From bc2fe1bd3e167fd8eed05f9ffeda3c255f445f70 Mon Sep 17 00:00:00 2001
From: Mikko Rasa <tdb@tdb.fi>
Date: Mon, 23 Nov 2015 18:18:21 +0200
Subject: [PATCH] Allow flagging meshes for winding test in Blender

---
 blender/io_mspgl/__init__.py    |  2 +-
 blender/io_mspgl/export_mesh.py |  6 ++++++
 blender/io_mspgl/properties.py  | 19 ++++++++++++++++++-
 3 files changed, 25 insertions(+), 2 deletions(-)

diff --git a/blender/io_mspgl/__init__.py b/blender/io_mspgl/__init__.py
index 2c9d8f72..c13345fa 100644
--- a/blender/io_mspgl/__init__.py
+++ b/blender/io_mspgl/__init__.py
@@ -171,7 +171,7 @@ def menu_func_export(self, context):
 	self.layout.operator(ExportMspGLArmature.bl_idname, text="Msp GL armature")
 	self.layout.operator(ExportMspGLScene.bl_idname, text="Msp GL scene")
 
-from .properties import MspGLProperties
+from .properties import MspGLMeshProperties, MspGLObjectProperties
 
 def register():
 	bpy.utils.register_module(__name__)
diff --git a/blender/io_mspgl/export_mesh.py b/blender/io_mspgl/export_mesh.py
index 07f457a1..8f868882 100644
--- a/blender/io_mspgl/export_mesh.py
+++ b/blender/io_mspgl/export_mesh.py
@@ -230,7 +230,10 @@ class MeshExporter:
 
 		mesh = None
 		bmeshes = []
+		winding_test = False
 		for o, m in objs:
+			if o.data.winding_test:
+				winding_test = True
 			bmesh = o.to_mesh(context.scene, True, "PREVIEW")
 			bmeshes.append(bmesh)
 			me = Mesh(bmesh)
@@ -387,6 +390,9 @@ class MeshExporter:
 				out_file.write("indices", l.vertices[0].index, l.vertices[1].index)
 			out_file.end()
 
+		if winding_test:
+			out_file.write("winding", "COUNTERCLOCKWISE")
+
 		if progress:
 			progress.set_task("Done", 1.0, 1.0)
 
diff --git a/blender/io_mspgl/properties.py b/blender/io_mspgl/properties.py
index 30aed9a9..129b02e6 100644
--- a/blender/io_mspgl/properties.py
+++ b/blender/io_mspgl/properties.py
@@ -1,6 +1,22 @@
 import bpy
 
-class MspGLProperties(bpy.types.Panel):
+class MspGLMeshProperties(bpy.types.Panel):
+	bl_idname = "MESH_PT_mspgl_properties"
+	bl_label = "MspGL properties"
+	bl_space_type = "PROPERTIES"
+	bl_region_type = "WINDOW"
+	bl_context = "data"
+
+	@classmethod
+	def poll(cls, context):
+		return context.active_object.type=="MESH"
+
+	def draw(self, context):
+		mesh = context.active_object.data
+
+		self.layout.prop(mesh, "winding_test")
+
+class MspGLObjectProperties(bpy.types.Panel):
 	bl_idname = "OBJECT_PT_mspgl_properties"
 	bl_label = "MspGL properties"
 	bl_space_type = "PROPERTIES"
@@ -20,6 +36,7 @@ class MspGLProperties(bpy.types.Panel):
 			self.layout.prop(obj, "lod_index")
 
 def register_properties():
+	bpy.types.Mesh.winding_test = bpy.props.BoolProperty(name="Winding test", description="Perform winding test to skip back faces")
 	bpy.types.Object.technique = bpy.props.StringProperty(name="Technique", description="Name of the technique to use for rendering")
 	bpy.types.Object.inherit_tech = bpy.props.BoolProperty(name="Inherit technique", description="Inherit from the technique to customize textures")
 	bpy.types.Object.override_material = bpy.props.BoolProperty(name="Override material", description="Override material in the inherited texture as well", default=True)
-- 
2.43.0