fixed double-sided switch and only-selectable

doublesided switch in blender 2.9x did not work before, it was always
rendered single sided in MG.
I added a new switch only-selectable which allows to create unvisible
but selectable meshes. This helps with selection of small units which
can now have an unvisible  hand craftet select object around them for
example..

source/glest_game/graphics/renderer.cpp

@@ -7896,7 +7896,7 @@ vector<Unit *> Renderer::renderUnitsFast(bool renderingShadows, bool colorPickin
 					unitsList.push_back(unit);
 				}
 
-				modelRenderer->render(model,rmSelection);
+				modelRenderer->render(model,renderingShadows?rmShadows:rmSelection);
 
 				glPopMatrix();
 

source/shared_lib/include/graphics/model.h

@@ -74,6 +74,7 @@ private:
 	bool customColor;
 	bool noSelect;
 	bool glow;
+	bool onlySelect;
 
 	uint32 textureFlags;
 
@@ -136,6 +137,7 @@ public:
 	bool getCustomTexture() const	{return customColor;}
 	bool getNoSelect() const		{return noSelect;}
 	bool getGlow() const		{return glow;}
+	bool getOnlySelect() const		{return onlySelect;}
 	string getName() const		{return name;}
 
 	uint32 getTextureFlags() const { return textureFlags; }

source/shared_lib/include/graphics/model_header.h

@@ -44,7 +44,8 @@ enum MeshPropertyFlag{
 	mpfCustomColor= 1,
 	mpfTwoSided= 2,
 	mpfNoSelect= 4,
-	mpfGlow= 8
+	mpfGlow= 8,
+	mpfOnlySelect= 16
 };
 
 enum MeshTexture{

source/shared_lib/include/graphics/model_renderer.h

@@ -21,6 +21,7 @@ namespace Shared{ namespace Graphics{
 enum RenderMode{
 	rmNormal,
 	rmSelection,
+	rmShadows,
 
 	renderModeCount
 };

source/shared_lib/sources/graphics/gl/model_renderer_gl.cpp

@@ -163,6 +163,11 @@ void ModelRendererGl::renderMesh(Mesh *mesh,int renderMode) {
 	{// don't render this and do nothing
 		return;
 	}
+	if(renderMode!=rmSelection){
+		if(mesh->getOnlySelect()) {
+			return;
+		}
+	}
 	//assertions
 	assertGl();
 

source/shared_lib/sources/graphics/model.cpp

@@ -226,6 +226,7 @@ Mesh::Mesh() {
 	customColor= false;
 	noSelect= false;
 	glow= false;
+	onlySelect=false;
 
 	textureFlags=0;
 
@@ -448,6 +449,7 @@ void Mesh::loadV2(int meshIndex, const string &dir, FILE *f, TextureManager *tex
 	customColor= false;
 	noSelect= false;
 	glow= false;
+	onlySelect= false;
 
 	if(SystemFlags::VERBOSE_MODE_ENABLED) printf("Load v2, this = %p Found meshHeader.hasTexture = %d, texName [%s] mtDiffuse = %d meshIndex = %d modelFile [%s]\n",this,meshHeader.hasTexture,toLower(reinterpret_cast<char*>(meshHeader.texName)).c_str(),mtDiffuse,meshIndex,modelFile.c_str());
 
@@ -589,6 +591,7 @@ void Mesh::loadV3(int meshIndex, const string &dir, FILE *f,
 	customColor= (meshHeader.properties & mp3CustomColor) != 0;
 	noSelect = false;
 	glow = false;
+	onlySelect=false;
 
 	textureFlags= 0;
 	if((meshHeader.properties & mp3NoTexture) != mp3NoTexture) {
@@ -785,6 +788,7 @@ void Mesh::load(int meshIndex, const string &dir, FILE *f, TextureManager *textu
 	twoSided= (meshHeader.properties & mpfTwoSided) != 0;
 	noSelect= (meshHeader.properties & mpfNoSelect) != 0;
 	glow= (meshHeader.properties & mpfGlow) != 0;
+	onlySelect= (meshHeader.properties & mpfOnlySelect) != 0;
 
 	//material
 	diffuseColor= Vec3f(meshHeader.diffuseColor);
@@ -916,6 +920,9 @@ void Mesh::save(int meshIndex, const string &dir, FILE *f, TextureManager *textu
 	if(glow) {
 		meshHeader.properties |= mpfGlow;
 	}
+	if(onlySelect){
+		meshHeader.properties|= mpfOnlySelect;
+	}
 
 	meshHeader.textures = textureFlags;
 	fwrite(&meshHeader, sizeof(MeshHeader), 1, f);
@@ -1550,6 +1557,7 @@ void Mesh::copyInto(Mesh *dest, bool ignoreInterpolationData,
 	dest->customColor 	= this->customColor;
 	dest->noSelect 		= this->noSelect;
 	dest->glow 			= this->glow;
+	dest->onlySelect = this->onlySelect;
 
 	dest->textureFlags 	= this->textureFlags;
 

source/tools/glexemel/g3d_support_b290.py

@@ -255,6 +255,7 @@ class G3DMeshHeaderv4:  # Read Meshheader
         self.istwosided = bool(self.properties & 2)
         self.noselect = bool(self.properties & 4)
         self.glow = bool(self.properties & 8)
+        self.onlySelect = bool(self.properties & 16)
 
         self.hastexture = False
         self.diffusetexture = None
@@ -432,14 +433,15 @@ def createMesh(filename, header, data, toblender, operator):
     mesh.polygons.foreach_set(
         "use_smooth", (True,)*len(mesh.polygons.data.polygons))
     mesh.g3d_customColor = header.customalpha
-    # mesh.show_double_sided = header.istwosided
+    mesh.show_double_sided = header.istwosided
     if header.isv4:
         mesh.g3d_noSelect = header.noselect
         mesh.g3d_glow = header.glow
+        mesh.g3d_onlySelect = header.onlySelect
     else:
         mesh.g3d_noSelect = False
         mesh.glow = False
-    mesh.g3d_fullyOpaque = False
+    #mesh.g3d_onlySelect = False
 
     # ===================================================================================================
     # Material Setup
@@ -895,11 +897,15 @@ def G3DSaver(filepath, context, toglest, operator):
                 properties |= 2
         except Exception as e:
             print("No material, backface culling not set: ", e)
-        
+            
+        if mesh.show_double_sided:
+            properties |= 2
         if mesh.g3d_noSelect:
             properties |= 4
         if mesh.g3d_glow:
             properties |= 8
+        if mesh.g3d_onlySelect:
+            properties |= 16
 
         #MeshData
         vertices = []
@@ -932,7 +938,7 @@ def G3DSaver(filepath, context, toglest, operator):
 
         context.scene.frame_set(fcurrent)
 
-        if mesh.g3d_fullyOpaque:
+        if mesh.g3d_onlySelect:
             opacity = 1.0
 
         # MeshHeader
@@ -987,7 +993,7 @@ class G3DPanel(bpy.types.Panel):
                          "show_double_sided",
                          text="double sided")
         self.layout.prop(context.object.data, "g3d_noSelect")
-        self.layout.prop(context.object.data, "g3d_fullyOpaque")
+        self.layout.prop(context.object.data, "g3d_onlySelect")
         self.layout.prop(context.object.data, "g3d_glow")
 
 
@@ -1094,9 +1100,9 @@ def register():
         description="replace alpha channel of texture with team color")
     bpy.types.Mesh.g3d_noSelect = bpy.props.BoolProperty(
         name="non-selectable", description="click on mesh doesn't select unit")
-    bpy.types.Mesh.g3d_fullyOpaque = bpy.props.BoolProperty(
-        name="fully opaque",
-        description="sets opacity to 1.0, ignoring what's set in materials")
+    bpy.types.Mesh.g3d_onlySelect = bpy.props.BoolProperty(
+        name="only-selectable",
+        description="this mesh is not visible, only selectable")
     bpy.types.Mesh.g3d_glow = bpy.props.BoolProperty(
         name="glow", description="let objects glow like particles")
     bpy.types.Mesh.show_double_sided = bpy.props.BoolProperty(