OC/3dPirnter

local component = require "component"
local event = require "event"
local printer = component.printer3d
local gpu = component.gpu

local X_SHIFT = 2
local X_CELL_QUANTUM = 2

--UTILS--
local function quantization(value, quantum_value)
  return quantum_value >= 1 and value-(value+1)%quantum_value
end

local function quantizationCoords(x, y, qx, qy)
  return qx >= 1 and x-(x+1)%qx or x, qy >= 1 and y-(y+1)%qy or y
end

function fillChess(gpu, color1, color2, startX, startY, screenX, screenY)
  local shift = 0
  --Fill using color1
  gpu.setBackground(color1)
  gpu.fill(startX, startY, screenX, screenY, ' ')

  --Fill using color2
  gpu.setBackground(color2)
  for y=startY, screenY+startY-1, 1 do
    for x=startX, screenX+startX-2, 4 do
      gpu.fill(x+shift, y, 2, 1, ' ')
    end
    shift = shift ~= X_SHIFT and X_SHIFT or 0
  end
end

--TOOLS LOGIC--
local rectangle = function(self, gpu, event)
  local x, y = quantizationCoords(event[3], event[4], X_CELL_QUANTUM, 0)

  if ( event[1] == "touch" and event[5] == 0 ) then
    if ( not self.state.drawMode ) then
      self.state.drawMode = true
      self.state.pixelUnderMark = { gpu.get(x, y) }
      self.state.x = x
      self.state.y = y

      gpu.fill(x, y, 2, 1, ' ')
    else
      --ДОРАБОТАТЬ!
      local startX, startY = math.min(self.state.x, x), math.min(self.state.y, y)
      local endX, endY = math.max(self.state.x, x), math.max(self.state.y, y)

      gpu.fill( startX, startY, endX-startX+2, endY-startY+1, ' ' )
      self.state = {}
    end
  elseif ( event[1] == "key_down" and event[3] == 96 ) then
    if ( self.state.drawMode ) then
      local prevBackground = gpu.getBackground()
      gpu.setBackground(self.state.pixelUnderMark[3])
      gpu.fill(self.state.x, self.state.y, 2, 1, ' ')
      gpu.setBackground(prevBackground)
      self.state = {}
    end
  end
end

local TOOLS = {
  ["ERASER"]    = { ["id"] = 0,  ["action"] = eraser,    ["state"] = {} },
  ["PENCIL"]    = { ["id"] = 5,  ["action"] = pencil,    ["state"] = {} },
  ["BRUSH"]     = { ["id"] = 10, ["action"] = brush,     ["state"] = {} },
  ["PIPETTE"]   = { ["id"] = 15, ["action"] = pipette,   ["state"] = {} },
  ["RECTANGLE"] = { ["id"] = 20, ["action"] = rectangle, ["state"] = {} },
}

--INITIALIZATION AND MAIN LOOP--
local screenX, screenY = gpu.getResolution()

fillChess(gpu, 0xffffff, 0xE5E5E5, 1, 1, screenX, screenY)
gpu.setBackground(0)

local currentTool = "RECTANGLE"

while true do
  local e = {event.pull()}

  TOOLS[currentTool]:action(gpu, e)

  if ( e[5] == 1 ) then
    break
  end
end