get("#388") -- rect functions
get("#428") -- findContents
get("#430") -- makeIcon
get("#433") -- iconDiff

-- fw/fh: 8/17

cursor_unfocused = [[
RRRRRRRRRR
RAAAAAAAAR
RAAAAAAAAR
RAAAAAAAAR
RAAAAAAAAR
RAAAAAAAAR
RAAAAAAAAR
RAAAAAAAAR
RAAAAAAAAR
RAAAAAAAAR
RAAAAAAAAR
RAAAAAAAAR
RAAAAAAAAR
RAAAAAAAAR
RAAAAAAAAR
RAAAAAAAAR
RAAAAAAAAR
RAAAAAAAAR
RRRRRRRRRR]]

cursor_focused = "AAAAAAAAAA.ARRRRRRRRA.ARRRRRRRRA.ARRRRRRRRA.ARRRRRRRRA.ARRRRRRRRA.IRRRRRRRRA.ERRRRRRRRA.ARRRRRRRRA.ARRRRRRRRA.ARRRRRRRRA.ARRRRRRRRA.ARRRRRRRRA.ARRRRRRRRA.ARRRRRRRRA.ARRRRRRRRA.ARRRRRRRRA.ARRRRRRRRA.AAAAAAAAAA"

cursor_unfocused = cursor_unfocused:gsub("\n", ".")

return function()
  problem = findContents()
  if problem then return problem end
  
  print("Searching cursor in "..contents_x1..", "..contents_y1..", "..contents_x2..", "..contents_y2)
  
  fw, fh = 8, 17 -- font width/height
  tw = math.floor((contents_x2-contents_x1)/fw+0.5)
  th = math.floor((contents_y2-contents_y1)/fh+0.5)
  
  tolerance = 0.01
  
  local function recog(x, y)
    xx, yy = contents_x1+x*fw, contents_y1+y*fh-1
    cropped = {width=fw+2, height=fh+2,
      getInt = function(x, y) return img.getInt(xx+x, yy+y) end}
  
    icon = makeIcon(cropped)
    diff = iconDiffWithLimit(icon, cursor_unfocused, tolerance, fw+2, fh+2)
    if diff ~= nil and diff <= tolerance then
      print("Cursor diff:", diff)
      lastCurX, lastCurY = x, y
      return "Cursor: "..xx..", "..yy..", "..
        xx+cropped.width..", "..yy+cropped.height..
        ". Cursor position: "..(x+1).."/"..(y+1)..
        ". Window not focused."
    end
    diff2 = iconDiffWithLimit(icon, cursor_focused, tolerance, fw+2, fh+2)
    --[[if y == 23 then
      print(x, y, diff, diff2)
      if x == 37 or x == 38 then
        print(icon)
      end
    end]]
    if diff2 ~= nil and diff2 <= tolerance then
      print("Cursor diff (focused):", diff2)
      lastCurX, lastCurY = x, y
      return "Cursor: "..xx..", "..yy..", "..xx+cropped.width..", "..yy+cropped.height..". Cursor position: "..(x+1).."/"..(y+1)..". Window focused."
    end
  end
  
  print("lastCur:", lastCurX, lastCurY)
  if lastCurX then
    local r = recog(lastCurX, lastCurY)
    if r then
      print("Cached cursor found!")
      return r
    end
    
    -- try whole line
    for x = 0, tw-1 do
      local r = recog(x, lastCurY)
      if r then return r end
    end
  end
  
  -- not found on cached line, try whole screen
  for y = 0, th-1 do
    if y ~= lastCurY then
      for x = 0, tw-1 do
        local r = recog(x, y)
        if r then return r end
      end
    end
  end
  
  return "Cursor not found"
end

Began life as a copy of #434