feat: persist cutting parameters and add pierce clearance UI

Save/restore cutting parameters as JSON in user settings so values
survive between sessions. Add pierce clearance numeric input to the
CuttingParametersForm.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

OpenNest/Forms/CuttingParametersForm.Designer.cs

@@ -114,7 +114,7 @@ namespace OpenNest.Forms
             this.bottomPanel.Controls.Add(this.acceptButton);
             this.bottomPanel.Controls.Add(this.cancelButton);
             this.bottomPanel.Dock = System.Windows.Forms.DockStyle.Bottom;
-            this.bottomPanel.Location = new System.Drawing.Point(0, 406);
+            this.bottomPanel.Location = new System.Drawing.Point(0, 466);
             this.bottomPanel.Name = "bottomPanel";
             this.bottomPanel.Size = new System.Drawing.Size(380, 50);
             this.bottomPanel.TabIndex = 1;
@@ -125,7 +125,7 @@ namespace OpenNest.Forms
             this.AutoScaleDimensions = new System.Drawing.SizeF(8F, 16F);
             this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
             this.CancelButton = this.cancelButton;
-            this.ClientSize = new System.Drawing.Size(380, 456);
+            this.ClientSize = new System.Drawing.Size(380, 516);
             this.Controls.Add(this.tabControl);
             this.Controls.Add(this.bottomPanel);
             this.Font = new System.Drawing.Font("Microsoft Sans Serif", 9.75F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((byte)(0)));

OpenNest/Forms/CuttingParametersForm.cs

@@ -22,8 +22,20 @@ namespace OpenNest.Forms
 
         private CheckBox chkTabsEnabled;
         private NumericUpDown nudTabWidth;
+        private NumericUpDown nudPierceClearance;
 
-        public CuttingParameters Parameters { get; set; } = new CuttingParameters();
+        private bool hasCustomParameters;
+        private CuttingParameters parameters = new CuttingParameters();
+
+        public CuttingParameters Parameters
+        {
+            get => parameters;
+            set
+            {
+                parameters = value;
+                hasCustomParameters = true;
+            }
+        }
 
         public CuttingParametersForm()
         {
@@ -54,9 +66,33 @@ namespace OpenNest.Forms
         protected override void OnLoad(EventArgs e)
         {
             base.OnLoad(e);
+
+            // If caller didn't provide custom parameters, try loading saved ones
+            if (!hasCustomParameters)
+            {
+                var json = Properties.Settings.Default.CuttingParametersJson;
+                if (!string.IsNullOrEmpty(json))
+                {
+                    try { Parameters = CuttingParametersSerializer.Deserialize(json); }
+                    catch { /* use defaults on corrupt data */ }
+                }
+            }
+
             LoadFromParameters(Parameters);
         }
 
+        protected override void OnFormClosing(FormClosingEventArgs e)
+        {
+            base.OnFormClosing(e);
+
+            if (DialogResult == System.Windows.Forms.DialogResult.OK)
+            {
+                var json = CuttingParametersSerializer.Serialize(BuildParameters());
+                Properties.Settings.Default.CuttingParametersJson = json;
+                Properties.Settings.Default.Save();
+            }
+        }
+
         private static void SetupTab(TabPage tab,
             out ComboBox leadInCombo, out Panel leadInPanel,
             out ComboBox leadOutCombo, out Panel leadOutPanel)
@@ -164,6 +200,35 @@ namespace OpenNest.Forms
             grpTabs.Controls.Add(nudTabWidth);
 
             Controls.Add(grpTabs);
+
+            var grpPierce = new GroupBox
+            {
+                Text = "Pierce",
+                Location = new System.Drawing.Point(4, 410),
+                Size = new System.Drawing.Size(372, 55),
+                Anchor = AnchorStyles.Top | AnchorStyles.Left | AnchorStyles.Right
+            };
+
+            grpPierce.Controls.Add(new Label
+            {
+                Text = "Pierce Clearance:",
+                Location = new System.Drawing.Point(12, 23),
+                AutoSize = true
+            });
+
+            nudPierceClearance = new NumericUpDown
+            {
+                Location = new System.Drawing.Point(130, 20),
+                Size = new System.Drawing.Size(100, 22),
+                DecimalPlaces = 4,
+                Increment = 0.0625m,
+                Minimum = 0,
+                Maximum = 9999,
+                Value = 0.0625m
+            };
+            grpPierce.Controls.Add(nudPierceClearance);
+
+            Controls.Add(grpPierce);
         }
 
         private void PopulateDropdowns()
@@ -305,6 +370,8 @@ namespace OpenNest.Forms
             chkTabsEnabled.Checked = p.TabsEnabled;
             if (p.TabConfig != null)
                 nudTabWidth.Value = (decimal)p.TabConfig.Size;
+
+            nudPierceClearance.Value = (decimal)p.PierceClearance;
         }
 
         private static void LoadLeadIn(ComboBox combo, Panel panel, LeadIn leadIn)
@@ -379,7 +446,8 @@ namespace OpenNest.Forms
                 ArcCircleLeadIn = BuildLeadIn(cboArcCircleLeadIn, pnlArcCircleLeadIn),
                 ArcCircleLeadOut = BuildLeadOut(cboArcCircleLeadOut, pnlArcCircleLeadOut),
                 TabsEnabled = chkTabsEnabled.Checked,
-                TabConfig = new NormalTab { Size = (double)nudTabWidth.Value }
+                TabConfig = new NormalTab { Size = (double)nudTabWidth.Value },
+                PierceClearance = (double)nudPierceClearance.Value
             };
             return p;
         }

OpenNest/Forms/CuttingParametersSerializer.cs

@@ -0,0 +1,138 @@
+using OpenNest.CNC.CuttingStrategy;
+using System.Text.Json;
+
+namespace OpenNest.Forms
+{
+    internal static class CuttingParametersSerializer
+    {
+        private static readonly JsonSerializerOptions JsonOptions = new()
+        {
+            WriteIndented = false,
+            PropertyNamingPolicy = JsonNamingPolicy.CamelCase
+        };
+
+        public static string Serialize(CuttingParameters p)
+        {
+            var dto = new CuttingParametersDto
+            {
+                ExternalLeadIn = ToDto(p.ExternalLeadIn),
+                ExternalLeadOut = ToLeadOutDto(p.ExternalLeadOut),
+                InternalLeadIn = ToDto(p.InternalLeadIn),
+                InternalLeadOut = ToLeadOutDto(p.InternalLeadOut),
+                ArcCircleLeadIn = ToDto(p.ArcCircleLeadIn),
+                ArcCircleLeadOut = ToLeadOutDto(p.ArcCircleLeadOut),
+                TabsEnabled = p.TabsEnabled,
+                TabWidth = p.TabConfig?.Size ?? 0.25,
+                PierceClearance = p.PierceClearance
+            };
+            return JsonSerializer.Serialize(dto, JsonOptions);
+        }
+
+        public static CuttingParameters Deserialize(string json)
+        {
+            var dto = JsonSerializer.Deserialize<CuttingParametersDto>(json, JsonOptions);
+            if (dto == null)
+                return new CuttingParameters();
+
+            return new CuttingParameters
+            {
+                ExternalLeadIn = FromDto(dto.ExternalLeadIn),
+                ExternalLeadOut = FromLeadOutDto(dto.ExternalLeadOut),
+                InternalLeadIn = FromDto(dto.InternalLeadIn),
+                InternalLeadOut = FromLeadOutDto(dto.InternalLeadOut),
+                ArcCircleLeadIn = FromDto(dto.ArcCircleLeadIn),
+                ArcCircleLeadOut = FromLeadOutDto(dto.ArcCircleLeadOut),
+                TabsEnabled = dto.TabsEnabled,
+                TabConfig = new NormalTab { Size = dto.TabWidth },
+                PierceClearance = dto.PierceClearance
+            };
+        }
+
+        private static LeadInDto ToDto(LeadIn leadIn)
+        {
+            return leadIn switch
+            {
+                LineLeadIn line => new LeadInDto { Type = "Line", Length = line.Length, ApproachAngle = line.ApproachAngle },
+                ArcLeadIn arc => new LeadInDto { Type = "Arc", Radius = arc.Radius },
+                LineArcLeadIn la => new LeadInDto { Type = "LineArc", LineLength = la.LineLength, ArcRadius = la.ArcRadius, ApproachAngle = la.ApproachAngle },
+                CleanHoleLeadIn ch => new LeadInDto { Type = "CleanHole", LineLength = ch.LineLength, ArcRadius = ch.ArcRadius, Kerf = ch.Kerf },
+                LineLineLeadIn ll => new LeadInDto { Type = "LineLine", Length1 = ll.Length1, Angle1 = ll.ApproachAngle1, Length2 = ll.Length2, Angle2 = ll.ApproachAngle2 },
+                _ => new LeadInDto { Type = "None" }
+            };
+        }
+
+        private static LeadIn FromDto(LeadInDto dto)
+        {
+            if (dto == null) return new NoLeadIn();
+            return dto.Type switch
+            {
+                "Line" => new LineLeadIn { Length = dto.Length, ApproachAngle = dto.ApproachAngle },
+                "Arc" => new ArcLeadIn { Radius = dto.Radius },
+                "LineArc" => new LineArcLeadIn { LineLength = dto.LineLength, ArcRadius = dto.ArcRadius, ApproachAngle = dto.ApproachAngle },
+                "CleanHole" => new CleanHoleLeadIn { LineLength = dto.LineLength, ArcRadius = dto.ArcRadius, Kerf = dto.Kerf },
+                "LineLine" => new LineLineLeadIn { Length1 = dto.Length1, ApproachAngle1 = dto.Angle1, Length2 = dto.Length2, ApproachAngle2 = dto.Angle2 },
+                _ => new NoLeadIn()
+            };
+        }
+
+        private static LeadOutDto ToLeadOutDto(LeadOut leadOut)
+        {
+            return leadOut switch
+            {
+                LineLeadOut line => new LeadOutDto { Type = "Line", Length = line.Length, ApproachAngle = line.ApproachAngle },
+                ArcLeadOut arc => new LeadOutDto { Type = "Arc", Radius = arc.Radius },
+                MicrotabLeadOut mt => new LeadOutDto { Type = "Microtab", GapSize = mt.GapSize },
+                _ => new LeadOutDto { Type = "None" }
+            };
+        }
+
+        private static LeadOut FromLeadOutDto(LeadOutDto dto)
+        {
+            if (dto == null) return new NoLeadOut();
+            return dto.Type switch
+            {
+                "Line" => new LineLeadOut { Length = dto.Length, ApproachAngle = dto.ApproachAngle },
+                "Arc" => new ArcLeadOut { Radius = dto.Radius },
+                "Microtab" => new MicrotabLeadOut { GapSize = dto.GapSize },
+                _ => new NoLeadOut()
+            };
+        }
+
+        private class CuttingParametersDto
+        {
+            public LeadInDto ExternalLeadIn { get; set; }
+            public LeadOutDto ExternalLeadOut { get; set; }
+            public LeadInDto InternalLeadIn { get; set; }
+            public LeadOutDto InternalLeadOut { get; set; }
+            public LeadInDto ArcCircleLeadIn { get; set; }
+            public LeadOutDto ArcCircleLeadOut { get; set; }
+            public bool TabsEnabled { get; set; }
+            public double TabWidth { get; set; }
+            public double PierceClearance { get; set; }
+        }
+
+        private class LeadInDto
+        {
+            public string Type { get; set; } = "None";
+            public double Length { get; set; }
+            public double ApproachAngle { get; set; }
+            public double Radius { get; set; }
+            public double LineLength { get; set; }
+            public double ArcRadius { get; set; }
+            public double Kerf { get; set; }
+            public double Length1 { get; set; }
+            public double Angle1 { get; set; }
+            public double Length2 { get; set; }
+            public double Angle2 { get; set; }
+        }
+
+        private class LeadOutDto
+        {
+            public string Type { get; set; } = "None";
+            public double Length { get; set; }
+            public double ApproachAngle { get; set; }
+            public double Radius { get; set; }
+            public double GapSize { get; set; }
+        }
+    }
+}

OpenNest/Properties/Settings.Designer.cs

@@ -226,5 +226,17 @@ namespace OpenNest.Properties {
                 this["DisabledStrategies"] = value;
             }
         }
+
+        [global::System.Configuration.UserScopedSettingAttribute()]
+        [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]
+        [global::System.Configuration.DefaultSettingValueAttribute("")]
+        public string CuttingParametersJson {
+            get {
+                return ((string)(this["CuttingParametersJson"]));
+            }
+            set {
+                this["CuttingParametersJson"] = value;
+            }
+        }
     }
 }

OpenNest/Properties/Settings.settings

@@ -53,5 +53,8 @@
     <Setting Name="DisabledStrategies" Type="System.String" Scope="User">
       <Value Profile="(Default)" />
     </Setting>
+    <Setting Name="CuttingParametersJson" Type="System.String" Scope="User">
+      <Value Profile="(Default)" />
+    </Setting>
   </Settings>
 </SettingsFile>

OpenNest/app.config

@@ -56,6 +56,9 @@
       <setting name="LastPierceTime" serializeAs="String">
         <value>0</value>
       </setting>
+      <setting name="CuttingParametersJson" serializeAs="String">
+        <value/>
+      </setting>
     </OpenNest.Properties.Settings>
     <OpenNest.Resources.Settings>
       <setting name="MainFormLocation" serializeAs="String">