camera.lua

-- 
--  camera.lua
--  redditgamejam-05
--  
--  Created by Jay Roberts on 2011-01-06.
--  Copyright 2011 GloryFish.org. All rights reserved.
-- 

require 'class'
require 'vector'

Camera = class(function(camera)

  camera.offset = vector(0, 0)
  camera.bounds = {
    top = 0,
    right = love.graphics.getWidth(),
    bottom = love.graphics.getHeight(),
    left = 0
  }
  camera.position = vector(love.graphics.getWidth() / 2, love.graphics.getHeight() / 2)
  camera.focus = vector(love.graphics.getWidth() / 2, love.graphics.getHeight() / 2)
  camera.deadzone = 100

end)


function Camera:update(dt)
  -- Move the camera if we are outside the deadzone
  if self.position:dist(self.focus) > self.deadzone then 
    self.position = self.position - (self.position - self.focus) * dt
  end

  -- Clamp camera to bounds
  local halfWidth = love.graphics.getWidth() / 2
  local halfHeight = love.graphics.getHeight() / 2
  
  if self.position.x - halfWidth < self.bounds.left then
    self.position.x = self.bounds.left + halfWidth
  end 

  if self.position.x + halfWidth > self.bounds.right then
    self.position.x = self.bounds.right - halfWidth
  end 

  if self.position.y - halfHeight < self.bounds.top then
    self.position.y = self.bounds.top + halfHeight
  end 

  if self.position.y + halfHeight > self.bounds.bottom then
    self.position.y = self.bounds.bottom - halfHeight
  end
  
  -- Update the offset
  self.offset = vector(math.floor(camera.position.x - love.graphics.getWidth() / 2), 
                       math.floor(camera.position.y - love.graphics.getHeight() / 2))
end