{-# LANGUAGE NoImplicitPrelude #-} {- | Copyright : (c) Henning Thielemann 2008 License : GPL Maintainer : synthesizer@henning-thielemann.de Stability : provisional Portability : requires multi-parameter type classes -} module Synthesizer.Dimensional.RateAmplitude.Noise (white, whiteBandEnergy, randomPeeks, whiteGen, whiteBandEnergyGen, randomPeeksGen, ) where import qualified Synthesizer.State.NoiseCustom as Noise import qualified Synthesizer.State.Signal as Sig import qualified Synthesizer.RandomKnuth as Knuth import qualified Synthesizer.Dimensional.RateAmplitude.Signal as SigA import qualified Synthesizer.Dimensional.Rate.Dirac as Dirac import qualified Synthesizer.Dimensional.Process as Proc import Synthesizer.Dimensional.Process (($#), ) import qualified Number.DimensionTerm as DN import qualified Algebra.DimensionTerm as Dim import Number.DimensionTerm ((&*&)) import qualified Algebra.Algebraic as Algebraic import qualified Algebra.Field as Field import qualified Algebra.Ring as Ring import System.Random (Random, RandomGen, mkStdGen) import NumericPrelude import PreludeBase as P {-# INLINE white #-} {- The Field.C constraint could be replaced by Ring.C if Noise instead of faster NoiseCustom would be used -} white :: (Field.C yv, Random yv, Algebraic.C q, Dim.C u, Dim.C v) => DN.T (Dim.Recip u) q {-^ width of the frequency band -} -> DN.T v q {-^ volume caused by the given frequency band -} -> Proc.T s u q (SigA.R s v q yv) {-^ noise -} white = -- FIXME: there was a bug in GHC-6.4's standard random generator where genRange returned minBound::Int as lower bound but actually generated numbers were always positive -- this is fixed in GHC-6.6 and thus the standard generator can be used whiteGen (Knuth.cons 6746) -- whiteGen (mkStdGen 6746) {-# INLINE whiteGen #-} whiteGen :: (Field.C yv, Random yv, RandomGen g, Algebraic.C q, Dim.C u, Dim.C v) => g {-^ random generator, can be used to choose a seed -} -> DN.T (Dim.Recip u) q {-^ width of the frequency band -} -> DN.T v q {-^ volume caused by the given frequency band -} -> Proc.T s u q (SigA.R s v q yv) {-^ noise -} whiteGen gen bandWidth volume = do bw <- SigA.toFrequencyScalar bandWidth return $ SigA.fromSamples (DN.scale (sqrt $ 3 / bw) volume) (Noise.whiteGen gen) {-# INLINE whiteBandEnergy #-} whiteBandEnergy :: (Field.C yv, Random yv, Algebraic.C q, Dim.C u, Dim.C v) => DN.T (Dim.Mul u (Dim.Sqr v)) q {-^ energy per frequency band -} -> Proc.T s u q (SigA.R s v q yv) {-^ noise -} whiteBandEnergy = whiteBandEnergyGen (mkStdGen 6746) {-# INLINE whiteBandEnergyGen #-} whiteBandEnergyGen :: (Field.C yv, Random yv, RandomGen g, Algebraic.C q, Dim.C u, Dim.C v) => g {-^ random generator, can be used to choose a seed -} -> DN.T (Dim.Mul u (Dim.Sqr v)) q {-^ energy per frequency band -} -> Proc.T s u q (SigA.R s v q yv) {-^ noise -} whiteBandEnergyGen gen energy = do rate <- Proc.getSampleRate return $ SigA.fromSamples (DN.sqrt $ DN.scale 3 $ DN.rewriteDimension (Dim.identityLeft . Dim.applyLeftMul Dim.cancelLeft . Dim.associateLeft) $ rate &*& energy) (Noise.whiteGen gen) {- The Field.C q constraint could be lifted to Ring.C if we would use direct division instead of toFrequencyScalar. -} {-# INLINE randomPeeks #-} randomPeeks :: (Field.C q, Random q, Ord q, Dim.C u) => Proc.T s u q ( SigA.R s (Dim.Recip u) q q {- v instantaneous densities (frequency), @p@ means that there is about one peak in the time range of @1\/p@. -} -> SigA.R s (Dim.Recip u) q q) {- ^ Every occurrence is represented by a peak of area 1. If you smooth the input and the output signal to the same degree they should be rather similar. -} randomPeeks = randomPeeksGen (mkStdGen 876) {-# INLINE randomPeeksGen #-} randomPeeksGen :: (Field.C q, Random q, Ord q, Dim.C u, RandomGen g) => g {- ^ random generator, can be used to choose a seed -} -> Proc.T s u q ( SigA.R s (Dim.Recip u) q q {- v momentary densities (frequency), @p@ means that there is about one peak in the time range of @1\/p@. -} -> SigA.R s (Dim.Recip u) q q) {- ^ Every occurrence is represented by a peak of area 1. -} randomPeeksGen g = Proc.withParam $ \ dens -> do freq <- SigA.toFrequencyScalar (SigA.amplitude dens) Dirac.toAmplitudeSignal $# (Dirac.Cons $ Sig.zipWith (<) (Noise.randomRs (0, recip freq) g) (SigA.samples dens))