--[[
	font_api mod for Minetest - Library creating 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