Fix drag offset during PTZ operations in Select tool

editor/src/messages/portfolio/document/document_message_handler.rs

@@ -1496,8 +1496,9 @@ impl MessageHandler<DocumentMessage, DocumentMessageContext<'_>> for DocumentMes
 				if !self.graph_view_overlay_open {
 					let transform = self.navigation_handler.calculate_offset_transform(viewport.center_in_viewport_space().into(), &self.document_ptz);
 					self.network_interface.set_document_to_viewport_transform(transform);
-					// Ensure selection box is kept in sync with the pointer when the PTZ changes
-					responses.add(SelectToolMessage::PointerMove {
+					// Ensure dragging operations are kept in sync with the pointer when the PTZ changes
+					// Using DocumentPTZUpdate allows tools to recalculate viewport positions from document-space
+					responses.add(SelectToolMessage::DocumentPTZUpdate {
 						modifier_keys: SelectToolPointerKeys {
 							axis_align: Key::Shift,
 							snap_angle: Key::Shift,

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

@@ -2,7 +2,7 @@
 
 use super::tool_prelude::*;
 use crate::consts::*;
-use crate::messages::input_mapper::utility_types::input_mouse::ViewportPosition;
+use crate::messages::input_mapper::utility_types::input_mouse::{DocumentPosition, ViewportPosition};
 use crate::messages::portfolio::document::graph_operation::utility_types::TransformIn;
 use crate::messages::portfolio::document::overlays::utility_types::OverlayContext;
 use crate::messages::portfolio::document::utility_types::document_metadata::{DocumentMetadata, LayerNodeIdentifier};
@@ -116,6 +116,10 @@ pub enum SelectToolMessage {
 		offset: Option<DVec2>,
 		flush: bool,
 	},
+	/// Called when PTZ (Pan/Tilt/Zoom) changes occur to update viewport-space positions
+	DocumentPTZUpdate {
+		modifier_keys: SelectToolPointerKeys,
+	},
 }
 
 impl ToolMetadata for SelectTool {
@@ -378,6 +382,8 @@ impl Default for SelectToolFsmState {
 struct SelectToolData {
 	drag_start: ViewportPosition,
 	drag_current: ViewportPosition,
+	/// Document-space position of drag start, used to maintain correct positions during PTZ changes
+	drag_start_document: DocumentPosition,
 	lasso_polygon: Vec<ViewportPosition>,
 	selection_mode: Option<SelectionMode>,
 	layers_dragging: Vec<LayerNodeIdentifier>, // Unordered, often used as temporary buffer
@@ -1023,6 +1029,8 @@ impl Fsm for SelectToolFsmState {
 			) => {
 				tool_data.drag_start = input.mouse.position;
 				tool_data.drag_current = input.mouse.position;
+				// Store drag start in document space to handle PTZ changes during dragging
+				tool_data.drag_start_document = document.metadata().document_to_viewport.inverse().transform_point2(input.mouse.position);
 				tool_data.selection_mode = None;
 
 				let mut selected: Vec<_> = document.network_interface.selected_nodes().selected_visible_and_unlocked_layers(&document.network_interface).collect();
@@ -1393,6 +1401,39 @@ impl Fsm for SelectToolFsmState {
 
 				state
 			}
+			// Handle PTZ (Pan/Tilt/Zoom) updates during dragging operations
+			(
+				SelectToolFsmState::Dragging {
+					axis,
+					using_compass,
+					has_dragged,
+					deepest,
+					remove,
+				},
+				SelectToolMessage::DocumentPTZUpdate { modifier_keys },
+			) => {
+				// Recalculate drag_start in viewport space from the stored document-space position
+				let new_drag_start = document.metadata().document_to_viewport.transform_point2(tool_data.drag_start_document);
+				let shift = new_drag_start - tool_data.drag_start;
+				tool_data.drag_start = new_drag_start;
+				tool_data.drag_current += shift;
+
+				// Trigger a PointerMove to update the layer positions
+				responses.add(SelectToolMessage::PointerMove { modifier_keys });
+
+				SelectToolFsmState::Dragging {
+					axis,
+					using_compass,
+					has_dragged,
+					deepest,
+					remove,
+				}
+			}
+			// For non-dragging states, just trigger a PointerMove
+			(state, SelectToolMessage::DocumentPTZUpdate { modifier_keys }) => {
+				responses.add(SelectToolMessage::PointerMove { modifier_keys });
+				state
+			}
 			(SelectToolFsmState::Dragging { has_dragged, remove, deepest, .. }, SelectToolMessage::DragStop { remove_from_selection }) => {
 				// Deselect layer if not snap dragging
 				responses.add(DocumentMessage::EndTransaction);