function OnAbout(event)
   ctrl = event:GetTextCtrl()
   ctrl:AppendText("DXF post processor\n")
   ctrl:AppendText("\n")
end



--   Created 19/10/2005

post.ForceExtension("dxf")


function OnInit()
   bigArcs = 1 --stitch arc segments together
   minArcSize = 0.05 --arcs smaller than this are converted to moves

   post.Text("  0\nSECTION\n")
   post.Text("  2\nENTITIES\n")

   angscale = 180/math.pi --convert rads to degrees
   numFmt = "0.############"
   curLayer = "Unknown"
end

function OnNewLine()
end


function OnFinish()
   post.Text("  0\nENDSEC\n")
   post.Text("  0\nEOF\n")
end

function OnRapid()
end

function OnMove()
   if(math.hypot(currentX - endX, currentY - endY) < 0.0000001) then return end
   post.Text("  0\nLINE")
   post.Text("\n  8\n", curLayer)
   post.Text("\n  10\n")
   post.Number(currentX * scale, numFmt)
   post.Text("\n  20\n")
   post.Number(currentY * scale, numFmt)
   post.Text("\n  30\n")
   post.Number(currentZ * scale, numFmt)
   post.Text("\n  11\n")
   post.Number(endX * scale, numFmt)
   post.Text("\n  21\n")
   post.Number(endY * scale, numFmt)
   post.Text("\n  31\n")
   post.Number(endZ * scale, numFmt)
   post.Eol()
end

function OnArc()
   diffx = arcCentreX - currentX
   diffy = arcCentreY - currentY
   rad = math.hypot(diffx,diffy)
   startang = -math.atan2(diffx,diffy) * angscale
   startang = startang + 270

   diffx = arcCentreX - endX
   diffy = arcCentreY - endY
   endang = -math.atan2(diffx,diffy) * angscale
   endang = endang + 270

   if(arcAngle >0) then
      atemp = startang
      startang = endang
      endang = atemp
   end
   
   if(math.hypot(currentX - endX, currentY - endY) < 0.0001 and math.abs(arcAngle) > 3.14) then -- a circle
      post.Text("  0\nCIRCLE")
      post.Text("\n  8\n", curLayer)
      post.Text("\n  10\n")
      post.Number(arcCentreX * scale, numFmt)
      post.Text("\n  20\n")
      post.Number(arcCentreY * scale, numFmt)
      post.Text("\n  30\n")
      post.Number(currentZ * scale, numFmt)
      post.Text("\n  40\n")
      post.Number(rad * scale, numFmt)
      post.Eol()
      return
   end

   post.Text("  0\nARC")
   post.Text("\n  8\n", curLayer)
   post.Text("\n  10\n")
   post.Number(arcCentreX * scale, numFmt)
   post.Text("\n  20\n")
   post.Number(arcCentreY * scale, numFmt)
   post.Text("\n  30\n")
   post.Number(currentZ * scale, numFmt)
   post.Text("\n  40\n")
   post.Number(rad * scale, numFmt)
   post.Text("\n  50\n")
   post.Number(startang, numFmt)
   post.Text("\n  51\n")
   post.Number(endang, numFmt)
   post.Eol()
end


function OnSpindleCW()
end

function OnSpindleCCW()
end

function OnSpindleOff()
end


function OnNewOperation()
   local pts = sc.Parts.Get()
   local pt = pts:op_index(partIndex):GetParentPart()
   local op = pt.operations:op_index(operationIndex):DynamicCast("OperationWithPaths")
   if op then
      curLayer = op.layerName:op_get()
   end
end

function OnToolChange()
end

function OnSpindleChanged()
end

function OnNewPart()
end


function OnFloodOn()
end

function OnMistOn()
end

function OnCoolantOff()
end

function OnDrill()
   post.Text("  0\nLINE")
   post.Text("\n  8\n", curLayer)
   post.Text("\n  10\n")
   post.Number(endX * scale, numFmt)
   post.Text("\n  20\n")
   post.Number(endY * scale, numFmt)
   post.Text("\n  30\n")
   post.Number(drillStart * scale, numFmt)
   post.Text("\n  11\n")
   post.Number(endX * scale, numFmt)
   post.Text("\n  21\n")
   post.Number(endY * scale, numFmt)
   post.Text("\n  31\n")
   post.Number(drillZ * scale, numFmt)
   post.Eol()
end