fucking things up, frozen

src/map_nextgen.lua

@@ -5,6 +5,13 @@ local simplex_map = require "lib.simplex_map"
 
 local biomes = {
   -- biomes are checked in order, with the first candidate always being selected
+  [800] = {
+    name = "sea ice",
+    altitude = {min = -math.huge, max = 0},
+    temperature = {min = -math.huge, max = -2},
+    rainfall = {min = -math.huge, max = math.huge},
+    color = {0.6, 0.6, 1, 1},
+  },
   [900] = {
     name = "deep ocean",
     altitude = {min = -math.huge, max = -5000},
@@ -19,6 +26,13 @@ local biomes = {
     rainfall = {min = -math.huge, max = math.huge},
     color = {0, 0, 0.5, 1},
   },
+  [1500] = {
+    name = "frozen (definition, 0 C)",
+    altitude = {min = -math.huge, max = math.huge},
+    temperature = {min = -math.huge, max = 0},
+    rainfall = {min = -math.huge, max = math.huge},
+    color = {1, 1, 1, 1},
+  },
   [2000] = {
     name = "snowline (middle estimate)",
     altitude = {min = 4000, max = math.huge},
@@ -59,8 +73,8 @@ local generate = function()
   }
   map.temperature = simplex_map.generate{   -- in celsius
     -- -20 to 45 chosen by looking at the temperature range shown on https://openclimatemap.org/
-    size = map.size, scale = 0.005, min = -20, max = 45, -- approximate target extremes of -89.2 to 56.7
-    octaves = 1, lacunarity = 2, gain = 0.5,
+    size = map.size, scale = 0.005, min = 20, max = 65, -- approximate target extremes of -89.2 to 56.7
+    octaves = 2, lacunarity = 2, gain = 0.5,
   }
   map.rainfall = simplex_map.generate{   -- in millimeters of rainfall
     size = map.size, scale = 0.005, -- min = 18, max = 3240,
@@ -103,8 +117,8 @@ local generate = function()
           temperature = temperature + altitude / 1000 -- -1 C / km (deep water adjustment)
         end
         -- modify temperature by latitude
-        local polar_distance = math.abs(y - (map.size / 2))^1.1 -- experimenting with slight non-linearity
-        local max_temperature_delta = 40
+        local polar_distance = math.abs(y - (map.size / 2))^1.3 -- experimenting with slight non-linearity
+        local max_temperature_delta = 10
         temperature = temperature - (polar_distance / map.size * 2 * max_temperature_delta)
         -- 'save' temperature changes
         map.temperature[x][y] = temperature