Symbols: Reset Transformation returns an instance to its symbol's scale, rotation and shear

The Symbols panel menu's Reset Transformation and the Control bar's Reset
(shown while symbol instances are selected) give the selected instances
their symbol's own scale again, without rotation, shear or reflection, as
one undo step (symbol.instance.resetTransform). Each instance keeps the
center of its art's bounding box in place. Instances in perspective and
instances already at their symbol's scale are left as they are, no undo
step is added when nothing changes, and both controls are enabled only
while a selected instance would change.

Docs: docs/mcp.md, docs/target-app-parity.md.

crates/engine/src/cmd.rs

@@ -722,6 +722,10 @@ pub use pathops::shape_count;
 /// The gaps View › Show Live Paint Gaps shows on a Live Paint group.
 pub use buildcmds::live_paint_gaps;
 
+/// The transform Reset Transformation gives a symbol instance (the Symbols panel menu and the
+/// Control bar enable it when there is one).
+pub use brushsym::reset_transformation;
+
 /// Command ids kept only so older scripts keep working: `(alias, the command it duplicates)`.
 /// They run as before but the command palette leaves them out (it lists the command once).
 pub const ALIASES: &[(&str, &str)] = &[("object.convertDocumentColorMode", "file.documentColorMode")];

crates/engine/src/cmd/brushsym.rs

@@ -24,6 +24,9 @@ use super::{
 };
 use crate::EngineError;
 
+/// The transform Reset Transformation gives a symbol instance.
+pub use symbols::reset_transformation;
+
 mod brushes;
 mod dynamic;
 mod symbols;
@@ -40,8 +43,8 @@ pub(crate) use symbols::{
     stored_natural_size,
 };
 use symbols::{
-    symbol_adjust, symbol_break_link, symbol_delete, symbol_duplicate, symbol_list, symbol_new, symbol_options, symbol_place, symbol_replace,
-    symbol_select_instances, symbol_set_current, symbol_spray, symbol_unused, symbol_update,
+    symbol_adjust, symbol_break_link, symbol_delete, symbol_duplicate, symbol_instance_reset_transform, symbol_list, symbol_new, symbol_options,
+    symbol_place, symbol_replace, symbol_select_instances, symbol_set_current, symbol_spray, symbol_unused, symbol_update,
 };
 
 const SIZES_KEY: &str = vectorcraft_doc::SYMBOL_SIZES;
@@ -272,6 +275,15 @@ pub fn specs() -> Vec<CommandSpec> {
             has_selection,
             symbol_instance_reset
         ),
+        cmd!(
+            "symbol.instance.resetTransform",
+            "Reset Transformation",
+            [],
+            None,
+            "{ids?|id?} give the selected symbol instances (in groups too) their symbol's own scale, without rotation, shear or reflection, keeping the center of each one's bounding box in place, as one undo step; other objects, instances in perspective and instances already at their symbol's scale are left as they are, and no undo step is added when nothing changes; an id naming no object, or no symbol instance among the objects, is an error → {ids: the instances changed}",
+            has_selection,
+            symbol_instance_reset_transform
+        ),
         cmd!(
             "symbol.setCurrent",
             "Current Symbol",

crates/engine/src/cmd/brushsym/symbols.rs

@@ -696,6 +696,52 @@ pub(super) fn symbol_replace(s: &mut Session, p: &Value) -> Result<Value> {
     Ok(json!({ "ids": ids_json(&ids) }))
 }
 
+/// How far a transform coefficient may be from Reset Transformation's for the instance to count as
+/// already reset.
+const RESET_TOLERANCE: f64 = 1e-9;
+
+/// The transform Reset Transformation gives instance `n` of the document of `boxes`: its symbol's
+/// own scale, without rotation, shear or reflection, with the center of its art's bounding box
+/// where it is. `None` when `n` is not an instance of a symbol the document holds, is in
+/// perspective, or already has that transform.
+pub fn reset_transformation(boxes: &vectorcraft_doc::SymbolBoxes, n: &Node) -> Option<Affine> {
+    let d = boxes.document();
+    let NodeKind::SymbolInstance { symbol, xf } = &n.kind else { return None };
+    if n.extras().perspective.is_some() || !d.symbols.iter().any(|s| s.name == *symbol) {
+        return None;
+    }
+    let (w, h) = natural_size(d, symbol);
+    let scale = Affine::scale_non_uniform(w / (2.0 * HALF), h / (2.0 * HALF));
+    // The art's box in symbol space (the ±HALF square when the art cannot be measured): its
+    // center keeps its place on the page.
+    let art = boxes.art_bounds(symbol).unwrap_or_else(|| vectorcraft_geom::Rect::new(-HALF, -HALF, HALF, HALF));
+    let center = xf.transform_rect_bbox(art).center();
+    let new = Affine::translate(center - scale * art.center()) * scale;
+    xf.as_coeffs().iter().zip(new.as_coeffs()).any(|(a, b)| (a - b).abs() > RESET_TOLERANCE).then_some(new)
+}
+
+pub(super) fn symbol_instance_reset_transform(s: &mut Session, p: &Value) -> Result<Value> {
+    let ids = selected_instances(s, p)?;
+    if ids.is_empty() {
+        return Err(EngineError::Other("no symbol instances selected".into()));
+    }
+    let d = &s.doc()?.doc;
+    let boxes = d.symbol_boxes();
+    let changes: Vec<(NodeId, Affine)> = ids.iter().filter_map(|id| Some((*id, reset_transformation(&boxes, d.node(*id)?)?))).collect();
+    if !changes.is_empty() {
+        s.edit("Reset Transformation", |d, _| {
+            for (id, new) in &changes {
+                if let Some(NodeKind::SymbolInstance { xf, .. }) = d.node_mut(*id).map(|n| &mut n.kind) {
+                    *xf = *new;
+                }
+            }
+            Ok(())
+        })?;
+    }
+    let changed: Vec<NodeId> = changes.iter().map(|(id, _)| *id).collect();
+    Ok(json!({ "ids": ids_json(&changed) }))
+}
+
 pub(super) fn symbol_set_current(s: &mut Session, p: &Value) -> Result<Value> {
     let name = resolve_symbol(&s.doc()?.doc, p, "symbol.setCurrent")?;
     set_unknown(s, CURRENT_SYMBOL, Some(json!(name)))?;

crates/engine/src/tests/brushsym.rs

@@ -1343,6 +1343,117 @@ fn delete_duplicate_and_replace_symbols() {
     assert!(s.execute("symbol.delete", &json!({"name": "Small"})).is_err());
 }
 
+fn xf_of(s: &Session, id: NodeId) -> vectorcraft_geom::Affine {
+    match node(s, id).kind {
+        NodeKind::SymbolInstance { xf, .. } => xf,
+        _ => panic!("{id:?} is not a symbol instance"),
+    }
+}
+
+fn close_xf(a: vectorcraft_geom::Affine, b: vectorcraft_geom::Affine) -> bool {
+    a.as_coeffs().iter().zip(b.as_coeffs()).all(|(x, y)| (x - y).abs() < 1e-9)
+}
+
+fn undo_len(s: &Session) -> usize {
+    s.doc().unwrap().history.undo.len()
+}
+
+/// Reset Transformation gives rotated, scaled, sheared and reflected instances (in a group too)
+/// their symbol's own scale again, each keeping the center of its bounding box, as one undo step.
+#[test]
+fn reset_transformation_restores_the_symbols_scale_and_keeps_the_center() {
+    let mut s = session();
+    let (a, name, placed) = make_symbol(&mut s);
+    let b = NodeId(s.execute("symbol.place", &json!({"name": name, "x": 300, "y": 200})).unwrap()["id"].as_u64().unwrap());
+    let c = NodeId(s.execute("symbol.place", &json!({"name": name, "x": 100, "y": 220})).unwrap()["id"].as_u64().unwrap());
+    let master = xf_of(&s, b).with_translation(vectorcraft_geom::Vec2::ZERO);
+    select(&mut s, &[a]);
+    s.execute("object.rotate", &json!({"angle": 30})).unwrap();
+    s.execute("object.scale", &json!({"sx": 150, "sy": 50})).unwrap();
+    select(&mut s, &[b]);
+    s.execute("object.shear", &json!({"angle": 20})).unwrap();
+    select(&mut s, &[c]);
+    s.execute("object.reflect", &json!({"axis": "vertical"})).unwrap();
+    let turned: Vec<_> = [a, b, c].iter().map(|id| xf_of(&s, *id)).collect();
+    let centers: Vec<_> = [a, b, c].iter().map(|id| bounds(&s, *id).center()).collect();
+    let plain = rect(&mut s, 0.0, 0.0, 10.0, 10.0);
+    select(&mut s, &[b, c]);
+    let group = NodeId(s.execute("object.group", &json!({})).unwrap()["id"].as_u64().unwrap());
+    select(&mut s, &[a, group, plain]);
+    let plain_before = node(&s, plain);
+    let before = undo_len(&s);
+    let r = s.execute("symbol.instance.resetTransform", &json!({})).unwrap();
+    assert_eq!(r["ids"], json!([a.0, b.0, c.0]));
+    assert_eq!(undo_len(&s), before + 1, "one undo step");
+    for (id, center) in [a, b, c].into_iter().zip(&centers) {
+        let got = bounds(&s, id);
+        assert!((got.width() - placed.width()).abs() < 1e-9 && (got.height() - placed.height()).abs() < 1e-9, "{id:?}: {got:?}");
+        assert!((got.center() - *center).hypot() < 1e-9, "{id:?} keeps its center: {got:?} vs {center:?}");
+        let xf = xf_of(&s, id);
+        assert!(close_xf(xf.with_translation(vectorcraft_geom::Vec2::ZERO), master), "{id:?}: {xf:?}");
+    }
+    assert!(node(&s, plain) == plain_before, "other objects are left as they are");
+    s.execute("edit.undo", &json!({})).unwrap();
+    for (id, xf) in [a, b, c].into_iter().zip(turned) {
+        assert!(close_xf(xf_of(&s, id), xf), "Undo gives {id:?} its own transform back");
+    }
+}
+
+/// An instance of a symbol whose art lies away from the symbol's origin (as imported symbols can)
+/// keeps the center of the box its art fills when Reset Transformation turns it back.
+#[test]
+fn reset_transformation_keeps_the_center_of_art_away_from_the_origin() {
+    let mut s = session();
+    let r = rect(&mut s, 300.0, 10.0, 20.0, 20.0);
+    let art = node(&s, r);
+    s.execute("edit.clear", &json!({"ids": [r.0]})).unwrap();
+    let st = s.doc_mut().unwrap();
+    let d = std::sync::Arc::make_mut(&mut st.doc);
+    d.symbols.push(vectorcraft_doc::Symbol { dynamic: false, name: "Off".into(), art: std::sync::Arc::new(art) });
+    let layer = d.layers[0].id;
+    let id = d.alloc_id();
+    let xf = vectorcraft_geom::Affine::translate((100.0, 100.0)) * vectorcraft_geom::Affine::rotate(0.5);
+    d.insert(Some(layer), usize::MAX, Node::new(id, NodeKind::SymbolInstance { symbol: "Off".into(), xf })).unwrap();
+    let measured = |s: &Session| s.doc().unwrap().doc.bounds_of(&[id], false).unwrap();
+    let before = measured(&s);
+    assert_eq!(s.execute("symbol.instance.resetTransform", &json!({"ids": [id.0]})).unwrap()["ids"], json!([id.0]));
+    let after = measured(&s);
+    assert!((after.center() - before.center()).hypot() < 1e-9, "{after:?} vs {before:?}");
+    assert!((after.width() - 20.0).abs() < 1e-9 && (after.height() - 20.0).abs() < 1e-9, "{after:?}");
+}
+
+/// Reset Transformation adds no undo step for an instance already at its symbol's scale or for
+/// one in perspective, and refuses an id naming no object and objects without an instance,
+/// changing nothing.
+#[test]
+fn reset_transformation_leaves_unchanged_instances_and_refuses_bad_ids() {
+    let mut s = Session::new();
+    s.execute("file.new", &json!({"width": 1000, "height": 800})).unwrap();
+    let (inst, name, _) = make_symbol(&mut s);
+    let before = undo_len(&s);
+    assert_eq!(s.execute("symbol.instance.resetTransform", &json!({"ids": [inst.0]})).unwrap()["ids"], json!([]));
+    assert_eq!(undo_len(&s), before, "nothing changed: no undo step");
+    let plain = rect(&mut s, 0.0, 0.0, 10.0, 10.0);
+    select(&mut s, &[inst]);
+    s.execute("object.rotate", &json!({"angle": 45})).unwrap();
+    let turned = s.doc().unwrap().doc.clone();
+    let before = undo_len(&s);
+    for bad in [json!({"ids": [inst.0, 999_999]}), json!({"id": 999_999}), json!({"ids": [plain.0]}), json!({"ids": "x"})] {
+        assert!(s.execute("symbol.instance.resetTransform", &bad).is_err(), "{bad}");
+    }
+    assert!(*s.doc().unwrap().doc == *turned && undo_len(&s) == before, "the refusals change nothing");
+    // An instance in perspective is left as it is.
+    s.execute("perspective.grid.preset", &json!({"kind": 2})).unwrap();
+    let projected = NodeId(s.execute("symbol.place", &json!({"name": name, "x": 500, "y": 350})).unwrap()["id"].as_u64().unwrap());
+    select(&mut s, &[projected]);
+    s.execute("object.rotate", &json!({"angle": 30})).unwrap();
+    s.execute("perspective.attach", &json!({"ids": [projected.0], "plane": "right"})).unwrap();
+    let xf = xf_of(&s, projected);
+    let before = undo_len(&s);
+    assert_eq!(s.execute("symbol.instance.resetTransform", &json!({"ids": [projected.0]})).unwrap()["ids"], json!([]));
+    assert!(undo_len(&s) == before && close_xf(xf_of(&s, projected), xf), "an instance in perspective stays as it was");
+}
+
 /// New Symbol and Duplicate Symbol trim the name they are given, as Symbol Options trims
 /// `newName`; the trimmed name is the one compared with the symbols there are.
 #[test]

crates/ui-egui/src/i18n/bg.tsv

@@ -2670,6 +2670,7 @@ digits	Malayalam	Малаялам
 	Replace it with another file, or ignore it: its images keep showing the preview saved with the document.	Заменете го с друг файл или го игнорирайте: неговите изображения ще продължат да показват записания с документа преглед.
 	Replace Spine	Замяна на оста
 	Replace Symbol	Замяна на символ
+	Reset Transformation	Нулиране на трансформацията
 	Replace With Font	Замяна с шрифт
 	Replace With Font From	Замяна с шрифт от
 	System	Система

crates/ui-egui/src/i18n/bs.tsv

@@ -3163,6 +3163,7 @@ theme	Appearance	Izgled
 	Redefine Symbol	Ponovo definiši simbol
 	Remove Brush Stroke	Ukloni potez četkicom
 	Replace Symbol	Zamijeni simbol
+	Reset Transformation	Vrati transformaciju na početno
 	Select All Instances	Odaberi sve instance
 	Symbol Sprayer	Raspršivač simbola
 	Symbolism Tool	Alat simbolizam

crates/ui-egui/src/i18n/ca.tsv

@@ -3372,6 +3372,7 @@ digits	Malayalam	Malaiàlam
 	Replace it with another file, or ignore it: its images keep showing the preview saved with the document.	Reemplaça’l per un altre fitxer o ignora’l: les seves imatges continuaran mostrant la previsualització desada amb el document.
 	Replace Spine	Reemplaça l’espina
 	Replace Symbol	Reemplaça el símbol
+	Reset Transformation	Restableix la transformació
 	Replace With Font	Reemplaça per un tipus de lletra
 	Replace With Font From	Reemplaça per un tipus de lletra de
 	System	Sistema

crates/ui-egui/src/i18n/cs.tsv

@@ -3202,6 +3202,7 @@ theme	Appearance	Motiv
 	Redefine Symbol	Předefinovat symbol
 	Remove Brush Stroke	Odebrat tah štětcem
 	Replace Symbol	Nahradit symbol
+	Reset Transformation	Obnovit transformaci
 	Select All Instances	Vybrat všechny instance
 	Symbol Sprayer	Rozprašovač symbolů
 	Symbolism Tool	Nástroj symbolů

crates/ui-egui/src/i18n/da.tsv

@@ -2946,6 +2946,7 @@ theme	Appearance	Udseende
 	Redefine Symbol	Omdefinér symbol
 	Remove Brush Stroke	Fjern penselstrøg
 	Replace Symbol	Erstat symbol
+	Reset Transformation	Nulstil transformation
 	Select All Instances	Markér alle forekomster
 	Symbol Sprayer	Symbolsprøjter
 	Symbolism Tool	Symbolværktøj

crates/ui-egui/src/i18n/de.tsv

@@ -2697,6 +2697,7 @@ digits	Malayalam	Malayalam
 	Replace it with another file, or ignore it: its images keep showing the preview saved with the document.	Ersetzen Sie sie durch eine andere Datei oder ignorieren Sie sie: Ihre Bilder zeigen weiterhin die mit dem Dokument gespeicherte Vorschau.
 	Replace Spine	Achse ersetzen
 	Replace Symbol	Symbol ersetzen
+	Reset Transformation	Transformation zurücksetzen
 	Replace With Font	Durch Schrift ersetzen
 	Replace With Font From	Ersetzende Schrift aus
 	System	System

crates/ui-egui/src/i18n/el.tsv

@@ -3296,6 +3296,7 @@ digits	Malayalam	Μαλαγιάλαμ
 	Replace it with another file, or ignore it: its images keep showing the preview saved with the document.	Αντικαταστήστε το με άλλο αρχείο ή αγνοήστε το: οι εικόνες του θα συνεχίσουν να εμφανίζουν την προεπισκόπηση που αποθηκεύτηκε στο έγγραφο.
 	Replace Spine	Αντικατάσταση κεντρικής καμπύλης
 	Replace Symbol	Αντικατάσταση συμβόλου
+	Reset Transformation	Επαναφορά μετασχηματισμού
 	Replace With Font	Αντικατάσταση με γραμματοσειρά
 	Replace With Font From	Αντικατάσταση με γραμματοσειρά από
 	System	Σύστημα

crates/ui-egui/src/i18n/es.tsv

@@ -2740,6 +2740,7 @@ digits	Malayalam	Malayálam
 	Replace it with another file, or ignore it: its images keep showing the preview saved with the document.	Reemplázalo con otro archivo o ignóralo: sus imágenes seguirán mostrando la vista previa guardada con el documento.
 	Replace Spine	Reemplazar eje
 	Replace Symbol	Reemplazar símbolo
+	Reset Transformation	Restablecer transformación
 	Replace With Font	Reemplazar con fuente
 	Replace With Font From	Reemplazar con fuente de
 	System	Sistema

crates/ui-egui/src/i18n/fi.tsv

@@ -3141,6 +3141,7 @@ theme	Appearance	Ulkoasu
 	Redefine Symbol	Määritä symboli uudelleen
 	Remove Brush Stroke	Poista sivellinviiva
 	Replace Symbol	Korvaa symboli
+	Reset Transformation	Palauta muunnos
 	Select All Instances	Valitse kaikki ilmentymät
 	Symbol Sprayer	Symbolisuihkutin
 	Symbolism Tool	Symbolityökalu

crates/ui-egui/src/i18n/fr.tsv

@@ -2732,6 +2732,7 @@ digits	Malayalam	Malayalam
 	Replace it with another file, or ignore it: its images keep showing the preview saved with the document.	Remplacez-le par un autre fichier ou ignorez-le : ses images continueront d’afficher l’aperçu enregistré avec le document.
 	Replace Spine	Remplacer la dorsale
 	Replace Symbol	Remplacer le symbole
+	Reset Transformation	Réinitialiser la transformation
 	Replace With Font	Remplacer par la police
 	Replace With Font From	Remplacer par une police de
 	System	Système

crates/ui-egui/src/i18n/hi.tsv

@@ -3685,6 +3685,7 @@
 	Replace Missing Fonts…	अनुपलब्ध फ़ॉन्ट रिप्लेस करें…
 	Replace Spine	स्पाइन रिप्लेस करें
 	Replace Symbol	सिंबल रिप्लेस करें
+	Reset Transformation	रूपांतरण रीसेट करें
 	Replace With Font	इस फ़ॉन्ट से रिप्लेस करें
 	Replace With Font From	इस स्रोत के फ़ॉन्ट से रिप्लेस करें
 	Replace with Top Object	सबसे ऊपर के ऑब्जेक्ट से रिप्लेस करें

crates/ui-egui/src/i18n/hu.tsv

@@ -3268,6 +3268,7 @@ mark-style	Japanese	Japán
 	Replace it with another file, or ignore it: its images keep showing the preview saved with the document.	Cseréld le egy másik fájlra, vagy hagyd ki: a képei a dokumentummal mentett előnézetet mutatják tovább.
 	Replace Spine	Gerinc cseréje
 	Replace Symbol	Szimbólum cseréje
+	Reset Transformation	Átalakítás visszaállítása
 	Replace With Font	Helyettesítő betűtípus
 	Replace With Font From	Helyettesítő betűtípus forrása
 	System	Rendszer

crates/ui-egui/src/i18n/id.tsv

@@ -2946,6 +2946,7 @@ theme	Appearance	Tampilan
 	Redefine Symbol	Definisikan ulang simbol
 	Remove Brush Stroke	Hapus guratan kuas
 	Replace Symbol	Ganti simbol
+	Reset Transformation	Atur ulang transformasi
 	Select All Instances	Pilih semua instansi
 	Symbol Sprayer	Penyemprot simbol
 	Symbolism Tool	Alat simbolisme

crates/ui-egui/src/i18n/it.tsv

@@ -2773,6 +2773,7 @@ digits	Malayalam	Malayalam
 	Replace it with another file, or ignore it: its images keep showing the preview saved with the document.	Sostituiscilo con un altro file oppure ignoralo: le sue immagini continueranno a mostrare l'anteprima salvata con il documento.
 	Replace Spine	Sostituisci dorsale
 	Replace Symbol	Sostituisci simbolo
+	Reset Transformation	Reimposta trasformazione
 	Replace With Font	Sostituisci con font
 	Replace With Font From	Sostituisci con font da
 	System	Sistema

crates/ui-egui/src/i18n/ja.tsv

@@ -2753,6 +2753,7 @@ mark-style	Japanese	日本式
 	Replace:	置換:
 	Replace Font	フォントを置換
 	Replace Symbol	シンボルを置き換え
+	Reset Transformation	変形をリセット
 	Replace With Font	置換するフォント
 	Replace With Font From	置換するフォントの一覧
 	System	システム

crates/ui-egui/src/i18n/ka.tsv

@@ -2765,6 +2765,7 @@ theme	Appearance	იერსახე
 	Redefine Symbol	სიმბოლოს ხელახლა განსაზღვრა
 	Remove Brush Stroke	ფუნჯის შტრიხის მოხსნა
 	Replace Symbol	სიმბოლოს ჩანაცვლება
+	Reset Transformation	გარდაქმნის ჩამოყრა
 	Select All Instances	ყველა ეგზემპლარის მონიშვნა
 	Symbol Sprayer	სიმბოლოების სპრეი
 	Symbolism Tool	სიმბოლოების ხელსაწყო

crates/ui-egui/src/i18n/ko.tsv

@@ -2742,6 +2742,7 @@ mark-style	Japanese	일본식
 	Replace:	바꾸기:
 	Replace Font	글꼴 바꾸기
 	Replace Symbol	심볼 바꾸기
+	Reset Transformation	변형 재설정
 	Replace With Font	바꿀 글꼴
 	Replace With Font From	바꿀 글꼴 목록
 	System	시스템

crates/ui-egui/src/i18n/nl.tsv

@@ -2960,6 +2960,7 @@ theme	Appearance	Vormgeving
 	Redefine Symbol	Symbool opnieuw definiëren
 	Remove Brush Stroke	Penseelstreek verwijderen
 	Replace Symbol	Symbool vervangen
+	Reset Transformation	Transformatie opnieuw instellen
 	Select All Instances	Alle exemplaren selecteren
 	Symbol Sprayer	Symboolspuit
 	Symbolism Tool	Symbolisatiegereedschap

crates/ui-egui/src/i18n/pl.tsv

@@ -3081,6 +3081,7 @@ theme	Appearance	Wygląd
 	Redefine Symbol	Zdefiniuj ponownie symbol
 	Remove Brush Stroke	Usuń pociągnięcie pędzla
 	Replace Symbol	Zastąp symbol
+	Reset Transformation	Resetuj przekształcenie
 	Select All Instances	Zaznacz wszystkie wystąpienia
 	Symbol Sprayer	Rozpylanie symboli
 	Symbolism Tool	Narzędzie symboli

crates/ui-egui/src/i18n/pt-br.tsv

@@ -2282,6 +2282,7 @@ digits	Malayalam	Malaiala
 	Replace Font	Substituir Fonte
 	Replace Spine	Substituir Coluna
 	Replace Symbol	Substituir Símbolo
+	Reset Transformation	Redefinir Transformação
 	Replace With Font	Substituir Com Fonte
 	Replace With Font From	Substituir Com Fonte De
 	System	Sistema

crates/ui-egui/src/i18n/ru.tsv

@@ -2768,6 +2768,7 @@ digits	Malayalam	Малаялам
 	Replace it with another file, or ignore it: its images keep showing the preview saved with the document.	Замените его другим файлом или игнорируйте: его изображения продолжат показывать предварительный просмотр, сохранённый с документом.
 	Replace Spine	Заменить остов
 	Replace Symbol	Заменить символ
+	Reset Transformation	Сбросить трансформацию
 	Replace With Font	Заменить шрифтом
 	Replace With Font From	Заменить шрифтом из
 	System	Система

crates/ui-egui/src/i18n/sv.tsv

@@ -2676,6 +2676,7 @@ digits	Malayalam	Malayalam
 	Replace it with another file, or ignore it: its images keep showing the preview saved with the document.	Ersätt den med en annan fil eller ignorera den: dess bilder fortsätter att visa förhandsgranskningen som sparats med dokumentet.
 	Replace Spine	Ersätt ryggrad
 	Replace Symbol	Ersätt symbol
+	Reset Transformation	Återställ transformering
 	Replace With Font	Ersätt med typsnitt
 	Replace With Font From	Ersätt med typsnitt från
 	System	System

crates/ui-egui/src/i18n/tr.tsv

@@ -2545,6 +2545,7 @@ digits	Malayalam	Malayalam
 	Replace it with another file, or ignore it: its images keep showing the preview saved with the document.	Onu başka bir dosyayla değiştirin veya yok sayın: resimleri, belgeyle birlikte kaydedilen önizlemeyi göstermeye devam eder.
 	Replace Spine	Omurgayı Değiştir
 	Replace Symbol	Sembolü Değiştir
+	Reset Transformation	Dönüşümü Sıfırla
 	Replace With Font	Yazı Tipiyle Değiştir
 	Replace With Font From	Değiştirilecek Yazı Tipi Kaynağı
 	System	Sistem

crates/ui-egui/src/i18n/uk.tsv

@@ -2765,6 +2765,7 @@ digits	Malayalam	Малаялам
 	Replace it with another file, or ignore it: its images keep showing the preview saved with the document.	Замініть його іншим файлом або ігноруйте: зображення продовжать показувати попередній перегляд, збережений з документом.
 	Replace Spine	Замінити вісь
 	Replace Symbol	Замінити символ
+	Reset Transformation	Скинути трансформацію
 	Replace With Font	Замінити шрифтом
 	Replace With Font From	Замінити шрифтом з
 	System	Система

crates/ui-egui/src/i18n/vi.tsv

@@ -3036,6 +3036,7 @@ mark-style	Japanese	Kiểu Nhật
 	Replace it with another file, or ignore it: its images keep showing the preview saved with the document.	Thay thế bằng tệp khác hoặc bỏ qua: ảnh của nó vẫn hiển thị bản xem trước đã lưu cùng tài liệu.
 	Replace Spine	Thay thế trục
 	Replace Symbol	Thay thế ký hiệu
+	Reset Transformation	Đặt lại biến đổi
 	Replace With Font	Thay thế bằng phông chữ
 	Replace With Font From	Thay thế bằng phông chữ từ
 	System	Hệ thống

crates/ui-egui/src/i18n/zh-hans.tsv

@@ -2644,6 +2644,7 @@ digits	Malayalam	马拉雅拉姆数字
 	Replace it with another file, or ignore it: its images keep showing the preview saved with the document.	将其替换为其他文件，或忽略：其图像继续显示随文档保存的预览。
 	Replace Spine	替换脊线
 	Replace Symbol	替换符号
+	Reset Transformation	重置变换
 	Replace With Font	替换为字体
 	Replace With Font From	替换字体来源
 	System	系统

crates/ui-egui/src/i18n/zh-hant.tsv

@@ -3637,6 +3637,7 @@ digits	Malayalam	馬來亞拉姆數字
 	Replace it with another file, or ignore it: its images keep showing the preview saved with the document.	以其他檔案取代，或忽略：其影像會繼續顯示隨文件儲存的預覽。
 	Replace Spine	取代脊線
 	Replace Symbol	取代符號
+	Reset Transformation	重設變形
 	Replace With Font	取代為字體
 	Replace With Font From	取代字體來源
 	System	系統

crates/ui-egui/src/panels/symbols.rs

@@ -160,6 +160,14 @@ pub(crate) fn changed_instances_selected(app: &VectorcraftApp) -> bool {
     instance_selected(app, |c| !c.extras().symbol_overrides.is_empty())
 }
 
+/// Does the selection hold a symbol instance whose scale, rotation or shear differs from its
+/// symbol's, which Reset Transformation restores?
+fn transformed_instances_selected(app: &VectorcraftApp) -> bool {
+    let Some(doc) = app.session.active().map(|st| st.doc.clone()) else { return false };
+    let boxes = doc.symbol_boxes();
+    instance_selected(app, |c| vectorcraft_engine::cmd::reset_transformation(&boxes, c).is_some())
+}
+
 /// The symbols of the selected objects when every one is a symbol instance; `None` otherwise.
 fn selected_instance_symbols(app: &VectorcraftApp) -> Option<Vec<String>> {
     let st = app.session.active()?;
@@ -178,7 +186,9 @@ fn selected_instance_symbols(app: &VectorcraftApp) -> Option<Vec<String>> {
 /// The Control bar's Replace menu while symbol instances alone are selected: the document's
 /// symbols, showing the one the instances share (blank when they differ); picking another
 /// replaces them all, as "Select a new symbol from the Replace dropdown in the Control panel"
-/// (<https://helpx.adobe.com/illustrator/desktop/manage-objects/traces-mockups-symbols/edit-symbols.html>).
+/// (<https://helpx.adobe.com/illustrator/desktop/manage-objects/traces-mockups-symbols/edit-symbols.html>),
+/// and the Reset button, which gives them their symbol's scale, rotation and shear again
+/// (<https://helpx.adobe.com/illustrator/desktop/manage-objects/traces-mockups-symbols/transform-symbols.html>).
 pub(crate) fn control_bar(app: &mut VectorcraftApp, ui: &mut Ui) {
     let Some(symbols) = selected_instance_symbols(app) else { return };
     let Some(st) = app.session.active() else { return };
@@ -199,6 +209,14 @@ pub(crate) fn control_bar(app: &mut VectorcraftApp, ui: &mut Ui) {
     {
         app.status(e);
     }
+    // Reset: Reset Transformation, enabled while an instance's scale, rotation or shear differs
+    // from its symbol's.
+    let reset = transformed_instances_selected(app);
+    if ui.add_enabled_ui(reset, |ui| widgets::flat_button_fit(ui, tl!("Reset"), 48.0).on_hover_text(tl!("Reset Transformation"))).inner.clicked()
+        && let Err(e) = app.run("symbol.instance.resetTransform", json!({}))
+    {
+        app.status(e);
+    }
     ui.add_space(4.0);
 }
 
@@ -328,7 +346,7 @@ pub fn menu(app: &mut VectorcraftApp, ui: &mut Ui) {
     if menu_item(ui, tl!("Delete Symbol"), sel.is_some() || !marked.is_empty(), false) {
         delete(app, &marked, sel.as_deref(), false);
     }
-    let items: [(&str, bool, &str, Value); 7] = [
+    let items: [(&str, bool, &str, Value); 8] = [
         (tl!("Symbol Options…"), sel.is_some(), "ui.symbolOptions", json!({"edit": true, "name": sel})),
         // The selected instance, else the symbol selected in the panel.
         (tl!("Edit Symbol"), inst || sel.is_some(), "symbol.edit", if inst { json!({}) } else { name.clone() }),
@@ -336,6 +354,7 @@ pub fn menu(app: &mut VectorcraftApp, ui: &mut Ui) {
         (tl!("Replace Symbol"), inst && sel.is_some(), "symbol.replace", name.clone()),
         (tl!("Break Link to Symbol"), inst, "symbol.breakLink", json!({})),
         (tl!("Reset Symbol Instance"), changed_instances_selected(app), "symbol.instance.reset", json!({})),
+        (tl!("Reset Transformation"), transformed_instances_selected(app), "symbol.instance.resetTransform", json!({})),
         (tl!("Select All Instances"), sel.is_some(), "symbol.selectInstances", name),
     ];
     for (label, enabled, cmd, params) in items {
@@ -1300,4 +1319,64 @@ mod tests {
         let doc = &app.session.active().unwrap().doc;
         assert!(matches!(&doc.node(leaf).unwrap().kind, NodeKind::SymbolInstance { symbol, .. } if symbol == "Star"), "the instance is replaced");
     }
+
+    /// The panel menu's Reset Transformation and the Control bar's Reset are enabled only while a
+    /// selected instance's scale, rotation or shear differs from its symbol's, and give the
+    /// instance its symbol's again.
+    #[test]
+    fn reset_transformation_is_enabled_for_a_transformed_instance_and_resets_it() {
+        let mut app = leaf_and_dot();
+        let leaf = instance_of(&app, "Leaf").expect("a Leaf instance");
+        app.run("select.set", json!({"ids": [leaf.0]})).unwrap();
+        let xf = |app: &VectorcraftApp| match app.session.active().unwrap().doc.node(leaf).map(|n| &n.kind) {
+            Some(NodeKind::SymbolInstance { xf, .. }) => *xf,
+            _ => panic!("the Leaf instance"),
+        };
+        let master = xf(&app);
+        let ctx = egui::Context::default();
+        crate::theme::install_fonts(&ctx);
+        ctx.enable_accesskit();
+        let item_disabled = |app: &mut VectorcraftApp| {
+            let raw = egui::RawInput { screen_rect: Some(Rect::from_min_size(Pos2::ZERO, vec2(236.0, 400.0))), ..Default::default() };
+            let mut out = ctx.run_ui(raw, |ui| menu(app, ui));
+            out.textures_delta.clear();
+            let nodes = &out.platform_output.accesskit_update.as_ref().expect("an accessibility tree").nodes;
+            nodes
+                .iter()
+                .find(|(_, n)| n.label().is_some_and(|l| l.trim() == "Reset Transformation"))
+                .map(|(_, n)| n.is_disabled())
+                .expect("the menu item")
+        };
+        // At its symbol's scale the menu item is disabled and a click changes nothing.
+        assert!(item_disabled(&mut app), "the item is disabled at the symbol's scale");
+        let before = app.session.active().unwrap().doc.clone();
+        click_menu(&ctx, &mut app, "Reset Transformation");
+        assert!(Arc::ptr_eq(&before, &app.session.active().unwrap().doc), "the item is disabled");
+        app.run("object.rotate", json!({"angle": 30})).unwrap();
+        assert!(!item_disabled(&mut app), "a turned instance enables it");
+        click_menu(&ctx, &mut app, "Reset Transformation");
+        let close =
+            |a: vectorcraft_geom::Affine, b: vectorcraft_geom::Affine| a.as_coeffs().iter().zip(b.as_coeffs()).all(|(x, y)| (x - y).abs() < 1e-9);
+        assert!(close(xf(&app), master), "the menu item resets the instance: {:?} vs {master:?}", xf(&app));
+        // The Control bar's Reset.
+        let bar = |app: &mut VectorcraftApp, events: Vec<egui::Event>| {
+            let raw = egui::RawInput { screen_rect: Some(Rect::from_min_size(Pos2::ZERO, vec2(800.0, 400.0))), events, ..Default::default() };
+            let mut out = ctx.run_ui(raw, |ui| {
+                ui.horizontal(|ui| control_bar(app, ui));
+            });
+            out.textures_delta.clear();
+            out
+        };
+        let reset_disabled = |out: &egui::FullOutput| {
+            let nodes = &out.platform_output.accesskit_update.as_ref().expect("an accessibility tree").nodes;
+            nodes.iter().find(|(_, n)| n.label().is_some_and(|l| l.trim() == "Reset")).map(|(_, n)| n.is_disabled()).expect("a Reset button")
+        };
+        assert!(reset_disabled(&bar(&mut app, vec![])), "Reset is disabled at the symbol's scale");
+        app.run("object.scale", json!({"sx": 150, "sy": 50})).unwrap();
+        let out = bar(&mut app, vec![]);
+        assert!(!reset_disabled(&out));
+        let at = clickable(&out).into_iter().find(|(l, _)| l == "Reset").expect("a Reset button").1;
+        bar(&mut app, vec![egui::Event::PointerMoved(at), button(at, true), button(at, false)]);
+        assert!(close(xf(&app), master), "the Control bar's Reset resets the instance: {:?} vs {master:?}", xf(&app));
+    }
 }

docs/mcp.md

@@ -1717,6 +1717,13 @@ already walks Image Trace. Short agent entry points:
   `symbol.selectInstances {name}`, `symbol.delete {name | names, expandInstances?}` (`names` deletes several in one
   undo step). `symbol.new` and `symbol.duplicate {name, newName?}` trim the white space around the
   name they are given, as `symbol.options` trims `newName`; a blank one gives "New Symbol" or "<name> copy".
+- Reset Transformation (the Symbols panel menu, and Reset on the Control bar while symbol instances are selected):
+  `symbol.instance.resetTransform {ids?}` gives the selected symbol instances, in groups too, their symbol's own
+  scale again, without rotation, shear or reflection, as one undo step. VectorCraft's own rules: each instance keeps
+  the center of its bounding box in place; other objects, instances in perspective and instances already at their
+  symbol's scale are left as they are, and no undo step is added when nothing changes; an id that names no object, or
+  objects without a symbol instance, is an error. It returns `{ids}`, the instances it changed. The menu item and the
+  button are enabled only while a selected instance would change.
 - Dynamic symbols: an instance of a symbol whose `type` is `dynamic` changes the appearance of objects in the symbol's
   art for itself only and stays linked. `symbol.instance.setAppearance {id?, path, fill?, stroke?, opacity?, blend?}`
   names the object by `path`, child indices in paint order from the art's root down through its groups (`[]` is the

docs/target-app-parity.md

@@ -713,6 +713,7 @@ Moved from the ROADMAP's "Shipped so far" on 2026-10-10. Update it when a featur
   - **Delete Symbol asks first** ([Symbols panel](https://helpx.adobe.com/illustrator/desktop/manage-objects/traces-mockups-symbols/symbols-panel-options.html), [symbol libraries](https://helpx.adobe.com/illustrator/desktop/manage-objects/traces-mockups-symbols/create-or-import-symbol-libraries.html), [Alt-click Delete](https://helpx.adobe.com/illustrator/using/default-keyboard-shortcuts.html)): the Symbols panel's Delete Symbol button and menu item ask "Delete the selected symbol?" with Yes and No for a symbol no instance uses. For a symbol with placed instances they ask with Expand Instances (the instances become ordinary art), Delete Instances and Cancel; either Instances button deletes the symbol in one undo step. Alt-click on the button deletes an unused symbol without asking and still asks about one with instances. A question left open while another document became active deletes nothing. `symbol.delete` itself does not ask. Tests: `panels::symbols::tests::delete_symbol_asks_first_and_alt_click_deletes_an_unused_symbol_at_once`, `the_in_use_question_expands_or_deletes_the_instances`, `a_stale_delete_symbol_question_deletes_nothing`, `the_delete_symbol_questions_show_their_buttons`.
   - **Symbols › Select All Unused** ([Symbols panel](https://helpx.adobe.com/illustrator/desktop/manage-objects/traces-mockups-symbols/symbols-panel-options.html), #4918): the Symbols panel menu's Select All Unused shows the symbols nothing places selected (`symbol.unused`): instances in the art (opacity masks included), graph designs, pattern tiles and brush art count, and so do instances in a used symbol's art. Delete Symbol, the button or the menu item, then asks "Delete the selected symbols?" once and deletes those still unused in one undo step (`symbol.delete {names}`); Alt-click on the button deletes them without asking, and a click on a symbol picks just it again. Tests: `tests::brushsym::symbol_unused_lists_the_symbols_nothing_places_and_delete_takes_several`, `panels::symbols::tests::select_all_unused_picks_the_unused_symbols_and_delete_deletes_them`, `dialogs::symbol_delete::tests::several_symbols_get_the_plural_question`.
   - **Expand of symbol instances:** Object › Expand turns selected symbol instances (without effects, not in perspective, in groups or placed documents too) into their art as Break Link to Symbol places it, one level deep, as one undo step; the Expand dialog's Fill and Stroke reach that art (`object.expand`, `crates/engine/src/tests/expand_symbols.rs`; estimated, score unchanged).
+  - **Reset Transformation** ([Transform symbols](https://helpx.adobe.com/illustrator/desktop/manage-objects/traces-mockups-symbols/transform-symbols.html), [Symbols panel options](https://helpx.adobe.com/illustrator/desktop/manage-objects/traces-mockups-symbols/symbols-panel-options.html)): the Symbols panel menu's Reset Transformation and the Control bar's Reset, shown while symbol instances are selected, give the selected instances their symbol's own scale again, without rotation or shear, as one undo step (`symbol.instance.resetTransform`); an instance in perspective is left as it is. VectorCraft's own rules: each instance keeps the center of its bounding box in place, reflection is removed too, and the menu item and the button are enabled only while a selected instance would change. Tests: `tests::brushsym::reset_transformation_restores_the_symbols_scale_and_keeps_the_center`, `reset_transformation_leaves_unchanged_instances_and_refuses_bad_ids`, `panels::symbols::tests::reset_transformation_is_enabled_for_a_transformed_instance_and_resets_it`.
   - **Expand of dimensions:** Object › Expand, Expand Appearance, Create Outlines and Outline Stroke turn a dimension whose art they change into a plain group of that art, which stays as it is through later moves, scales and edits of what it measured; undo gives the live dimension back (`crates/engine/tests/it/dimensions.rs`; VectorCraft's own rule; estimated, score unchanged).
   - **Brush libraries** ([public source](https://helpx.adobe.com/illustrator/desktop/paint-and-fill/apply-and-edit-strokes/create-new-brush-libraries.html), [import](https://helpx.adobe.com/illustrator/desktop/paint-and-fill/apply-and-edit-strokes/import-brushes-from-brush-libraries-or-other-files.html), [Brushes panel](https://helpx.adobe.com/illustrator/desktop/paint-and-fill/apply-and-edit-strokes/brushes-panel-overview.html)): Window › Brush Libraries, the Brushes panel's Brush Libraries Menu and its menu's Open Brush Library open each library in a library panel of its own, as swatch, graphic style and symbol libraries do. The built-in libraries (Art Ribbons, Calligraphic Nibs, Pattern Borders, Scatter Shapes) are original brushes generated in code (`crates/engine/src/cmd/brushlib.rs`); Striped Ribbon's art is filled with the library's own pattern and Sparkles scatters the library's own symbol. A click on a brush adds it to the document's Brushes as one undo step with every resource its art uses (patterns, symbols, swatches, graphic styles, images), makes it the current brush and, with paths selected, applies it to them in the same step; a brush the document already has is not added again and a different brush of the same name comes in numbered ("Wave 2"). Shift/Cmd-clicks select brushes for Add to Brushes; a brush dragged onto a path is added and applied to it, and one dragged onto the Brushes panel is added. Save Brushes… / the Brushes panel's Save Brush Library… write the document's brushes (or the selected ones) as a `.vectorcraft` library into the `Brushes` folder next to the preferences, listed under User Defined, or to a file; Other Library… reads the brushes of any document VectorCraft opens. Thumbnails, in the library panels, the Brushes panel and Brush Options, render brush art with the patterns and symbols it uses. Copying brushed art now carries the patterns and symbols its brush's art uses too. Tests: `crates/engine/src/tests/brushlib.rs`, `crates/ui-egui/src/panels/tests_brush_libraries.rs`, `panels::brushes::tests::library_brush_previews_show_the_patterns_their_art_uses`, `canvas::tests::a_library_brush_dropped_on_a_path_is_added_and_applied_in_one_step`.
   - A canvas context menu: right-click selects the object under the pointer and lists what applies to the selection (Undo/Redo, clipboard, group, isolation, join, Remove Anchor Points when anchors are selected, masks, compound paths, guides, Transform, Arrange, Select, Export Selection), or the view commands on empty canvas.