preview generation

autoplace_tool.lua

@@ -95,13 +95,13 @@ minetest.register_tool("building_lib:autoplace", {
 
         local success, building_name, rotation = building_lib.can_autoplace(mapblock_pos1, playername, autoplacer_name)
         if not success then
-            building_lib.clear_preview(playername)
+            building_lib.clear_display(playername)
             return
         end
 
         local building_def = building_lib.get_building(building_name)
         if not building_def then
-            building_lib.clear_preview(playername)
+            building_lib.clear_display(playername)
             return
         end
 
@@ -114,7 +114,7 @@ minetest.register_tool("building_lib:autoplace", {
             color = "#ffff00"
         end
 
-        building_lib.show_preview(
+        building_lib.show_display(
             playername,
             "building_lib_autoplace.png",
             color,
@@ -126,6 +126,6 @@ minetest.register_tool("building_lib:autoplace", {
     end,
     on_deselect = function(_, player)
         local playername = player:get_player_name()
-        building_lib.clear_preview(playername)
+        building_lib.clear_display(playername)
     end
 })

build_tool.lua

@@ -114,7 +114,7 @@ minetest.register_tool("building_lib:place", {
 
         local building_def, mb_pos1, mb_pos2, rotation = building_lib.get_next_buildable_position(player, buildingname)
         if building_def then
-            building_lib.show_preview(
+            building_lib.show_display(
                 playername,
                 "building_lib_place.png",
                 "#00ff00",
@@ -124,11 +124,11 @@ minetest.register_tool("building_lib:place", {
                 rotation
             )
         else
-            building_lib.clear_preview(playername)
+            building_lib.clear_display(playername)
         end
     end,
     on_deselect = function(_, player)
         local playername = player:get_player_name()
-        building_lib.clear_preview(playername)
+        building_lib.clear_display(playername)
     end
 })

display.lua

@@ -0,0 +1,89 @@
+
+-- playername => key
+local active_display = {}
+
+function building_lib.show_display(playername, texture, color, building_def, mapblock_pos1, mapblock_pos2, rotation)
+	texture = texture .. "^[colorize:" .. color
+
+	mapblock_pos2 = mapblock_pos2 or mapblock_pos1
+	local key =
+		minetest.pos_to_string(mapblock_pos1) .. "/" ..
+		minetest.pos_to_string(mapblock_pos2) .. "/" ..
+		texture .. "/" ..
+		rotation
+
+	if active_display[playername] == key then
+		-- already active on the same region
+		return
+	end
+	-- clear previous entities
+	building_lib.clear_display(playername)
+	active_display[playername] = key
+
+	local min, _ = mapblock_lib.get_mapblock_bounds_from_mapblock(mapblock_pos1)
+
+	local size_mapblocks = vector.subtract(vector.add(mapblock_pos2, 1), mapblock_pos1) -- 1 .. n
+	local size = vector.multiply(size_mapblocks, 16) -- 16 .. n
+	local half_size = vector.divide(size, 2) -- 8 .. n
+
+	local origin = vector.add(min, half_size)
+	origin = vector.subtract(origin, 0.5)
+
+	local ent = building_lib.add_cube_entity(origin, key)
+	ent:set_properties({
+		visual_size = size,
+		textures = {
+			texture,
+			texture,
+			texture,
+			texture,
+			texture,
+			texture
+		}
+	})
+
+	if building_def and building_def.markers then
+		-- add markers
+		local texture_modifier = "^[colorize:" .. color
+		local unrotated_size = building_lib.get_building_size(building_def, 360 - rotation)
+
+		for _, marker_opts in ipairs(building_def.markers) do
+			local marker = building_lib.create_marker(marker_opts)
+			local center_rel_pos = vector.add(marker.position, 0.5)
+			local rotated_position = mapblock_lib.rotate_pos(center_rel_pos, unrotated_size, rotation)
+			local node_pos = vector.multiply(vector.add(mapblock_pos1, rotated_position), 16)
+			node_pos = vector.subtract(node_pos, 0.5)
+			local z_rotation = marker.rotation.z
+
+			if rotation == 90 then
+				z_rotation = z_rotation - math.pi/2
+			elseif rotation == 180 then
+				z_rotation = z_rotation + math.pi
+			elseif rotation == 270 then
+				z_rotation = z_rotation + math.pi/2
+			end
+
+			ent = building_lib.add_entity(node_pos, key)
+			ent:set_properties({
+				visual_size = marker.size,
+				textures = {marker.texture .. texture_modifier}
+			})
+			ent:set_rotation({
+				x=marker.rotation.x,
+				y=marker.rotation.y,
+				z=z_rotation
+			})
+		end
+	end
+end
+
+function building_lib.clear_display(playername)
+	if active_display[playername] then
+		building_lib.remove_entities(active_display[playername])
+		active_display[playername] = nil
+	end
+end
+
+minetest.register_on_leaveplayer(function(player)
+	building_lib.clear_display(player:get_player_name())
+end)

init.lua

@@ -20,12 +20,13 @@ building_lib = {
 local MP = minetest.get_modpath("building_lib")
 dofile(MP .. "/memoize.lua")
 dofile(MP .. "/entity.lua")
-dofile(MP .. "/preview.lua")
+dofile(MP .. "/display.lua")
 dofile(MP .. "/api.lua")
 dofile(MP .. "/common.lua")
 dofile(MP .. "/markers.lua")
 dofile(MP .. "/placements/mapblock_lib.lua")
 dofile(MP .. "/placements/dummy.lua")
+dofile(MP .. "/preview.lua")
 dofile(MP .. "/conditions.lua")
 dofile(MP .. "/build.lua")
 dofile(MP .. "/build_tool.lua")
@@ -39,11 +40,6 @@ dofile(MP .. "/events.lua")
 dofile(MP .. "/hacks.lua")
 dofile(MP .. "/mapgen.lua")
 
-local ie = minetest.request_insecure_environment()
-if ie and minetest.get_modpath("isogen") then
-	loadfile(MP .. "/previewgen.lua")(ie)
-end
-
 if minetest.get_modpath("mtt") and mtt.enabled then
 	dofile(MP .. "/events.spec.lua")
 	dofile(MP .. "/conditions.spec.lua")

preview.lua

@@ -1,89 +1,123 @@
+local cube_len = 8
 
--- playername => key
+-- name -> { png, width, height, timestamp }
-local active_preview = {}
+local previews = {}
 
-function building_lib.show_preview(playername, texture, color, building_def, mapblock_pos1, mapblock_pos2, rotation)
+function building_lib.generate_building_preview(building_def)
-	texture = texture .. "^[colorize:" .. color
+    local catalog
+    local offset = {x=0, y=0, z=0}
+    local size
 
-	mapblock_pos2 = mapblock_pos2 or mapblock_pos1
+    if type(building_def.catalog) == "table" then
-	local key =
+        catalog = mapblock_lib.get_catalog(building_def.catalog.filename)
-		minetest.pos_to_string(mapblock_pos1) .. "/" ..
+        offset = building_def.catalog.offset or {x=0, y=0, z=0}
-		minetest.pos_to_string(mapblock_pos2) .. "/" ..
+        size = building_def.catalog.size or {x=1, y=1, z=1}
-		texture .. "/" ..
+    else
-		rotation
+        catalog = mapblock_lib.get_catalog(building_def.catalog)
+        size = catalog:get_size()
+    end
 
-	if active_preview[playername] == key then
+    local mb_pos2 = vector.add(offset, vector.subtract(size, 1))
-		-- already active on the same region
-		return
-	end
-	-- clear previous entities
-	building_lib.clear_preview(playername)
-	active_preview[playername] = key
 
-	local min, _ = mapblock_lib.get_mapblock_bounds_from_mapblock(mapblock_pos1)
+    local min = mapblock_lib.get_mapblock_bounds_from_mapblock(offset)
+    local _, max = mapblock_lib.get_mapblock_bounds_from_mapblock(mb_pos2)
 
-	local size_mapblocks = vector.subtract(vector.add(mapblock_pos2, 1), mapblock_pos1) -- 1 .. n
+    local png = isogen.draw(min, max, {
-	local size = vector.multiply(size_mapblocks, 16) -- 16 .. n
+        cube_len = cube_len,
-	local half_size = vector.divide(size, 2) -- 8 .. n
+        get_node = function(pos)
+            return catalog:get_node(pos)
+        end
+    })
 
-	local origin = vector.add(min, half_size)
+    local node_size = vector.add(vector.subtract(max, min), 1)
-	origin = vector.subtract(origin, 0.5)
+    local width, height = isogen.calculate_image_size(node_size, cube_len)
 
-	local ent = building_lib.add_cube_entity(origin, key)
+    return {
-	ent:set_properties({
+        png = minetest.encode_base64(png),
-		visual_size = size,
+        width = width,
-		textures = {
+        height = height,
-			texture,
+        timestamp = os.time()
-			texture,
+    }
-			texture,
-			texture,
-			texture,
-			texture
-		}
-	})
-
-	if building_def and building_def.markers then
-		-- add markers
-		local texture_modifier = "^[colorize:" .. color
-		local unrotated_size = building_lib.get_building_size(building_def, 360 - rotation)
-
-		for _, marker_opts in ipairs(building_def.markers) do
-			local marker = building_lib.create_marker(marker_opts)
-			local center_rel_pos = vector.add(marker.position, 0.5)
-			local rotated_position = mapblock_lib.rotate_pos(center_rel_pos, unrotated_size, rotation)
-			local node_pos = vector.multiply(vector.add(mapblock_pos1, rotated_position), 16)
-			node_pos = vector.subtract(node_pos, 0.5)
-			local z_rotation = marker.rotation.z
-
-			if rotation == 90 then
-				z_rotation = z_rotation - math.pi/2
-			elseif rotation == 180 then
-				z_rotation = z_rotation + math.pi
-			elseif rotation == 270 then
-				z_rotation = z_rotation + math.pi/2
-			end
-
-			ent = building_lib.add_entity(node_pos, key)
-			ent:set_properties({
-				visual_size = marker.size,
-				textures = {marker.texture .. texture_modifier}
-			})
-			ent:set_rotation({
-				x=marker.rotation.x,
-				y=marker.rotation.y,
-				z=z_rotation
-			})
-		end
-	end
 end
 
-function building_lib.clear_preview(playername)
+-- preview file in the world folder
-	if active_preview[playername] then
+local preview_filename = minetest.get_worldpath() .. "/building_preview.json"
-		building_lib.remove_entities(active_preview[playername])
+
-		active_preview[playername] = nil
+minetest.register_chatcommand("building_previewgen", {
-	end
+    params = "[modname]",
+    privs = {
+        mapblock_lib = true
+    },
+    func = function(name, modname)
+        local world_previews = {}
+
+        local f = io.open(preview_filename, "rb")
+        if f then
+            -- read previous previews
+            local json = f:read("*all")
+            f:close()
+            world_previews = minetest.parse_json(json)
+        end
+
+        local buildings = building_lib.get_buildings()
+        local list = {}
+        for _, building in pairs(buildings) do
+            if building.modname == modname and building.placement == "mapblock_lib" then
+                table.insert(list, building)
+            end
+        end
+
+        if #list == 0 then
+            return false, "no buildings found with given modname"
+        end
+
+        local count = 0
+        local worker
+        worker = function()
+            local building = table.remove(list)
+            if not building then
+                minetest.chat_send_player(name, "Done generating " .. count .. " previews")
+                minetest.safe_file_write(preview_filename, minetest.write_json(world_previews))
+                return
+            end
+
+            minetest.chat_send_player(name, "Generating preview for '" .. building.name .. "'")
+            count = count + 1
+            local data, err = building_lib.generate_building_preview(building)
+            if not data then
+                minetest.chat_send_player(
+                    name,
+                    "Preview generation failed for building: '" .. building.name .. "', error: " .. err
+                )
+            else
+                world_previews[building.name] = data
+                minetest.after(0, worker)
+            end
+        end
+
+        minetest.after(0, worker)
+        return true, "Scheduled " .. #list .. " buildings for preview-generation"
+    end
+})
+
+-- returns a cached or ad-hoc generated preview table
+function building_lib.get_building_preview(building_name)
+    if previews[building_name] then
+        return previews[building_name]
+    end
+
+    local building_def = building_lib.get_building(building_name)
+    if not building_def then
+        return false, "building not found: '" .. building_name .. "'"
+    end
+
+    local preview, err = building_lib.generate_building_preview(building_def)
+    if err then
+        return false, "generate preview error: " .. err
+    end
+
+    previews[building_name] = preview
+    return preview
 end
 
-minetest.register_on_leaveplayer(function(player)
+-- TODO: generate all previews on startup
-	building_lib.clear_preview(player:get_player_name())
-end)

previewgen.lua

@@ -1,82 +0,0 @@
-local ie = ...
-
-local function generate_preview(building_def)
-    local catalog
-    local offset = {x=0, y=0, z=0}
-    local size
-
-    if type(building_def.catalog) == "table" then
-        catalog = mapblock_lib.get_catalog(building_def.catalog.filename)
-        offset = building_def.catalog.offset or {x=0, y=0, z=0}
-        size = building_def.catalog.size or {x=1, y=1, z=1}
-    else
-        catalog = mapblock_lib.get_catalog(building_def.catalog)
-        size = catalog:get_size()
-    end
-
-    local mb_pos2 = vector.add(offset, vector.subtract(size, 1))
-
-    local min = mapblock_lib.get_mapblock_bounds_from_mapblock(offset)
-    local _, max = mapblock_lib.get_mapblock_bounds_from_mapblock(mb_pos2)
-
-    local png = isogen.draw(min, max, {
-        cube_len = 8,
-        get_node = function(pos)
-            return catalog:get_node(pos)
-        end
-    })
-
-    local filename = building_lib.get_preview_filename(building_def)
-    local f = ie.io.open(filename, "wb")
-    if not f then
-        return false, "could not open file: '" .. filename .. "'"
-    end
-
-    f:write(png)
-    f:close()
-
-    return true
-end
-
-minetest.register_chatcommand("building_previewgen", {
-    params = "[modname]",
-    privs = {
-        mapblock_lib = true
-    },
-    func = function(name, modname)
-        local buildings = building_lib.get_buildings()
-        local list = {}
-        for _, building in pairs(buildings) do
-            if building.modname == modname and building.placement == "mapblock_lib" then
-                table.insert(list, building)
-            end
-        end
-
-        if #list == 0 then
-            return false, "no buildings found with given modname"
-        end
-
-        local worker
-        worker = function()
-            local building = table.remove(list)
-            if not building then
-                minetest.chat_send_player(name, "Done generating previews")
-                return
-            end
-
-            minetest.chat_send_player(name, "Generating preview for '" .. building.name .. "'")
-            local success, err = generate_preview(building)
-            if not success then
-                minetest.chat_send_player(
-                    name,
-                    "Preview generation failed for building: '" .. building.name .. "', error: " .. err
-                )
-            else
-                minetest.after(0, worker)
-            end
-        end
-
-        minetest.after(0, worker)
-        return true, "Scheduled " .. #list .. " buildings for preview-generation"
-    end
-})

remove_tool.lua

@@ -5,18 +5,24 @@ minetest.register_tool("building_lib:remove", {
     stack_max = 1,
     range = 0,
     on_use = function(_, player)
+        local playername = player:get_player_name()
+
         local _, mb_pos1 = building_lib.get_next_removable_position(player)
+        if not mb_pos1 then
+            minetest.chat_send_player(playername, "nothing to remove found")
+            return
+        end
 
         local success, err = building_lib.remove(mb_pos1)
         if not success then
-            minetest.chat_send_player(player:get_player_name(), err)
+            minetest.chat_send_player(playername, err)
         end
     end,
     on_step = function(_, player)
         local playername = player:get_player_name()
         local building_def, mb_pos1, mb_pos2, rotation = building_lib.get_next_removable_position(player)
         if building_def then
-            building_lib.show_preview(
+            building_lib.show_display(
                 playername,
                 "building_lib_remove.png",
                 "#ff0000",
@@ -26,12 +32,12 @@ minetest.register_tool("building_lib:remove", {
                 rotation
             )
         else
-            building_lib.clear_preview(playername)
+            building_lib.clear_display(playername)
         end
     end,
     on_deselect = function(_, player)
         local playername = player:get_player_name()
-        building_lib.clear_preview(playername)
+        building_lib.clear_display(playername)
     end
 })