music - profiles.go

     1  package music
     2  
     3  import "math"
     4  
     5  type Profile func(pos float64) float64
     6  
     7  func Steady(_ float64) float64 {
     8  	return 1
     9  }
    10  
    11  func Adjust(amount float64) Profile {
    12  	return func(_ float64) float64 {
    13  		return amount
    14  	}
    15  }
    16  
    17  func AdjustProfile(amount float64, p Profile) Profile {
    18  	return func(pos float64) float64 {
    19  		return amount * p(pos)
    20  	}
    21  }
    22  
    23  func RampUp(pos float64) float64 {
    24  	return pos
    25  }
    26  
    27  func RampDown(pos float64) float64 {
    28  	return 1 - pos
    29  }
    30  
    31  func ExponentialUp(pos float64) float64 {
    32  	return math.Pow(math.E, 6*(pos-1))
    33  }
    34  
    35  func ExponentialDown(pos float64) float64 {
    36  	return math.Pow(math.E, -6*pos)
    37  }
    38  
    39  func InverseExponentialUp(pos float64) float64 {
    40  	return 1 - ExponentialDown(pos)
    41  }
    42  
    43  func InverseExponentialDown(pos float64) float64 {
    44  	return 1 - ExponentialUp(pos)
    45  }