Print: Functions › Bleed (corner crop marks on the trim line)

Photoshop's Print dialog has Functions › Bleed: crop marks print inside
the image by the bleed width, so trimming on them cuts through the
artwork and leaves no paper-white sliver. target-app-parity listed it as
missing ("No Separations/bleed").

- file.print / file.printOneCopy take "bleed" in inches (default 0),
  report it back, and Print One Copy remembers it.
- Corner crop marks move onto the trim line, still starting 6 pt outside
  the image. Centre and registration marks are unchanged (a symmetric
  bleed doesn't move the midlines).
- One helper (corner_crop_segments) drives both the PDF writer and the
  native Windows primitives; the dialog preview draws the marks there too.
- Negative, non-numeric or too-wide bleeds are BadParams, never a panic;
  bleed without corner crop marks changes nothing and reports 0.
- With bleed absent or 0 the PDF is byte-identical (tested).

The Print dialog field is a follow-up: every tl! label needs all
translations.

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

crates/engine/src/print_cmds.rs

@@ -61,6 +61,27 @@ pub struct Marks {
     pub corner_crop: bool,
     pub center_crop: bool,
     pub registration: bool,
+    /// Photoshop's Functions › Bleed, in points: corner crop marks sit this far inside the image
+    /// edge, so the trim cuts through the image and leaves no paper-white sliver. 0 = on the edge.
+    pub bleed: f64,
+}
+
+/// Gap between the image edge and a crop mark, and the mark's length (pt).
+const MARK_GAP: f64 = 6.0;
+const MARK_LEN: f64 = 18.0;
+
+/// Corner crop marks around `(x, y, w, h)` as eight `(from, to)` segments, a horizontal then a
+/// vertical one per corner. Each starts `MARK_GAP` outside the image (so it never prints on it)
+/// and lies on the trim line, `bleed` inside the edge. The inset is symmetric, so this holds for
+/// both bottom-up (PDF) and top-down (Windows) coordinates.
+fn corner_crop_segments(bleed: f64, (x, y, w, h): (f64, f64, f64, f64)) -> [((f64, f64), (f64, f64)); 8] {
+    let mut out = [((0.0, 0.0), (0.0, 0.0)); 8];
+    for (i, (cx, cy, dx, dy)) in [(x, y, -1.0, -1.0), (x + w, y, 1.0, -1.0), (x, y + h, -1.0, 1.0), (x + w, y + h, 1.0, 1.0)].into_iter().enumerate() {
+        let (tx, ty) = (cx - dx * bleed, cy - dy * bleed);
+        out[2 * i] = ((cx + dx * MARK_GAP, ty), (cx + dx * (MARK_GAP + MARK_LEN), ty));
+        out[2 * i + 1] = ((tx, cy + dy * MARK_GAP), (tx, cy + dy * (MARK_GAP + MARK_LEN)));
+    }
+    out
 }
 
 /// One page: paper (pt), image box (pt, origin bottom-left), marks and texts.
@@ -102,12 +123,11 @@ fn deflate(data: &[u8]) -> Vec<u8> {
 /// Vector marks around `(x, y, w, h)`.
 fn marks_ops(m: Marks, (x, y, w, h): (f64, f64, f64, f64)) -> String {
     let mut s = String::from("q 0 G 0.3 w\n");
-    let (gap, len) = (6.0, 18.0);
+    let (gap, len) = (MARK_GAP, MARK_LEN);
     let line = |s: &mut String, x0: f64, y0: f64, x1: f64, y1: f64| s.push_str(&format!("{x0:.2} {y0:.2} m {x1:.2} {y1:.2} l S\n"));
     if m.corner_crop {
-        for (cx, cy, dx, dy) in [(x, y, -1.0, -1.0), (x + w, y, 1.0, -1.0), (x, y + h, -1.0, 1.0), (x + w, y + h, 1.0, 1.0)] {
-            line(&mut s, cx + dx * gap, cy, cx + dx * (gap + len), cy);
-            line(&mut s, cx, cy + dy * gap, cx, cy + dy * (gap + len));
+        for ((x0, y0), (x1, y1)) in corner_crop_segments(m.bleed, (x, y, w, h)) {
+            line(&mut s, x0, y0, x1, y1);
         }
     }
     if m.center_crop {
@@ -303,10 +323,16 @@ pub fn layout(doc: &Document, p: &Value, cmd: &str) -> Result<PrintLayout> {
     let (pw, ph) = paper(p, cmd)?;
     let dpi = f64::from(doc.resolution_dpi.max(1.0));
     let (iw, ih) = (f64::from(doc.size.width) * 72.0 / dpi, f64::from(doc.size.height) * 72.0 / dpi);
-    let marks = Marks {
+    // Bleed in inches, like Photoshop's Position fields; the marks need it in points.
+    let bleed = match p.get("bleed") {
+        None | Some(Value::Null) => 0.0,
+        Some(v) => v.as_f64().filter(|b| b.is_finite() && *b >= 0.0).ok_or_else(|| bad(cmd, "bleed is a width in inches, 0 or more"))? * 72.0,
+    };
+    let mut marks = Marks {
         corner_crop: p.get("cornerCropMarks").and_then(Value::as_bool).unwrap_or(false),
         center_crop: p.get("centerCropMarks").and_then(Value::as_bool).unwrap_or(false),
         registration: p.get("registrationMarks").and_then(Value::as_bool).unwrap_or(false),
+        bleed,
     };
     let margin = if marks.corner_crop || marks.center_crop || marks.registration { 36.0 } else { 18.0 };
     let fit = p.get("scaleToFit").and_then(Value::as_bool).unwrap_or(false);
@@ -316,6 +342,14 @@ pub fn layout(doc: &Document, p: &Value, cmd: &str) -> Result<PrintLayout> {
         p.get("scale").and_then(Value::as_f64).filter(|v| *v > 0.0).unwrap_or(100.0) / 100.0
     };
     let (w, h) = (iw * scale, ih * scale);
+    // The trim box must keep some area, or the marks of opposite corners would cross.
+    if 2.0 * marks.bleed >= w.min(h) {
+        return Err(bad(cmd, format!("bleed {:.3} in leaves no image inside the trim ({:.2} × {:.2} in printed)", marks.bleed / 72.0, w / 72.0, h / 72.0)));
+    }
+    // Bleed only moves crop marks; without them it has nothing to change.
+    if !marks.corner_crop {
+        marks.bleed = 0.0;
+    }
     let center = p.get("center").and_then(Value::as_bool).unwrap_or(true);
     let (x, y) = if center {
         ((pw - w) / 2.0, (ph - h) / 2.0)
@@ -398,7 +432,7 @@ fn render_and_spool(doc: &Document, p: &Value, cmd: &str) -> Result<Value> {
         require_printing_enabled()?;
         let printed = print_windows(&page, p, &doc.name, copies)?;
         return Ok(json!({
-            "pdf": Value::Null, "paper": [pw, ph], "imageRect": [x, y, w, h], "emulsionDown": emulsion_down, "scale": scale * 100.0,
+            "pdf": Value::Null, "paper": [pw, ph], "imageRect": [x, y, w, h], "emulsionDown": emulsion_down, "bleed": marks.bleed / 72.0, "scale": scale * 100.0,
             "copies": copies, "command": Value::Null, "sent": true, "spooler": printed, "color": color,
         }));
     }
@@ -431,7 +465,7 @@ fn render_and_spool(doc: &Document, p: &Value, cmd: &str) -> Result<Value> {
         sent = true;
     }
     Ok(
-        json!({"pdf": pdf_path, "bytes": pdf.len(), "paper": [pw, ph], "imageRect": [x, y, w, h], "emulsionDown": emulsion_down, "scale": scale * 100.0, "copies": copies, "command": command, "sent": sent, "spooler": spool, "color": color}),
+        json!({"pdf": pdf_path, "bytes": pdf.len(), "paper": [pw, ph], "imageRect": [x, y, w, h], "emulsionDown": emulsion_down, "bleed": marks.bleed / 72.0, "scale": scale * 100.0, "copies": copies, "command": command, "sent": sent, "spooler": spool, "color": color}),
     )
 }
 
@@ -750,7 +784,7 @@ pub fn specs() -> Vec<CommandSpec> {
             CommandSpec { id: $id, label: $label, menu: $menu, shortcut: $sc, params: $params, enabled: $enabled, journal: true, run: $run }
         };
     }
-    const PRINT_PARAMS: &str = r##"{"printerSettings":hex? (Windows driver settings),"printer":name? (default printer),"copies":1..999=1,"paper":"letter|legal|tabloid|a3|a4|a5|4x6|5x7"|[w,h] pt="letter","orientation":"portrait|landscape"="portrait","center":bool=true,"top":in?,"left":in?,"scale":%=100,"scaleToFit":bool=false,"colorHandling":"printerManages|photocraftManages|noColorManagement"="printerManages","printerProfile":profile? (photocraftManages),"intent":"perceptual|relative|saturation|absolute"="relative","bpc":bool=true,"cornerCropMarks":bool,"centerCropMarks":bool,"registrationMarks":bool,"description":bool,"labels":bool,"emulsionDown":bool=false (mirror the page left to right, for sublimation and other transfer printing),"output":pdf path? (print to PDF; then "send" defaults to false),"send":bool?,"dryRun":bool=false (render the PDF, report the backend command, don't spool; write a PDF only at an explicit output path)} → {pdf:path|null (null without explicit output), imageRect, command:diagnostic array|null, sent}"##;
+    const PRINT_PARAMS: &str = r##"{"printerSettings":hex? (Windows driver settings),"printer":name? (default printer),"copies":1..999=1,"paper":"letter|legal|tabloid|a3|a4|a5|4x6|5x7"|[w,h] pt="letter","orientation":"portrait|landscape"="portrait","center":bool=true,"top":in?,"left":in?,"scale":%=100,"scaleToFit":bool=false,"colorHandling":"printerManages|photocraftManages|noColorManagement"="printerManages","printerProfile":profile? (photocraftManages),"intent":"perceptual|relative|saturation|absolute"="relative","bpc":bool=true,"cornerCropMarks":bool,"centerCropMarks":bool,"registrationMarks":bool,"bleed":in=0 (Functions › Bleed: corner crop marks this far inside the image edge, on the trim line),"description":bool,"labels":bool,"emulsionDown":bool=false (mirror the page left to right, for sublimation and other transfer printing),"output":pdf path? (print to PDF; then "send" defaults to false),"send":bool?,"dryRun":bool=false (render the PDF, report the backend command, don't spool; write a PDF only at an explicit output path)} → {pdf:path|null (null without explicit output), imageRect, command:diagnostic array|null, sent}"##;
 
     vec![
         spec!("file.print", "Print…", &["File"], Some("Cmd+P"), PRINT_PARAMS, native_doc, print),

crates/engine/src/print_cmds/tests.rs

@@ -434,3 +434,74 @@ fn printers_lists_the_spooler_destinations_without_a_document() {
         None => assert!(list.iter().all(|p| p["default"] == false)),
     }
 }
+
+/// A dry-run print to `name`.pdf with `extra` params; returns the result and the PDF content stream.
+fn print_with(s: &mut Session, dir: &str, name: &str, extra: Value) -> (Value, Vec<u8>) {
+    let mut p = json!({"output": format!("{dir}/{name}.pdf"), "dryRun": true, "paper": "a4", "center": false, "left": 1.0, "top": 1.0});
+    for (k, v) in extra.as_object().unwrap() {
+        p[k] = v.clone();
+    }
+    let r = s.execute("file.print", p).unwrap();
+    let pdf = std::fs::read(r["pdf"].as_str().unwrap()).unwrap();
+    (r, pdf)
+}
+
+#[test]
+fn zero_bleed_prints_exactly_as_before() {
+    let mut s = session("rgb", 8);
+    let dir = tmp("bleed-zero");
+    let (plain, a) = print_with(&mut s, &dir, "plain", json!({"cornerCropMarks": true}));
+    let (zero, b) = print_with(&mut s, &dir, "zero", json!({"cornerCropMarks": true, "bleed": 0.0}));
+    assert_eq!(a, b, "bleed 0 must not change a single byte");
+    assert_eq!(plain["bleed"], 0.0);
+    assert_eq!(zero["bleed"], 0.0);
+    let _ = std::fs::remove_dir_all(&dir);
+}
+
+#[test]
+fn bleed_puts_corner_crop_marks_on_the_trim_line_outside_the_image() {
+    let mut s = session("rgb", 8);
+    let dir = tmp("bleed");
+    let (r, pdf) = print_with(&mut s, &dir, "bleed", json!({"cornerCropMarks": true, "centerCropMarks": true, "bleed": 0.125}));
+    assert_eq!(r["bleed"], 0.125);
+    let rect: Vec<f64> = r["imageRect"].as_array().unwrap().iter().map(|v| v.as_f64().unwrap()).collect();
+    let (x, y, w, h) = (rect[0], rect[1], rect[2], rect[3]);
+    let c = pdf_content(&pdf);
+    // Bottom-left corner (PDF is bottom-up): the horizontal mark runs left from 6 pt outside the
+    // image, 9 pt (0.125 in) above the image's bottom edge; the vertical one 9 pt right of its left edge.
+    assert!(c.contains(&format!("{:.2} {:.2} m {:.2} {:.2} l S", x - 6.0, y + 9.0, x - 24.0, y + 9.0)), "{c}");
+    assert!(c.contains(&format!("{:.2} {:.2} m {:.2} {:.2} l S", x + 9.0, y - 6.0, x + 9.0, y - 24.0)), "{c}");
+    // Top-right corner, mirrored.
+    assert!(c.contains(&format!("{:.2} {:.2} m {:.2} {:.2} l S", x + w + 6.0, y + h - 9.0, x + w + 24.0, y + h - 9.0)), "{c}");
+    assert!(c.contains(&format!("{:.2} {:.2} m {:.2} {:.2} l S", x + w - 9.0, y + h + 6.0, x + w - 9.0, y + h + 24.0)), "{c}");
+    // Centre crop marks are on the midlines, which a symmetric bleed does not move.
+    assert!(c.contains(&format!("{:.2} {:.2} m {:.2} {:.2} l S", x + w / 2.0, y - 6.0, x + w / 2.0, y - 24.0)), "{c}");
+    // Print One Copy repeats the last print, bleed included.
+    let again = s.execute("file.printOneCopy", json!({"output": format!("{dir}/again.pdf"), "dryRun": true})).unwrap();
+    assert_eq!(again["bleed"], 0.125);
+    // The image box itself is unchanged: bleed moves marks, not pixels.
+    let (plain, _) = print_with(&mut s, &dir, "plain", json!({"cornerCropMarks": true}));
+    assert_eq!(plain["imageRect"], r["imageRect"]);
+    let _ = std::fs::remove_dir_all(&dir);
+}
+
+#[test]
+fn bleed_without_corner_crop_marks_changes_nothing() {
+    let mut s = session("rgb", 8);
+    let dir = tmp("bleed-nomarks");
+    let (_, a) = print_with(&mut s, &dir, "plain", json!({"registrationMarks": true}));
+    let (r, b) = print_with(&mut s, &dir, "bleed", json!({"registrationMarks": true, "bleed": 0.1}));
+    assert_eq!(a, b);
+    assert_eq!(r["bleed"], 0.0);
+    let _ = std::fs::remove_dir_all(&dir);
+}
+
+#[test]
+fn bad_bleed_is_an_error_not_a_panic() {
+    let mut s = session("rgb", 8);
+    // The test document prints 300 × 150 pt, so 1.05 in (75.6 pt) leaves no trim box.
+    for bleed in [json!(-0.1), json!("0.1"), json!(true), json!([0.1]), json!(1.05), json!(1e308)] {
+        let r = s.execute("file.print", json!({"dryRun": true, "send": false, "output": "", "cornerCropMarks": true, "bleed": bleed}));
+        assert!(matches!(r, Err(EngineError::BadParams { .. })), "bleed {bleed}: {r:?}");
+    }
+}

crates/engine/src/print_cmds/windows_marks.rs

@@ -1,5 +1,5 @@
 //! App-owned print-mark composition in points from the sheet's top-left.
-use super::Marks;
+use super::{MARK_GAP, MARK_LEN, Marks, corner_crop_segments};
 use craft_print::rgb::{Primitive, Shape};
 
 pub(super) fn primitives(marks: Marks, (x, y, w, h): (f64, f64, f64, f64)) -> Vec<Primitive> {
@@ -7,11 +7,10 @@ pub(super) fn primitives(marks: Marks, (x, y, w, h): (f64, f64, f64, f64)) -> Ve
     let line = |out: &mut Vec<Primitive>, x0, y0, x1, y1| {
         out.push(Primitive { shape: Shape::Line { from: (x0, y0), to: (x1, y1) }, width: 0.3, color: [0; 3] });
     };
-    let (gap, len) = (6.0, 18.0);
+    let (gap, len) = (MARK_GAP, MARK_LEN);
     if marks.corner_crop {
-        for (cx, cy, dx, dy) in [(x, y, -1.0, -1.0), (x + w, y, 1.0, -1.0), (x, y + h, -1.0, 1.0), (x + w, y + h, 1.0, 1.0)] {
-            line(&mut out, cx + dx * gap, cy, cx + dx * (gap + len), cy);
-            line(&mut out, cx, cy + dy * gap, cx, cy + dy * (gap + len));
+        for ((x0, y0), (x1, y1)) in corner_crop_segments(marks.bleed, (x, y, w, h)) {
+            line(&mut out, x0, y0, x1, y1);
         }
     }
     if marks.center_crop {
@@ -37,11 +36,24 @@ mod tests {
     use super::*;
     #[test]
     fn marks_surround_the_final_image_box_in_physical_points() {
-        let out = primitives(Marks { corner_crop: true, center_crop: true, registration: true }, (100.0, 200.0, 144.0, 72.0));
+        let out = primitives(Marks { corner_crop: true, center_crop: true, registration: true, bleed: 0.0 }, (100.0, 200.0, 144.0, 72.0));
         assert_eq!(out.len(), 24);
         assert_eq!(out[0].shape, Shape::Line { from: (94.0, 200.0), to: (76.0, 200.0) });
         assert_eq!(out[12].shape, Shape::Ellipse { bounds: (167.0, 180.0, 10.0, 10.0) });
         assert!(out.iter().all(|p| p.width == 0.3 && p.color == [0; 3]));
         assert!(primitives(Marks::default(), (0.0, 0.0, 10.0, 10.0)).is_empty());
     }
+
+    #[test]
+    fn bleed_moves_corner_crop_marks_onto_the_trim_line_in_top_down_coordinates() {
+        let rect = (100.0, 200.0, 144.0, 72.0);
+        let out = primitives(Marks { corner_crop: true, bleed: 9.0, ..Marks::default() }, rect);
+        assert_eq!(out.len(), 8);
+        // Top-left corner: still outside the image, but on the trim line 9 pt in (y down here).
+        assert_eq!(out[0].shape, Shape::Line { from: (94.0, 209.0), to: (76.0, 209.0) });
+        assert_eq!(out[1].shape, Shape::Line { from: (109.0, 194.0), to: (109.0, 176.0) });
+        // Bottom-right corner, mirrored.
+        assert_eq!(out[6].shape, Shape::Line { from: (250.0, 263.0), to: (268.0, 263.0) });
+        assert_eq!(out[7].shape, Shape::Line { from: (235.0, 278.0), to: (235.0, 296.0) });
+    }
 }

crates/ui-egui/src/file_ui.rs

@@ -921,11 +921,13 @@ fn print_body(app: &mut PhotocraftApp, ui: &mut egui::Ui, f: &mut Map<String, Va
                     clip.image(tex.id(), img, uv, egui::Color32::WHITE);
                     let mark = egui::Stroke::new(1.0, egui::Color32::BLACK);
                     if l.marks.corner_crop {
+                        // Bleed puts the marks on the trim line, inside the image edge.
+                        let b = l.marks.bleed as f32 * k;
                         for (c, dx, dy) in
                             [(img.left_top(), -1.0, -1.0), (img.right_top(), 1.0, -1.0), (img.left_bottom(), -1.0, 1.0), (img.right_bottom(), 1.0, 1.0)]
                         {
-                            clip.line_segment([c + egui::vec2(dx * 3.0, 0.0), c + egui::vec2(dx * 12.0, 0.0)], mark);
-                            clip.line_segment([c + egui::vec2(0.0, dy * 3.0), c + egui::vec2(0.0, dy * 12.0)], mark);
+                            clip.line_segment([c + egui::vec2(dx * 3.0, -dy * b), c + egui::vec2(dx * 12.0, -dy * b)], mark);
+                            clip.line_segment([c + egui::vec2(-dx * b, dy * 3.0), c + egui::vec2(-dx * b, dy * 12.0)], mark);
                         }
                     }
                     if l.marks.registration {

docs/target-app-parity.md

@@ -1,6 +1,6 @@
 # PhotoCraft vs Adobe Photoshop: target-app parity
 
-> **Last reviewed:** 2026-10-12 · **Last updated:** 2026-10-13 · **Change:** minor (on-canvas corner radius widgets, TOOL-214-12; `.atn` import maps 112 events; Free Transform H/V skew fields; stale rows corrected against `main` and the scorecard, estimates unchanged; Photoshop Actions `.atn` load and save; 2026-10-10: Tilt-Shift measurements added; earlier the same day: major, full re-measure against Photoshop 2026 27.11.0; merged `parity-estimate.md` and the roadmap's honest assessment; stale missing-tool rows corrected: Color Replacement and Red Eye are live toolbar tools, Frame landed; percentages unchanged) · **Target:** Adobe Photoshop 2026
+> **Last reviewed:** 2026-10-12 · **Last updated:** 2026-10-15 · **Change:** minor (Print › Functions › Bleed through `file.print`; on-canvas corner radius widgets, TOOL-214-12; `.atn` import maps 112 events; Free Transform H/V skew fields; stale rows corrected against `main` and the scorecard, estimates unchanged; Photoshop Actions `.atn` load and save; 2026-10-10: Tilt-Shift measurements added; earlier the same day: major, full re-measure against Photoshop 2026 27.11.0; merged `parity-estimate.md` and the roadmap's honest assessment; stale missing-tool rows corrected: Color Replacement and Red Eye are live toolbar tools, Frame landed; percentages unchanged) · **Target:** Adobe Photoshop 2026
 
 The authoritative answer to "how close is PhotoCraft to Photoshop, and how much work is left". The
 one-page summary is [`ROADMAP.md`](../ROADMAP.md); the ranked work list is [`gaps.md`](gaps.md);
@@ -286,7 +286,7 @@ just presence.
 | Transform, warp, puppet, perspective, liquify | ~88% | No Face-Aware Liquify (needs a landmark model) |
 | Automation: CLI, MCP, headless server, control channel | ~95% | Ahead of Photoshop here (see below) |
 | Image modes (RGB/Gray/CMYK/Lab/Indexed/Duotone/Multichannel) | ~85% | Multichannel display-only; no ink-plate model |
-| Print / export / Save for Web / slices / Generator | ~85% | No Separations/bleed; droplets basic |
+| Print / export / Save for Web / slices / Generator | ~85% | No Separations; Bleed only through `file.print` (no Print dialog field yet); droplets basic |
 | Computational photo (Photomerge, HDR, Lens, Camera Raw, Wide Angle) | ~70% | Classical implementations; generic lens profiles only |
 | Data-driven graphics (Variables, Data Sets) | ~0% | Not started (5 menu items) |
 | Video / Timeline / animation | ~0% | Not started (13 menu items) — a whole subsystem |
@@ -565,6 +565,7 @@ See [method, raw measurements and reproduction](five-algorithm-performance.md).
 
 | Date | Change | Summary |
 |---|---|---|
+| 2026-10-15 | minor | Print: Functions › Bleed (`file.print` / `file.printOneCopy` `bleed`, corner crop marks on the trim line, PDF and Windows paths); the Print dialog field is still missing; percentages unchanged |
 | 2026-10-13 | minor | Vector shapes: on-canvas corner radius widgets on live rectangles (TOOL-214-12); estimates unchanged |
 | 2026-10-13 | minor | Stale "missing tool" rows corrected against main: Color Replacement (`paint.colorReplacement`), Red Eye (`paint.redEye`) and Add/Delete Anchor Point (the Pen flyout) are live toolbar tools and Frame landed, so Art History Brush is the only tool still missing; percentages unchanged |
 | 2026-10-12 | minor | Free Transform options bar H/V skew fields; percentages unchanged |