-- Base room visual class
BaseRoom = {}
BaseRoom.__index = BaseRoom

function BaseRoom:new(asset)
  self = setmetatable({}, BaseRoom)
  self.time = 0
  self.config = asset.config or {}
  self.background = asset.imageLoader("background")
  self.maskShader = love.graphics.newShader [[
      vec4 effect(vec4 color, Image texture, vec2 texture_coords, vec2 screen_coords) {
        if (Texel(texture, texture_coords).rgb == vec3(0.0)) {
            // a discarded pixel wont be applied as the stencil.
            discard;
        }
        return vec4(1.0);
      }
  ]]
  return self
end

function BaseRoom:update(dt)
  self.time = self.time + dt
end

function BaseRoom:drawBack()
end

function BaseRoom:drawFront()
end

function BaseRoom:drawBackground()
  if self.background then
    love.graphics.draw(self.background, 0, 0)
  end
end

function BaseRoom:drawForeground()
end

function BaseRoom:drawWithMask(mask)
  if self.background then
    if mask then
      local stencilFunc = function()
        love.graphics.setShader(self.maskShader)
        love.graphics.draw(mask, 0, 0)
        love.graphics.setShader()
      end
      love.graphics.stencil(stencilFunc, "replace", 1)
      love.graphics.setStencilTest("greater", 0)
    end
    love.graphics.draw(self.background, 0, 0)
    love.graphics.setStencilTest()
  end
end

function BaseRoom:drawShaderWithMask(shader, mask)
  if self.background then
    if mask then
      shader:send("time", self.time)
      local stencilFunc = function()
        love.graphics.setShader(self.maskShader)
        love.graphics.draw(mask, 0, 0)
        love.graphics.setShader()
      end
      love.graphics.stencil(stencilFunc, "replace", 1)
      love.graphics.setStencilTest("greater", 0)
    end

    love.graphics.setShader(shader)
    love.graphics.draw(self.background, 0, 0)
    love.graphics.setShader()
    love.graphics.setStencilTest()
  end
end

return BaseRoom