Simplify creature stride length

src/Dodge/Creature/Picture.hs

@@ -78,7 +78,7 @@ chaseUpperBody cr =  colorSH (_skinUpper cskin)
     vocaltilt = case cr ^? crVocalization . vcTime of
         Just x | x < 20 -> -pi * 0.05 * (10 - abs (fromIntegral x - 10))
         _ -> 0
-    sLen = _strideLength $ _crStance cr
+    sLen = strideLength cr
     tbob = 5 * (1 - oneSmooth (abs llegpos))
     llegpos = case cr ^? crStance . carriage of
         Just (Walking sa LeftForward) -> f sa
@@ -101,7 +101,7 @@ feet cr = case cr ^? crStance . carriage of
     sh x = translateSHxy x off aFoot <> translateSHxy (- x) (- off) aFoot
     aFoot = upperPrismPolyST 10 $ polyCirc 3 4
     off = 5
-    sLen = _strideLength $ _crStance cr
+    sLen = strideLength cr
 --    f i = 8 * (sLen - 2*i) / sLen
     f i = 8 * oneSmooth ((sLen - 2*i) / sLen)