set cut_paste_input [stack 0]
push $cut_paste_input
Group {
 name Tonemap_PiecewiseHyperbolic
 label "Piecewise Hyperbolic\n Decoupled White Pivoted Toe + Surround"
 addUserKnob {20 Tonemap}
 addUserKnob {78 g l grey t "input -> output grey" n 2}
 g {0.18 0.1}
 addUserKnob {78 w l white t "input -> output white" n 2}
 w {16 1}
 addUserKnob {7 p l contrast R 0.8 2}
 p 1.2
 addUserKnob {7 ps l surround t "surround compensation: un-pivoted power function" R 0.8 1.2}
 ps 1
 addUserKnob {7 t0 l toe R 0 0.1}
 addUserKnob {78 s l scale n 2}
 s {{pow(g.1,1/p)/g.0} {(s.0*pow(w.0-g.0,2)*pow(g.0*s.0-pow(w.1,1/p),2))/pow(s.0*w.0-pow(w.1,1/p),2)}}
 addUserKnob {4 direction M {forward inverse}}
 addUserKnob {26 "" +STARTLINE}
 addUserKnob {26 plot_label l " " T "<style>a:link \{color:#ccc\}</style><a href=\"https://www.desmos.com/calculator/j9clgrfkop\">desmos plot</a>"}
}
 Input {
  inputs 0
  name Input
  xpos -40
  ypos -40
 }
set Nace3c80 [stack 0]
 Expression {
  expr0 w.1*pow(r/w.1,1/ps)
  expr1 w.1*pow(g/w.1,1/ps)
  expr2 w.1*pow(b/w.1,1/ps)
  name InvSurround
  xpos 70
  ypos 21
 }
 Expression {
  temp_name0 st
  temp_expr0 (w.1+t0)/w.1
  expr0 (r+sqrt(r*(4*st*t0+r)))/(2*st)
  expr1 (g+sqrt(g*(4*st*t0+g)))/(2*st)
  expr2 (b+sqrt(b*(4*st*t0+b)))/(2*st)
  name InvToe
  xpos 70
  ypos 51
 }
 Expression {
  temp_name0 h0
  temp_expr0 g.0-sqrt(s.1/s.0)
  temp_name1 h1
  temp_expr1 s.0*g.0+sqrt(s.0*s.1)
  expr0 r>g.1?h0-s.1/(pow(r,1/p)-h1):pow(r,1/p)/s.0
  expr1 g>g.1?h0-s.1/(pow(g,1/p)-h1):pow(g,1/p)/s.0
  expr2 b>g.1?h0-s.1/(pow(b,1/p)-h1):pow(b,1/p)/s.0
  name InvCompress
  xpos 70
  ypos 81
 }
push $Nace3c80
 Expression {
  temp_name0 h0
  temp_expr0 g.0-sqrt(s.1/s.0)
  temp_name1 h1
  temp_expr1 s.0*g.0+sqrt(s.0*s.1)
  expr0 r>g.0?pow(h1-s.1/(r-h0),p):pow(s.0*r,p)
  expr1 g>g.0?pow(h1-s.1/(g-h0),p):pow(s.0*g,p)
  expr2 b>g.0?pow(h1-s.1/(b-h0),p):pow(s.0*b,p)
  name Compress
  xpos -150
  ypos 21
 }
 Expression {
  temp_name0 st
  temp_expr0 (w.1+t0)/w.1
  expr0 (st*r*r)/(r+t0)
  expr1 (st*g*g)/(g+t0)
  expr2 (st*b*b)/(b+t0)
  name Toe
  xpos -150
  ypos 51
 }
 Expression {
  expr0 w.1*pow(r/w.1,ps)
  expr1 w.1*pow(g/w.1,ps)
  expr2 w.1*pow(b/w.1,ps)
  name Surround
  xpos -150
  ypos 81
 }
 Switch {
  inputs 2
  which {{parent.direction}}
  name SwitchDirection
  xpos -40
  ypos 141
 }
 Output {
  name Output
  xpos -40
  ypos 200
 }
end_group