Added glaciers, and re-organized noise definitions

init.lua

@@ -7,6 +7,9 @@ dofile(modpath .. 'settings.lua')
 local blocksize = mapgen_rivers.blocksize
 local sea_level = mapgen_rivers.sea_level
 local riverbed_slope = mapgen_rivers.riverbed_slope
+local elevation_chill = mapgen_rivers.elevation_chill
+
+dofile(modpath .. 'noises.lua')
 
 local make_polygons = dofile(modpath .. 'polygons.lua')
 
@@ -23,43 +26,6 @@ end
 
 local data = {}
 
-local noise_x_params = {
-	offset = 0,
-	scale = 1,
-	seed = -4574,
-	spread = {x=64, y=32, z=64},
-	octaves = 3,
-	persistence = 0.75,
-	lacunarity = 2,
-}
-
-local noise_z_params = {
-	offset = 0,
-	scale = 1,
-	seed = -7940,
-	spread = {x=64, y=32, z=64},
-	octaves = 3,
-	persistence = 0.75,
-	lacunarity = 2,
-}
-
-local noise_distort_params = {
-	offset = 0,
-	scale = 10,
-	seed = 676,
-	spread = {x=1024, y=1024, z=1024},
-	octaves = 5,
-	persistence = 0.5,
-	lacunarity = 2,
-	flags = "absvalue",
-}
-
-local noise_heat_params = minetest.get_mapgen_setting_noiseparams('mg_biome_np_heat')
-local noise_heat_blend_params = minetest.get_mapgen_setting_noiseparams('mg_biome_np_heat_blend')
-
-local elevation_chill = 0.25
-noise_heat_params.offset = noise_heat_params.offset + sea_level*elevation_chill
-
 local noise_x_obj, noise_z_obj, noise_distort_obj, noise_heat_obj, noise_heat_blend_obj
 local noise_x_map = {}
 local noise_z_map = {}
@@ -82,11 +48,11 @@ local function generate(minp, maxp, seed)
 			y = chulens.y+1,
 			z = chulens.z,
 		}
-		noise_x_obj = minetest.get_perlin_map(noise_x_params, mapsize)
+		noise_x_obj = minetest.get_perlin_map(mapgen_rivers.noise_params.distort_x, mapsize)
-		noise_z_obj = minetest.get_perlin_map(noise_z_params, mapsize)
+		noise_z_obj = minetest.get_perlin_map(mapgen_rivers.noise_params.distort_z, mapsize)
-		noise_heat_obj = minetest.get_perlin_map(noise_heat_params, chulens)
+		noise_heat_obj = minetest.get_perlin_map(mapgen_rivers.noise_params.heat, chulens)
-		noise_heat_blend_obj = minetest.get_perlin_map(noise_heat_blend_params, chulens)
+		noise_heat_blend_obj = minetest.get_perlin_map(mapgen_rivers.noise_params.heat_blend, chulens)
-		noise_distort_obj = minetest.get_perlin_map(noise_distort_params, chulens)
+		noise_distort_obj = minetest.get_perlin_map(mapgen_rivers.noise_params.distort_amplitude, chulens)
 		init = true
 	end
 

noises.lua

@@ -0,0 +1,37 @@
+mapgen_rivers.noise_params = {
+	distort_x = {
+		offset = 0,
+		scale = 1,
+		seed = -4574,
+		spread = {x=64, y=32, z=64},
+		octaves = 3,
+		persistence = 0.75,
+		lacunarity = 2,
+	},
+
+	distort_z = {
+		offset = 0,
+		scale = 1,
+		seed = -7940,
+		spread = {x=64, y=32, z=64},
+		octaves = 3,
+		persistence = 0.75,
+		lacunarity = 2,
+	},
+
+	distort_amplitude = {
+		offset = 0,
+		scale = 10,
+		seed = 676,
+		spread = {x=1024, y=1024, z=1024},
+		octaves = 5,
+		persistence = 0.5,
+		lacunarity = 2,
+		flags = "absvalue",
+	},
+
+	heat = minetest.get_mapgen_setting_noiseparams('mg_biome_np_heat'),
+	heat_blend = minetest.get_mapgen_setting_noiseparams('mg_biome_np_heat_blend'),
+}
+
+mapgen_rivers.noise_params.heat.offset = mapgen_rivers.noise_params.heat.offset + mapgen_rivers.sea_level*mapgen_rivers.elevation_chill

polygons.lua

@@ -74,9 +74,28 @@ local function river_width(flow)
 	return math.min(wfactor * flow ^ wpower, 1)
 end
 
+local noise_heat -- Need a large-scale noise here so no heat blend
+local elevation_chill = mapgen_rivers.elevation_chill
+local function get_temperature(x, y, z)
+	local pos = {x=x, y=z}
+	return noise_heat:get2d(pos) - y*elevation_chill
+end
+
+local glaciers = mapgen_rivers.glaciers
+local glacier_factor = mapgen_rivers.glacier_factor
+
+local init = false
+
 -- On map generation, determine into which polygon every point (in 2D) will fall.
 -- Also store polygon-specific data
 local function make_polygons(minp, maxp)
+	if not init then
+		if glaciers then
+			noise_heat = minetest.get_perlin(mapgen_rivers.noise_params.heat)
+		end
+		init = true
+	end
+
 	local chulens = maxp.z - minp.z + 1
 
 	local polygons = {}
@@ -141,7 +160,8 @@ local function make_polygons(minp, maxp)
 				end
 			end
 
-			polygon.dem = {dem[iA], dem[iB], dem[iC], dem[iD]}
+			local poly_dem = {dem[iA], dem[iB], dem[iC], dem[iD]}
+			polygon.dem = poly_dem
 			polygon.lake = math.min(lakes[iA], lakes[iB], lakes[iC], lakes[iD])
 
 			-- Now, rivers.
@@ -150,6 +170,21 @@ local function make_polygons(minp, maxp)
 			local riverB = river_width(rivers[iB])
 			local riverC = river_width(rivers[iC])
 			local riverD = river_width(rivers[iD])
+			if glaciers then -- Widen the river
+				if get_temperature(poly_x[1]*blocksize, poly_dem[1], poly_z[1]*blocksize) < 0 then
+					riverA = math.min(riverA*glacier_factor, 1)
+				end
+				if get_temperature(poly_x[2]*blocksize, poly_dem[2], poly_z[2]*blocksize) < 0 then
+					riverB = math.min(riverB*glacier_factor, 1)
+				end
+				if get_temperature(poly_x[3]*blocksize, poly_dem[3], poly_z[3]*blocksize) < 0 then
+					riverC = math.min(riverC*glacier_factor, 1)
+				end
+				if get_temperature(poly_x[4]*blocksize, poly_dem[4], poly_z[4]*blocksize) < 0 then
+					riverD = math.min(riverD*glacier_factor, 1)
+				end
+			end
+
 			polygon.river_corners = {riverA, 1-riverB, 2-riverC, 1-riverD}
 
 			-- Flow directions

settings.lua

@@ -9,6 +9,8 @@ local function get_settings(key, dtype, default)
 			return storage:get_int(key)
 		elseif dtype == "float" then
 			return storage:get_float(key)
+		elseif dtype == "bool" then
+			return storage:get_string(key) == 'true'
 		end
 	end
 
@@ -20,7 +22,7 @@ local function get_settings(key, dtype, default)
 		elseif dtype == "float" then
 			conf_val = tonumber(conf_val)
 			storage:set_float(key, conf_val)
-		elseif dtype == "string" then
+		elseif dtype == "string" or dtype == "bool" then
 			storage:set_string(key, conf_val)
 		end
 
@@ -32,6 +34,8 @@ local function get_settings(key, dtype, default)
 			storage:set_float(key, default)
 		elseif dtype == "string" then
 			storage:set_string(key, default)
+		elseif dtype == "bool" then
+			storage:set_string(key, tostring(default))
 		end
 
 		return default
@@ -43,3 +47,7 @@ mapgen_rivers.sea_level = get_settings('sea_level', 'int', 1)
 mapgen_rivers.min_catchment = get_settings('min_catchment', 'float', 25)
 mapgen_rivers.max_catchment = get_settings('max_catchment', 'float', 40000)
 mapgen_rivers.riverbed_slope = get_settings('riverbed_slope', 'float', 0.4) * mapgen_rivers.blocksize
+--mapgen_rivers.distort = get_settings('distort', 'bool', true) To be implemented: should be possible to disable distorsion
+mapgen_rivers.glaciers = get_settings('glaciers', 'bool', true)
+mapgen_rivers.glacier_factor = get_settings('glacier_factor', 'float', 8)
+mapgen_rivers.elevation_chill = get_settings('elevation_chill', 'float', 0.25)