From b128c6434774f79998b95525ed06e420bfe0306b Mon Sep 17 00:00:00 2001
From: Mikko Rasa <tdb@tdb.fi>
Date: Mon, 4 May 2020 01:28:28 +0300
Subject: [PATCH] Remove attribute proxying from Mesh in the Blender exporter

Instead just copy all the data.  This makes the script easier to read and
avoids holding references to stale data.
---
 blender/io_mspgl/mesh.py | 63 ++++++++++------------------------------
 1 file changed, 15 insertions(+), 48 deletions(-)

diff --git a/blender/io_mspgl/mesh.py b/blender/io_mspgl/mesh.py
index 4403c6a0..42adabe6 100644
--- a/blender/io_mspgl/mesh.py
+++ b/blender/io_mspgl/mesh.py
@@ -9,10 +9,8 @@ def make_edge_key(i1, i2):
 class Edge:
 	def __init__(self, edge):
 		if edge.__class__==Edge:
-			self._edge = edge._edge
 			self.smooth = edge.smooth
 		else:
-			self._edge = edge
 			self.smooth = False
 		if edge:
 			self.vertices = edge.vertices[:]
@@ -22,9 +20,6 @@ class Edge:
 			self.key = None
 		self.faces = []
 
-	def __getattr__(self, attr):
-		return getattr(self._edge, attr)
-
 	def check_smooth(self, limit):
 		if len(self.faces)!=2:
 			return
@@ -51,12 +46,10 @@ class Edge:
 class Vertex:
 	def __init__(self, vertex):
 		if vertex.__class__==Vertex:
-			self._vertex = vertex._vertex
 			self.uvs = vertex.uvs[:]
 			self.tan = vertex.tan
 			self.bino = vertex.bino
 		else:
-			self._vertex = vertex
 			self.uvs = []
 			self.tan = None
 			self.bino = None
@@ -68,9 +61,6 @@ class Vertex:
 		self.faces = []
 		self.groups = vertex.groups[:]
 
-	def __getattr__(self, attr):
-		return getattr(self._vertex, attr)
-
 	def __cmp__(self, other):
 		if other is None:
 			return 1
@@ -79,26 +69,23 @@ class Vertex:
 
 class VertexGroup:
 	def __init__(self, group):
-		self._group = group
 		self.group = group.group
 		self.weight = group.weight
 
-	def __getattr__(self, attr):
-		return getattr(self._group, attr)
-
 
 class Face:
 	def __init__(self, face):
-		self._face = face
 		self.index = face.index
 		self.edges = []
+		self.edge_keys = face.edge_keys
 		self.vertices = face.vertices[:]
+		self.loop_indices = face.loop_indices
+		self.normal = face.normal
+		self.use_smooth = face.use_smooth
+		self.material_index = face.material_index
 		self.uvs = []
 		self.flag = False
 
-	def __getattr__(self, attr):
-		return getattr(self._face, attr)
-
 	def __cmp__(self, other):
 		if other is None:
 			return 1
@@ -142,13 +129,11 @@ class Line:
 class UvLayer:
 	def __init__(self, arg):
 		if type(arg)==str:
-			self._layer = None
 			self.name = arg
 			self.uvs = []
 		else:
-			self._layer = arg
 			self.name = arg.name
-			self.uvs = [mathutils.Vector(d.uv) for d in self.data]
+			self.uvs = [mathutils.Vector(d.uv) for d in arg.data]
 
 		self.unit = None
 		self.hidden = False
@@ -161,17 +146,16 @@ class UvLayer:
 			elif ext==".hidden":
 				self.hidden = True
 
-	def __getattr__(self, attr):
-		return getattr(self._layer, attr)
-
 
 class Mesh:
 	def __init__(self, mesh):
-		self._mesh = mesh
 		self.name = mesh.name
 
 		self.winding_test = mesh.winding_test
+		self.smoothing = mesh.smoothing
+		self.use_uv = mesh.use_uv
 		self.tbn_vecs = mesh.tbn_vecs
+		self.tbn_uvtex = mesh.tbn_uvtex
 		self.vertex_groups = mesh.vertex_groups
 
 		# Clone basic data
@@ -184,8 +168,11 @@ class Mesh:
 		self.loops = mesh.loops[:]
 		self.materials = mesh.materials[:]
 
+		self.use_auto_smooth = mesh.use_auto_smooth
+		self.auto_smooth_angle = mesh.auto_smooth_angle
+
 		# Clone only the desired UV layers
-		if self.use_uv=='NONE' or not mesh.uv_layers:
+		if mesh.use_uv=='NONE' or not mesh.uv_layers:
 			self.uv_layers = []
 		else:
 			self.uv_layers = [UvLayer(u) for u in mesh.uv_layers]
@@ -200,7 +187,7 @@ class Mesh:
 
 			self.uv_layers = sorted(self.uv_layers, key=(lambda u: u.unit))
 
-			if self.use_uv=='UNIT0':
+			if mesh.use_uv=='UNIT0':
 				self.uv_layers = [self.uv_layers[0]]
 				if self.uv_layers[0].unit!=0:
 					self.uv_layers = []
@@ -227,16 +214,13 @@ class Mesh:
 				v.edges.append(e)
 
 		# Store loose edges as lines
-		if self.use_lines:
+		if mesh.use_lines:
 			self.lines = [Line(e) for e in self.edges if not e.faces]
 		else:
 			self.lines = []
 
 		self.vertex_sequence = []
 
-	def __getattr__(self, attr):
-		return getattr(self._mesh, attr)
-
 	def transform(self, matrix):
 		for v in self.vertices:
 			v.co = matrix@v.co
@@ -749,19 +733,6 @@ class Mesh:
 		for e in self.edges:
 			e.key = make_edge_key(e.vertices[0].index, e.vertices[1].index)
 
-	def drop_references(self):
-		for v in self.vertices:
-			v._vertex = None
-			for g in v.groups:
-				g._group = None
-		for e in self.edges:
-			e._edge = None
-		for f in self.faces:
-			f._face = None
-		for u in self.uv_layers:
-			u._layer = None
-		self._mesh = None
-
 
 def create_mesh_from_object(context, obj, progress, *, material_map=None):
 	if obj.type!="MESH":
@@ -823,10 +794,6 @@ def create_mesh_from_object(context, obj, progress, *, material_map=None):
 	progress.set_task("Render sequence", 0.8, 1.0)
 	mesh.prepare_sequence(progress)
 
-	# Discard the temporary Blender meshes after making sure there's no
-	# references to the data
-	mesh.drop_references()
-
 	progress.pop_task()
 
 	return mesh
-- 
2.45.2