Make vector mesh branch detection and free-point click targets O(n) instead of O(n^2) (#4255)

* Make is_branching and free-point click targets O(n) instead of O(n^2)

* usize -> u8

* Fix profiling CI treating performance improvements as regressions

.github/workflows/comment-profiling-changes.yaml

@@ -137,6 +137,7 @@ jobs:
             const sectionTitles = ['Compilation', 'Update', 'Run Once', 'Cached Execution'];
 
             let hasSignificantChanges = false;
+            let hasRegressions = false;
             let regressionDetails = [];
 
             for (let i = 0; i < allOutputs.length; i++) {
@@ -153,19 +154,25 @@ jobs:
 
                   if (isSignificantChange(diffPct, absoluteChange, outputName)) {
                     hasSignificantChanges = true;
-                    regressionDetails.push({
-                      module_path: benchmark.module_path,
-                      id: benchmark.id,
-                      diffPct,
-                      absoluteChange,
-                      sectionTitle
-                    });
+
+                    // Only an increase in instruction count is a regression; improvements must not fail CI.
+                    if (diffPct > 0) {
+                      hasRegressions = true;
+                      regressionDetails.push({
+                        module_path: benchmark.module_path,
+                        id: benchmark.id,
+                        diffPct,
+                        absoluteChange,
+                        sectionTitle
+                      });
+                    }
                   }
                 }
               }
             }
 
             core.setOutput('has-significant-changes', hasSignificantChanges);
+            core.setOutput('has-regressions', hasRegressions);
             core.setOutput('regression-details', JSON.stringify(regressionDetails));
 
       - name: Comment PR
@@ -319,7 +326,7 @@ jobs:
             }
 
       - name: Fail on significant regressions
-        if: steps.analyze.outputs.has-significant-changes == 'true'
+        if: steps.analyze.outputs.has-regressions == 'true'
         uses: actions/github-script@v8
         with:
           script: |

node-graph/libraries/rendering/src/renderer.rs

@@ -1714,8 +1714,14 @@ fn extend_targets_from_vector(targets: &mut Vec<ClickTarget>, vector_list: &List
 }
 
 fn extend_free_point_targets(vector: &Vector, transform: DAffine2) -> impl Iterator<Item = ClickTarget> + '_ {
-	vector.point_domain.ids().iter().filter_map(move |&point_id| {
-		if vector.any_connected(point_id) {
+	// Mark every point index touched by a segment endpoint in one `O(points + segments)` pass, avoiding a per-point `any_connected` scan
+	let mut connected = vec![false; vector.point_domain.len()];
+	for &point_index in vector.segment_domain.start_point().iter().chain(vector.segment_domain.end_point()) {
+		connected[point_index] = true;
+	}
+
+	vector.point_domain.ids().iter().enumerate().filter_map(move |(point_index, &point_id)| {
+		if connected[point_index] {
 			return None;
 		}
 

node-graph/libraries/vector-types/src/vector/vector_attributes.rs

@@ -1223,7 +1223,15 @@ impl Vector {
 	}
 
 	pub fn is_branching(&self) -> bool {
-		(0..self.point_domain.len()).any(|point_index| self.segment_domain.connected_count(point_index) > 2)
+		// Tally segment endpoints per point in one `O(points + segments)` pass, short-circuiting once any point exceeds two
+		let mut connected_count = vec![0_u8; self.point_domain.len()];
+		for &point_index in self.segment_domain.start_point().iter().chain(self.segment_domain.end_point()) {
+			connected_count[point_index] += 1;
+			if connected_count[point_index] > 2 {
+				return true;
+			}
+		}
+		false
 	}
 
 	pub fn has_regions(&self) -> bool {