add seagrass

mods/fl_mapgen/decorations.lua

@@ -82,4 +82,22 @@ minetest.register_decoration({
             {ypos = 3, prob = 160}
         }
     }
-})
+})
+
+for i = 1, 3 do
+    minetest.register_decoration({
+        name = "fl_topsoil:sea_grass_" .. i,
+        deco_type = "simple",
+        place_on = {"fl_stone:sand"},
+        sidelen = 16,
+        fill_ratio = 0.06,
+        --biomes = {"grassland", "deciduousforest"},
+        place_offset_y = -1,
+        y_max = 0,
+        y_min = -16,
+        param2 = 0,
+        param2_max = 4,
+        flags = "force_placement",
+        decoration = "fl_topsoil:sea_grass_" .. i
+    })
+end

mods/fl_topsoil/topsoil.lua

@@ -189,6 +189,31 @@ minetest.register_node("fl_topsoil:permafrost_with_stones", {
     },
     groups = {dig_stone = 2},
 })
+for i=1, 3 do
+    minetest.register_node("fl_topsoil:sea_grass_" .. i, {
+        description = "sea grass",
+        drawtype = "plantlike_rooted",
+        paramtype = "light",
+        paramtype2 = "meshoptions",
+        tiles = {"farlands_sand.png"},
+        special_tiles = {"[combine:16x16:0," .. 10 - 3*i .. "=farlands_sea_grass.png"},
+        inventory_image = "[combine:16x16:0," .. 10 - 3*i .. "=farlands_sea_grass.png",
+        wield_image = "[combine:16x16:0," .. 10 - 3*i .. "=farlands_sea_grass.png",
+        node_dig_prediction = "fl_stone:sand",
+        node_placement_prediction = "",
+        on_place = function(itemstack, placer, pointed_thing)
+            if pointed_thing.type ~= "node" then return end
+            if minetest.get_node_or_nil(pointed_thing.under)
+            and minetest.get_node_or_nil(pointed_thing.under).name == "fl_stone:sand" then
+                minetest.set_node(pointed_thing.under, {name = "fl_topsoil:sea_grass_" .. i})
+            end
+        end,
+        after_destruct  = function(pos, oldnode)
+            minetest.set_node(pos, {name = "fl_stone:sand"})
+        end,
+        groups = {not_in_creative_inventory = 1, dig_sand = 3},
+    })
+end
 
 minetest.register_alias("fl_terrain:dirt", "fl_topsoil:dirt")
 minetest.register_alias("fl_terrain:dirt_with_grass", "fl_topsoil:dirt_with_grass")