From 33e539c5b3dca6e3599210763f0b92caa686b37e Mon Sep 17 00:00:00 2001
From: Shaun Williams <shaunewilliams@gmail.com>
Date: Sun, 15 Mar 2015 16:05:15 -0500
Subject: [PATCH] fix winkel tripel artifacts (just a hack)

---
 game/lua-scripts/lenses/winkeltripel.lua | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/game/lua-scripts/lenses/winkeltripel.lua b/game/lua-scripts/lenses/winkeltripel.lua
index 82f4954..7a94c39 100644
--- a/game/lua-scripts/lenses/winkeltripel.lua
+++ b/game/lua-scripts/lenses/winkeltripel.lua
@@ -27,6 +27,9 @@ function lens_inverse(x,y)
   if abs(y) >= lens_height/2 then
     return nil
   end
+  if is_inside_artifact_box(x,y) then
+    return nil
+  end
 
   local lambda = x
   local phi = y
@@ -82,3 +85,12 @@ lens_height = 2*y
 
 x,y = lens_forward(latlon_to_ray(0,pi))
 lens_width = 2*x
+
+
+-- there are some bad artifacts in the corners of the image
+-- (just remove them here manually)
+artifact_x = lens_width/2*0.71
+artifact_y = lens_height/2*0.81
+function is_inside_artifact_box(x,y)
+  return abs(x) > artifact_x and abs(y) > artifact_y
+end