function OnAbout(event)
   ctrl = event:GetTextCtrl()
   ctrl:AppendText("Designed for use with Mach4 and MachMotion's X15-250-PK(xxxx) controls, with the Neuron Torch Height Controller.\n")
   ctrl:AppendText("Last Updated on 04-20-16\n")
   ctrl:AppendText("\n")
   ctrl:AppendText("Post Processor Comments:\n")
   ctrl:AppendText("Modal G-codes and coordinates\n")
   ctrl:AppendText("Comments enclosed with ( and )\n")
   ctrl:AppendText("M6 Toolchange: Tools 1-99 are plasma, 100-249 are drill bits, and 250-255 custom/marker-tools.\n")
   ctrl:AppendText("Post variables:\n")
   ctrl:AppendText("Ref distance - set the distance between each reference\n")
end

--The cutter will slow down for corners and turn off THC below this radius
SlowRadius = 15.8750

--Minimum slow down speed.
--This is a scale factor. For instance 0.5 = 50% of the current feed rate
SlowPercent = 0.8  
LasttoolClass = ""
THCDisable = false

--This breaks the arc's up in 90 degree segments
post.SetOptions(post.ARC_SEGMENTS)
post.DefineVariable("SlowRadius",sc.unitLINEAR,-1e17,1e17)
post.DefineVariable("SlowPercent",sc.unitPERCENT,-1e17,1e17)

post.DefineCustomToolParam("PlasmaTool", "Amperage", "Amperage", sc.unit4DECPLACE, 40, 0, 600)
post.DefineCustomToolParam("PlasmaTool", "Arc Voltage", "ArcVoltage", sc.unit4DECPLACE, 110, 0, 350)
post.DefineCustomToolParam("FlameTool", "Preheat Height", "PreheatHeight", sc.unitLINEAR, 2.54, 0, 75)


function OnInit()
   post.SetCommentChars ("()", "[]")  --make sure ( and ) characters do not appear in system text
   post.Text (" (Filename: ", fileName, ")\n")
   post.Text (" (Post processor: ", postName, ")\n")
   post.Text (" (Date: ", date, ")\n")
   post.Text (" (Material: Type: , Thickness: ", materialThick * scale,")\n")
   
   if(scale == metric) then
      post.Text (" G21 (Units: Metric)\n") --metric mode
   else
      post.Text (" G20 (Units: Inches)\n") --inch mode
   end
   post.Text (" G90 G90.1 G40\n")

   switchoffset = 0
   minArcSize = 0.05 --arcs smaller than this are converted to moves
end

function OnNewLine()
   post.Text ("N")
   post.Number (lineNumber, "0000")
   lineNumber = lineNumber + 10
end

function OnFinish()
   post.Text (" M05 (Torch Off)\n")
   post.Text (" M30 (Program Rewind)\n")
end

function OnRapid()
   if (endX * scale) > 10000 or (endY * scale) > 10000 then return end
   if(math.hypot(endX-currentX , endY-currentY) < 0.001) then return end
   post.Eol()
   post.Text (" G00")
   post.NonModalNumber (" X", endX * scale, "0.0000")
   post.NonModalNumber (" Y", endY * scale, "0.0000")
   post.Eol()
end

function OnMove()
   if (endX * scale) > 10000 or (endY * scale) > 10000 then return end
   --if(math.hypot(endX-currentX , endY-currentY) < 0.001) then return end --Carl removed this line on 12-5-16
   post.Text (" G01")
   post.NonModalNumber (" X", endX * scale, "0.0000")
   post.NonModalNumber (" Y", endY * scale, "0.0000")
   post.ModalNumber (" F", feedRate * scale, "0.###")
   post.Eol()
end

--function OnArc()
--    post.ArcAsMoves(0.01)
--end

function OnArc()
   local radius = math.hypot(currentX - arcCentreX, currentY - arcCentreY)
   if (radius < SlowRadius) and (math.abs(arcAngle) > 0.5) then
      feed = (radius / SlowRadius)
      if(feed < SlowPercent) then
         feed = SlowPercent
      end
      feed = feed * feedRate
      --ThcOff()
   else
      feed = feedRate
      --ThcOn()
   end
 
   --feed = feedRate
 
   if(arcAngle <0) then
      post.Text(" G03")
   else
      post.Text(" G02")
   end
   post.NonModalNumber (" X", endX * scale, "0.0000")
   post.NonModalNumber (" Y", endY * scale, "0.0000")
   post.Text (" I")
   post.Number ((arcCentreX) * scale, "0.0000")
   post.Text (" J")
   post.Number ((arcCentreY) * scale, "0.0000")
   post.ModalNumber (" F", feed * scale, "0.0###")
   post.Eol()
end

function OnPenDown()
   if (toolClass == "MarkerTool") then 
      OnRapid()
      post.Eol()
      post.Text (" M70 ")
      post.Text (" (Plate Marker Down)")
      post.Eol()
      post.CancelModalNumbers()
   elseif (toolClass == "PlasmaTool") or (toolClass == "FlameTool") then 
      post.Eol()
      post.Text(" M3 (Torch Down, Torch On)\n")
      post.Eol()
      post.CancelModalNumbers()
   end
   
   
   --if(toolClass == "FlameTool") then
   --   post.Eol()
   --   post.Text(" M460 (PreHeat, Cut On, Pierce Delay)\n")
   --   post.CancelModalNumbers()   
   --end
end

function OnPenUp()
   if (toolClass == "MarkerTool") then 
      post.Eol()
      post.Text (" M71 ")
      post.Text (" (Plate Marker Up)")
      post.Eol()
   elseif (toolClass == "PlasmaTool") or (toolClass == "FlameTool") then 
      post.Text (" M5 (Torch Off, Torch Up)\n")
   end

   --if (endDelay > 0) then
   --   post.Text (" G04 P")
   --   post.Number (endDelay,"0.###")
   --   post.Text (" (Delay)")
   --   post.Eol()
   --end
end

function OnNewOperation()
   post.Text (" (Process: ", operationName, ")\n")
end

function OnComment()
  post.Text(" (",commentText,")\n")
end

function OnToolChange()
   if (LasttoolClass ~= toolClass) and (toolClass == "PlasmaTool") then
      local TempArcVoltage = 0
      local TempAmperage = 0
      
      if ArcVoltage ~= nil and ArcVoltage > 0 then
         TempArcVoltage = ArcVoltage
      end
      
      if Amperage ~= nil and Amperage > 0 then
         TempAmperage = Amperage
      end 
      
      post.Text (" (Plasma: Pierce Height: ")
      if pierceHeight > 0 then
         post.Number (pierceHeight * scale, "0.0000")
      end
      post.Text (" Pierce Time: ")
      if pierceDelay > 0 then
         post.Number (pierceDelay, "0.0000")
      end
      post.Text (")")
      post.Eol()
   
      post.Text (" (Plasma: Cut Height: ")
      if cutHeight > 0 then
         post.Number (cutHeight * scale, "0.0000")
      end
      post.Text (")")
      post.Eol()   
   
      post.Text (" (Plasma: Arc Voltage: ")
      if TempArcVoltage > 0 then
         post.Number (TempArcVoltage, "0.0000") 
      end
      post.Text (" Amperage: ")
      if TempAmperage > 0 then
         post.Number (TempAmperage, "0.0000")
      end
      post.Text (")")
      post.Eol()
   end
   
   if (LasttoolClass ~= toolClass) and (toolClass == "FlameTool") then
      local TempPreheatHeight = 0
      if PreheatHeight ~= nil and PreheatHeight > 0 then
         TempPreheatHeight = PreheatHeight * scale
      end
      
      post.Text (" (Flame: Preheat Height: ")
      if TempPreheatHeight > 0 then
         post.Number (TempPreheatHeight, "0.0000")
      end
      post.Text (" Preheat Time: ")
      if preheat > 0 then
         post.Number (preheat, "0.0000")
      end
      post.Text (")")
      post.Eol()
    
      post.Text (" (Flame: Pierce Height: ")
      if pierceHeight > 0 then
         post.Number (pierceHeight * scale, "0.0000")
      end
      post.Text (" Pierce Time: ")
      if pierceDelay > 0 then
         post.Number (pierceDelay, "0.0000")
      end
      post.Text (")")
      post.Eol()
      
      post.Text (" (Flame: Cut Height: ")
      if cutHeight > 0 then
         post.Number (cutHeight * scale, "0.0000")
      end
      post.Text (")")
      post.Eol()
   end
   
   if (LasttoolClass == "DrillTool") and (toolClass ~= "DrillTool") then --turn off spindle
      post.Text (" M5 (Spindle Off)")
      post.Eol()
   end
   
   if (toolClass == "PlasmaTool") then
      post.Text (" M06 T1")
   elseif (toolClass == "FlameTool") then
      post.Text (" M06 T2")
   elseif (toolClass == "MarkerTool") then
      post.Text (" M06 T10")
   elseif (toolClass == "DrillTool") then
      post.Text (" M06 T")
      post.Number (tool, "0")
      post.Eol()
      post.Text (" M3 (Spindle On)")
   end
   
   post.Text (" (", toolName, ")\n")
   if (feedRate <= 0) then
      post.Warning("WARNING: Feed rate is zero")
   end
   
   
   if toolClass == "DrillTool" and spindleSpeed > 0 then 
      post.Eol()
      post.Text(" S")
      post.Number(spindleSpeed, "0.0###")
      post.Text(" (Spindle Speed)")
      post.Eol()
   end
   
   post.NonModalNumber(" F", feedRate * scale, "0.###")
   
   LasttoolClass = toolClass
end

function OnNewPart()
   post.Text(" (Part: ",partName,")\n");
end

function OnDrill()
   if toolClass == "PlasmaTool" then 
      OnRapid()
      post.Eol()
      post.Text (" M3 ")
      post.Text (" (Plasma Pierce)")
      post.Eol()
      post.Text (" M5 ")
      post.Text (" (Retract)")
      post.Eol()
   else
      OnRapid()
      post.Eol()
      post.Text (" M80 ")
      post.Text (" (Drill Cycle)")
      post.Eol()
   end
end

--[[function ThcOff()
   if THCDisable ~= true then
      post.Eol()
      post.ModalText (" M62 P60 (THC Freeze On)")
      post.Eol()
      THCDisable = true
   end
end

function ThcOn()
   if THCDisable ~= false then
      post.Eol()
      post.Text (" M63 P60 (THC Freeze Off)")
      post.Eol()
      THCDisable = false
   end
end
--]]