Added options to disable trees, plants, and landcover in Lua side

Author: gaelysam

README.md

@@ -115,9 +115,13 @@ Geo Mapgen can calculate automatically the positions of rivers with the elevatio
 Be aware that rivers calculation can be *very* slow (around 15 minutes for a 6000x6000 map).
 
 ## Configuration file
-A config file `heightmap.dat.conf` is generated in the world directory. It has the same syntax than `minetest.conf`, and currently supports 6 parameters:
+A config file `heightmap.dat.conf` is generated in the world directory. It has the same syntax than `minetest.conf`, and currently supports the following parameters:
 - `scale_x`, `scale_y`, scale_z`: set the scale for each axis. Size of objects is **divided** by this value.
 - `offset_x`, `offset_y`, `offset_z`: Offset of the world rectangle in nodes.
+- `rivers`: Enable or disable land cover. Default to `true`.
+- `landcover`: Enable or disable land cover.
+- `plants`: Enable or disable decorations (grass, ferns, trees etc.)
+- `trees`: Enable or disable schematic decorations (trees)
 
 For example if you have generated a map with a resolution of 100 meters by pixel, and you set this in `heightmap.dat.conf`:
 ```

init.lua

@@ -15,6 +15,21 @@ local offset_x = tonumber(conf:get("offset_x")) or 0
 local offset_y = tonumber(conf:get("offset_y")) or 0
 local offset_z = tonumber(conf:get("offset_z")) or 0
 
+local function get_bool(name)
+	local v = conf:get_bool(name)
+	if v == nil then
+		return true -- Enable by default, disable only if explicitly set to false
+	end
+	return false
+end
+
+local enable_rivers = get_bool("rivers")
+local enable_landcover = get_bool("landcover")
+local enable_trees = get_bool("trees")
+local enable_plants = get_bool("plants")
+
+print(enable_rivers, enable_landcover, enable_trees, enable_plants)
+
 local remove_delay = 10 -- Number of mapgen calls until a chunk is unloaded
 
 local function parse(str, signed) -- little endian
@@ -133,11 +148,11 @@ for l=1, layer_count do
 	elseif datatype == 1 then
 		print("Rivermap enabled!")
 		rivermap = layer
-		rivers = true
+		rivers = enable_rivers
 	elseif datatype == 2 then
 		print("Biomemap enabled!")
 		biomemap = layer
-		biomes = true
+		biomes = enable_landcover
 
 		local biomes_by_name = dofile(modpath .. "/landcover.lua") -- Load biome descriptions
 		local biomenames = meta:split(',', true)
@@ -235,11 +250,13 @@ minetest.register_on_generated(function(minp, maxp, seed)
 					top = biome.top
 					nfiller = biome.filler_depth
 					ntop = biome.top_depth
-					if maxp.y >= h and not river_here then -- Generate decoration
+					if enable_plants and maxp.y >= h and not river_here then -- Generate decoration
 						local deco, is_schem = choose_deco(biome.decos)
 						if deco then
 							if is_schem then
-								table.insert(schems_to_generate, {pos={x=x-2,y=h+1,z=z-2}, schem=deco}) -- Schem size is not known. Assuming that most of schematics have a size of 5, hardcode offset to 2. TODO: Change that when schematic flags will be available on minetest.place_schematic_on_vmanip
+								if enable_trees then
+									table.insert(schems_to_generate, {pos={x=x-2,y=h+1,z=z-2}, schem=deco}) -- Schem size is not known. Assuming that most of schematics have a size of 5, hardcode offset to 2. TODO: Change that when schematic flags will be available on minetest.place_schematic_on_vmanip
+								end
 							else
 								node_deco = deco
 							end
@@ -287,7 +304,7 @@ minetest.register_on_generated(function(minp, maxp, seed)
 			if river_here then
 				data[ivm] = c_rwater
 				ivm = ivm + ystride
-			elseif node_deco and h >= 0 then
+			elseif node_deco and h >= offset_y then
 				data[ivm] = node_deco
 			end