module Dodge.LightSource.Update where

import Control.Lens
import Dodge.Data.LightSource
import Geometry

updateTempLightSource :: TLSUpdate -> TempLightSource -> Maybe TempLightSource
updateTempLightSource tlsu = case tlsu of
    DestroyTLS -> const Nothing
    TimerTLS -> timerTLS
    IntensityTLS ConstantIntensity -> updateTempLightSource TimerTLS
    IntensityTLS (TLSFade startcol x) -> fadeTLS startcol x

fadeTLS :: Point3 -> Int -> TempLightSource -> Maybe TempLightSource
fadeTLS startcol x tls
    | t < 1 = Nothing
    | t < x = Just $ tls & tlsParam . lsCol .~ (1 / fromIntegral (x - t)) *.*.* startcol
    | otherwise = Just $ tls & tlsParam . lsCol .~ startcol -- this is wasteful, should be set once at begining
  where
    t = _tlsTime tls

timerTLS :: TempLightSource -> Maybe TempLightSource
timerTLS t
    | _tlsTime t <= 0 = Nothing
    | otherwise = Just $ t & tlsTime -~ 1