Add PTZ support for flipping the canvas

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

@@ -342,13 +342,26 @@ impl MessageHandler<DocumentMessage, DocumentMessageData<'_>> for DocumentMessag
 						continue;
 					}
 					let Some(bounds) = self.metadata().bounding_box_document(layer) else { continue };
+					let [min, max] = [bounds[0].min(bounds[1]), bounds[0].max(bounds[1])];
 
 					let name = self.network_interface.frontend_display_name(&layer.to_node(), &[]);
 
+					// Calculate position of the text
+					let corner_pos = if !self.document_ptz.canvas_flipped {
+						min // Use the top left corner
+					} else {
+						DVec2::new(max.x, min.y) // Use the top right corner (appears to be the top left due to flipping)
+					};
+
+					// When canvas is flipped, reverse the flip so the text reads in the same direction
+					let scale = if !self.document_ptz.canvas_flipped { DVec2::ONE } else { DVec2::new(-1., 1.) };
+
+					// Create a transform that puts the text at the true top-left regardless of flip
 					let transform = self.metadata().document_to_viewport
-						* DAffine2::from_translation(bounds[0].min(bounds[1]))
+						* DAffine2::from_translation(corner_pos)
 						* DAffine2::from_scale(DVec2::splat(self.document_ptz.zoom().recip()))
-						* DAffine2::from_translation(-DVec2::Y * 4.);
+						* DAffine2::from_translation(-DVec2::Y * 4.)
+						* DAffine2::from_scale(scale); // Counter the flip for the text itself
 
 					overlay_context.text(&name, COLOR_OVERLAY_GRAY, None, transform, 0., [Pivot::Start, Pivot::End]);
 				}
@@ -2529,7 +2542,7 @@ impl<'a> ClickXRayIter<'a> {
 	}
 }
 
-pub fn navigation_controls(ptz: &PTZ, navigation_handler: &NavigationMessageHandler, tooltip_name: &str) -> [WidgetHolder; 5] {
+pub fn navigation_controls(ptz: &PTZ, navigation_handler: &NavigationMessageHandler, tooltip_name: &str) -> [WidgetHolder; 7] {
 	[
 		IconButton::new("ZoomIn", 24)
 			.tooltip("Zoom In")
@@ -2547,6 +2560,11 @@ pub fn navigation_controls(ptz: &PTZ, navigation_handler: &NavigationMessageHand
 			.on_update(|_| NavigationMessage::CanvasTiltResetAndZoomTo100Percent.into())
 			.disabled(ptz.tilt().abs() < 1e-4 && (ptz.zoom() - 1.).abs() < 1e-4)
 			.widget_holder(),
+		CheckboxInput::new(ptz.canvas_flipped)
+			.on_update(|_| NavigationMessage::FlipCanvas.into())
+			.tooltip("Flip Canvas Horizontally")
+			.widget_holder(),
+		TextLabel::new("Flip Canvas").widget_holder(),
 		// PopoverButton::new()
 		// 	.popover_layout(vec![
 		// 		LayoutGroup::Row {

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

@@ -26,4 +26,5 @@ pub enum NavigationMessage {
 	FitViewportToBounds { bounds: [DVec2; 2], prevent_zoom_past_100: bool },
 	FitViewportToSelection,
 	PointerMove { snap: Key },
+	FlipCanvas,
 }

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

@@ -396,9 +396,11 @@ impl MessageHandler<NavigationMessage, NavigationMessageData<'_>> for Navigation
 						..
 					} => {
 						let tilt_raw_not_snapped = {
+							// Compute the angle in document space to counter for any flipping
+							let viewport_to_document = network_interface.document_metadata().document_to_viewport.inverse();
 							let half_viewport = ipp.viewport_bounds.size() / 2.;
-							let start_offset = self.mouse_position - half_viewport;
-							let end_offset = ipp.mouse.position - half_viewport;
+							let start_offset = viewport_to_document.transform_vector2(self.mouse_position - half_viewport);
+							let end_offset = viewport_to_document.transform_vector2(ipp.mouse.position - half_viewport);
 							let angle = start_offset.angle_to(end_offset);
 
 							tilt_raw_not_snapped + angle
@@ -459,6 +461,17 @@ impl MessageHandler<NavigationMessage, NavigationMessageData<'_>> for Navigation
 
 				self.mouse_position = ipp.mouse.position;
 			}
+			NavigationMessage::FlipCanvas => {
+				let Some(ptz) = get_ptz_mut(document_ptz, network_interface, graph_view_overlay_open, breadcrumb_network_path) else {
+					log::error!("Could not get mutable PTZ in FlipCanvas");
+					return;
+				};
+
+				ptz.canvas_flipped = !ptz.canvas_flipped;
+
+				responses.add(DocumentMessage::PTZUpdate);
+				responses.add(BroadcastEvent::CanvasTransformed);
+			}
 		}
 	}
 
@@ -516,15 +529,16 @@ impl NavigationMessageHandler {
 		let tilt = ptz.tilt();
 		let zoom = ptz.zoom();
 
-		let scaled_center = viewport_center / self.snapped_zoom(zoom);
+		let scale = self.snapped_zoom(zoom);
+		let scale_vec = if ptz.canvas_flipped { DVec2::new(-scale, scale) } else { DVec2::splat(scale) };
+		let scaled_center = viewport_center / scale_vec;
 
 		// Try to avoid fractional coordinates to reduce anti aliasing.
-		let scale = self.snapped_zoom(zoom);
 		let rounded_pan = ((pan + scaled_center) * scale).round() / scale - scaled_center;
 
 		// TODO: replace with DAffine2::from_scale_angle_translation and fix the errors
 		let offset_transform = DAffine2::from_translation(scaled_center);
-		let scale_transform = DAffine2::from_scale(DVec2::splat(scale));
+		let scale_transform = DAffine2::from_scale(scale_vec);
 		let angle_transform = DAffine2::from_angle(self.snapped_tilt(tilt));
 		let translation_transform = DAffine2::from_translation(rounded_pan);
 		scale_transform * offset_transform * angle_transform * translation_transform

editor/src/messages/portfolio/document/utility_types/misc.rs

@@ -639,11 +639,18 @@ pub struct PTZ {
 	tilt: f64,
 	/// Scale factor.
 	zoom: f64,
+	/// Whether the canvas is horizontally flipped.
+	pub canvas_flipped: bool,
 }
 
 impl Default for PTZ {
 	fn default() -> Self {
-		Self { pan: DVec2::ZERO, tilt: 0., zoom: 1. }
+		Self {
+			pan: DVec2::ZERO,
+			tilt: 0.,
+			zoom: 1.,
+			canvas_flipped: false,
+		}
 	}
 }