plant-fitness can now depend on multiple plants

src/Environment.hs

@@ -145,22 +145,27 @@ instance Eq Plant where
 
 type Fitness = Double
 
-fitness :: Plant -> World Fitness
-fitness p = do
-  nutrients <- absorbNutrients p           -- absorb soil
-  products <- produceCompounds p nutrients -- produce compounds
-  survivalRate <- deterPredators products  -- defeat predators with produced compounds
-  let sumEnzymes = sum $ (\(_,q,a) -> fromIntegral q*a) <$> genome p -- amount of enzymes * activation = resources "wasted"
-      staticCostOfEnzymes = 1 - 0.01*sumEnzymes -- static cost of creating enzymes
+fitness :: [Plant] -> World [Fitness]
+fitness ps = do
+  nutrients <- mapM absorbNutrients ps           -- absorb soil
+  products <- sequenceA $ zipWith produceCompounds ps nutrients -- produce compounds
+  ds <- liftIO $ randoms <$> newStdGen
+  preds <- asks predators
+  let
+     appearingPredators = fmap fst . filter (\((_,p),r) -> p > r) $ zip preds ds -- assign one probability to each predator, filter those who appear, throw random data away again.
+                                                                              -- appearingPredators is now a sublist of ps.
+  survivalRate <- mapM (deterPredators products preds) products  -- defeat predators with produced compounds
+  let sumEnzymes = sum . fmap (\(_,q,a) -> fromIntegral q*a) . genome <$>  ps -- amount of enzymes * activation = resources "wasted"
+      staticCostOfEnzymes = (\x -> 1 - 0.01*x) <$> sumEnzymes -- static cost of creating enzymes
       -- primaryEnzymes = filter (\(e,_,_) -> case (fst.fst.synthesis) e of -- select enzymes which use substrate
       --                                        Substrate _ -> True
       --                                        otherwise   -> False)
       --                         (genome p)
   nutrientsAvailable <- fmap snd <$> asks soil
-  let nutrientsLeft = [products ! i | i <- [0..fromEnum (maxBound :: Nutrient)]]
-      nutrientRatio = minimum $ zipWith (/) nutrientsLeft nutrientsAvailable
-      costOfEnzymes = max 0 $ staticCostOfEnzymes - nutrientRatio * 0.1 -- cost to keep enzymes are static costs + amount of nutrient sucked out of the primary cycle
-  return $ survivalRate * costOfEnzymes
+  let nutrientsLeft = (\p -> [p ! i | i <- [0..fromEnum (maxBound :: Nutrient)]]) <$> products
+      nutrientRatio = minimum . zipWith (flip (/)) nutrientsAvailable <$> nutrientsLeft
+      costOfEnzymes = max 0 <$> zipWith (\s n -> s-n*0.1) staticCostOfEnzymes nutrientRatio -- cost to keep enzymes are static costs + amount of nutrient sucked out of the primary cycle
+  return $ zipWith (*) survivalRate costOfEnzymes
   -- can also be written as, but above is more clear.
   -- fitness p = absorbNutrients p >>= produceCompounds p >>= deterPredators
 
@@ -183,21 +188,17 @@ produceCompounds (Plant genes _) substrate = do
 
 
 -- TODO:
--- - choose predators beforehand, then only apply those who appear in full force.
 -- - dampen full-force due to auto-mimicry-effect. => Fitness would not depend on single plant.
-deterPredators :: Vector Amount -> World Probability
-deterPredators cs = do
-  ps <- asks predators
+deterPredators :: [Vector Amount] -> [(Predator,Amount)] -> Vector Amount -> World Probability
+deterPredators others appearingPredators cs = do
+  -- ps <- asks predators
   ts <- asks toxicCompounds
-  ds <- liftIO $ randoms <$> newStdGen
   let
-     appearingPredators = fmap fst . filter (\((_,p),r) -> p > r) $ zip ps ds -- assign one probability to each predator, filter those who appear, throw random data away again.
-                                                                              -- appearingPredators is now a sublist of ps.
      deter :: Predator -> Double
          -- multiply   (toxicity of t with 100% effectiveness at l| for all toxins t; and t in p's irresistance-list)
      deter p = product [1 - min 1 (cs ! fromEnum t / l)           | (t,l) <- ts,       t `elem` irresistance p]
          -- multiply  (probability of occurence * intensity of destruction / probability to deter predator | for all predators)
-  return $ product ([min 1 ((1-prob) * fitnessImpact p / deter p) | (p,prob) <- appearingPredators])
+  return $ product [min 1 ((1-prob) * fitnessImpact p / deter p) | (p,prob) <- appearingPredators]
 
 -- Mating & Creation of diversity
 -- ------------------------------