From b8ec3e3f474460b323b982e96800cbee237c7d09 Mon Sep 17 00:00:00 2001
From: grilledham <jrdgillham@gmail.com>
Date: Thu, 29 Mar 2018 19:23:58 +0100
Subject: [PATCH] add sine fill builder

---
 map_gen/shared/builders.lua | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/map_gen/shared/builders.lua b/map_gen/shared/builders.lua
index cfd755ad..6d404f68 100644
--- a/map_gen/shared/builders.lua
+++ b/map_gen/shared/builders.lua
@@ -88,6 +88,20 @@ function oval_builder(x_radius, y_radius)
     end
 end
 
+function sine_fill_builder(width, height)
+    width_inv = tau / width
+    height_inv = -2 / height
+    return function(x, y)
+        local x2 = x * width_inv
+        local y2 = y * height_inv
+        if y <= 0 then
+            return y2 < math.sin(x2)
+        else
+            return y2 > math.sin(x2)
+        end        
+    end
+end
+
 local tile_map = {
     [1] = false,
     [2] = true,