Allow tweaking z buffer when rendering polygon, improve explosion render

src/Dodge/WorldEvent/Explosion.hs

@@ -12,6 +12,7 @@ import Dodge.SoundLogic
 import Dodge.SoundLogic.Synonyms
 import Dodge.WorldEvent.Shockwave
 import Geometry
+import Geometry.Vector3D
 import Picture
 
 import Control.Monad.State
@@ -71,14 +72,16 @@ makeExplosionAt p w
     $ makeShockwaveAt [] p 50 10 1 white w
   where 
     fVs  = replicateM 75 (randInCirc 1)  & evalState $ _randGen w
-    fPs' = replicateM 75 (randInCirc 15) & evalState $ _randGen w
+    fPs'' = replicateM 75 (fmap (15 *.*.*) randInHemisphere) & evalState $ _randGen w
+    (fPs',zs) = let (a,b,c) = unzip3 fPs''
+                in (zip a b, c)
     fPs  = map (pushAgainstWalls . (+.+) p . (*.*) 0.5) fPs'
     inversePushOut v = (15 - magV v) * 0.01 *.* v
     fVs' = zipWith (+.+) fVs $ map inversePushOut fPs'
     sizes = randomRs (2,6) $ _randGen w
     times = randomRs (20,25) $ _randGen w
-    mF q v size time = makeFlameletTimed q v Nothing size time
-    newFs = zipWith4 mF fPs (fmap (3 *.*) fVs') sizes times
+    mF q z v size time = makeFlameletTimed q z v Nothing size time
+    newFs = zipWith5 mF fPs zs (fmap (3 *.*) fVs') sizes times
     addFlames w' = foldr ($) w' newFs
     pushAgainstWalls q = maybe q (uncurry (+.+)) $ reflectPointWalls p q $ wallsNearPoint q w