## reb Class REB_TrapShapeTractrix

```Object
common:Generic
common:TrapShape
reb:REB_TrapShapeTractrix
```

`class TrapShape:REB_TrapShapeTractrix`

This shape uses the tractrix function.

This variant of the function has a signed and absolute value version of the distance. The function also has a complex conjugate variant. The transformed value is the complex return value of the function.

Ultra Fractal Source
``` class REB_TrapShapeTractrix(common.ulb:TrapShape) {
; This shape uses the tractrix function.<br>
; <p>
; This variant of the function has a signed and absolute value
; version of the distance. The function also has a complex conjugate variant.
; The transformed value is the complex return value of the function.
public:
import "common.ulb"

; Constructor
func REB_TrapShapeTractrix(Generic pparent)
TrapShape.TrapShape(pparent)
endfunc

; Call this for each iteration being trapped.
float func Iterate(complex pz)
TrapShape.Iterate(pz)
float theta = 0
float d =  0
theta = atan2(pz)
int sgn = 1
if @sgn
sgn = -1
endif
complex af1 = @a*(log(tan(theta/2))-@afn1(theta))
complex af2 = @a*@afn2(theta)
complex as = 0.25*(af1 + sgn*flip(af2))
m_LastZ = as
if @absval
d = abs(cabs(pz) - cabs(as))
else
d = cabs(pz - (as))
endif
return d
endfunc

default:
title = "Tractrix"
int param v_trapshapetractrix
caption = "Version (Trap Shape Tractrix)"
default = 101
hint = "This version parameter is used to detect when a change has been made to the formula that is incompatible with the previous version. When that happens, this field will reflect the old version number to alert you to the fact that an alternate rendering is being used."
visible = @v_trapshapetractrix < 101
endparam

float param a
caption = "Polar parameter"
default = 0.2
hint = "Affects spread and scale of trap"
endparam
func afn1
caption = "Function #1"
default = cos()
endfunc
func afn2
caption = "Function #2"
default = sin()
endfunc
bool param sgn
caption = "Conjugate transform"
default = false
endparam
param absval
caption = "Absolute Value"
default = false
endparam
}
```

Constructor Summary
`REB_TrapShapeTractrix()`

`REB_TrapShapeTractrix(Generic pparent)`
Constructor

Method Summary
` float` `Iterate(complex pz)`
Call this for each iteration being trapped.

Methods inherited from class common:TrapShape
`GetColorChannel, GetTextureValue, GetTransformedPoint, Init, IterateSilent, SetThreshold`

Methods inherited from class common:Generic
`GetParent`

Methods inherited from class Object

Constructor Detail

### REB_TrapShapeTractrix

`public REB_TrapShapeTractrix(Generic pparent)`
Constructor

### REB_TrapShapeTractrix

`public REB_TrapShapeTractrix()`
Method Detail

### Iterate

`public float Iterate(complex pz)`
Call this for each iteration being trapped.

Overrides:
`Iterate` in class `TrapShape`