Loading Levels From Files

While we are talking about splitting the code, I also want to move level definitions into separate files. This is not immediately necessary, but will become convenient later, when the amount of levels will grow.

The files with the levels descriptions will be kept at the levels folder. It is possible to write each level-file as a separate Lua module. However, it is considered a good practice to avoid any code in level files, preferably making them data-only. Therefore, the only thing that remains from the Lua module structure is the return statement. Here is an example of hey.lua:

return {
   { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 },
   { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 },
   { 1, 0, 1, 0, 2, 2, 2, 0, 3, 0, 3 },
   { 1, 0, 1, 0, 2, 0, 0, 0, 3, 0, 3 },
   { 1, 1, 1, 0, 2, 2, 0, 0, 0, 3, 0 },
   { 1, 0, 1, 0, 2, 0, 0, 0, 0, 3, 0 },
   { 1, 0, 1, 0, 2, 2, 2, 0, 0, 3, 0 },
   { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 }
}

To maintain the order of the levels, the levels.sequence also has to be move into separate file:

return {
   "hey",
   "bye"
}

The levels.sequence has to be required levels.sequence = require "levels/sequence". Also the level files:

function levels.require_current_level()
   local level_filename = "levels/" ..
      levels.sequence[ levels.current_level ]
   local level = require( level_filename )
   return level
end

Corresponding chages in love.load and levels.switch_to_next_level( bricks, ball ).

function love.load()
   level = levels.require_current_level()
   bricks.construct_level( level )
   walls.construct_walls()
end

There are couple of other things I want to introduce in this part. To facilitate the process of destroying bricks and moving to next level quickly:

function love.keyreleased( key, code )
   if key == 'c' then
      bricks.clear_current_level_bricks()
   .....   
end

function bricks.clear_current_level_bricks()
   for i in pairs( bricks.current_level_bricks ) do
      bricks.current_level_bricks[i] = nil
   end
end

The second one is brick coloring depending on the brick`s type:

function bricks.draw_brick( single_brick )
   love.graphics.rectangle( 'line',
			    single_brick.position.x,
			    single_brick.position.y,
			    single_brick.width,
			    single_brick.height )
   local r, g, b, a = love.graphics.getColor( )
   if single_brick.bricktype == 1 then
      love.graphics.setColor( 255, 0, 0, 100 )
   elseif single_brick.bricktype == 2 then
      love.graphics.setColor( 0, 255, 0, 100 )
   elseif single_brick.bricktype == 3 then
      love.graphics.setColor( 0, 0, 255, 100 )
   end
   love.graphics.rectangle( 'fill',
			    single_brick.position.x,
			    single_brick.position.y,
			    single_brick.width,
			    single_brick.height )
   love.graphics.setColor( r, g, b, a )
end