Allow tweaking z buffer when rendering polygon, improve explosion render

src/Geometry/Vector3D.hs

@@ -4,6 +4,8 @@ module Geometry.Vector3D
 import Geometry.Vector
 import Geometry.Data
 
+import Data.List
+
 infixl 6 +.+.+, -.-.-
 infixl 7 *.*.*
 
@@ -56,3 +58,33 @@ magV3 (x,y,z) = sqrt $ x^i + y^i + z^i
 normalizeV3 :: Point3 -> Point3
 normalizeV3 (0,0,0) = (0,0,0)
 normalizeV3 p = (1 / magV3 p) *.*.* p
+
+addZ :: Float -> Point2 -> Point3
+addZ z (x,y) = (x,y,z)
+
+orderAround3
+    :: Point3 -- ^ Vector to order around
+    -> [Point3]
+    -> [Point3]
+orderAround3 v ps = sortOn (argV . prj) ps
+  where
+    xdir = crossProd v (head ps)
+    ydir = crossProd v xdir
+    prj p = (dotV3 xdir p, dotV3 ydir p)
+
+vCen3 :: [Point3] -> Point3
+vCen3 ps = (1 / fromIntegral (length ps)) *.*.* foldr (+.+.+) (0,0,0) ps 
+
+dotV3
+    :: Point3
+    -> Point3
+    -> Float
+dotV3 (x,y,z) (a,b,c) = x*a + y*b + z*c
+
+projV3
+    :: Point3
+    -> Point3
+    -> Point3
+projV3 = undefined
+
+