Better management of display_api integration

font_api/depends.txt

@@ -0,0 +1 @@
+display_api?

font_api/display_api.lua

@@ -0,0 +1,77 @@
+--[[
+	font_api mod for Minetest - Library to create textures with fonts and text
+	(c) Pierre-Yves Rollo
+
+	This program is free software: you can redistribute it and/or modify
+	it under the terms of the GNU General Public License as published by
+	the Free Software Foundation, either version 3 of the License, or
+	(at your option) any later version.
+
+	This program is distributed in the hope that it will be useful,
+	but WITHOUT ANY WARRANTY; without even the implied warranty of
+	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+	GNU General Public License for more details.
+
+	You should have received a copy of the GNU General Public License
+	along with this program.  If not, see <http://www.gnu.org/licenses/>.
+--]]
+
+-- Integration with display API
+
+if minetest.get_modpath("display_api") then
+	--- Standard on_display_update entity callback.
+	-- Node should have properly configured display_entity.
+	-- @param pos Node position
+	-- @param objref Object reference of entity
+
+	font_api.on_display_update = function (pos, objref)
+		local meta = minetest.get_meta(pos)
+		local ndef = minetest.registered_nodes[minetest.get_node(pos).name]
+		local entity = objref:get_luaentity()
+
+		if not entity or not ndef.display_entities[entity.name] then
+			return
+		end
+
+		local def = ndef.display_entities[entity.name]
+		local font = font_api.get_font(meta:get_string("font") ~= ""
+			and meta:get_string("font") or def.font_name)
+
+		local text = meta:get_string(def.meta_text or "display_text")
+
+		-- Compute entity resolution accroding to given attributes
+		local texturew, textureh
+		textureh = font:get_height(def.lines or def.maxlines or 1)
+
+		if def.columns then
+			if font.fixedwidth then
+				texturew = def.columns * font.fixedwidth
+				if def.aspect_ratio then
+					minetest.log('warning', "[font_api] 'aspect_ratio' ignored because 'columns' is specified")
+				end
+			else
+				minetest.log('warning', "[font_api] 'columns' ignored because '"..font.name.."' is not a fixed width font.")
+			end
+		end
+
+		if not texturew then
+			if not def.aspect_ratio then
+				minetest.log('warning', "[font_api] No 'aspect_ratio' specified, using default 1.")
+			end
+			texturew = textureh * def.size.x / def.size.y	/ (def.aspect_ratio or 1)
+		end
+
+		objref:set_properties({
+			textures={ font:render(text, texturew, textureh, {
+				lines = def.maxlines or def.lines,
+				halign = def.halign,
+				valign = def.valign,
+				color = def.color} ) },
+			visual_size = def.size,
+		})
+	end
+else
+	font_api.on_display_update = function (pos, objref)
+		minetest.log('error', '[font_api] font_api.on_display_update called but display_api mod not enabled.')
+	end
+end

font_api/init.lua

@@ -30,58 +30,8 @@ font_api.path = minetest.get_modpath(font_api.name)
 dofile(font_api.path.."/font.lua")
 dofile(font_api.path.."/registry.lua")
 dofile(font_api.path.."/fontform.lua")
-
+if minetest.get_modpath("display_api") then
---- Standard on_display_update entity callback.
+	dofile(font_api.path.."/display_api.lua")
--- Node should have a corresponding display_entity with size, resolution and
--- maxlines fields and optionally halign, valign and color fields
--- @param pos Node position
--- @param objref Object reference of entity
-
-function font_api.on_display_update(pos, objref)
-	local meta = minetest.get_meta(pos)
-	local ndef = minetest.registered_nodes[minetest.get_node(pos).name]
-	local entity = objref:get_luaentity()
-
-	if not entity or not ndef.display_entities[entity.name] then
-		return
-	end
-
-	local def = ndef.display_entities[entity.name]
-	local font = font_api.get_font(meta:get_string("font") ~= ""
-		and meta:get_string("font") or def.font_name)
-
-	local text = meta:get_string(def.meta_text or "display_text")
-
-	-- Compute entity resolution accroding to given attributes
-	local texturew, textureh
-	textureh = font:get_height(def.lines or def.maxlines or 1)
-
-	if def.columns then
-		if font.fixedwidth then
-			texturew = def.columns * font.fixedwidth
-			if def.aspect_ratio then
-				minetest.log('warning', "[font_api] 'aspect_ratio' ignored because 'columns' is specified")
-			end
-		else
-			minetest.log('warning', "[font_api] 'columns' ignored because '"..font.name.."' is not a fixed width font.")
-		end
-	end
-
-	if not texturew then
-		if not def.aspect_ratio then
-			minetest.log('warning', "[font_api] No 'aspect_ratio' specified, using default 1.")
-		end
-		texturew = textureh * def.size.x / def.size.y	/ (def.aspect_ratio or 1)
-	end
-
-	objref:set_properties({
-		textures={ font:render(text, texturew, textureh, {
-			lines = def.maxlines or def.lines,
-			halign = def.halign,
-			valign = def.valign,
-			color = def.color} ) },
-		visual_size = def.size,
-	})
 end
 
 -- Compatibility