add ores

res/content/base/generators/demo.files/ores.json

@@ -0,0 +1,3 @@
+[
+    {"struct": "coal_ore0", "rarity": 22000}
+]

res/content/base/generators/demo.files/script.lua

@@ -1,13 +1,32 @@
-function place_structures(x, z, w, d, seed, hmap, chunk_height)
-    local placements = {}
-    for i=1,10 do
-        local sx = math.random() * w
-        local sz = math.random() * d
-        local sy = math.random() * (chunk_height * 0.5)
-        if sy < hmap:at(sx, sz) * chunk_height - 6 then
-            table.insert(placements, {"coal_ore0", {sx, sy, sz}, math.random()*4})
+BLOCKS_PER_CHUNK = 65536
+
+local _, dir = parse_path(__DIR__)
+ores = file.read_combined_list(dir.."/ores.json")
+
+local function place_ores(placements, x, z, w, d, seed, hmap, chunk_height)
+    for _, ore in ipairs(ores) do
+        local count = BLOCKS_PER_CHUNK / ore.rarity
+
+        -- average count is less than 1
+        local addchance = math.fmod(count, 1.0)
+        if math.random() < addchance then
+            count = count + 1
+        end
+
+        for i=1,count do
+            local sx = math.random() * w
+            local sz = math.random() * d
+            local sy = math.random() * (chunk_height * 0.5)
+            if sy < hmap:at(sx, sz) * chunk_height - 6 then
+                table.insert(placements, {ore.struct, {sx, sy, sz}, math.random()*4})
+            end
         end
     end
+end
+
+function place_structures(x, z, w, d, seed, hmap, chunk_height)
+    local placements = {}
+    place_ores(placements, x, z, w, d, seed, hmap, chunk_height)
     return placements
 end
 
@@ -23,7 +42,7 @@ function generate_heightmap(x, y, w, h, seed, s)
     map.noiseSeed = seed
     map:noise({x, y}, 0.8*s, 4, 0.02)
     map:cellnoise({x, y}, 0.1*s, 3, 0.3, umap, vmap)
-    map:add(0.4)
+    map:add(0.7)
 
     local rivermap = Heightmap(w, h)
     rivermap.noiseSeed = seed
@@ -32,7 +51,6 @@ function generate_heightmap(x, y, w, h, seed, s)
     rivermap:mul(2.0)
     rivermap:pow(0.15)
     rivermap:max(0.3)
-    map:add(0.3)
     map:mul(rivermap)
     return map
 end