working mapgen

init.lua

@@ -15,6 +15,7 @@ dofile(MP .. "/build.lua")
 dofile(MP .. "/remove.lua")
 dofile(MP .. "/chat.lua")
 dofile(MP .. "/tools.lua")
+dofile(MP .. "/mapgen.lua")
 
 if minetest.get_modpath("mtt") and mtt.enabled then
 	dofile(MP .. "/build.spec.lua")

mapgen.lua

@@ -0,0 +1,83 @@
+
+local function select_biome(biomes, temperature, humidity)
+    local selected_score = -1
+    local selected_biome
+
+    for _, biome in ipairs(biomes) do
+        local score = math.abs(temperature - biome.temperature) + math.abs(humidity - biome.humidity)
+        if not selected_biome or score > selected_score then
+            selected_biome = biome
+        end
+    end
+
+    return selected_biome
+end
+
+function building_lib.create_mapgen(opts)
+    assert(#opts.biomes > 0)
+
+    local map_lengths_xyz = {x=1, y=1, z=1}
+
+    opts.height_params = opts.height_params or {
+        offset = 0,
+        scale = 1,
+        spread = {x=64, y=64, z=64},
+        seed = 5477835,
+        octaves = 2,
+        persist = 0.5
+    }
+
+    opts.temperature_params = opts.temperature_params or {
+        offset = 0,
+        scale = 1,
+        spread = {x=64, y=64, z=64},
+        seed = 952995,
+        octaves = 2,
+        persist = 0.5
+    }
+
+    opts.humidity_params = opts.humidity_params or {
+        offset = 0,
+        scale = 1,
+        spread = {x=128, y=128, z=128},
+        seed = 2946271,
+        octaves = 2,
+        persist = 0.5
+    }
+
+    local height_perlin, temperature_perlin, humidity_perlin
+
+    return function(minp, maxp)
+        local min_mapblock = mapblock_lib.get_mapblock(minp)
+        local max_mapblock = mapblock_lib.get_mapblock(maxp)
+
+        height_perlin = height_perlin or minetest.get_perlin_map(opts.height_params, map_lengths_xyz)
+        temperature_perlin = temperature_perlin or minetest.get_perlin_map(opts.temperature_params, map_lengths_xyz)
+        humidity_perlin = humidity_perlin or minetest.get_perlin_map(opts.humidity_params, map_lengths_xyz)
+
+        for z=min_mapblock.z,max_mapblock.z do
+        for x=min_mapblock.x,max_mapblock.x do
+        for y=min_mapblock.y,max_mapblock.y do
+            local mapblock_pos = { x=x, y=y, z=z }
+            local height_perlin_map = {}
+            local temperature_perlin_map = {}
+            local humidity_perlin_map = {}
+
+            height_perlin:get_2d_map_flat({x=mapblock_pos.x, y=mapblock_pos.z}, height_perlin_map)
+            temperature_perlin:get_2d_map_flat({x=mapblock_pos.x, y=mapblock_pos.z}, temperature_perlin_map)
+            humidity_perlin:get_2d_map_flat({x=mapblock_pos.x, y=mapblock_pos.z}, humidity_perlin_map)
+
+            local height = math.floor(math.abs(height_perlin_map[1]) * 6) -1
+            local temperature = math.floor(math.abs(temperature_perlin_map[1]) * 100)
+            local humidity = math.floor(math.abs(humidity_perlin_map[1]) * 100)
+
+            local biome = select_biome(opts.biomes, temperature, humidity)
+
+            if mapblock_pos.y <= height then
+                building_lib.do_build_mapgen(mapblock_pos, biome.buildings.full, 0)
+            end
+        end --y
+        end --x
+        end --z
+    end
+end