some work from long ago

backend.py

@@ -0,0 +1,56 @@
+from abc import ABC, abstractmethod, abstractproperty
+from collections import namedtuple
+from pathlib import Path
+
+
+PackageBrief = namedtuple('PackageBrief', ['name', 'probe_fun'])
+
+
+M_SCRIPTS = Path(__file__).parent / 'script'
+OUTPUT_DIR = Path(__file__).parent / 'out'
+GATEWAY_DIR = Path(__file__).parent / 'gateway'
+PACKAGES = [PackageBrief(name='jsonlab', probe_fun='loadjson'),
+            PackageBrief(name='iso2mesh', probe_fun='s2m')]
+
+
+class BackendABC(ABC):
+    @abstractmethod
+    def __init__(self, engine_type: str):
+        pass
+
+    @
+
+class OctaveBackend(BackendABC):
+    def __init__(self, engine_type: str):
+        self.engine_type = engine_type.lower()
+        if self.engine_type == 'octave':
+            self.EngineError2 = self.EngineError1 = __import__('oct2py.utils', globals(), locals(), ['Oct2PyError'], 0)
+            self.engine = __import__('oct2py', globals(), locals(), ['Oct2Py'], 0)
+        else:
+            matlab_stuff = __import__('matlab.engine', globals(), locals(), ['MatlabEngine',
+                                                                             'MatlabExecutionError',
+                                                                             'RejectedExecutionError'], 0)
+            self.EngineError1 = matlab_stuff.MatlabExecutionError
+            self.EngineError1 = matlab_stuff.RejectedExecutionError
+            self.engine = matlab_stuff.MatlabEngine
+
+    def __getattr__(self, item):
+        def inner(*args, nout: int = 0):
+            with self.engine() as engine:
+                # import
+                engine.addpath(M_SCRIPTS)
+                try:
+                    packages_to_load = filter(lambda p: p['name'] in PACKAGES, engine.pkg('list').tolist()[0])
+                    for package in packages_to_load:
+                        engine.addpath(str(Path(package['dir'])))
+                except IndexError:
+                    raise ImportError('No local packages installed for Octave')  # TODO: another exception type
+                try:
+                    return engine.feval(item, *args, nargout=nout)
+                except self.EngineError1:
+                    return engine.feval(item, *args, nout=nout)
+        return inner
+
+
+def get_backend(engine_type='octave'):
+    return Backend(engine_type)

blender2mesh.py

@@ -27,6 +27,7 @@
 import jdata as jd
 import os
 from bpy.utils import register_class, unregister_class
+from .backend import get_backend
 from .utils import *
 
 G_MAXVOL = 1.0
@@ -75,7 +76,7 @@ def description(cls, context, properties):
         return [desc for idx, _, desc in ENUM_ENDSTEP if idx == properties.endstep][0]
 
     def func(self):
-        outputdir = GetBPWorkFolder()
+        outputdir = get_bp_work_folder()
         if not os.path.isdir(outputdir):
             os.makedirs(outputdir)
 
@@ -166,30 +167,8 @@ def func(self):
         if self.endstep < '6':
             return
 
-        try:
-            if bpy.context.scene.blender_photonics.backend == "octave":
-                import oct2py as op
-                from oct2py.utils import Oct2PyError as OcError1
-                OcError2 = OcError1
-                oc = op.Oct2Py()
-            else:
-                import matlab.engine as op
-                from matlab.engine import MatlabExecutionError as OcError1, RejectedExecutionError as OcError2
-                oc = op.start_matlab()
-        except ImportError:
-            raise ImportError(
-                'To run this feature, you must install the oct2py or matlab.engine Python modulem first, based on '
-                'your choice of the backend')
-
-        oc.addpath(os.path.join(os.path.dirname(os.path.abspath(__file__)), 'script'))
-
-        try:
-            oc.feval('blender2mesh', os.path.join(outputdir, 'blendermesh.jmsh'), nargout=0)
-        except OcError1 as e:
-            if 'too many outputs' in e.args[0]:
-                oc.feval('blender2mesh', os.path.join(outputdir, 'blendermesh.jmsh'), nout=0)
-            else:
-                raise
+        backend = get_backend(bpy.context.scene.blender_photonics.backend)
+        backend.blender2mesh(os.path.join(outputdir, 'blendermesh.jmsh'))
 
         # import volume mesh to blender(just for user to check the result)
         bpy.ops.object.mode_set(mode='OBJECT')
@@ -198,12 +177,12 @@ def func(self):
 
         if not self.onlysurf:
             outputmesh = jd.load(os.path.join(outputdir, 'volumemesh.jmsh'))
-            LoadTetMesh(outputmesh, 'Iso2Mesh')
+            load_tet_mesh(outputmesh, 'Iso2Mesh')
             bpy.context.view_layer.objects.active = bpy.data.objects['Iso2Mesh']
         else:
             regiondata = jd.load(os.path.join(outputdir, 'regionmesh.jmsh'))
             if len(regiondata.keys()) > 0:
-                LoadReginalMesh(regiondata, 'region_')
+                load_regional_mesh(regiondata, 'region_')
                 bpy.context.view_layer.objects.active = bpy.data.objects['region_1']
 
         bpy.context.space_data.shading.type = 'WIREFRAME'
@@ -212,7 +191,7 @@ def func(self):
         if self.endstep < '7':
             return
 
-        ShowMessageBox(
+        show_message_box(
             "Mesh generation is complete. The combined tetrahedral mesh is imported for inspection. To set optical "
             "properties for each region, please click 'Load mesh and setup simulation'",
             "BlenderPhotonics")
@@ -252,9 +231,9 @@ def execute(self, context):
         print(self.filepath)
         if not (self.filepath == ""):
             if os.name == 'nt':
-                os.popen("copy '" + os.path.join(GetBPWorkFolder(), 'blendermesh.jmsh') + "' '" + self.filepath + "'")
+                os.popen("copy '" + os.path.join(get_bp_work_folder(), 'blendermesh.jmsh') + "' '" + self.filepath + "'")
             else:
-                os.popen("cp '" + os.path.join(GetBPWorkFolder(), 'blendermesh.jmsh') + "' '" + self.filepath + "'")
+                os.popen("cp '" + os.path.join(get_bp_work_folder(), 'blendermesh.jmsh') + "' '" + self.filepath + "'")
         return {'FINISHED'}
 
     def invoke(self, context, event):

exceptions.py

@@ -0,0 +1,14 @@
+class BlenderPhotonicsError(Exception):
+    pass
+
+
+class BlenderPhotonicsDependencyError(BlenderPhotonicsError):
+    """Errors concerning missing system or Python utilities/modules/packages"""
+    def __init__(self, dep: str, *args, **kwargs):
+        self.missing_dep = dep
+        super().__init__(f'Required dependency not found: {dep}', *args)
+
+
+class BlenderPhotonicsMeshingError(BlenderPhotonicsError):
+    """Meshing failure, typically a forwarding of some backend error"""
+    pass

mesh2blender.py

@@ -42,10 +42,10 @@ def importmesh(self):
         bpy.ops.object.delete()
 
         # folder path for importing .jmsh files
-        outputdir = GetBPWorkFolder()
+        outputdir = get_bp_work_folder()
 
         regiondata = jd.load(os.path.join(outputdir, 'regionmesh.jmsh'))
-        bbx = LoadReginalMesh(regiondata, 'region_')
+        bbx = load_regional_mesh(regiondata, 'region_')
 
         # add properties
         for obj in bpy.data.objects:

nii2mesh.py

@@ -59,7 +59,7 @@ class nii2mesh(bpy.types.Operator):
 
     def vol2mesh(self):
         # Remove last .jmsh file
-        outputdir = GetBPWorkFolder()
+        outputdir = get_bp_work_folder()
         if not os.path.isdir(outputdir):
             os.makedirs(outputdir)
         if os.path.exists(os.path.join(outputdir, 'regionmesh.jmsh')):
@@ -106,7 +106,7 @@ def vol2mesh(self):
         bpy.ops.object.delete()
 
         regiondata = jd.load(os.path.join(outputdir, 'regionmesh.jmsh'))
-        regiondata = JMeshFallback(regiondata)
+        regiondata = jmesh_fallback(regiondata)
         n = len(regiondata.keys()) - 1
 
         # To import mesh.ply in batches
@@ -115,11 +115,11 @@ def vol2mesh(self):
             if not isinstance(regiondata[surfkey], np.ndarray):
                 regiondata[surfkey] = np.asarray(regiondata[surfkey], dtype=np.uint32)
             regiondata[surfkey] -= 1
-            AddMeshFromNodeFace(regiondata['MeshVertex3'], regiondata[surfkey].tolist(), 'region_' + str(i + 1))
+            add_mesh_from_node_face(regiondata['MeshVertex3'], regiondata[surfkey].tolist(), 'region_' + str(i + 1))
 
         bpy.context.space_data.shading.type = 'WIREFRAME'
 
-        ShowMessageBox(
+        show_message_box(
             "Mesh generation is complete. The combined tetrahedral mesh is imported for inspection. To set optical "
             "properties for each region, please click 'Load mesh and setup simulation'",
             "BlenderPhotonics")

obj2surf.py

@@ -73,15 +73,15 @@ def description(cls, context, properties):
         return [desc for idx, _, desc in ENUM_ACTION if idx == properties.action][0]
 
     def func(self):
-        outputdir = GetBPWorkFolder()
+        outputdir = get_bp_work_folder()
         if not os.path.isdir(outputdir):
             os.makedirs(outputdir)
 
         if os.path.exists(os.path.join(outputdir, 'surfacemesh.jmsh')):
             os.remove(os.path.join(outputdir, 'surfacemesh.jmsh'))
 
         if len(bpy.context.selected_objects) < 1:
-            ShowMessageBox("Must select at least one object (for Boolean operations, select two)", "BlenderPhotonics")
+            show_message_box("Must select at least one object (for Boolean operations, select two)", "BlenderPhotonics")
             return
 
         # remove camera and light objects
@@ -97,7 +97,7 @@ def func(self):
             bpy.ops.mesh.quads_convert_to_tris(quad_method='BEAUTY', ngon_method='BEAUTY')
 
         if len(bpy.context.selected_objects) < 1:
-            ShowMessageBox("No mesh-like object was selected, skip", "BlenderPhotonics")
+            show_message_box("No mesh-like object was selected, skip", "BlenderPhotonics")
             return
 
         bpy.ops.object.mode_set(mode='OBJECT')
@@ -107,7 +107,7 @@ def func(self):
                                               'http://mcx.space/BlenderPhotonics)'},
                     'MeshGroup': []}
         for ob in bpy.context.selected_objects:
-            objsurf = GetNodeFacefromObject(ob, self.convtri)
+            objsurf = get_node_face_from_object(ob, self.convtri)
             surfdata['MeshGroup'].append(objsurf)
 
         surfdata['param'] = {'action': self.action, 'level': self.actionparam}
@@ -156,20 +156,20 @@ def func(self):
             if 'MeshVertex3' in ob:
                 if ('_DataInfo_' in ob) and ('BlenderObjectName' in ob['_DataInfo_']):
                     objname = ob['_DataInfo_']['BlenderObjectName']
-                AddMeshFromNodeFace(ob['MeshVertex3'], (np.array(ob['MeshTri3']) - 1).tolist(), objname)
+                add_mesh_from_node_face(ob['MeshVertex3'], (np.array(ob['MeshTri3']) - 1).tolist(), objname)
                 bpy.context.view_layer.objects.active = bpy.data.objects[objname]
             else:
                 for ob in surfdata['MeshGroup']:
                     objname = 'surf_' + str(idx)
                     if ('_DataInfo_' in ob) and ('BlenderObjectName' in ob['_DataInfo_']):
                         objname = ob['_DataInfo_']['BlenderObjectName']
-                    AddMeshFromNodeFace(ob['MeshVertex3'], (np.array(ob['MeshTri3']) - 1).tolist(), objname)
+                    add_mesh_from_node_face(ob['MeshVertex3'], (np.array(ob['MeshTri3']) - 1).tolist(), objname)
                     bpy.context.view_layer.objects.active = bpy.data.objects[objname]
                     idx += 1
 
         bpy.context.space_data.shading.type = 'WIREFRAME'
 
-        ShowMessageBox("Mesh generation is complete. The combined surface mesh is imported for inspection.",
+        show_message_box("Mesh generation is complete. The combined surface mesh is imported for inspection.",
                        "BlenderPhotonics")
 
     def execute(self, context):
@@ -211,9 +211,9 @@ def execute(self, context):
         print(self.filepath)
         if not (self.filepath == ""):
             if os.name == 'nt':
-                os.popen("copy '" + os.path.join(GetBPWorkFolder(), 'blendersurf.jmsh') + "' '" + self.filepath + "'")
+                os.popen("copy '" + os.path.join(get_bp_work_folder(), 'blendersurf.jmsh') + "' '" + self.filepath + "'")
             else:
-                os.popen("cp '" + os.path.join(GetBPWorkFolder(), 'blendersurf.jmsh') + "' '" + self.filepath + "'")
+                os.popen("cp '" + os.path.join(get_bp_work_folder(), 'blendersurf.jmsh') + "' '" + self.filepath + "'")
         return {'FINISHED'}
 
     def invoke(self, context, event):
@@ -256,7 +256,7 @@ def execute(self, context):
 
         oc.addpath(os.path.join(os.path.dirname(os.path.abspath(__file__)), 'script'))
         surfdata = oc.feval('surf2jmesh', self.filepath)
-        AddMeshFromNodeFace(surfdata['MeshVertex3'], (np.array(surfdata['MeshTri3']) - 1).tolist(), 'importedsurf')
+        add_mesh_from_node_face(surfdata['MeshVertex3'], (np.array(surfdata['MeshTri3']) - 1).tolist(), 'importedsurf')
 
         return {'FINISHED'}
 

runmmc.py

@@ -87,7 +87,7 @@ def preparemmc(self):
                'method': self.method, 'outputtype': self.outputtype, 'basisorder': self.basisorder,
                'debuglevel': self.debuglevel, 'gpuid': self.gpuid}
         print(obj['srctype'])
-        outputdir = GetBPWorkFolder()
+        outputdir = get_bp_work_folder()
         if not os.path.isdir(outputdir):
             os.makedirs(outputdir)
 
@@ -127,11 +127,11 @@ def preparemmc(self):
         bpy.ops.object.delete()
 
         outputmesh = jd.load(os.path.join(outputdir, 'volumemesh.jmsh'))
-        outputmesh = JMeshFallback(outputmesh)
+        outputmesh = jmesh_fallback(outputmesh)
         if not isinstance(outputmesh['MeshTri3'], np.ndarray):
             outputmesh['MeshTri3'] = np.asarray(outputmesh['MeshTri3'], dtype=np.uint32)
         outputmesh['MeshTri3'] -= 1
-        AddMeshFromNodeFace(outputmesh['MeshVertex3'], outputmesh['MeshTri3'].tolist(), "Iso2Mesh")
+        add_mesh_from_node_face(outputmesh['MeshVertex3'], outputmesh['MeshTri3'].tolist(), "Iso2Mesh")
 
         # add color to blender model
         obj = bpy.data.objects['Iso2Mesh']

script/blender2mesh.m

@@ -50,4 +50,4 @@ function blender2mesh(filename)
 save('-v7',bpmwpath('meshdata.mat'),'node','elem');
 disp(['begin to save region mesh'])
 
-blendersavemesh(node,elem);
+blendersavemesh(node,elem,regionmesh_fname, volumemesh_fname);

script/blendersavemesh.m

@@ -1,4 +1,4 @@
-function blendersavemesh(node,elem)
+function blendersavemesh(node,elem,regionmesh_fname,volumemesh_fname)
 %
 % blendersavemesh(node,elem)
 %
@@ -9,6 +9,8 @@ function blendersavemesh(node,elem)
 % input:
 %	 node: the node coordinate list of a tetrahedral mesh (nn x 3)
 %	 elem: the tetrahedral element list of the mesh (ne x 4)
+%    regionmesh_fname: file name to save the region mesh
+%    volumemesh_fname: file name to save the volume mesh
 %
 % output:
 %	 two JMesh files are saved under the temporary folder bpmwpath('')
@@ -59,9 +61,9 @@ function blendersavemesh(node,elem)
     outputmesh=rmfield(outputmesh,encodevarname('MeshTri3(1)'));
 end
 disp(['begin to save whole volumic mesh.'])
-savejson('',outputmesh,'FileName',bpmwpath('regionmesh.jmsh'),'ArrayIndent',0);
+savejson('',outputmesh,'FileName','regionmesh.jmsh','ArrayIndent',0);
 faces = meshface(elem(:,1:4));
 
 meshdata.MeshTri3=faces;
-savejson('',meshdata,'FileName',bpmwpath('volumemesh.jmsh'),'ArrayIndent',0);
+savejson('',meshdata,'FileName','volumemesh.jmsh','ArrayIndent',0);
 disp(['saving complete.'])