spaceship.lua

-------------------------------------------------------------------------------
--
--		eLua SpaceShip Game
--
--
-- LED Lab @ PUC-Rio - 2009
--   Dado Sutter
--   Ives Negreiros
--   Ricardo Rosa
--   Pedro Bittencourt
--   Teo Benjamin
--
--
-- Initial Version by Téo Benjamin, Aug 2009
--
-------------------------------------------------------------------------------

local xcanvas = 124						-- Real screen X size
local xcanvas = xcanvas - 12			-- Canvas size with wall
local ycanvas = 96						-- Screen Y size
local pressed = {}						-- This table is used to help the buttonClicked function. If the btn if pressed,
--	pressed[ btn ] = true, when it is released, pressed[ btn ] = nil
local ShipChar = ">"					-- This is the char that is printed to represent the SpaceShip
local shotChar = "-"					-- This char is printed to represent the shots
local enemyChar = "@"					-- This char is used to represent the enemies
local sy = 16							-- Ship's Y position
local sx = 0							-- Ship's X position
local bullets = 70						-- Number of bullets left
local score = 0							-- Player's score
local numOfEnemies = 5					-- Number of simultaneous enemies
local won = false						-- If the player won the game, this value is true. If not, it's false.

-- Initialization
local kit = require( pd.board() )

local canvasMap = {}	-- canvasMap[ line ][ #shot ]
-- canvasMap[ i ][ j ]: i represents the y position and j is a numeric index for each shot in that line. The value is the x position.
-- canvasMap[ i ].e represents the x position of the enemy in that line, if any.
-- Enemies can only appear in lines 5, 15, 25, 35, ..., 75 and 85
for i = 1, ycanvas, 1 do
  canvasMap[ i ] = {}
end
for i = 5, 85, 10 do
  canvasMap[ i ].e = false
end

function drawWall( x, y )
  for i = 0, y, 7 do
    lm3s.disp.print( "|", xcanvas + 1, i, 0 )
  end
  xcanvas = x
  for i = 0, y, 7 do
    lm3s.disp.print( "|", xcanvas + 1, i, 6 )
  end

end

function drawShip( x, y, color, movement )

  if ( movement == 0 ) then
      lm3s.disp.print( ShipChar, x, y,  color )
  elseif ( movement > 0 ) then -- Moving Down
    if y < 8 then
      lm3s.disp.print( ShipChar, x, 0,  0 )
    else
      lm3s.disp.print( ShipChar, x, y - 8 , 0 )
    end
    lm3s.disp.print( ShipChar, x, y,  color )
  elseif ( movement < 0 ) then -- Moving Up
    lm3s.disp.print( ShipChar, x, y + 8, 0 )
    lm3s.disp.print( ShipChar, x, y,  color )
  end
end


function updateShipPos()
  if kit.btn_pressed( kit.BTN_UP ) then
    if ( sy > 1 ) then
      sy = sy - 1
      drawShip( sx, sy, 11, -1 )
    else
      tmr.delay( 1, 1700 )
    end
  elseif kit.btn_pressed( kit.BTN_DOWN ) then
    if ( sy + 7 < ycanvas ) then
      sy = sy + 1
      drawShip( sx, sy, 11, 1 )
    else
      tmr.delay( 1, 1600 )
    end
  else
    drawShip( sx, sy, 11, 0 )
    tmr.delay( 1, 300 ) -- Maintain function processing time aprox the same
  end
end



function updateShots()
  for i in ipairs( canvasMap ) do
    for j in ipairs( canvasMap[ i ] ) do
      if canvasMap[ i ][ j ] then
        lm3s.disp.print( shotChar, canvasMap[ i ][ j ], i, 0 )
        canvasMap[ i ][ j ] = canvasMap[ i ][ j ] + 2
        lm3s.disp.print( shotChar, canvasMap[ i ][ j ], i, 13 )
        if canvasMap[ i ][ j ] + 4 >= xcanvas then
          lm3s.disp.print( shotChar, canvasMap[ i ][ j ], i, 0 )
          table.remove( canvasMap[ i ], j )
          break
        end
        local en = math.floor( i / 10 ) * 10 + 5
        if canvasMap[ en ].e then
          if ( canvasMap[ i ][ j ] <= canvasMap[ en ].e ) and ( canvasMap[ i ][ j ] + 4 >= canvasMap[ en ].e ) then
            destroyEnemy( i, j, en )
            createEnemy()
          end
        end
      else
        tmr.delay( 1, 1200 )
      end
    end
  end
end

function shot()
  if bullets > 0 then
    table.insert( canvasMap[ sy ], sx + 6 )
    bullets = bullets - 1
  end
  sound()
end

function buttonClicked( button )
  if kit.btn_pressed( button ) then
    pressed[ button ] = true
  else
    if pressed[ button ] then
      pressed[ button ] = false
      return true
    end
    pressed[ button ] = false
  end
  return false
end

function printBulletsNum()
  lm3s.disp.print( string.format( "%2d", bullets ), xcanvas + 4, 2, 6 )
end

function printScore()
  lm3s.disp.print( string.format( "%2d", score ), xcanvas + 4, ycanvas - 10, 6 )
end

function sound()
  pwm.start( 1 )
  tmr.delay( 0, 20000 )
  pwm.stop( 1 )
end


function updateEnemiesPos()
  for i = 5, 85, 10 do
    if canvasMap[ i ].e then
      lm3s.disp.print( enemyChar, canvasMap[ i ].e, i, 0 )
      canvasMap[ i ].e = canvasMap[ i ].e - 1
      lm3s.disp.print( enemyChar, canvasMap[ i ].e, i, 11 )
      if canvasMap[ i ].e <= 0 then
        lm3s.disp.print( enemyChar, canvasMap[ i ].e, i, 0 )
        canvasMap[ i ].e = nil
        createEnemy()
      end
    end
  end
end

function createEnemy()
  while true do
    local en = ( math.random( 0, 8 ) )*10 + 5
    if not canvasMap[ en ].e then
      canvasMap[ en ].e = xcanvas - 5
      break
    end
  end
end

function addEnemy()
  if numOfEnemies < 9 then
    numOfEnemies = numOfEnemies + 1
    createEnemy()
  end
end
function destroyEnemy( i, j, en )
  lm3s.disp.print( shotChar, canvasMap[ i ][ j ], i, 0 )
  table.remove( canvasMap[ i ], j )
  lm3s.disp.print( enemyChar, canvasMap[ en ].e, en, 0 )
  canvasMap[ en ].e = nil
  score = score + 1
end

function destroyAll()
  for i in ipairs( canvasMap ) do
    for j in ipairs( canvasMap[ i ] ) do
      lm3s.disp.print( shotChar, canvasMap[ i ][ j ], i, 0 )
      table.remove( canvasMap[ i ], j )
    end
    local en = math.floor( i / 10 ) * 10 + 5
    if canvasMap[ en ].e then
      lm3s.disp.print( enemyChar, canvasMap[ en ].e, en, 0 )
      canvasMap[ en ].e = nil
    end
  end

end

for i = 1, numOfEnemies, 1 do
  createEnemy()
end


lm3s.disp.init( 1000000 )

-- Initial information
lm3s.disp.print( "eLua SpaceShip", 10, 10, 11 )
lm3s.disp.print( "Press SELECT -->", 10, 40, 11 )
local seed = 0
while not buttonClicked( kit.BTN_SELECT ) do
  seed = seed + 1
end
math.randomseed( seed )
lm3s.disp.clear()

-------------------------------------------------------------------------------
--
--				MAIN LOOP
--
-------------------------------------------------------------------------------
pwm.setclock( 1, 25000000 )
pwm.setup( 1, 1000, 70 )

drawWall( xcanvas, ycanvas )

while true do
  updateEnemiesPos()
  for i = 1, 3, 1 do
    updateShipPos()
    updateShots()
  end
  printBulletsNum()
  printScore()
  if buttonClicked( kit.BTN_SELECT ) then shot() end
  if buttonClicked( kit.BTN_RIGHT ) then
    destroyAll()
    for i = 1, numOfEnemies, 1 do
      createEnemy()
    end
  end
  if score >= 50 then
    won = true
    break
  end
  if bullets <= 0 then
    won = false
    break
  end
  tmr.delay(1, 12000)
  collectgarbage("collect")
end
if won then
  lm3s.disp.clear()
  lm3s.disp.print( "You won!", 20, 30, 11 )
  lm3s.disp.print( "Congratulations!", 5, 50, 11 )
else
  lm3s.disp.clear()
  lm3s.disp.print( "Game Over! :(", 20, 20, 11 )
end