Add StitchCut macro for sheet metal stitch cuts

StitchCut/README.md

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+# StitchCut Macro
+
+The StitchCut macro creates evenly spaced stitch cuts along a selected line in a sketch,
+primarily for sheet metal flat patterns to allow easier hand folding.
+
+## Features
+- Start & end offset from edges
+- Automatic cut length calculation
+- User-defined number of cuts
+- Inserts cuts directly into the active sketch
+
+## Usage
+1. Enter **edit mode** on a sketch.
+2. Select the line to apply stitch cuts to.
+3. Run the macro.
+4. Enter:
+   - Start & End Offset
+   - Number of cuts
+5. The original line is replaced with stitch cuts.
+
+## Author
+John Hyslop
+## FreeCAD Version
+Tested on FreeCAD 1.02
+
+## License
+Free for personal, educational, and commercial use.
+
+Please credit the author.

StitchCut/StitchCut.py

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+"""
+StitchCut.py
+
+Author: John Hyslop
+Description:
+    This FreeCAD macro allows you to create evenly spaced "stitch cuts" along a selected
+    straight line in a sketch. The user can specify the start & end offsets, gap between cuts,
+    and number of cuts. The macro will calculate the cut lengths and insert them directly
+    into the sketch.
+
+    Created with a little extra help from ChatGPT.
+"""
+# --- Macro Metadata ---
+__Name__ = "StitchCut"
+__Comment__ = "Creates evenly spaced stitch cuts along a selected line in a sketch, for hand-folding sheet metal."
+__Author__ = "John Hyslop"
+__Date__ = "2025-12-15"
+__Version__ = "1.0"
+__License__ = "Free for personal, educational, and commercial use. Please credit the author."
+__Web__ = "https://github.com/JohnHyslop/MyFreeCADMacros/StitchCut"
+__Wiki__ = "https://wiki.freecad.org/StitchCut"
+__Icon__ = ""
+__Xpm__ = ""
+__Help__ = "Select a line in a sketch, run macro, and define offsets, gap, and number of cuts."
+__Status__ = "Stable"
+__Requires__ = "FreeCAD >= 1.02"
+__Communication__ = "https://github.com/JohnHyslop/MyFreeCADMacros/issues"
+__Files__ = "StitchCut.py"
+
+import FreeCAD, FreeCADGui
+from PySide import QtGui
+import math, Part
+
+# --- Dialog ---
+class StitchCutDialog(QtGui.QDialog):
+    def __init__(self, line_length, parent=None):
+        super().__init__(parent)
+        self.setWindowTitle("Stitch Cut Parameters")
+        self.line_length = line_length
+
+        self.edge_offset_edit = QtGui.QLineEdit("3")  # Changed label
+        self.gap_edit = QtGui.QLineEdit("3")
+        self.num_cuts_edit = QtGui.QLineEdit("5")
+        self.cut_length_display = QtGui.QLabel("0")
+
+        layout = QtGui.QFormLayout()
+        layout.addRow("Start & End Offset:", self.edge_offset_edit)
+        layout.addRow("Gap between cuts:", self.gap_edit)
+        layout.addRow("Number of Cuts:", self.num_cuts_edit)
+        layout.addRow("Calculated Cut Length:", self.cut_length_display)
+
+        buttons = QtGui.QDialogButtonBox(QtGui.QDialogButtonBox.Ok | QtGui.QDialogButtonBox.Cancel)
+        buttons.accepted.connect(self.accept)
+        buttons.rejected.connect(self.reject)
+        layout.addWidget(buttons)
+
+        self.setLayout(layout)
+
+        # update calculation dynamically
+        self.edge_offset_edit.textChanged.connect(self.update_cut_length)
+        self.gap_edit.textChanged.connect(self.update_cut_length)
+        self.num_cuts_edit.textChanged.connect(self.update_cut_length)
+        self.update_cut_length()
+
+    def update_cut_length(self):
+        try:
+            edge_offset = float(self.edge_offset_edit.text())
+            gap = float(self.gap_edit.text())
+            num = int(self.num_cuts_edit.text())
+            usable = self.line_length - 2*edge_offset - (num - 1) * gap
+            if usable <= 0:
+                self.cut_length_display.setText("N/A")
+            else:
+                self.cut_length_display.setText(f"{usable/num:.3f}")
+        except:
+            self.cut_length_display.setText("Error")
+
+    def getValues(self):
+        try:
+            edge_offset = float(self.edge_offset_edit.text())
+            gap = float(self.gap_edit.text())
+            num = int(self.num_cuts_edit.text())
+            usable = self.line_length - 2*edge_offset - (num - 1) * gap
+            if usable <= 0:
+                return None
+            cut_length = usable / num
+            return edge_offset, gap, num, cut_length
+        except:
+            return None
+
+# --- Get selected line ---
+def get_selected_line():
+    sel = FreeCADGui.Selection.getSelectionEx()
+    if len(sel) != 1:
+        QtGui.QMessageBox.critical(None, "Error", "Select exactly one line in a sketch.")
+        return None, None
+    sk = sel[0].Object
+    if sk.TypeId != "Sketcher::SketchObject":
+        QtGui.QMessageBox.critical(None, "Error", "Selection is not a sketch.")
+        return None, None
+    if len(sel[0].SubElementNames) != 1:
+        QtGui.QMessageBox.critical(None, "Error", "Select exactly one edge.")
+        return None, None
+    edge_name = sel[0].SubElementNames[0]
+    idx = int(edge_name.replace("Edge","")) - 1
+    geo = sk.Geometry[idx]
+    if geo.TypeId != 'Part::GeomLineSegment':
+        QtGui.QMessageBox.critical(None, "Error", "Selected geometry is not a straight line.")
+        return None, None
+    return sk, idx
+
+# --- Main macro ---
+def stitch_cut():
+    sk, idx = get_selected_line()
+    if not sk:
+        return
+
+    line = sk.Geometry[idx]
+    p1 = line.StartPoint
+    p2 = line.EndPoint
+
+    vec = p2.sub(p1)
+    length = vec.Length
+    direction = vec.normalize()
+
+    dlg = StitchCutDialog(length)
+    if dlg.exec_() != QtGui.QDialog.Accepted:
+        return
+
+    values = dlg.getValues()
+    if not values:
+        QtGui.QMessageBox.critical(None, "Error", "Invalid parameters, cuts won't fit.")
+        return
+    edge_offset, gap, num_cuts, cut_length = values
+
+    # Remove original line
+    sk.delGeometry(idx)
+
+    # Add stitch cuts
+    for i in range(num_cuts):
+        start_dist = edge_offset + i*(cut_length + gap)
+        end_dist = start_dist + cut_length
+        if end_dist > length - edge_offset:
+            end_dist = length - edge_offset
+        ptA = FreeCAD.Vector(p1.x + direction.x*start_dist,
+                             p1.y + direction.y*start_dist,
+                             p1.z + direction.z*start_dist)
+        ptB = FreeCAD.Vector(p1.x + direction.x*end_dist,
+                             p1.y + direction.y*end_dist,
+                             p1.z + direction.z*end_dist)
+        sk.addGeometry(Part.LineSegment(ptA, ptB), False)
+
+    sk.Document.recompute()
+    QtGui.QMessageBox.information(None, "Done", "Stitch cuts applied!")
+
+# --- Run ---
+stitch_cut()
+