#1153 New mitre command for 2D cad (like chamfer with 0 distance)

src/blenderbim/blenderbim/bim/module/cad/__init__.py

@@ -21,6 +21,7 @@ from . import operator, workspace
 
 classes = (
     operator.CadTrimExtend,
+    operator.CadMitre,
     workspace.CadHotkey,
 )
 

src/blenderbim/blenderbim/bim/module/cad/operator.py

@@ -28,11 +28,8 @@ messages = {
 
 
 class CadTrimExtend(bpy.types.Operator):
-    """Weld intersecting edges, project converging edges towards their intersection"""
-
     bl_idname = "bim.cad_trim_extend"
     bl_label = "CAD Trim / Extend"
-    join_type: bpy.props.StringProperty()
 
     @classmethod
     def poll(cls, context):
@@ -61,7 +58,53 @@ class CadTrimExtend(bpy.types.Operator):
         edges = [e for e in bm.edges if e.select and not e.hide]
 
         if len(edges) == 2:
-            message = tool.Cad.do_vtx_if_appropriate(bm, edges)
+            message = tool.Cad.do_vtx_if_appropriate(bm, edges, mode="T")
+            if isinstance(message, set):
+                msg = messages.get(message.pop())
+                return self.cancel_message(msg)
+            bm = message
+        else:
+            return self.cancel_message("select two edges!")
+
+        bm.verts.index_update()
+        bm.edges.index_update()
+        bmesh.update_edit_mesh(me, loop_triangles=True)
+
+        return {"FINISHED"}
+
+
+class CadMitre(bpy.types.Operator):
+    bl_idname = "bim.cad_mitre"
+    bl_label = "CAD Trim / Extend"
+
+    @classmethod
+    def poll(cls, context):
+        obj = context.active_object
+        return bool(obj) and obj.type == "MESH"
+
+    def cancel_message(self, msg):
+        print(msg)
+        self.report({"WARNING"}, msg)
+        return {"CANCELLED"}
+
+    def execute(self, context):
+        # final attempt to enter unfragmented bm/mesh
+        # ghastly, but what can I do? it works with these
+        # fails without.
+        bpy.ops.object.mode_set(mode="OBJECT")
+        bpy.ops.object.mode_set(mode="EDIT")
+
+        obj = context.active_object
+        me = obj.data
+
+        bm = bmesh.from_edit_mesh(me)
+        bm.verts.ensure_lookup_table()
+        bm.edges.ensure_lookup_table()
+
+        edges = [e for e in bm.edges if e.select and not e.hide]
+
+        if len(edges) == 2:
+            message = tool.Cad.do_vtx_if_appropriate(bm, edges, mode="V")
             if isinstance(message, set):
                 msg = messages.get(message.pop())
                 return self.cancel_message(msg)

src/blenderbim/blenderbim/bim/module/cad/workspace.py

@@ -36,6 +36,7 @@ class CadTool(WorkSpaceTool):
     # https://docs.blender.org/api/current/bpy.types.KeyMapItems.html
     bl_keymap = (
         ("bim.cad_hotkey", {"type": "E", "value": "PRESS", "shift": True}, {"properties": [("hotkey", "S_E")]}),
+        ("bim.cad_hotkey", {"type": "T", "value": "PRESS", "shift": True}, {"properties": [("hotkey", "S_T")]}),
     )
 
     def draw_settings(context, layout, tool):
@@ -61,4 +62,7 @@ class CadHotkey(bpy.types.Operator):
         return {"FINISHED"}
 
     def hotkey_S_E(self):
-        bpy.ops.bim.cad_trim_extend(join_type="T")
+        bpy.ops.bim.cad_trim_extend()
+
+    def hotkey_S_T(self):
+        bpy.ops.bim.cad_mitre()

src/blenderbim/blenderbim/tool/cad.py

@@ -24,6 +24,7 @@
 # Changes include:
 #
 #  - Instead of AutoVTX, user explicitly chooses V, T, or X mode
+#  - Instead of adding edges, existing edges are extended
 
 
 import sys
@@ -261,12 +262,18 @@ class Cad:
         bm.edges.index_update()
         return bm
 
+    @classmethod
+    def perform_v(cls, bm, pt, target, edge, pts, vertex_indices):
+        bm = cls.perform_t(bm, pt, target, edge, pts, vertex_indices)
+        bm = cls.perform_t(bm, pt, edge, target, pts, vertex_indices)
+        return bm
+
     @classmethod
     def prioritise_active_edge(cls, bm, edges):
         return [edges[0], edges[1]] if bm.select_history.active == edges[0] else [edges[1], edges[0]]
 
     @classmethod
-    def do_vtx_if_appropriate(cls, bm, edges):
+    def do_vtx_if_appropriate(cls, bm, edges, mode):
         vertex_indices = cls.get_vert_indices_from_bmedges(edges)
 
         # test 1, are there shared vers? if so return non-viable
@@ -285,6 +292,9 @@ class Cad:
             return {"NON_PLANAR_EDGES"}
 
         edges = cls.prioritise_active_edge(bm, edges)
-        # point must lie on an edge or the virtual extention of an edge
-        bm = cls.perform_t(bm, point, edges[0], edges[1], (p1, p2, p3, p4), vertex_indices)
+        # point must lie on an edge or the virtual extension of an edge
+        if mode == "T":
+            bm = cls.perform_t(bm, point, edges[0], edges[1], (p1, p2, p3, p4), vertex_indices)
+        elif mode == "V":
+            bm = cls.perform_v(bm, point, edges[0], edges[1], (p1, p2, p3, p4), vertex_indices)
         return bm