives an image its name and opacity mask when the
operators that end its raster (XH, Xr and the N after %AI5_EndRaster) come
before its dictionary, reads an empty relative folder as the document's
own folder, and looks for the %%EndData that ends an image's samples
after the alpha channel its XI operands give it, preferring one whose next
line is XH, so samples that hold the marker's bytes are read whole.
Tests: the round trip of every kind of image and its state, a second write
of what is read back giving the same bytes, the raster and placed-file
forms, previews of large linked images, and the engine's editing copy with
every save option; a fuzz case for damaged images and placed files.
Docs: docs/file-format-parity.md.
In the legacy format, area type whose story flows through several linked
areas has one text path (`Tp` ... `TP`) for each area, each with its own
matrix and frame (version 7 specification, sections 15 and 15.5.3). The
reader kept only the first frame, placed it with the text object's last
valid matrix, and put the whole story in that one frame.
Each linked area with a frame now opens as its own area type object,
placed with its own matrix, and the frames are threaded in file order.
The first frame holds the story: the characters after every `TP`, and
the overflow text. When the file opens, the story is laid out again
through the thread (section 15.1 lists the flow from area to area as
final-form information). A linked area without a frame is left out.
Area type with one area opens as before.
The dictionary that follows a text object (its opacity mask, text wrap,
name and other keys) went to its one object. Its opacity mask and text
wrap now go on every frame, and its other keys on the first frame.
Point type is read with its first text path's matrix, and type on a
path with the matrix and start of the first text path that has a path.
Area type with no frame at all opens as point type with its first text
path's matrix. Before, these used the last valid matrix and, for type
on a path, the last start.
One text object reads at most 4,096 text paths. The number of frames
times the story's character count is kept to 4,194,304, so a longer
story keeps fewer frames. Frames past either limit are left out, with a
warning.
A legacy .ai in the version 7 form names a linked image's file with
`(path) modified XG` and draws the image with `XF`, which takes the
operands `XI` takes and has no samples after it (Adobe Illustrator File
Format Specification 7.0, sections 8.2 and 8.3). The reader ignored both
operators, so the image was dropped without a warning.
- `XF` after `XG` becomes a linked image of that file, its pixels placed
as an `XI` image of the same operands is placed. The file keeps no
pixels of it, so a placeholder stands in until the file is relinked in
the Links panel, with a note in the open result. No pixels are read,
so the image is not held to the pixel limit of `XI`'s samples.
- An `XF` without a file name before it, or with operands `XI` couldn't
read (no matrix, too few numbers, no pixels, or samples of other than
1 or 8 bits), is left out with the existing "an image VectorCraft
can't read was left out" warning. An `XG` applies only to the image
after it in the same raster object; `() 1 XG` before an embedded `XI`
keeps that image embedded.
- A PostScript page draws nothing for `XF`, so there the placeholder's
area is left out of the comparison of the layers with the page, and
the file keeps its layers. A PDF part draws the image's pixels, so a
file with one is compared with it there as before, and its layers are
not used without the PDF part.
- Linked images of different files get image keys of their own even
when they show the same pixels (the placeholder, or two identical
placed-file previews), so updating or exporting one file's image
reads that file only.
- `vectorcraft_doc::links::missing_placeholder` draws the placeholder: a
light tile, crossed out, as SVG import shows for a missing file.
Tests: reader tests for the placement, the image keys and the cases left
out, an end-to-end test of a legacy file with a linked image, a test of
a file with a PDF part, and a fuzz case for damaged files with `XG` and
`XF`. The new note has a row in each catalog that translates the
placed-file note.
Type in the text document of a .ai or EPS file's editing data that names
no character or paragraph style, a story without style runs included, is
set in [Normal Character Style] and [Normal Paragraph Style]. The reader
took what such type leaves out from the text document's base attributes
instead, or built-in defaults for a story without paragraph runs, and it
did not read paragraph styles.
A Large Canvas file (1:10) holds the normal styles' lengths at the art's
scale (1.2 for 12 pt) and the base attributes' at the page's (12). The
reader scaled the base attributes' 12 by 10, so the type came in at
120 pt. In an EPS the page comparison then rejected the layers, and the
file opened as its printed page without its linked images.
In any file whose normal styles differ from the base attributes, such
type now takes what the normal styles set, such as font, size, colors,
stroke, alignment, indents, space before and after, and hyphenation.
`.ai` and EPS editing-data import now reads object tags
(`/identifier (string) XT`) and applies each one to the object before it,
whatever kind of object it is. The `AdobeURL` tag sets the object's URL.
Every other tag is added to the object's data in order, up to 64 per
object. A tag with no object right before it, with an empty identifier,
or with an identifier or string longer than 64 KiB is ignored, and so
are tags in a pattern's or brush's art. A clipping path keeps its own
tags; the copy that paints its fill gets none.
Before, a tag on art that shows was an operator the reader did not know,
so it stopped the editing data from being read, and brush art holding a
tag was not read, so the brushes using it were left out.
An image's tags follow the `XH` that ends its data, and the state written
after a group or a gradient mesh is still theirs when their tags come
first. When a drawn look stands for an object whose style is not found,
the look keeps the object's note, URL and data, and a live blend keeps
those of its drawn steps.
The editing copy for other apps now writes linear and radial gradients and
grid patterns as themselves instead of as average colors and cut tiles.
- Gradients the art uses are defined in the setup (`n Bn`, then
`%AI5_BeginGradient` … `Bd`, the stops as `Bs` with their opacity and
midpoints, `BD`), and gradient swatches nothing uses in a non-printing
block. Stops keep gray, CMYK, RGB and spot colors at a tint. A
gradient that isn't a swatch gets a name that no swatch or pattern of
the document has.
- Each fill or stroke with a gradient is an instance around its painting
operator (`Bb`, `Bh`, `Bg`, `Xm`, `Bm`, `Bc`, `BB`), on a compound
path's last subpath and on clipping paths too. `Bg` places the gradient
relative to the path: a linear one by its angle and its start and length
as fractions of the path's extent along it, a radial one by the matrix
that takes the unit circle onto its extent ellipse, its center as
fractions of the path's bounds in that circle's space and its radius as
a multiple of the one the center's distances to the right side and to
the bottom give. In a pattern's tile the placement is mirrored top to
bottom.
- Patterns whose tiles make a grid and hold their art are defined with
`%AI3_BeginPattern` … `E`, the tile's box first, and fills and strokes
paint with `p` and `P`; gradient and pattern swatches are in the palette.
- Freeform gradients, gradients along or across a stroke and gradients
without stops, with more than 256 stops or without extent are written
as their average color, and other patterns as their tiles cut to the
shape, each with a warning. Gradients that dither or mix perceptually
are written as classic ones, stops linked to global process colors as
their colors, and pattern swatches without the placement that moves,
turns or scales their pattern, with warnings.
- Reading: an unpainted box that a pattern's definition marks as its
tile's box (`AIPattern_Editor_Backing_Tile_Rect`) is no longer read as
art, and a linear gradient whose stops all lie at one place keeps each
stop on its side.
The definitions, instances and patterns follow sections 3.4, 3.5 and 14
of the version 7 specification
(http://mercator.elte.hu/~saman/hu/okt/AI7FileFormat.pdf). The stop
opacity, `Bg`'s placement and the marked tile box follow the newer form
that current .ai files carry, which that specification predates.
Each of these is written in the form VectorCraft's .ai reader reads, and
the tests read the written data back through that reader.
Docs: docs/file-format-parity.md.