comment {
;
; Coloring formulas by Piotr Borys
; utak3r@o2.pl
; http://pborys.topcities.com/
;
; Last update: 13.12.2004
; For a little help see pb.txt file
}

IterationPower {
;
; Colors by iteration with a parameter
; For a little help see pb.txt file
;
final:
  #index = @power * #numiter
default:
  title = "Iteration power"
  float param power
    caption = "Power"
    default = 0.015
  endparam
}

WavyTraps {
;
; Original idea taken from Damien M. Jones,
; and then expanded to my personal wishes.
; Try this with polynomials or Newton-like fractals.
;
; Thanks goes to Toby Marshall for his help :)
;
; For a little help see pb.txt file
;
init:
  float d = 0.0
  float a1
  float b1
  float a2
  float b2
  complex z2 = (0,0)
  int iter = 0
  complex r = (0,1) ^ (@angle / 90.0)
  complex trapcenter2 = @trapcenter
  if @screencenter
    trapcenter2 = #center
  endif
  float closest = 1e38
  bool usesolid = true
  complex zvalues[#maxiter+1]
  zvalues[0] = #z

loop:
  iter = iter + 1
  z2 = #z
  z2 = (z2 - trapcenter2) * r
  zvalues[iter] = z2

  if (iter > @iterskip) && (iter < @itermax)
    a1 = abs(imag(z2)^@power1)
    b1 = cabs(@trapfunc(((real(z2))^@power2)*@trapfreq))*@trapheight
    d = abs(a1 - @diameter + b1)

    if @modifying && (iter > 1)
      a2 = abs(imag(zvalues[iter-1])^@power1)
      b2 = cabs(@trapfunc(((real(zvalues[iter-1]))^@power2)*@trapfreq))*@trapheight
      d = d + @modfactor*cabs(@modfunc(abs(a2 - @diameter + b2)))
    endif
  endif

  if (d < closest)
    closest = d
  endif
  if (d < @threshold)
    usesolid = false
  endif

final:
  if @solidcolor
    #solid = usesolid
  else
    #solid = false
  endif

  #index = closest

default:
  title = "Wavy Traps"

  heading
    caption = "Parameters"
  endheading
  param diameter
    caption = "  Diameter"
    default = 1.0
    hint = "The diameter of the trap."
  endparam
  param trapheight
    caption = "  Height"
    default = 1.0
    hint = "The height of waves."
  endparam
  param trapfreq
    caption = "  Frequency"
    default = 1.5
    hint = "The frequency of waves."
  endparam
  param angle
    caption = "  Rotation"
    default = 0.0
    hint = "Rotation of a trap, in degrees."
  endparam

  heading
    caption = "Type"
  endheading
  param power1
    caption = "  Power 1"
    hint = "The power of the first equation part."
    default = 1.0
  endparam
  param power2
    caption = "  Power 2"
    hint = "The power of the second equation part."
    default = 2.0
  endparam
  func trapfunc
    caption = "  Trap function"
    hint = "Function involved in creation of the trap."
    default = sin()
  endfunc
  param modifying
    caption = "  Iteration Modifying"
    hint = "When enabled, the iterations chain modifies coloring"
    default = true
  endparam
  func modfunc
    caption = "  Modifying Function"
    hint = "Function calculated when building the iterations chain."
    default = sinh()
    visible = @modifying == true
  endfunc
  param modfactor
    caption = "  Modifying Strength"
    hint = "Strength of the iterations chain modifier."
    default = 0.3
    visible = @modifying == true
  endparam

  heading
    caption = "Options"
  endheading
  param trapcenter
    caption = "  Trap Center"
    default = (0,0)
    hint = "This is the location of the trap in the complex plane."
    visible = @screencenter == false
  endparam
  param screencenter
    caption = "  Use Screen Center"
    default = false
    hint = "If enabled, trap center will be set to the screen center."
  endparam
  param iterskip
    caption = "  Skip Iterations"
    default = 0
  endparam
  param itermax
    caption = "  Max Iterations"
    default = 256
  endparam
  param solidcolor
    caption = "  Use Solid Color"
    default = false
    hint = "If enabled, areas 'outside' the trap area will be colored \
            with the 'solid color' on the coloring tab."
  endparam
  param threshold
    caption = "  Threshold"
    hint = "This is the width of the trap area."
    default = 0.2
    min = 0
  endparam
}