From e74116e7b458c75cb89cac219fef227e159d27f6 Mon Sep 17 00:00:00 2001
From: Adam Johnson <AdamJohnso@gmail.com>
Date: Mon, 24 Feb 2020 18:37:43 -0500
Subject: [PATCH] Export Blender double-sided meshes correctly.

This enables the Blender Mesh Normal panel and exports any double sided
mesh with double sided layers to Plasma. The implication is that the
mesh will be rendered twice in game--the second time with the winding
reversed. Wavesets marked double sided are ignored due to the runtime
generation of layers in game. Trying to make a double sided waveset is
therefore nonsense.
---
 korman/exporter/material.py | 27 +++++++++++++++++++--------
 korman/render.py            |  1 +
 2 files changed, 20 insertions(+), 8 deletions(-)

diff --git a/korman/exporter/material.py b/korman/exporter/material.py
index b56ea8b..4b973e4 100644
--- a/korman/exporter/material.py
+++ b/korman/exporter/material.py
@@ -179,10 +179,9 @@ class MaterialConverter:
     def export_material(self, bo, bm):
         """Exports a Blender Material as an hsGMaterial"""
 
-        # Sometimes, a material might need to be single-use. Right now, the most apparent example
-        # of that situation is when a lightmap image is baked. There are others, but as of right now,
-        # it can all be determined by what mods are attached.
-        single_user = any((i.copy_material for i in bo.plasma_modifiers.modifiers))
+        # Sometimes, a material might need to be single-use due to settings like baked lighting,
+        # being a waveset, doublesided, etc.
+        single_user = self._requires_single_user(bo, bm)
         if single_user:
             mat_name = "{}_AutoSingle".format(bm.name) if bo.name == bm.name else "{}_{}".format(bo.name, bm.name)
             self._report.msg("Exporting Material '{}' as single user '{}'", bm.name, mat_name, indent=1)
@@ -251,7 +250,7 @@ class MaterialConverter:
         # material had no Textures, we will need to initialize a default layer
         if not hsgmat.layers:
             layer = self._mgr.find_create_object(plLayer, name="{}_AutoLayer".format(bm.name), bl=bo)
-            self._propagate_material_settings(bm, layer)
+            self._propagate_material_settings(bo, bm, layer)
             hsgmat.addLayer(layer.key)
 
         # Cache this material for later
@@ -342,7 +341,7 @@ class MaterialConverter:
 
         # Materials MUST have one layer. Wavesets need alpha blending...
         layer = self._mgr.add_object(plLayer, name=unique_name, bl=bo)
-        self._propagate_material_settings(bm, layer)
+        self._propagate_material_settings(bo, bm, layer)
         layer.state.blendFlags |= hsGMatState.kBlendAlpha
         hsgmat.addLayer(layer.key)
 
@@ -403,7 +402,7 @@ class MaterialConverter:
         self._report.msg("Exporting Plasma Layer '{}'", name, indent=2)
         layer = self._mgr.find_create_object(plLayer, name=name, bl=bo)
         if bm is not None and not slot.use_map_normal:
-            self._propagate_material_settings(bm, layer)
+            self._propagate_material_settings(bo, bm, layer)
 
         # UVW Channel
         if slot.texture_coords == "UV":
@@ -1186,10 +1185,17 @@ class MaterialConverter:
     def _mgr(self):
         return self._exporter().mgr
 
-    def _propagate_material_settings(self, bm, layer):
+    def _propagate_material_settings(self, bo, bm, layer):
         """Converts settings from the Blender Material to corresponding plLayer settings"""
         state = layer.state
 
+        is_waveset = bo.plasma_modifiers.water_basic.enabled
+        if bo.data.show_double_sided:
+            if is_waveset:
+                self._report.warn("FORCING single sided--this is a waveset (are you insane?)")
+            else:
+                state.miscFlags |= hsGMatState.kMiscTwoSided
+
         # Shade Flags
         if not bm.use_mist:
             state.shadeFlags |= hsGMatState.kShadeNoFog # Dead in CWE
@@ -1216,6 +1222,11 @@ class MaterialConverter:
                                         bm.diffuse_color.b * emit_scale,
                                         1.0)
 
+    def _requires_single_user(self, bo, bm):
+        if bo.data.show_double_sided:
+            return True
+        return any((i.copy_material for i in bo.plasma_modifiers.modifiers))
+
     @property
     def _report(self):
         return self._exporter().report
diff --git a/korman/render.py b/korman/render.py
index 8855b98..2ce7de6 100644
--- a/korman/render.py
+++ b/korman/render.py
@@ -37,6 +37,7 @@ properties_material.MATERIAL_PT_shadow.COMPAT_ENGINES.add("PLASMA_GAME")
 del properties_material
 
 from bl_ui import properties_data_mesh
+properties_data_mesh.DATA_PT_normals.COMPAT_ENGINES.add("PLASMA_GAME")
 properties_data_mesh.DATA_PT_uv_texture.COMPAT_ENGINES.add("PLASMA_GAME")
 properties_data_mesh.DATA_PT_vertex_colors.COMPAT_ENGINES.add("PLASMA_GAME")
 del properties_data_mesh