M4.83: overprinting fills and strokes overprint in PDF

Advanced > Overprint: Preserve (the default; document.exportPdf
advanced.overprint) writes each overprinting fill and stroke (an object's
own, a character's, a type object's) with a graphics state of /OP true
/op true /OPM 1 (/OPM 0 in PDF/A); Discard writes none. White ones knock out
when Document Setup's Discard White Overprint is on, as in print. Mask art
never overprints. File > Print's composite PDF honours Print > Advanced >
Overprints: Preserve the same way (separations keep multiplying plates).

Each overprinting fill or stroke is drawn as a form marked to overprint
(crates/pdf/src/forms.rs); after writing, its content starts by setting the
overprinting graphics state, and the PDF/X self-check runs on the result.
The engine's "overprint is not written to PDF yet" warning and print's
"overprints print as knockouts in composite output" warning are gone.

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

crates/engine/src/cmd/fileio/pdf.rs

@@ -7,7 +7,7 @@ use std::borrow::Cow;
 use serde::Deserialize;
 use serde_json::{Value, json};
 use vectorcraft_doc::Document;
-use vectorcraft_pdf::{Overprint, PdfError, PdfOptions, PdfPreset, PdfSettings, Standard};
+use vectorcraft_pdf::{PdfError, PdfOptions, PdfPreset, PdfSettings, Standard};
 
 use super::super::flatten::{FlattenOptions, flatten_document, see_through_images};
 use super::super::*;
@@ -91,7 +91,7 @@ pub fn specs() -> Vec<CommandSpec> {
             "Export PDF",
             [],
             None,
-            "{path?, preset?: \"VectorCraft Default\" (built-in or saved: pdf.preset.list), artboard? | artboards?: [i…] | range?: \"1-3, 5\" (1-based; default all, one page each), standard?: none|pdfA2b|pdfX1a (CMYK, grey and spot colours only: colours and images converted to output.destination or the CMYK output intent, untagged; transparency flattened with the High Resolution flattener preset; PDF 1.3)|pdfX3 (colours ICC-tagged; transparency flattened; PDF 1.3)|pdfX4 (transparency and layers kept; colours ICC-tagged; PDF 1.6 at most) (PDF/X: a /GTS_PDFX output intent, by default the CMYK profile in effect, embedded; TrimBox, Trapped, GTS_PDFXVersion, title and dates; fonts embedded or outlined), compatibility?: 1.4|1.5|1.6|1.7 (default)|2.0 (choosing a standard sets the latest it allows: 1.7 for pdfA2b, 1.6 for pdfX4, 1.4 for pdfX1a and pdfX3, written as PDF 1.3), preserveEditing? (on in VectorCraft Default: the native document as an embedded file, which document.open restores; choosing a standard turns it off, a standard refuses it), thumbnails?, fastWebView?, viewAfterSaving? (the app opens the written file), createLayers? (each top-level layer but template layers as a PDF layer, an optional content group: hidden layers off, non-printing ones /PrintState /OFF, locked ones locked; needs 1.5 or later; they reopen as layers; choosing pdfX1a or pdfX3 turns it off; they refuse it), includeNonPrinting? (keep layers whose Print option is off; left out by default unless createLayers), compression?: {color?, gray?: {downsample: none|average|subsample|bicubic, ppi: 300, abovePpi: 450, compression: none|zip|jpeg|jpeg2000|auto, quality: minimum|low|medium|high|maximum}, mono?: {downsample, ppi: 1200, abovePpi: 1800, compression: none|ccittG3|ccittG4|zip|runLength} (black-and-white images), compressText?: true} (images above abovePpi are resampled to ppi; auto keeps JPEGs JPEG, the others lossless; JPEG needs opaque images; none, jpeg2000, CCITT and runLength are written as ZIP with a warning), marks?: {trim, registration, colorBars, pageInfo, kind: roman|japanese, weight: 0.25 (trim marks and targets), offset: 6 (pt from the artboard, at least the bleed)} (printer's marks in [Registration], every plate: trim marks, registration targets mid-side, CMYK/spot/black-tint colour bars on top, page information (title, artboard, date UTC) below), bleed?: {useDocument (the document's bleed, document.setup), top, bottom, left, right} (pt; art in the bleed is kept). Each page: TrimBox = artboard, BleedBox = artboard + bleed, MediaBox = that + the marks' room (art clipped to the BleedBox), output?: {conversion: none (default)|destination (every colour into the destination profile's model, CMYK or RGB, also colours of that model in another profile)|preserveNumbers (only colours of the other model and Lab; those in the destination's model keep their numbers) (grey stays grey; images are converted too, printer's marks are not), destination: profile name (edit.colorSettings lists them; default: the document's profile for its colour mode), profiles: none (device colours)|all|destination|taggedSource (documents assigned a profile: edit.assignProfile) (ICC-based colours: CMYK with the destination or document CMYK profile, RGB as sRGB, grey with the sRGB tone curve; PDF/A always), outputIntent: profile name (embedded as the catalog's /GTS_PDFX output intent; a name that isn't a profile is only named, which pdfX1a and pdfX3 allow only with a registry and pdfX4 refuses; pdfX1a needs a CMYK one), outputCondition, outputConditionId (default: outputIntent), registry, trapped (/Trapped /True; /False when an output intent is written)} (PDF/A files keep their own output intent), advanced?: {fontSubsetPercent: 100 (below 100 is accepted with a warning: fonts are always embedded as subsets), outlineText: true (false: type as real, selectable and searchable text in embedded subset fonts with a ToUnicode map; fonts whose licence forbids embedding, or allows only whole fonts, stay outlines with a warning), overprint: preserve|discard}, security?: {openPassword, permissionsPassword, printing: none|low|high, changes: none|pages|forms|comments|any, copy, screenReader, plaintextMetadata}} → {path, bytes, warnings}; no path → {dataBase64, bytes, warnings}. The options apply over the preset (null keeps its value); options accepted but not applied yet come back as warnings; a standard with a PDF version it doesn't allow and a password with a standard are refused, and so is a PDF/X file that would still break its standard (transparency the flattener left, RGB in pdfX1a, a font not embedded). document.export {format: pdf} takes the same options",
+            "{path?, preset?: \"VectorCraft Default\" (built-in or saved: pdf.preset.list), artboard? | artboards?: [i…] | range?: \"1-3, 5\" (1-based; default all, one page each), standard?: none|pdfA2b|pdfX1a (CMYK, grey and spot colours only: colours and images converted to output.destination or the CMYK output intent, untagged; transparency flattened with the High Resolution flattener preset; PDF 1.3)|pdfX3 (colours ICC-tagged; transparency flattened; PDF 1.3)|pdfX4 (transparency and layers kept; colours ICC-tagged; PDF 1.6 at most) (PDF/X: a /GTS_PDFX output intent, by default the CMYK profile in effect, embedded; TrimBox, Trapped, GTS_PDFXVersion, title and dates; fonts embedded or outlined), compatibility?: 1.4|1.5|1.6|1.7 (default)|2.0 (choosing a standard sets the latest it allows: 1.7 for pdfA2b, 1.6 for pdfX4, 1.4 for pdfX1a and pdfX3, written as PDF 1.3), preserveEditing? (on in VectorCraft Default: the native document as an embedded file, which document.open restores; choosing a standard turns it off, a standard refuses it), thumbnails?, fastWebView?, viewAfterSaving? (the app opens the written file), createLayers? (each top-level layer but template layers as a PDF layer, an optional content group: hidden layers off, non-printing ones /PrintState /OFF, locked ones locked; needs 1.5 or later; they reopen as layers; choosing pdfX1a or pdfX3 turns it off; they refuse it), includeNonPrinting? (keep layers whose Print option is off; left out by default unless createLayers), compression?: {color?, gray?: {downsample: none|average|subsample|bicubic, ppi: 300, abovePpi: 450, compression: none|zip|jpeg|jpeg2000|auto, quality: minimum|low|medium|high|maximum}, mono?: {downsample, ppi: 1200, abovePpi: 1800, compression: none|ccittG3|ccittG4|zip|runLength} (black-and-white images), compressText?: true} (images above abovePpi are resampled to ppi; auto keeps JPEGs JPEG, the others lossless; JPEG needs opaque images; none, jpeg2000, CCITT and runLength are written as ZIP with a warning), marks?: {trim, registration, colorBars, pageInfo, kind: roman|japanese, weight: 0.25 (trim marks and targets), offset: 6 (pt from the artboard, at least the bleed)} (printer's marks in [Registration], every plate: trim marks, registration targets mid-side, CMYK/spot/black-tint colour bars on top, page information (title, artboard, date UTC) below), bleed?: {useDocument (the document's bleed, document.setup), top, bottom, left, right} (pt; art in the bleed is kept). Each page: TrimBox = artboard, BleedBox = artboard + bleed, MediaBox = that + the marks' room (art clipped to the BleedBox), output?: {conversion: none (default)|destination (every colour into the destination profile's model, CMYK or RGB, also colours of that model in another profile)|preserveNumbers (only colours of the other model and Lab; those in the destination's model keep their numbers) (grey stays grey; images are converted too, printer's marks are not), destination: profile name (edit.colorSettings lists them; default: the document's profile for its colour mode), profiles: none (device colours)|all|destination|taggedSource (documents assigned a profile: edit.assignProfile) (ICC-based colours: CMYK with the destination or document CMYK profile, RGB as sRGB, grey with the sRGB tone curve; PDF/A always), outputIntent: profile name (embedded as the catalog's /GTS_PDFX output intent; a name that isn't a profile is only named, which pdfX1a and pdfX3 allow only with a registry and pdfX4 refuses; pdfX1a needs a CMYK one), outputCondition, outputConditionId (default: outputIntent), registry, trapped (/Trapped /True; /False when an output intent is written)} (PDF/A files keep their own output intent), advanced?: {fontSubsetPercent: 100 (below 100 is accepted with a warning: fonts are always embedded as subsets), outlineText: true (false: type as real, selectable and searchable text in embedded subset fonts with a ToUnicode map; fonts whose licence forbids embedding, or allows only whole fonts, stay outlines with a warning), overprint: preserve (overprinting fills and strokes set /OP /op true, /OPM 1; white ones knock out with document.setup discardWhiteOverprint)|discard (they knock out)}, security?: {openPassword, permissionsPassword, printing: none|low|high, changes: none|pages|forms|comments|any, copy, screenReader, plaintextMetadata}} → {path, bytes, warnings}; no path → {dataBase64, bytes, warnings}. The options apply over the preset (null keeps its value); options accepted but not applied yet come back as warnings; a standard with a PDF version it doesn't allow and a password with a standard are refused, and so is a PDF/X file that would still break its standard (transparency the flattener left, RGB in pdfX1a, a font not embedded). document.export {format: pdf} takes the same options",
             has_doc,
             export_pdf
         ),
@@ -254,9 +254,6 @@ pub(super) fn encode_carrying(cmd: &str, doc: &Document, p: &Value, native: impl
     }
     let r = super::super::rasterfx::export_pdf_with_report(flat.as_ref().unwrap_or(doc), &opts).map_err(|e| pdf_error(cmd, e))?;
     warnings.extend(r.warnings);
-    if opts.settings.advanced.overprint == Overprint::Preserve && doc.layers.iter().any(|l| l.has_overprint()) {
-        warnings.push("overprinting objects are written without overprint: overprint is not written to PDF yet".into());
-    }
     Ok((r.bytes, warnings))
 }
 

crates/engine/src/cmd/fileio/tests_pdflayers.rs

@@ -1,4 +1,5 @@
-//! `document.exportPdf {createLayers}` writes PDF layers that reopen as layers.
+//! `document.exportPdf {createLayers}` writes PDF layers that reopen as layers, and
+//! `advanced.overprint` keeps overprinting in the file or drops it.
 
 use serde_json::{Value, json};
 
@@ -43,3 +44,18 @@ fn export_pdf_create_layers_writes_layers_that_reopen_as_layers() {
     let v = s.execute("document.exportPdf", &json!({"createLayers": true, "compatibility": "1.4"})).unwrap();
     assert!(warnings(&v).iter().any(|w| w.contains("PDF 1.5")), "{:?}", warnings(&v));
 }
+
+#[test]
+fn export_pdf_overprint_is_preserved_or_discarded() {
+    let mut s = session();
+    s.execute("select.all", &json!({})).unwrap();
+    // The rectangles' strokes are black (their white fills would knock out: discardWhiteOverprint).
+    s.execute("object.setOverprint", &json!({"stroke": true})).unwrap();
+    let overprints = |s: &mut Session, p: Value| {
+        let v = s.execute("document.exportPdf", &p).unwrap();
+        assert!(warnings(&v).iter().all(|w| !w.contains("overprint")), "{:?}", warnings(&v));
+        String::from_utf8_lossy(&b64(&v)).matches("/OP true/op true/OPM 1").count()
+    };
+    assert_eq!(overprints(&mut s, json!({"compression": {"compressText": false}})), 1);
+    assert_eq!(overprints(&mut s, json!({"advanced": {"overprint": "discard"}})), 0);
+}

crates/engine/src/cmd/print.rs

@@ -21,7 +21,7 @@ pub fn specs() -> Vec<CommandSpec> {
             "Print Setup",
             [],
             None,
-            "{settings?: {copies: 1 (1–999), collate: true, reverse, artboards: all|range|ignore (all the art as one page), range: \"1-3, 5\" (1-based, with artboards: range), skipBlank (leave out artboards with no art that prints), media: letter|legal|tabloid|a3|a4|a5|b4|b5|custom, width, height (custom paper, 72–14400 pt), orientation: portrait|landscape|portraitFlipped|landscapeFlipped, autoRotate: true (turn the paper to each artboard; orientation ignored), transverse (the page a quarter turn on the paper), printLayers: visiblePrintable|visible|all (template layers never print), placement: {origin: topLeft|top|topRight|left|center|right|bottomLeft|bottom|bottomRight (the point of the printed area, the artboard with its bleed and marks, on the same point of the imageable area), x, y (pt, right and down)}, scaling: none|fit|custom|tileFull|tileImageable, scale: {width: 100, height: 100} (% with custom and tiling), overlap: 0 (pt between tiles), tileRange: \"\" (1-based tiles across then down; empty: all), margin: 0 (pt the device can't print around the paper: the imageable area is inside it), marks: {trim, registration, colorBars, pageInfo, kind: roman|japanese, weight: 0.25, offset: 6} (as document.exportPdf, at the paper's scale; page information adds the tile and the ink), bleed: {useDocument: true (the document's bleed, document.setup), top, bottom, left, right} (pt), output: {mode: composite|separations (one grey page per ink that prints), emulsion: up|down (down mirrors), image: positive|negative, spotsToProcess, inks: [{name: \"Cyan\"|…|a spot swatch, print: true, frequency (lpi, default 60), angle (default C 15, M 75, Y 0, K 45, spots 45)}]}, graphics: {autoFlatness: true, flatness: 1 (0.2–100), fonts: none|subset|complete}, color: {intent: perceptual|relativeColorimetric|saturation|absoluteColorimetric, preserveNumbers: true (CMYK colours keep their values), profile: \"\" (the printer profile, an RGB or CMYK one: composite PDF colours are converted to it with the intent, separations separate with a CMYK one; empty: as they are)}, advanced: {printAsBitmap (composite pages print as one image each, at the document's raster effects resolution), overprints: preserve|discard|simulate (composite output; simulate prints them as Overprint Preview shows them; separations always keep them), flattenerPreset: \"\" (a flattener preset, built-in or saved: transparency is flattened before printing; empty: it prints live; PostScript defaults to medium)}, tileOrigin: {placed: false, x, y} (where the Print Tiling tool put the pages: print.tiling.set)}} store the print settings with the document, over the ones it has (null keeps a value), as one undo step; no settings → {settings} (the current ones, defaults if never set up)",
+            "{settings?: {copies: 1 (1–999), collate: true, reverse, artboards: all|range|ignore (all the art as one page), range: \"1-3, 5\" (1-based, with artboards: range), skipBlank (leave out artboards with no art that prints), media: letter|legal|tabloid|a3|a4|a5|b4|b5|custom, width, height (custom paper, 72–14400 pt), orientation: portrait|landscape|portraitFlipped|landscapeFlipped, autoRotate: true (turn the paper to each artboard; orientation ignored), transverse (the page a quarter turn on the paper), printLayers: visiblePrintable|visible|all (template layers never print), placement: {origin: topLeft|top|topRight|left|center|right|bottomLeft|bottom|bottomRight (the point of the printed area, the artboard with its bleed and marks, on the same point of the imageable area), x, y (pt, right and down)}, scaling: none|fit|custom|tileFull|tileImageable, scale: {width: 100, height: 100} (% with custom and tiling), overlap: 0 (pt between tiles), tileRange: \"\" (1-based tiles across then down; empty: all), margin: 0 (pt the device can't print around the paper: the imageable area is inside it), marks: {trim, registration, colorBars, pageInfo, kind: roman|japanese, weight: 0.25, offset: 6} (as document.exportPdf, at the paper's scale; page information adds the tile and the ink), bleed: {useDocument: true (the document's bleed, document.setup), top, bottom, left, right} (pt), output: {mode: composite|separations (one grey page per ink that prints), emulsion: up|down (down mirrors), image: positive|negative, spotsToProcess, inks: [{name: \"Cyan\"|…|a spot swatch, print: true, frequency (lpi, default 60), angle (default C 15, M 75, Y 0, K 45, spots 45)}]}, graphics: {autoFlatness: true, flatness: 1 (0.2–100), fonts: none|subset|complete}, color: {intent: perceptual|relativeColorimetric|saturation|absoluteColorimetric, preserveNumbers: true (CMYK colours keep their values), profile: \"\" (the printer profile, an RGB or CMYK one: composite PDF colours are converted to it with the intent, separations separate with a CMYK one; empty: as they are)}, advanced: {printAsBitmap (composite pages print as one image each, at the document's raster effects resolution), overprints: preserve|discard|simulate (composite output; preserve writes them to overprint (/OP), simulate prints them as Overprint Preview shows them; separations always keep them), flattenerPreset: \"\" (a flattener preset, built-in or saved: transparency is flattened before printing; empty: it prints live; PostScript defaults to medium)}, tileOrigin: {placed: false, x, y} (where the Print Tiling tool put the pages: print.tiling.set)}} store the print settings with the document, over the ones it has (null keeps a value), as one undo step; no settings → {settings} (the current ones, defaults if never set up)",
             has_doc,
             setup
         ),