Preparing to add demos.

main.lua

@@ -20,6 +20,7 @@ local state
 state = {
 
   Reset = function()
+    state.tick = 0
     state.beat = {}
     state.startTime = love.timer.getTime()
     state.currentBeat = 1
@@ -92,7 +93,7 @@ OnImpact = function( impact )
 end
 local _OnImpact = OnImpact
 
-local function NewGame()
+local function NewGame( isDemo )
   love.graphics.setBackgroundColor( 245 / 255, 169 / 255, 184 / 255 ) --Trans pink.
   OnImpact = _OnImpact
   ExtrapolateBeatScore = _ExtrapolateBeatScore
@@ -105,6 +106,12 @@ local function NewGame()
   wave.Reset()
   text.Reset()
   audio.Reset()
+  recorder.Reset()
+
+  state.isDemo = isDemo
+  if isDemo then
+    recorder.Load()
+  end
 end
 
 function love.load()
@@ -203,6 +210,8 @@ end
 
 OnVictory = function()
 
+  recorder.Save()
+
   particles:setParticleLifetime( 0, 30 )
   particles:setSizes( 0.001, 0.0001, 0.0005 )
   particles:setColors( 
@@ -296,7 +305,16 @@ Update = function( dt )
 
   --Physics tick.
   while dt > step do
-    recorder.Update( marble.GetAcceleration() ) --For savegames.
+    
+    state.tick = state.tick + 1
+
+    if state.isDemo then
+      local ddx, ddy = recorder.NextTick()
+      if ddx then marble.SetAcceleration( ddx, ddy )
+      else state.isDemo = false end
+    else
+      recorder.Update( marble.GetAcceleration() ) --For savegames.
+    end
 
     marble.Integrate( step )
     wave.Integrate( step )
@@ -318,11 +336,14 @@ _Update = Update
 function love.keypressed( key, code, isRepeat )
   if key == "escape" then return love.event.quit() end
   if key == "space" then return NewGame() end
-  return marble.OnKey()
+  if code == "return" then return NewGame( true ) end --Play demo.
+  if code == "q" then recorder.Save() end
+  if state.isDemo then return end
+  return marble.OnKey( state.tick )
 end
 
 function love.keyreleased( key, code )
-  return marble.OnKey()
+  return marble.OnKey( state.tick )
 end
 
 function love.resize( w, h )

marble.lua

@@ -19,6 +19,8 @@ function marble.Next() return newState end
 
 function marble.GetAcceleration( ) return ddx, ddy end
 
+function marble.SetAcceleration( x, y ) ddx = x; ddy = y end
+
 function marble.Integrate( step )
   newState.t = love.timer.getTime()
   newState.dx = (1.0 - INERTIA) * curState.dx + INERTIA * ddx
@@ -86,10 +88,11 @@ end
 
 
 
-function marble.OnKey()
+function marble.OnKey( tick )
   ddx = (love.keyboard.isScancodeDown( "d" ) and 1.0 or 0.0) - (love.keyboard.isScancodeDown( "a" ) and 1.0 or 0.0)
   ddy = (love.keyboard.isScancodeDown( "w" ) and 1.0 or 0.0) - (love.keyboard.isScancodeDown( "s" ) and 1.0 or 0.0)
 
+  --print( tick, ddx, ddy )
   local n = math.sqrt( ddx * ddx + ddy * ddy )
   if n < 0.001 then return end
   ddx, ddy = ddx / n, ddy / n
@@ -177,6 +180,7 @@ function marble.Reset()
   INERTIA = 0.05
   MAXSPEED = 2.0
   
+  ddx, ddy = 0, 0
   oldState, curState, newState = State(), State(), State()
   marble.Resize()
   marble.Draw = marble._Draw

recorder.lua

@@ -4,8 +4,9 @@ local recorder = {}
 recorder.isLoaded = false
 local i = 0
 
-local function Reset()
+function recorder.Reset()
   i = 0
+  for k, _ in ipairs( recorder ) do recorder[k] = nil end
 end
 
 function recorder.Update( ddx, ddy )
@@ -16,17 +17,44 @@ function recorder.Update( ddx, ddy )
   if ddy < -0.5 then byte = byte + 8 end
   
   i = i + 1
-  recorder[i] = string.char( byte )
+  recorder[i] = string.char( byte + 48 )
 end
 
 function recorder.Load( )
   local s = love.filesystem.read( "demo" )
-  
+  if not s then return end
+  local j = 1
+  for c in s:gmatch( "." ) do
+    recorder[j] = string.byte( c ) - 48
+    j = j + 1
+  end
   recorder.isLoaded = true
+  i = 0
+  
+  return true
+end
+
+function recorder.NextTick( )
+  
+  local byte = recorder[ i + 1 ]
+  if not byte then return end
+  i = i + 1
+  
+  local a, b, c, d =
+    math.floor( byte     ) % 2,
+    math.floor( byte / 2 ) % 2,
+    math.floor( byte / 4 ) % 2,
+    math.floor( byte / 8 ) % 2
+  
+  local ddx, ddy = a - c, b - d
+  local n = math.sqrt( ddx * ddx + ddy * ddy )
+  if n < 0.001 then return 0, 0 end
+  ddx, ddy = ddx / n, ddy / n
+  return ddx, ddy
 end
 
 function recorder.Save( )
-  assert( love.filesystem.write( "demo", table.concat( recorder ) ) )
+  return assert( love.filesystem.write( "demo", table.concat( recorder, "", 1, i ) ) )
 end
 
 return recorder