From b95fd301cc474e2c0aed7f5ad431fd4892c8286b Mon Sep 17 00:00:00 2001
From: grilledham <jrdgillham@gmail.com>
Date: Mon, 25 Jun 2018 15:32:04 +0100
Subject: [PATCH] tiny ores

---
 map_gen/ores/tiny_ores.lua | 64 ++++++++++++++++++++++++++++++++++++++
 map_layout.lua             |  1 +
 2 files changed, 65 insertions(+)
 create mode 100644 map_gen/ores/tiny_ores.lua

diff --git a/map_gen/ores/tiny_ores.lua b/map_gen/ores/tiny_ores.lua
new file mode 100644
index 00000000..3874ae58
--- /dev/null
+++ b/map_gen/ores/tiny_ores.lua
@@ -0,0 +1,64 @@
+local Global = require 'utils.global'
+
+local resource_rate = 768
+local seed = 1234
+
+local generator
+
+Global.register_init(
+    {},
+    function(tbl)
+        tbl.generator = game.create_random_generator()
+    end,
+    function(tbl)
+        generator = tbl.generator
+    end
+)
+
+local function value(base, mult, pow)
+    return function(x, y)
+        local d = math.sqrt(x * x + y * y)
+        return base + mult * d ^ pow
+    end
+end
+
+local ores = {
+    {'iron-ore', value(40000, 20, 1.5), 100},
+    {'copper-ore', value(40000, 20, 1.5), 60},
+    {'coal', value(40000, 20, 1.25), 25},
+    {'stone', value(20000, 20, 1.25), 15},
+    {'uranium-ore', value(5000, 5, 1.35), 5},
+    {'crude-oil', value(600000, 200, 1.25), 4}
+}
+
+local total_weights = {}
+local t = 0
+for _, v in ipairs(ores) do
+    t = t + v[3]
+    table.insert(total_weights, t)
+end
+
+t = resource_rate * t
+table.insert(ores, {false})
+table.insert(total_weights, t)
+
+return function(x, y)
+    local r_seed = bit32.band(x * 374761393 + y * 668265263 + seed, 4294967295)
+    generator.re_seed(r_seed)
+    local i = generator(t)
+
+    local index = table.binary_search(total_weights, i)
+    if (index < 0) then
+        index = bit32.bnot(index)
+    end
+
+    local ore_data = ores[index]
+    local ore = ore_data[1]
+    if not ore then
+        return
+    end
+
+    local amount = ore_data[2](x, y)
+
+    return {name = ore, amount = amount}
+end
diff --git a/map_layout.lua b/map_layout.lua
index 84085e46..74873d3d 100644
--- a/map_layout.lua
+++ b/map_layout.lua
@@ -103,6 +103,7 @@ local entity_modules = {
 	--require "map_gen.ores.fluffy_rainbows",
 	--require "map_gen.ores.harmonic_gen",
 	--require "map_gen.ores.resource_clustertruck"
+	--require "map_gen.ores.tiny_ores"
 }
 
 local terrain_modules = {