Draw non-overlapping trees on map

init.lua

@@ -84,6 +84,8 @@ maps.create_map = function(pos, player_name)
 			{ 150, 105,  55 }, -- more liquid
 			{ 165, 120,  70 }, -- more liquid
 			{ 150, 105,  55 }, -- more liquid
+			{  60,  35,  16 }, -- tree outline
+			{ 150, 105,  55 }, -- tree fill
 		}
 		for x = 1,size,1 do
 			for z = 1,size,1 do
@@ -132,6 +134,80 @@ maps.create_map = function(pos, player_name)
 			end
 		end
 
+		local positions = minetest.find_nodes_in_area_under_air(
+			minp,
+			maxp,
+			{
+				"group:leaves",
+				"default:snow", -- snow-covered leaves
+			}
+		)
+		for _, p in ipairs(positions) do
+			local z = p.z - minp.z + 1
+			local x = p.x - minp.x + 1
+			local node = minetest.get_node({
+				x=p.x,
+				y=p.y - 4,
+				z=p.z,
+			})
+			local draw_tree = (
+				minetest.get_item_group(
+				   node.name,
+				   "tree"
+			) > 0 ) and (
+				z < size - 6 and
+				x > 3 and
+				x < size - 3
+			)
+			if draw_tree then
+				local tree = {}
+				if nil ~= node.name:find("pine") then
+					tree = {
+						"  #  ",
+						"#####",
+						"#...#",
+						" #.# ",
+						" #.# ",
+						"  #  ",
+					}
+				else
+					tree = {
+						"  #  ",
+						"  #  ",
+						" ### ",
+						"#...#",
+						"#...#",
+						"#...#",
+						" ### ",
+					}
+				end
+				local overlap = false
+				for t_z = 1,#tree do
+					for t_x = 1,#tree[t_z] do
+						local color = pixels[z + t_z][x + t_x - 3][1]
+						-- do not draw trees close together
+						if 7 == color then
+							overlap = true
+							break
+						end
+					end
+				end
+				if overlap then
+					tree = {}
+				end
+				for t_z = 1,#tree do
+					for t_x = 1,#tree[t_z] do
+						local byte = tree[t_z]:byte(t_x)
+						if 35 == byte then -- #
+							pixels[z + t_z][x + t_x - 3] = { 7 }
+						elseif 46 == byte then -- .
+							pixels[z + t_z][x + t_x - 3] = { 8 }
+						end
+					end
+				end
+			end
+		end
+
 		local filepath = textures_dir .. filename
 		tga_encoder.image(pixels):save(
 			filepath,