Correct snapping offsets after canvas transformation when using snap-reliant tools (#1370)

* fix: pen, spline tool incorrect snap offsets
- re-render snapping offsets if canvas transformed during line draw

* [wip]feat: add CanvasTransformed global message

* [wip]fix: synchronize line tool snap offsets

* fix: update offsets for shape tools on canvas transform

* chore: remove unneeded function parameter

* [wip]fix: use line tool at canvas level

* refactor: revert line tool changes

editor/src/messages/broadcast/broadcast_event.rs

@@ -6,6 +6,7 @@ use serde::{Deserialize, Serialize};
 #[impl_message(Message, BroadcastMessage, TriggerEvent)]
 pub enum BroadcastEvent {
 	DocumentIsDirty,
+	CanvasTransformed,
 	ToolAbort,
 	SelectionChanged,
 	WorkingColorChanged,

editor/src/messages/portfolio/document/navigation/navigation_message_handler.rs

@@ -211,6 +211,7 @@ impl MessageHandler<NavigationMessage, (&Document, Option<[DVec2; 2]>, &InputPre
 			TransformCanvasEnd => {
 				self.tilt = self.snapped_angle();
 				self.zoom = self.snapped_scale();
+				responses.add(BroadcastEvent::CanvasTransformed);
 				responses.add(BroadcastEvent::DocumentIsDirty);
 				responses.add(ToolMessage::UpdateCursor);
 				responses.add(ToolMessage::UpdateHints);
@@ -225,6 +226,7 @@ impl MessageHandler<NavigationMessage, (&Document, Option<[DVec2; 2]>, &InputPre
 				let transformed_delta = document.root.transform.inverse().transform_vector2(delta);
 
 				self.pan += transformed_delta;
+				responses.add(BroadcastEvent::CanvasTransformed);
 				responses.add(BroadcastEvent::DocumentIsDirty);
 				self.create_document_transform(&ipp.viewport_bounds, responses);
 			}

editor/src/messages/tool/common_functionality/resize.rs

@@ -24,6 +24,12 @@ impl Resize {
 		self.drag_start = root_transform.inverse().transform_point2(self.snap_manager.snap_position(responses, document, input.mouse.position));
 	}
 
+	/// Recalculates snap targets without snapping the starting position.
+	pub fn recalculate_snaps(&mut self, document: &DocumentMessageHandler, input: &InputPreprocessorMessageHandler, render_data: &RenderData) {
+		self.snap_manager.start_snap(document, input, document.bounding_boxes(None, None, render_data), true, true);
+		self.snap_manager.add_all_document_handles(document, input, &[], &[], &[]);
+	}
+
 	/// Calculate the drag start position in viewport space.
 	pub fn viewport_drag_start(&self, document: &DocumentMessageHandler) -> DVec2 {
 		let root_transform = document.document_legacy.root.transform;

editor/src/messages/tool/tool_messages/ellipse_tool.rs

@@ -54,6 +54,8 @@ pub enum EllipseOptionsUpdate {
 pub enum EllipseToolMessage {
 	// Standard messages
 	#[remain::unsorted]
+	CanvasTransformed,
+	#[remain::unsorted]
 	Abort,
 	#[remain::unsorted]
 	WorkingColorChanged,
@@ -165,6 +167,7 @@ impl<'a> MessageHandler<ToolMessage, &mut ToolActionHandlerData<'a>> for Ellipse
 impl ToolTransition for EllipseTool {
 	fn event_to_message_map(&self) -> EventToMessageMap {
 		EventToMessageMap {
+			canvas_transformed: Some(EllipseToolMessage::CanvasTransformed.into()),
 			tool_abort: Some(EllipseToolMessage::Abort.into()),
 			working_color_changed: Some(EllipseToolMessage::WorkingColorChanged.into()),
 			..Default::default()
@@ -209,6 +212,10 @@ impl Fsm for EllipseToolFsmState {
 
 		if let ToolMessage::Ellipse(event) = event {
 			match (self, event) {
+				(Drawing, CanvasTransformed) => {
+					tool_data.data.recalculate_snaps(document, input, render_data);
+					self
+				}
 				(Ready, DragStart) => {
 					shape_data.start(responses, document, input, render_data);
 					responses.add(DocumentMessage::StartTransaction);

editor/src/messages/tool/tool_messages/line_tool.rs

@@ -44,6 +44,10 @@ impl Default for LineOptions {
 pub enum LineToolMessage {
 	// Standard messages
 	#[remain::unsorted]
+	DocumentIsDirty,
+	#[remain::unsorted]
+	CanvasTransformed,
+	#[remain::unsorted]
 	Abort,
 	#[remain::unsorted]
 	WorkingColorChanged,
@@ -140,6 +144,7 @@ impl<'a> MessageHandler<ToolMessage, &mut ToolActionHandlerData<'a>> for LineToo
 impl ToolTransition for LineTool {
 	fn event_to_message_map(&self) -> EventToMessageMap {
 		EventToMessageMap {
+			canvas_transformed: Some(LineToolMessage::CanvasTransformed.into()),
 			tool_abort: Some(LineToolMessage::Abort.into()),
 			working_color_changed: Some(LineToolMessage::WorkingColorChanged.into()),
 			..Default::default()
@@ -219,7 +224,6 @@ impl Fsm for LineToolFsmState {
 					tool_data.snap_manager.cleanup(responses);
 					input.mouse.finish_transaction(tool_data.drag_start, responses);
 					tool_data.path = None;
-
 					Ready
 				}
 				(Drawing, Abort) => {

editor/src/messages/tool/tool_messages/pen_tool.rs

@@ -52,6 +52,8 @@ impl Default for PenOptions {
 pub enum PenToolMessage {
 	// Standard messages
 	#[remain::unsorted]
+	CanvasTransformed,
+	#[remain::unsorted]
 	DocumentIsDirty,
 	#[remain::unsorted]
 	Abort,
@@ -193,6 +195,7 @@ impl<'a> MessageHandler<ToolMessage, &mut ToolActionHandlerData<'a>> for PenTool
 impl ToolTransition for PenTool {
 	fn event_to_message_map(&self) -> EventToMessageMap {
 		EventToMessageMap {
+			canvas_transformed: Some(PenToolMessage::CanvasTransformed.into()),
 			document_dirty: Some(PenToolMessage::DocumentIsDirty.into()),
 			tool_abort: Some(PenToolMessage::Abort.into()),
 			selection_changed: Some(PenToolMessage::SelectionChanged.into()),
@@ -589,6 +592,10 @@ impl Fsm for PenToolFsmState {
 
 		if let ToolMessage::Pen(event) = event {
 			match (self, event) {
+				(_, PenToolMessage::CanvasTransformed) => {
+					tool_data.snap_manager.start_snap(document, input, document.bounding_boxes(None, None, render_data), true, true);
+					self
+				}
 				(_, PenToolMessage::DocumentIsDirty) => {
 					// When the document has moved / needs to be redraw, re-render the overlays
 					// TODO the overlay system should probably receive this message instead of the tool

editor/src/messages/tool/tool_messages/polygon_tool.rs

@@ -47,6 +47,8 @@ impl Default for PolygonOptions {
 pub enum PolygonToolMessage {
 	// Standard messages
 	#[remain::unsorted]
+	CanvasTransformed,
+	#[remain::unsorted]
 	Abort,
 	#[remain::unsorted]
 	WorkingColorChanged,
@@ -205,6 +207,7 @@ impl<'a> MessageHandler<ToolMessage, &mut ToolActionHandlerData<'a>> for Polygon
 impl ToolTransition for PolygonTool {
 	fn event_to_message_map(&self) -> EventToMessageMap {
 		EventToMessageMap {
+			canvas_transformed: Some(PolygonToolMessage::CanvasTransformed.into()),
 			tool_abort: Some(PolygonToolMessage::Abort.into()),
 			working_color_changed: Some(PolygonToolMessage::WorkingColorChanged.into()),
 			..Default::default()
@@ -249,6 +252,10 @@ impl Fsm for PolygonToolFsmState {
 
 		if let ToolMessage::Polygon(event) = event {
 			match (self, event) {
+				(Drawing, CanvasTransformed) => {
+					tool_data.data.recalculate_snaps(document, input, render_data);
+					self
+				}
 				(Ready, DragStart) => {
 					polygon_data.start(responses, document, input, render_data);
 					responses.add(DocumentMessage::StartTransaction);

editor/src/messages/tool/tool_messages/rectangle_tool.rs

@@ -53,6 +53,8 @@ pub enum RectangleOptionsUpdate {
 pub enum RectangleToolMessage {
 	// Standard messages
 	#[remain::unsorted]
+	CanvasTransformed,
+	#[remain::unsorted]
 	Abort,
 	#[remain::unsorted]
 	WorkingColorChanged,
@@ -164,6 +166,7 @@ impl ToolMetadata for RectangleTool {
 impl ToolTransition for RectangleTool {
 	fn event_to_message_map(&self) -> EventToMessageMap {
 		EventToMessageMap {
+			canvas_transformed: Some(RectangleToolMessage::CanvasTransformed.into()),
 			tool_abort: Some(RectangleToolMessage::Abort.into()),
 			working_color_changed: Some(RectangleToolMessage::WorkingColorChanged.into()),
 			..Default::default()
@@ -208,6 +211,10 @@ impl Fsm for RectangleToolFsmState {
 
 		if let ToolMessage::Rectangle(event) = event {
 			match (self, event) {
+				(Drawing, CanvasTransformed) => {
+					tool_data.data.recalculate_snaps(document, input, render_data);
+					self
+				}
 				(Ready, DragStart) => {
 					shape_data.start(responses, document, input, render_data);
 

editor/src/messages/tool/tool_messages/spline_tool.rs

@@ -45,6 +45,8 @@ impl Default for SplineOptions {
 pub enum SplineToolMessage {
 	// Standard messages
 	#[remain::unsorted]
+	CanvasTransformed,
+	#[remain::unsorted]
 	Abort,
 	#[remain::unsorted]
 	WorkingColorChanged,
@@ -178,6 +180,7 @@ impl<'a> MessageHandler<ToolMessage, &mut ToolActionHandlerData<'a>> for SplineT
 impl ToolTransition for SplineTool {
 	fn event_to_message_map(&self) -> EventToMessageMap {
 		EventToMessageMap {
+			canvas_transformed: Some(SplineToolMessage::CanvasTransformed.into()),
 			tool_abort: Some(SplineToolMessage::Abort.into()),
 			working_color_changed: Some(SplineToolMessage::WorkingColorChanged.into()),
 			..Default::default()
@@ -219,6 +222,10 @@ impl Fsm for SplineToolFsmState {
 
 		if let ToolMessage::Spline(event) = event {
 			match (self, event) {
+				(_, CanvasTransformed) => {
+					tool_data.snap_manager.start_snap(document, input, document.bounding_boxes(None, None, render_data), true, true);
+					self
+				}
 				(Ready, DragStart) => {
 					responses.add(DocumentMessage::StartTransaction);
 					responses.add(DocumentMessage::DeselectAllLayers);

editor/src/messages/tool/tool_messages/text_tool.rs

@@ -200,6 +200,7 @@ impl<'a> MessageHandler<ToolMessage, &mut ToolActionHandlerData<'a>> for TextToo
 impl ToolTransition for TextTool {
 	fn event_to_message_map(&self) -> EventToMessageMap {
 		EventToMessageMap {
+			canvas_transformed: None,
 			document_dirty: Some(TextToolMessage::DocumentIsDirty.into()),
 			tool_abort: Some(TextToolMessage::Abort.into()),
 			selection_changed: Some(TextToolMessage::DocumentIsDirty.into()),

editor/src/messages/tool/utility_types.rs

@@ -169,6 +169,7 @@ impl DocumentToolData {
 
 #[derive(Clone, Debug, Default)]
 pub struct EventToMessageMap {
+	pub canvas_transformed: Option<ToolMessage>,
 	pub document_dirty: Option<ToolMessage>,
 	pub selection_changed: Option<ToolMessage>,
 	pub tool_abort: Option<ToolMessage>,
@@ -189,6 +190,7 @@ pub trait ToolTransition {
 		};
 
 		let event_to_tool_map = self.event_to_message_map();
+		subscribe_message(event_to_tool_map.canvas_transformed, BroadcastEvent::CanvasTransformed);
 		subscribe_message(event_to_tool_map.document_dirty, BroadcastEvent::DocumentIsDirty);
 		subscribe_message(event_to_tool_map.tool_abort, BroadcastEvent::ToolAbort);
 		subscribe_message(event_to_tool_map.selection_changed, BroadcastEvent::SelectionChanged);
@@ -206,6 +208,7 @@ pub trait ToolTransition {
 		};
 
 		let event_to_tool_map = self.event_to_message_map();
+		unsubscribe_message(event_to_tool_map.canvas_transformed, BroadcastEvent::CanvasTransformed);
 		unsubscribe_message(event_to_tool_map.document_dirty, BroadcastEvent::DocumentIsDirty);
 		unsubscribe_message(event_to_tool_map.tool_abort, BroadcastEvent::ToolAbort);
 		unsubscribe_message(event_to_tool_map.selection_changed, BroadcastEvent::SelectionChanged);