DefaultGradientTransfer

Provides the same gradient transfer options as Ultra Fractal's built-in gradient options.

This transfer function emulates the normal gradient transfer method. It's designed primarily for conversion of a positive float to a final gradient index (also positive float) but does not mod it from 0 to 1 making it potentially useful for other transform purposes. Note that it deliberately returns negative values unchanged to ensure normal gradient behaviour. David Makin, May 2008

 class DefaultGradientTransfer(Transfer) {
   ; Provides the same gradient transfer options as Ultra Fractal's built-in gradient options.
   ; <p>
   ; This transfer function emulates the normal gradient transfer method.
   ; It's designed primarily for conversion of a positive float to a final
   ; gradient index (also positive float) but does not mod it from 0 to 1
   ; making it potentially useful for other transform purposes.
   ; Note that it deliberately returns negative values unchanged
   ; to ensure normal gradient behaviour.
   ; David Makin, May 2008
 
 public:
   float func Iterate(float pr)
     if (pr < 0.0)
       return @p_offset*0.0025
     endif
     float x = pr * @p_zscale
     if (@p_xfer == "Sqr")
       x = 2*sqr(x)
     elseif (@p_xfer == "Sqrt")
       x = 0.5*sqrt(x)
     elseif (@p_xfer == "Cube")
       x = 3*x^3
     elseif (@p_xfer == "CubeRoot")
       x = (x^(1/3))/3
     elseif (@p_xfer == "Log")
       x = log(1+x)
     elseif (@p_xfer == "Exp")
       if (x >= 100)
         x = exp(100)
       else
         x = exp(x)
       endif
     elseif (@p_xfer == "Sin")
       x = abs(sin(x))
     elseif (@p_xfer == "ArcTan")
       x = abs(atan(x))
     elseif (@p_xfer == "Cos")
       x = 1+cos(x)
     elseif (@p_xfer == "LogTan")
       x = log(1+abs(tan(x)))
     elseif (@p_xfer == "LogLog")
       x = log(1+log(1+x))
     elseif (@p_xfer == "InvArcTan")
       x = 0.0005*((2.0*#pi/atan(x))^2.0 - 1)
     endif
     return 0.0025*@p_offset + x * @p_zscale2
   endfunc
 
 default:
   title = "Default Gradient Transfer"
 
   int param v_defaultgradienttransfer
     caption = "Version (DefaultGradientTransfer)"
     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_defaultgradienttransfer < 100
   endparam
 
   param p_xfer
     caption = "Transfer Function"
     default = 0
     enum = "Linear" "Sqr" "Sqrt" "Cube" "CubeRoot" "Log" "Exp" "Sin" "ArcTan" "Cos" "LogTan" "LogLog" "InvArcTan"
     hint = "This function will be applied to the value."
   endparam
   param p_zscale
     caption = "Pre-Scale (Density)"
     default = 1.0
     exponential = true
     hint = "Applied prior to the 'Transfer Function'."
   endparam
   param p_zscale2
     caption = "Post-Scale"
     default = 1.0
     exponential = true
     hint = "Applied after the 'Transfer Function'."
   endparam
   param p_offset
     caption = "Offset"
     default = 0.0
     hint = "This is meant as a gradient index offset, so the value you give is actually divided by 400 in use."
   endparam
 }

common Class DefaultGradientTransfer

DefaultGradientTransfer

Iterate

common
Class DefaultGradientTransfer