Optional alpha channel support for entities

builtin/game/features.lua

@@ -11,6 +11,7 @@ core.features = {
 	area_store_custom_ids = true,
 	add_entity_with_staticdata = true,
 	no_chat_message_prediction = true,
+	object_use_texture_alpha = true,
 }
 
 function core.has_feature(arg)

doc/lua_api.txt

@@ -2660,7 +2660,7 @@ Strings that need to be translated can contain several escapes, preceded by `@`.
            chat_send_player_param3 = true,
            get_all_craft_recipes_works = true,
            use_texture_alpha = true,
-        -- ^ The transparency channel of textures can be used optionally
+        -- ^ The transparency channel of textures can optionally be used on nodes
            no_legacy_abms = true,
         -- ^ Tree and grass ABMs are no longer done from C++
            texture_names_parens = true,
@@ -2671,6 +2671,9 @@ Strings that need to be translated can contain several escapes, preceded by `@`.
         -- ^ add_entity supports passing initial staticdata to on_activate
            no_chat_message_prediction = true,
         -- ^ Chat messages are no longer predicted
+           object_use_texture_alpha = true
+        -- ^ The transparency channel of textures can optionally be used on
+        --   objects (ie: players and lua entities)
         }
 * `minetest.has_feature(arg)`: returns `boolean, missing_features`
     * `arg`: string or table in format `{foo=true, bar=true}`
@@ -4957,6 +4960,10 @@ Definition tables
     --  ^ "wielditem" expects 'textures = {itemname}' (see 'visual' above).
         colors = {},
     --  ^ Number of required colors depends on visual.
+        use_texture_alpha = false,
+    --  ^ Use texture's alpha channel, excludes "upright_sprite" and "wielditem"
+	--  ^ Note: currently causes visual issues when viewed through other
+	--  ^ semi-transparent materials such as water.
         spritediv = {x = 1, y = 1},
     --  ^ Used with spritesheet textures for animation and/or frame selection
     --    according to position relative to player.

src/content_cao.cpp

@@ -477,6 +477,9 @@ void GenericCAO::addToScene(ITextureSource *tsrc)
 		return;
 	}
 
+	video::E_MATERIAL_TYPE material_type = (m_prop.use_texture_alpha) ?
+		video::EMT_TRANSPARENT_ALPHA_CHANNEL : video::EMT_TRANSPARENT_ALPHA_CHANNEL_REF;
+
 	if (m_prop.visual == "sprite") {
 		infostream<<"GenericCAO::addToScene(): single_sprite"<<std::endl;
 		m_spritenode = RenderingEngine::get_scene_manager()->addBillboardSceneNode(
@@ -486,7 +489,7 @@ void GenericCAO::addToScene(ITextureSource *tsrc)
 				tsrc->getTextureForMesh("unknown_node.png"));
 		m_spritenode->setMaterialFlag(video::EMF_LIGHTING, false);
 		m_spritenode->setMaterialFlag(video::EMF_BILINEAR_FILTER, false);
-		m_spritenode->setMaterialType(video::EMT_TRANSPARENT_ALPHA_CHANNEL_REF);
+		m_spritenode->setMaterialType(material_type);
 		m_spritenode->setMaterialFlag(video::EMF_FOG_ENABLE, true);
 		u8 li = m_last_light;
 		m_spritenode->setColor(video::SColor(255,li,li,li));
@@ -564,7 +567,7 @@ void GenericCAO::addToScene(ITextureSource *tsrc)
 
 		m_meshnode->setMaterialFlag(video::EMF_LIGHTING, false);
 		m_meshnode->setMaterialFlag(video::EMF_BILINEAR_FILTER, false);
-		m_meshnode->setMaterialType(video::EMT_TRANSPARENT_ALPHA_CHANNEL_REF);
+		m_meshnode->setMaterialType(material_type);
 		m_meshnode->setMaterialFlag(video::EMF_FOG_ENABLE, true);
 	}
 	else if(m_prop.visual == "mesh") {
@@ -587,15 +590,12 @@ void GenericCAO::addToScene(ITextureSource *tsrc)
 
 			setAnimatedMeshColor(m_animated_meshnode, video::SColor(255,li,li,li));
 
-			bool backface_culling = m_prop.backface_culling;
-			if (m_is_player)
-				backface_culling = false;
-
 			m_animated_meshnode->setMaterialFlag(video::EMF_LIGHTING, true);
 			m_animated_meshnode->setMaterialFlag(video::EMF_BILINEAR_FILTER, false);
-			m_animated_meshnode->setMaterialType(video::EMT_TRANSPARENT_ALPHA_CHANNEL_REF);
+			m_animated_meshnode->setMaterialType(material_type);
 			m_animated_meshnode->setMaterialFlag(video::EMF_FOG_ENABLE, true);
-			m_animated_meshnode->setMaterialFlag(video::EMF_BACK_FACE_CULLING, backface_culling);
+			m_animated_meshnode->setMaterialFlag(video::EMF_BACK_FACE_CULLING,
+				m_prop.backface_culling);
 		}
 		else
 			errorstream<<"GenericCAO::addToScene(): Could not load mesh "<<m_prop.mesh<<std::endl;
@@ -994,12 +994,16 @@ void GenericCAO::updateTextures(std::string mod)
 	m_current_texture_modifier = mod;
 	m_glow = m_prop.glow;
 
+	video::E_MATERIAL_TYPE material_type = (m_prop.use_texture_alpha) ?
+		video::EMT_TRANSPARENT_ALPHA_CHANNEL : video::EMT_TRANSPARENT_ALPHA_CHANNEL_REF;
+
 	if (m_spritenode) {
 		if (m_prop.visual == "sprite") {
 			std::string texturestring = "unknown_node.png";
 			if (!m_prop.textures.empty())
 				texturestring = m_prop.textures[0];
 			texturestring += mod;
+			m_spritenode->getMaterial(0).MaterialType = material_type;
 			m_spritenode->setMaterialTexture(0,
 					tsrc->getTextureForMesh(texturestring));
 
@@ -1034,9 +1038,11 @@ void GenericCAO::updateTextures(std::string mod)
 
 				// Set material flags and texture
 				video::SMaterial& material = m_animated_meshnode->getMaterial(i);
+				material.MaterialType = material_type;
 				material.TextureLayer[0].Texture = texture;
 				material.setFlag(video::EMF_LIGHTING, true);
 				material.setFlag(video::EMF_BILINEAR_FILTER, false);
+				material.setFlag(video::EMF_BACK_FACE_CULLING, m_prop.backface_culling);
 
 				// don't filter low-res textures, makes them look blurry
 				// player models have a res of 64
@@ -1078,6 +1084,7 @@ void GenericCAO::updateTextures(std::string mod)
 
 				// Set material flags and texture
 				video::SMaterial& material = m_meshnode->getMaterial(i);
+				material.MaterialType = material_type;
 				material.setFlag(video::EMF_LIGHTING, false);
 				material.setFlag(video::EMF_BILINEAR_FILTER, false);
 				material.setTexture(0,

src/content_sao.cpp

@@ -803,6 +803,7 @@ PlayerSAO::PlayerSAO(ServerEnvironment *env_, RemotePlayer *player_, session_t p
 	m_prop.eye_height = 1.625f;
 	// End of default appearance
 	m_prop.is_visible = true;
+	m_prop.backface_culling = false;
 	m_prop.makes_footstep_sound = true;
 	m_prop.stepheight = PLAYER_DEFAULT_STEPHEIGHT * BS;
 	m_hp = m_prop.hp_max;

src/object_properties.cpp

@@ -68,6 +68,7 @@ std::string ObjectProperties::dump()
 	os << ", static_save=" << static_save;
 	os << ", eye_height=" << eye_height;
 	os << ", zoom_fov=" << zoom_fov;
+	os << ", use_texture_alpha=" << use_texture_alpha;
 	return os.str();
 }
 
@@ -113,6 +114,7 @@ void ObjectProperties::serialize(std::ostream &os) const
 	writeU16(os, breath_max);
 	writeF1000(os, eye_height);
 	writeF1000(os, zoom_fov);
+	writeU8(os, use_texture_alpha);
 
 	// Add stuff only at the bottom.
 	// Never remove anything, because we don't want new versions of this
@@ -164,4 +166,5 @@ void ObjectProperties::deSerialize(std::istream &is)
 	breath_max = readU16(is);
 	eye_height = readF1000(is);
 	zoom_fov = readF1000(is);
+	use_texture_alpha = readU8(is);
 }

src/object_properties.h

@@ -60,6 +60,7 @@ struct ObjectProperties
 	bool static_save = true;
 	float eye_height = 1.625f;
 	float zoom_fov = 0.0f;
+	bool use_texture_alpha = false;
 
 	ObjectProperties();
 	std::string dump();

src/script/common/c_content.cpp

@@ -304,6 +304,7 @@ void read_object_properties(lua_State *L, int index,
 	lua_pop(L, 1);
 
 	getfloatfield(L, -1, "zoom_fov", prop->zoom_fov);
+	getboolfield(L, -1, "use_texture_alpha", prop->use_texture_alpha);
 }
 
 /******************************************************************************/
@@ -386,6 +387,8 @@ void push_object_properties(lua_State *L, ObjectProperties *prop)
 	lua_setfield(L, -2, "wield_item");
 	lua_pushnumber(L, prop->zoom_fov);
 	lua_setfield(L, -2, "zoom_fov");
+	lua_pushboolean(L, prop->use_texture_alpha);
+	lua_setfield(L, -2, "use_texture_alpha");
 }
 
 /******************************************************************************/