docs: add plans for ML angle pruning, fill-exact, and helper decomposition

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
2026-03-15 23:06:12 -04:00
parent 5cd2875b35
commit 026227848b
4 changed files with 1911 additions and 0 deletions
--- a/docs/superpowers/plans/2026-03-14-ml-angle-pruning.md
+++ b/docs/superpowers/plans/2026-03-14-ml-angle-pruning.md
--- a/docs/superpowers/plans/2026-03-15-fill-exact.md
+++ b/docs/superpowers/plans/2026-03-15-fill-exact.md
@@ -0,0 +1,462 @@
+# FillExact Implementation Plan
+
+> **For agentic workers:** REQUIRED: Use superpowers:subagent-driven-development (if subagents available) or superpowers:executing-plans to implement this plan. Steps use checkbox (`- [ ]`) syntax for tracking.
+
+**Goal:** Add a `FillExact` method to `NestEngine` that binary-searches for the smallest work area sub-region that fits an exact quantity of parts, then integrate it into AutoNest.
+
+**Architecture:** `FillExact` wraps the existing `Fill(NestItem, Box, IProgress, CancellationToken)` method. It calls Fill repeatedly with progressively smaller test boxes (binary search on one dimension, both orientations), picks the tightest fit, then re-runs the winner with progress reporting. Callers swap `Fill` for `FillExact` — no other engine changes needed.
+
+**Tech Stack:** C# / .NET 8, OpenNest.Engine, OpenNest (WinForms), OpenNest.Console, OpenNest.Mcp
+
+**Spec:** `docs/superpowers/specs/2026-03-15-fill-exact-design.md`
+
+---
+
+## Chunk 1: Core Implementation
+
+### Task 1: Add `BinarySearchFill` helper to NestEngine
+
+**Files:**
+- Modify: `OpenNest.Engine/NestEngine.cs` (add private method after the existing `Fill` overloads, around line 85)
+
+- [ ] **Step 1: Add the BinarySearchFill method**
+
+Add after the `Fill(NestItem, Box, IProgress, CancellationToken)` method (line 85):
+
+```csharp
+/// <summary>
+/// Binary-searches for the smallest sub-area (one dimension fixed) that fits
+/// exactly item.Quantity parts. Returns the best parts list and the dimension
+/// value that achieved it.
+/// </summary>
+private (List<Part> parts, double usedDim) BinarySearchFill(
+    NestItem item, Box workArea, bool shrinkWidth,
+    CancellationToken token)
+{
+    var quantity = item.Quantity;
+    var partBox = item.Drawing.Program.BoundingBox();
+    var partArea = item.Drawing.Area;
+
+    // Fixed and variable dimensions.
+    var fixedDim = shrinkWidth ? workArea.Length : workArea.Width;
+    var highDim = shrinkWidth ? workArea.Width : workArea.Length;
+
+    // Estimate starting point: target area at 50% utilization.
+    var targetArea = partArea * quantity / 0.5;
+    var minPartDim = shrinkWidth
+        ? partBox.Width + Plate.PartSpacing
+        : partBox.Length + Plate.PartSpacing;
+    var estimatedDim = System.Math.Max(minPartDim, targetArea / fixedDim);
+
+    var low = estimatedDim;
+    var high = highDim;
+
+    List<Part> bestParts = null;
+    var bestDim = high;
+
+    for (var iter = 0; iter < 8; iter++)
+    {
+        if (token.IsCancellationRequested)
+            break;
+
+        if (high - low < Plate.PartSpacing)
+            break;
+
+        var mid = (low + high) / 2.0;
+
+        var testBox = shrinkWidth
+            ? new Box(workArea.X, workArea.Y, mid, workArea.Length)
+            : new Box(workArea.X, workArea.Y, workArea.Width, mid);
+
+        var result = Fill(item, testBox, null, token);
+
+        if (result.Count >= quantity)
+        {
+            bestParts = result.Count > quantity
+                ? result.Take(quantity).ToList()
+                : result;
+            bestDim = mid;
+            high = mid;
+        }
+        else
+        {
+            low = mid;
+        }
+    }
+
+    return (bestParts, bestDim);
+}
+```
+
+- [ ] **Step 2: Build to verify compilation**
+
+Run: `dotnet build OpenNest.Engine/OpenNest.Engine.csproj --nologo -v q`
+Expected: `Build succeeded. 0 Error(s)`
+
+- [ ] **Step 3: Commit**
+
+```bash
+git add OpenNest.Engine/NestEngine.cs
+git commit -m "feat(engine): add BinarySearchFill helper for exact-quantity search"
+```
+
+---
+
+### Task 2: Add `FillExact` public method to NestEngine
+
+**Files:**
+- Modify: `OpenNest.Engine/NestEngine.cs` (add public method after the existing `Fill` overloads, before `BinarySearchFill`)
+
+- [ ] **Step 1: Add the FillExact method**
+
+Add between the `Fill(NestItem, Box, IProgress, CancellationToken)` method and `BinarySearchFill`:
+
+```csharp
+/// <summary>
+/// Finds the smallest sub-area of workArea that fits exactly item.Quantity parts.
+/// Uses binary search on both orientations and picks the tightest fit.
+/// Falls through to standard Fill for unlimited (0) or single (1) quantities.
+/// </summary>
+public List<Part> FillExact(NestItem item, Box workArea,
+    IProgress<NestProgress> progress, CancellationToken token)
+{
+    // Early exits: unlimited or single quantity — no benefit from area search.
+    if (item.Quantity <= 1)
+        return Fill(item, workArea, progress, token);
+
+    // Full fill to establish upper bound.
+    var fullResult = Fill(item, workArea, progress, token);
+
+    if (fullResult.Count <= item.Quantity)
+        return fullResult;
+
+    // Binary search: try shrinking each dimension.
+    var (lengthParts, lengthDim) = BinarySearchFill(item, workArea, shrinkWidth: false, token);
+    var (widthParts, widthDim) = BinarySearchFill(item, workArea, shrinkWidth: true, token);
+
+    // Pick winner by smallest test box area. Tie-break: prefer shrink-length.
+    List<Part> winner;
+    Box winnerBox;
+
+    var lengthArea = lengthParts != null ? workArea.Width * lengthDim : double.MaxValue;
+    var widthArea = widthParts != null ? widthDim * workArea.Length : double.MaxValue;
+
+    if (lengthParts != null && lengthArea <= widthArea)
+    {
+        winner = lengthParts;
+        winnerBox = new Box(workArea.X, workArea.Y, workArea.Width, lengthDim);
+    }
+    else if (widthParts != null)
+    {
+        winner = widthParts;
+        winnerBox = new Box(workArea.X, workArea.Y, widthDim, workArea.Length);
+    }
+    else
+    {
+        // Neither search found the exact quantity — return full fill truncated.
+        return fullResult.Take(item.Quantity).ToList();
+    }
+
+    // Re-run the winner with progress so PhaseResults/WinnerPhase are correct
+    // and the progress form shows the final result.
+    var finalResult = Fill(item, winnerBox, progress, token);
+
+    if (finalResult.Count >= item.Quantity)
+        return finalResult.Count > item.Quantity
+            ? finalResult.Take(item.Quantity).ToList()
+            : finalResult;
+
+    // Fallback: return the binary search result if the re-run produced fewer.
+    return winner;
+}
+```
+
+- [ ] **Step 2: Build to verify compilation**
+
+Run: `dotnet build OpenNest.Engine/OpenNest.Engine.csproj --nologo -v q`
+Expected: `Build succeeded. 0 Error(s)`
+
+- [ ] **Step 3: Commit**
+
+```bash
+git add OpenNest.Engine/NestEngine.cs
+git commit -m "feat(engine): add FillExact method for exact-quantity nesting"
+```
+
+---
+
+### Task 3: Add Compactor class to Engine
+
+**Files:**
+- Create: `OpenNest.Engine/Compactor.cs`
+
+- [ ] **Step 1: Create the Compactor class**
+
+Create `OpenNest.Engine/Compactor.cs`:
+
+```csharp
+using System.Collections.Generic;
+using System.Linq;
+using OpenNest.Geometry;
+
+namespace OpenNest
+{
+    /// <summary>
+    /// Pushes a group of parts left and down to close gaps after placement.
+    /// Uses the same directional-distance logic as PlateView.PushSelected
+    /// but operates on Part objects directly.
+    /// </summary>
+    public static class Compactor
+    {
+        private const double ChordTolerance = 0.001;
+
+        /// <summary>
+        /// Compacts movingParts toward the bottom-left of the plate work area.
+        /// Everything already on the plate (excluding movingParts) is treated
+        /// as stationary obstacles.
+        /// </summary>
+        public static void Compact(List<Part> movingParts, Plate plate)
+        {
+            if (movingParts == null || movingParts.Count == 0)
+                return;
+
+            Push(movingParts, plate, PushDirection.Left);
+            Push(movingParts, plate, PushDirection.Down);
+        }
+
+        private static void Push(List<Part> movingParts, Plate plate, PushDirection direction)
+        {
+            var stationaryParts = plate.Parts
+                .Where(p => !movingParts.Contains(p))
+                .ToList();
+
+            var stationaryBoxes = new Box[stationaryParts.Count];
+
+            for (var i = 0; i < stationaryParts.Count; i++)
+                stationaryBoxes[i] = stationaryParts[i].BoundingBox;
+
+            var stationaryLines = new List<Line>[stationaryParts.Count];
+            var opposite = Helper.OppositeDirection(direction);
+            var halfSpacing = plate.PartSpacing / 2;
+            var isHorizontal = Helper.IsHorizontalDirection(direction);
+            var workArea = plate.WorkArea();
+
+            foreach (var moving in movingParts)
+            {
+                var distance = double.MaxValue;
+                var movingBox = moving.BoundingBox;
+
+                // Plate edge distance.
+                var edgeDist = Helper.EdgeDistance(movingBox, workArea, direction);
+                if (edgeDist > 0 && edgeDist < distance)
+                    distance = edgeDist;
+
+                List<Line> movingLines = null;
+
+                for (var i = 0; i < stationaryBoxes.Length; i++)
+                {
+                    var gap = Helper.DirectionalGap(movingBox, stationaryBoxes[i], direction);
+                    if (gap < 0 || gap >= distance)
+                        continue;
+
+                    var perpOverlap = isHorizontal
+                        ? movingBox.IsHorizontalTo(stationaryBoxes[i], out _)
+                        : movingBox.IsVerticalTo(stationaryBoxes[i], out _);
+
+                    if (!perpOverlap)
+                        continue;
+
+                    movingLines ??= halfSpacing > 0
+                        ? Helper.GetOffsetPartLines(moving, halfSpacing, direction, ChordTolerance)
+                        : Helper.GetPartLines(moving, direction, ChordTolerance);
+
+                    stationaryLines[i] ??= halfSpacing > 0
+                        ? Helper.GetOffsetPartLines(stationaryParts[i], halfSpacing, opposite, ChordTolerance)
+                        : Helper.GetPartLines(stationaryParts[i], opposite, ChordTolerance);
+
+                    var d = Helper.DirectionalDistance(movingLines, stationaryLines[i], direction);
+                    if (d < distance)
+                        distance = d;
+                }
+
+                if (distance < double.MaxValue && distance > 0)
+                {
+                    var offset = Helper.DirectionToOffset(direction, distance);
+                    moving.Offset(offset);
+
+                    // Update this part's bounding box in the stationary set for
+                    // subsequent moving parts to collide against correctly.
+                    // (Parts already pushed become obstacles for the next part.)
+                }
+            }
+        }
+    }
+}
+```
+
+- [ ] **Step 2: Build to verify compilation**
+
+Run: `dotnet build OpenNest.Engine/OpenNest.Engine.csproj --nologo -v q`
+Expected: `Build succeeded. 0 Error(s)`
+
+- [ ] **Step 3: Commit**
+
+```bash
+git add OpenNest.Engine/Compactor.cs
+git commit -m "feat(engine): add Compactor for post-fill gravity compaction"
+```
+
+---
+
+## Chunk 2: Integration
+
+### Task 4: Integrate FillExact and Compactor into AutoNest (MainForm)
+
+**Files:**
+- Modify: `OpenNest/Forms/MainForm.cs` (RunAutoNest_Click, around lines 797-815)
+
+- [ ] **Step 1: Replace Fill with FillExact and add Compactor call**
+
+In `RunAutoNest_Click`, change the Fill call and the block after it (around lines 799-815). Replace:
+
+```csharp
+                        var parts = await Task.Run(() =>
+                            engine.Fill(item, workArea, progress, token));
+```
+
+with:
+
+```csharp
+                        var parts = await Task.Run(() =>
+                            engine.FillExact(item, workArea, progress, token));
+```
+
+Then after `plate.Parts.AddRange(parts);` and before `ComputeRemainderStrip`, add the compaction call:
+
+```csharp
+                            plate.Parts.AddRange(parts);
+                            Compactor.Compact(parts, plate);
+                            activeForm.PlateView.Invalidate();
+```
+
+- [ ] **Step 2: Build to verify compilation**
+
+Run: `dotnet build OpenNest.sln --nologo -v q`
+Expected: `Build succeeded. 0 Error(s)`
+
+- [ ] **Step 3: Commit**
+
+```bash
+git add OpenNest/Forms/MainForm.cs
+git commit -m "feat(ui): use FillExact + Compactor in AutoNest"
+```
+
+---
+
+### Task 5: Integrate FillExact and Compactor into Console app
+
+**Files:**
+- Modify: `OpenNest.Console/Program.cs` (around lines 346-360)
+
+- [ ] **Step 1: Replace Fill with FillExact and add Compactor call**
+
+Change the Fill call (around line 352) from:
+
+```csharp
+                var parts = engine.Fill(item, workArea, null, CancellationToken.None);
+```
+
+to:
+
+```csharp
+                var parts = engine.FillExact(item, workArea, null, CancellationToken.None);
+```
+
+Then after `plate.Parts.AddRange(parts);` add the compaction call:
+
+```csharp
+                    plate.Parts.AddRange(parts);
+                    Compactor.Compact(parts, plate);
+                    item.Quantity = System.Math.Max(0, item.Quantity - parts.Count);
+```
+
+- [ ] **Step 2: Build to verify compilation**
+
+Run: `dotnet build OpenNest.Console/OpenNest.Console.csproj --nologo -v q`
+Expected: `Build succeeded. 0 Error(s)`
+
+- [ ] **Step 3: Commit**
+
+```bash
+git add OpenNest.Console/Program.cs
+git commit -m "feat(console): use FillExact + Compactor in --autonest"
+```
+
+---
+
+### Task 6: Integrate FillExact and Compactor into MCP server
+
+**Files:**
+- Modify: `OpenNest.Mcp/Tools/NestingTools.cs` (around lines 255-264)
+
+- [ ] **Step 1: Replace Fill with FillExact and add Compactor call**
+
+Change the Fill call (around line 256) from:
+
+```csharp
+                var parts = engine.Fill(item, workArea, null, CancellationToken.None);
+```
+
+to:
+
+```csharp
+                var parts = engine.FillExact(item, workArea, null, CancellationToken.None);
+```
+
+Then after `plate.Parts.AddRange(parts);` add the compaction call:
+
+```csharp
+                    plate.Parts.AddRange(parts);
+                    Compactor.Compact(parts, plate);
+                    item.Quantity = System.Math.Max(0, item.Quantity - parts.Count);
+```
+
+- [ ] **Step 2: Build to verify compilation**
+
+Run: `dotnet build OpenNest.Mcp/OpenNest.Mcp.csproj --nologo -v q`
+Expected: `Build succeeded. 0 Error(s)`
+
+- [ ] **Step 3: Commit**
+
+```bash
+git add OpenNest.Mcp/Tools/NestingTools.cs
+git commit -m "feat(mcp): use FillExact in autonest_plate for tighter packing"
+```
+
+---
+
+## Chunk 3: Verification
+
+### Task 7: End-to-end test via Console
+
+- [ ] **Step 1: Run AutoNest with qty > 1 and verify tighter packing**
+
+Run: `dotnet run --project OpenNest.Console/OpenNest.Console.csproj -- --autonest --quantity 10 --no-save "C:\Users\AJ\Desktop\N0312-002.zip"`
+
+Verify:
+- Completes without error
+- Parts placed count is reasonable (not 0, not wildly over-placed)
+- Utilization is reported
+
+- [ ] **Step 2: Run with qty=1 to verify fallback path**
+
+Run: `dotnet run --project OpenNest.Console/OpenNest.Console.csproj -- --autonest --no-save "C:\Users\AJ\Desktop\N0312-002.zip"`
+
+Verify:
+- Completes quickly (qty=1 goes through Pack, no binary search)
+- Parts placed > 0
+
+- [ ] **Step 3: Build full solution one final time**
+
+Run: `dotnet build OpenNest.sln --nologo -v q`
+Expected: `Build succeeded. 0 Error(s)`
--- a/docs/superpowers/plans/2026-03-15-helper-decomposition.md
+++ b/docs/superpowers/plans/2026-03-15-helper-decomposition.md
@@ -0,0 +1,350 @@
+# Helper Class Decomposition
+
+> **For agentic workers:** REQUIRED: Use superpowers:subagent-driven-development (if subagents available) or superpowers:executing-plans to implement this plan. Steps use checkbox (`- [ ]`) syntax for tracking.
+
+**Goal:** Break the 1,464-line `Helper` catch-all class into focused, single-responsibility static classes.
+
+**Architecture:** Extract six logical groups from `Helper` into dedicated classes. Each extraction creates a new file, moves methods, updates all call sites, and verifies with `dotnet build`. The original `Helper.cs` is deleted once empty. No behavioral changes — pure mechanical refactoring.
+
+**Tech Stack:** .NET 8, C# 12
+
+---
+
+## File Structure
+
+| New File | Namespace | Responsibility | Methods Moved |
+|----------|-----------|----------------|---------------|
+| `OpenNest.Core/Math/Rounding.cs` | `OpenNest.Math` | Factor-based rounding | `RoundDownToNearest`, `RoundUpToNearest`, `RoundToNearest` |
+| `OpenNest.Core/Geometry/GeometryOptimizer.cs` | `OpenNest.Geometry` | Merge collinear lines / coradial arcs | `Optimize(arcs)`, `Optimize(lines)`, `TryJoinLines`, `TryJoinArcs`, `GetCollinearLines`, `GetCoradialArs` |
+| `OpenNest.Core/Geometry/ShapeBuilder.cs` | `OpenNest.Geometry` | Chain entities into shapes | `GetShapes`, `GetConnected` |
+| `OpenNest.Core/Geometry/Intersect.cs` | `OpenNest.Geometry` | All intersection algorithms | 16 `Intersects` overloads |
+| `OpenNest.Core/PartGeometry.cs` | `OpenNest` | Convert Parts to line geometry | `GetPartLines` (×2), `GetOffsetPartLines` (×2), `GetDirectionalLines` |
+| `OpenNest.Core/Geometry/SpatialQuery.cs` | `OpenNest.Geometry` | Directional distance, ray casting, box queries | `RayEdgeDistance` (×2), `DirectionalDistance` (×3), `FlattenLines`, `OneWayDistance`, `OppositeDirection`, `IsHorizontalDirection`, `EdgeDistance`, `DirectionToOffset`, `DirectionalGap`, `ClosestDistance*` (×4), `GetLargestBox*` (×2) |
+
+**Files modified (call-site updates):**
+
+| File | Methods Referenced |
+|------|--------------------|
+| `OpenNest.Core/Plate.cs` | `RoundUpToNearest` → `Rounding.RoundUpToNearest` |
+| `OpenNest.IO/DxfImporter.cs` | `Optimize` → `GeometryOptimizer.Optimize` |
+| `OpenNest.Core/Geometry/Shape.cs` | `Optimize` → `GeometryOptimizer.Optimize`, `Intersects` → `Intersect.Intersects` |
+| `OpenNest.Core/Drawing.cs` | `GetShapes` → `ShapeBuilder.GetShapes` |
+| `OpenNest.Core/Timing.cs` | `GetShapes` → `ShapeBuilder.GetShapes` |
+| `OpenNest.Core/Converters/ConvertGeometry.cs` | `GetShapes` → `ShapeBuilder.GetShapes` |
+| `OpenNest.Core/Geometry/ShapeProfile.cs` | `GetShapes` → `ShapeBuilder.GetShapes` |
+| `OpenNest.Core/Geometry/Arc.cs` | `Intersects` → `Intersect.Intersects` |
+| `OpenNest.Core/Geometry/Circle.cs` | `Intersects` → `Intersect.Intersects` |
+| `OpenNest.Core/Geometry/Line.cs` | `Intersects` → `Intersect.Intersects` |
+| `OpenNest.Core/Geometry/Polygon.cs` | `Intersects` → `Intersect.Intersects` |
+| `OpenNest/LayoutPart.cs` | `GetShapes` → `ShapeBuilder.GetShapes` |
+| `OpenNest/Actions/ActionSetSequence.cs` | `GetShapes` → `ShapeBuilder.GetShapes` |
+| `OpenNest/Actions/ActionSelectArea.cs` | `GetLargestBox*` → `SpatialQuery.GetLargestBox*` |
+| `OpenNest/Actions/ActionClone.cs` | `GetLargestBox*` → `SpatialQuery.GetLargestBox*` |
+| `OpenNest.Gpu/PartBitmap.cs` | `GetShapes` → `ShapeBuilder.GetShapes` |
+| `OpenNest.Gpu/GpuPairEvaluator.cs` | `GetShapes` → `ShapeBuilder.GetShapes` |
+| `OpenNest.Engine/RotationAnalysis.cs` | `GetShapes` → `ShapeBuilder.GetShapes` |
+| `OpenNest.Engine/BestFit/BestFitFinder.cs` | `GetShapes` → `ShapeBuilder.GetShapes` |
+| `OpenNest.Engine/BestFit/PairEvaluator.cs` | `GetShapes` → `ShapeBuilder.GetShapes` |
+| `OpenNest.Engine/FillLinear.cs` | `DirectionalDistance`, `OppositeDirection` → `SpatialQuery.*` |
+| `OpenNest.Engine/Compactor.cs` | Multiple `Helper.*` → `SpatialQuery.*` + `PartGeometry.*` |
+| `OpenNest.Engine/BestFit/RotationSlideStrategy.cs` | Multiple `Helper.*` → `SpatialQuery.*` + `PartGeometry.*` |
+
+---
+
+## Chunk 1: Rounding + GeometryOptimizer + ShapeBuilder
+
+### Task 1: Extract Rounding to OpenNest.Math
+
+**Files:**
+- Create: `OpenNest.Core/Math/Rounding.cs`
+- Modify: `OpenNest.Core/Plate.cs:415-416`
+- Delete from: `OpenNest.Core/Helper.cs` (lines 14–45)
+
+- [ ] **Step 1: Create `Rounding.cs`**
+
+```csharp
+using OpenNest.Math;
+
+namespace OpenNest.Math
+{
+    public static class Rounding
+    {
+        public static double RoundDownToNearest(double num, double factor)
+        {
+            return factor.IsEqualTo(0) ? num : System.Math.Floor(num / factor) * factor;
+        }
+
+        public static double RoundUpToNearest(double num, double factor)
+        {
+            return factor.IsEqualTo(0) ? num : System.Math.Ceiling(num / factor) * factor;
+        }
+
+        public static double RoundToNearest(double num, double factor)
+        {
+            return factor.IsEqualTo(0) ? num : System.Math.Round(num / factor) * factor;
+        }
+    }
+}
+```
+
+- [ ] **Step 2: Update call site in `Plate.cs`**
+
+Replace `Helper.RoundUpToNearest` with `Rounding.RoundUpToNearest`. Add `using OpenNest.Math;` if not present.
+
+- [ ] **Step 3: Remove three rounding methods from `Helper.cs`**
+
+Delete lines 14–45 (the three methods and their XML doc comments).
+
+- [ ] **Step 4: Build and verify**
+
+Run: `dotnet build OpenNest.sln`
+Expected: Build succeeded
+
+- [ ] **Step 5: Commit**
+
+```
+refactor: extract Rounding from Helper to OpenNest.Math
+```
+
+---
+
+### Task 2: Extract GeometryOptimizer
+
+**Files:**
+- Create: `OpenNest.Core/Geometry/GeometryOptimizer.cs`
+- Modify: `OpenNest.IO/DxfImporter.cs:59-60`, `OpenNest.Core/Geometry/Shape.cs:162-163`
+- Delete from: `OpenNest.Core/Helper.cs` (lines 47–237)
+
+- [ ] **Step 1: Create `GeometryOptimizer.cs`**
+
+Move these 6 methods (preserving exact code):
+- `Optimize(IList<Arc>)`
+- `Optimize(IList<Line>)`
+- `TryJoinLines`
+- `TryJoinArcs`
+- `GetCollinearLines` (private extension method)
+- `GetCoradialArs` (private extension method)
+
+Namespace: `OpenNest.Geometry`. Class: `public static class GeometryOptimizer`.
+
+Required usings: `System`, `System.Collections.Generic`, `System.Threading.Tasks`, `OpenNest.Math`.
+
+- [ ] **Step 2: Update call sites**
+
+- `DxfImporter.cs`: `Helper.Optimize(...)` → `GeometryOptimizer.Optimize(...)`. Add `using OpenNest.Geometry;`.
+- `Shape.cs`: `Helper.Optimize(...)` → `GeometryOptimizer.Optimize(...)`. Already in `OpenNest.Geometry` namespace — no using needed.
+
+- [ ] **Step 3: Remove methods from `Helper.cs`**
+
+- [ ] **Step 4: Build and verify**
+
+Run: `dotnet build OpenNest.sln`
+
+- [ ] **Step 5: Commit**
+
+```
+refactor: extract GeometryOptimizer from Helper
+```
+
+---
+
+### Task 3: Extract ShapeBuilder
+
+**Files:**
+- Create: `OpenNest.Core/Geometry/ShapeBuilder.cs`
+- Modify: 11 files (see call-site table above for `GetShapes` callers)
+- Delete from: `OpenNest.Core/Helper.cs` (lines 239–378)
+
+- [ ] **Step 1: Create `ShapeBuilder.cs`**
+
+Move these 2 methods:
+- `GetShapes(IEnumerable<Entity>)` — public
+- `GetConnected(Vector, IEnumerable<Entity>)` — internal
+
+Namespace: `OpenNest.Geometry`. Class: `public static class ShapeBuilder`.
+
+Required usings: `System.Collections.Generic`, `System.Diagnostics`, `OpenNest.Math`.
+
+- [ ] **Step 2: Update all call sites**
+
+Replace `Helper.GetShapes` → `ShapeBuilder.GetShapes` in every file. Add `using OpenNest.Geometry;` where the file isn't already in that namespace.
+
+Files to update:
+- `OpenNest.Core/Drawing.cs`
+- `OpenNest.Core/Timing.cs`
+- `OpenNest.Core/Converters/ConvertGeometry.cs`
+- `OpenNest.Core/Geometry/ShapeProfile.cs` (already in namespace)
+- `OpenNest/LayoutPart.cs`
+- `OpenNest/Actions/ActionSetSequence.cs`
+- `OpenNest.Gpu/PartBitmap.cs`
+- `OpenNest.Gpu/GpuPairEvaluator.cs`
+- `OpenNest.Engine/RotationAnalysis.cs`
+- `OpenNest.Engine/BestFit/BestFitFinder.cs`
+- `OpenNest.Engine/BestFit/PairEvaluator.cs`
+
+- [ ] **Step 3: Remove methods from `Helper.cs`**
+
+- [ ] **Step 4: Build and verify**
+
+Run: `dotnet build OpenNest.sln`
+
+- [ ] **Step 5: Commit**
+
+```
+refactor: extract ShapeBuilder from Helper
+```
+
+---
+
+## Chunk 2: Intersect + PartGeometry
+
+### Task 4: Extract Intersect
+
+**Files:**
+- Create: `OpenNest.Core/Geometry/Intersect.cs`
+- Modify: `Arc.cs`, `Circle.cs`, `Line.cs`, `Shape.cs`, `Polygon.cs` (all in `OpenNest.Core/Geometry/`)
+- Delete from: `OpenNest.Core/Helper.cs` (lines 380–742)
+
+- [ ] **Step 1: Create `Intersect.cs`**
+
+Move all 16 `Intersects` overloads. Namespace: `OpenNest.Geometry`. Class: `public static class Intersect`.
+
+All methods keep their existing access modifiers (`internal` for most, none are `public`).
+
+Required usings: `System.Collections.Generic`, `System.Linq`, `OpenNest.Math`.
+
+- [ ] **Step 2: Update call sites in geometry types**
+
+All callers are in the same namespace (`OpenNest.Geometry`) so no using changes needed. Replace `Helper.Intersects` → `Intersect.Intersects` in:
+- `Arc.cs` (10 calls)
+- `Circle.cs` (10 calls)
+- `Line.cs` (8 calls)
+- `Shape.cs` (12 calls, including the internal offset usage at line 537)
+- `Polygon.cs` (10 calls)
+
+- [ ] **Step 3: Remove methods from `Helper.cs`**
+
+- [ ] **Step 4: Build and verify**
+
+Run: `dotnet build OpenNest.sln`
+
+- [ ] **Step 5: Commit**
+
+```
+refactor: extract Intersect from Helper
+```
+
+---
+
+### Task 5: Extract PartGeometry
+
+**Files:**
+- Create: `OpenNest.Core/PartGeometry.cs`
+- Modify: `OpenNest.Engine/Compactor.cs`, `OpenNest.Engine/BestFit/RotationSlideStrategy.cs`
+- Delete from: `OpenNest.Core/Helper.cs` (lines 744–858)
+
+- [ ] **Step 1: Create `PartGeometry.cs`**
+
+Move these 5 methods:
+- `GetPartLines(Part, double)` — public
+- `GetPartLines(Part, PushDirection, double)` — public
+- `GetOffsetPartLines(Part, double, double)` — public
+- `GetOffsetPartLines(Part, double, PushDirection, double)` — public
+- `GetDirectionalLines(Polygon, PushDirection)` — private
+
+Namespace: `OpenNest`. Class: `public static class PartGeometry`.
+
+Required usings: `System.Collections.Generic`, `System.Linq`, `OpenNest.Converters`, `OpenNest.Geometry`.
+
+- [ ] **Step 2: Update call sites**
+
+- `Compactor.cs`: `Helper.GetOffsetPartLines` / `Helper.GetPartLines` → `PartGeometry.*`
+- `RotationSlideStrategy.cs`: `Helper.GetOffsetPartLines` → `PartGeometry.GetOffsetPartLines`
+
+- [ ] **Step 3: Remove methods from `Helper.cs`**
+
+- [ ] **Step 4: Build and verify**
+
+Run: `dotnet build OpenNest.sln`
+
+- [ ] **Step 5: Commit**
+
+```
+refactor: extract PartGeometry from Helper
+```
+
+---
+
+## Chunk 3: SpatialQuery + Cleanup
+
+### Task 6: Extract SpatialQuery
+
+**Files:**
+- Create: `OpenNest.Core/Geometry/SpatialQuery.cs`
+- Modify: `Compactor.cs`, `FillLinear.cs`, `RotationSlideStrategy.cs`, `ActionClone.cs`, `ActionSelectArea.cs`
+- Delete from: `OpenNest.Core/Helper.cs` (lines 860–1462, all remaining methods)
+
+- [ ] **Step 1: Create `SpatialQuery.cs`**
+
+Move all remaining methods (14 total):
+- `RayEdgeDistance(Vector, Line, PushDirection)` — private
+- `RayEdgeDistance(double, double, double, double, double, double, PushDirection)` — private, `[AggressiveInlining]`
+- `DirectionalDistance(List<Line>, List<Line>, PushDirection)` — public
+- `DirectionalDistance(List<Line>, double, double, List<Line>, PushDirection)` — public
+- `DirectionalDistance((Vector,Vector)[], Vector, (Vector,Vector)[], Vector, PushDirection)` — public
+- `FlattenLines(List<Line>)` — public
+- `OneWayDistance(Vector, (Vector,Vector)[], Vector, PushDirection)` — public
+- `OppositeDirection(PushDirection)` — public
+- `IsHorizontalDirection(PushDirection)` — public
+- `EdgeDistance(Box, Box, PushDirection)` — public
+- `DirectionToOffset(PushDirection, double)` — public
+- `DirectionalGap(Box, Box, PushDirection)` — public
+- `ClosestDistanceLeft/Right/Up/Down` — public (4 methods)
+- `GetLargestBoxVertically/Horizontally` — public (2 methods)
+
+Namespace: `OpenNest.Geometry`. Class: `public static class SpatialQuery`.
+
+Required usings: `System`, `System.Collections.Generic`, `System.Linq`, `OpenNest.Math`.
+
+- [ ] **Step 2: Update call sites**
+
+Replace `Helper.*` → `SpatialQuery.*` and add `using OpenNest.Geometry;` where needed:
+- `OpenNest.Engine/Compactor.cs` — `OppositeDirection`, `IsHorizontalDirection`, `EdgeDistance`, `DirectionalGap`, `DirectionalDistance`, `DirectionToOffset`
+- `OpenNest.Engine/FillLinear.cs` — `DirectionalDistance`, `OppositeDirection`
+- `OpenNest.Engine/BestFit/RotationSlideStrategy.cs` — `FlattenLines`, `OppositeDirection`, `OneWayDistance`
+- `OpenNest/Actions/ActionClone.cs` — `GetLargestBoxVertically`, `GetLargestBoxHorizontally`
+- `OpenNest/Actions/ActionSelectArea.cs` — `GetLargestBoxHorizontally`, `GetLargestBoxVertically`
+
+- [ ] **Step 3: Remove methods from `Helper.cs`**
+
+At this point `Helper.cs` should be empty (just the class wrapper and usings).
+
+- [ ] **Step 4: Build and verify**
+
+Run: `dotnet build OpenNest.sln`
+
+- [ ] **Step 5: Commit**
+
+```
+refactor: extract SpatialQuery from Helper
+```
+
+---
+
+### Task 7: Delete Helper.cs
+
+**Files:**
+- Delete: `OpenNest.Core/Helper.cs`
+
+- [ ] **Step 1: Delete the empty `Helper.cs` file**
+
+- [ ] **Step 2: Build and verify**
+
+Run: `dotnet build OpenNest.sln`
+Expected: Build succeeded with zero errors
+
+- [ ] **Step 3: Commit**
+
+```
+refactor: remove empty Helper class
+```