Fix Path tool multi-point handle scaling behavior and double-click smooth/sharp conversion on rectangles (#2765)

* fixed double-click on anchor connected to linear segments

* fix when scaling when anchor

* Nit

---------

Co-authored-by: Keavon Chambers <keavon@keavon.com>

Author: 0SlowPoke0

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

@@ -9,9 +9,7 @@ use crate::messages::tool::common_functionality::shape_editor::ShapeState;
 use crate::messages::tool::utility_types::ToolType;
 use glam::{DAffine2, DMat2, DVec2};
 use graphene_std::renderer::Quad;
-use graphene_std::vector::VectorModificationType;
-use graphene_std::vector::{HandleExt, ManipulatorPointId};
-use graphene_std::vector::{HandleId, PointId};
+use graphene_std::vector::{HandleExt, HandleId, ManipulatorPointId, PointId, VectorModificationType};
 use std::collections::{HashMap, VecDeque};
 use std::f64::consts::PI;
 
@@ -616,7 +614,7 @@ impl<'a> Selected<'a> {
 			responses.add(GraphOperationMessage::Vector { layer, modification_type });
 		}
 
-		if transform_operation.is_some_and(|transform_operation| matches!(transform_operation, TransformOperation::Scaling(_))) && initial_points.anchors.len() > 1 {
+		if transform_operation.is_some_and(|transform_operation| matches!(transform_operation, TransformOperation::Scaling(_))) && (initial_points.anchors.len() == 2) {
 			return;
 		}
 

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

@@ -899,6 +899,9 @@ impl ShapeState {
 		let non_zero_handles = handles.iter().filter(|handle| handle.length(vector_data) > 1e-6).count();
 		let handle_segments = handles.iter().map(|handles| handles.segment).collect::<Vec<_>>();
 
+		// Check if the anchor is connected to linear segments and has no handles
+		let linear_segments = vector_data.connected_linear_segments(point_id) != 0;
+
 		// Grab the next and previous manipulator groups by simply looking at the next / previous index
 		let points = handles.iter().map(|handle| vector_data.other_point(handle.segment, point_id));
 		let anchor_positions = points
@@ -940,7 +943,7 @@ impl ShapeState {
 			handle_direction *= -1.;
 		}
 
-		if non_zero_handles != 0 {
+		if non_zero_handles != 0 && !linear_segments {
 			let [a, b] = handles.as_slice() else { return };
 			let (non_zero_handle, zero_handle) = if a.length(vector_data) > 1e-6 { (a, b) } else { (b, a) };
 			let Some(direction) = non_zero_handle
@@ -1772,10 +1775,13 @@ impl ShapeState {
 				.filter(|&handle| anchor.abs_diff_eq(handle, 1e-5))
 				.count();
 
+			// Check if the anchor is connected to linear segments.
+			let one_or_more_segment_linear = vector_data.connected_linear_segments(id) != 0;
+
 			// Check by comparing the handle positions to the anchor if this manipulator group is a point
 			for point in self.selected_points() {
 				let Some(point_id) = point.as_anchor() else { continue };
-				if positions != 0 {
+				if positions != 0 || one_or_more_segment_linear {
 					self.convert_manipulator_handles_to_colinear(&vector_data, point_id, responses, layer);
 				} else {
 					for handle in vector_data.all_connected(point_id) {

node-graph/gcore/src/vector/vector_data.rs

@@ -11,7 +11,7 @@ use crate::transform::Transform;
 use crate::vector::click_target::{ClickTargetType, FreePoint};
 use crate::{AlphaBlending, Color, GraphicGroupTable};
 pub use attributes::*;
-use bezier_rs::ManipulatorGroup;
+use bezier_rs::{BezierHandles, ManipulatorGroup};
 use core::borrow::Borrow;
 use core::hash::Hash;
 use dyn_any::DynAny;
@@ -334,6 +334,13 @@ impl VectorData {
 		index.flat_map(|index| self.segment_domain.connected_points(index).map(|index| self.point_domain.ids()[index]))
 	}
 
+	/// Returns the number of linear segments connected to the given point.
+	pub fn connected_linear_segments(&self, point_id: PointId) -> usize {
+		self.segment_bezier_iter()
+			.filter(|(_, bez, start, end)| ((*start == point_id || *end == point_id) && matches!(bez.handles, BezierHandles::Linear)))
+			.count()
+	}
+
 	/// Get an array slice of all segment IDs.
 	pub fn segment_ids(&self) -> &[SegmentId] {
 		self.segment_domain.ids()