public void Update()
{
//update the desired stage when requested
if (this._nextStage != null)
{
this._currentStage = this._nextStage;
this._currentStage.OnLoad(this._composition);
}
//wipes out the composition target
this._composition.Clear();
//compose the graphic scene
this._nextStage = this._currentStage.OnCompose(this._composition);
//dumps the composition to the physical device
this._renderer.Dump(this._composition);
}
public override GameStageBase OnCompose(CompositionTargetBase target)
{
GameStageBase result = null;
if (this._pausedClock == 0)
{
//here is the normal flow during the playable game
this.ShiftAliens = (this.Context.Clock & this._clockMask) == 0;
//update objects
this.Ship.Update(this);
this.Missile.Update(this);
this.Saucer.Update(this);
for (int i = 0; i < AliensPerRow; i++)
{
this.SmallAliens[i].Update(this);
this.LargeAliens[i].Update(this);
}
for (int i = 0; i < BombsCount; i++)
{
this.Bombs[i].Update(this);
}
//check collisions
if (this.Ship.DetectCollision(this))
{
}
if (this.Saucer.DetectCollision(this))
{
}
for (int i = 0; i < AliensPerRow; i++)
{
if (this.SmallAliens[i].DetectCollision(this))
{
break;
}
if (this.LargeAliens[i].DetectCollision(this))
{
break;
}
}
for (int i = 0; i < BarriersCount; i++)
{
if (this.Barriers[i].DetectCollision(this))
{
break;
}
}
//update context for next frame
this.CurrentAlienDir = this.NextAlienDir;
if (this.CurrentAlienDir == AlienDirection.GroundReached)
{
//aliens grounded: the game is over!
this._pausedClock = PausedTimeLong;
this._pauseStage = PauseStage.GameOver;
}
}
//this happens when some event has paused the game
else if (--this._pausedClock == 0)
{
//finalize the paused stage
switch (this._pauseStage)
{
case PauseStage.ShipsLeft:
//resume the game where was broken
this.ResumeLevel();
break;
case PauseStage.GameOver:
//back to the intro stage
result = new GameStageIntro(this.Context);
this.Context.Status = GameStatus.Registering;
break;
}
this._pauseStage = PauseStage.None;
}
//render the renderables
for (int i = 0; i < RenderableCount; i++)
{
this._renderables[i].OnRender(target);
}
//when paused, compose the required stage
if (this._pauseStage != PauseStage.None)
{
this._pauseStageHandlers[(int)this._pauseStage](target);
}
return(result);
}
public override GameStageBase OnCompose(CompositionTargetBase target)
{
GameStageBase result = null;
//the game begins on any button pressed
if (this.Context.FireButton ||
this.Context.RightButton ||
this.Context.LeftButton)
{
if (this.Context.Status == GameStatus.Idle)
{
result = new GameStagePlay(this.Context);
}
}
else if (this.Context.Status == GameStatus.RegComplete)
{
//this prevents the game to begin when
//a button is still pressed since a prev stage
this.Context.Status = GameStatus.Idle;
}
bool flasher = (this.Context.Clock & 8) != 0;
if (this._frame == 0)
{
this._posT0 = new Point(34, 4);
this._posT1 = new Point(40, 4);
this._posAlien = new Point(-25, 4);
}
if (this._frame < 24)
{
target.DrawString("O", AlienFont.Instance, Brushes.Lime, _posT0);
target.DrawString(Title1, Fonts.Fixed5x7, Brushes.Lime, _posT1);
_posT0.X--;
_posT1.X--;
}
else if (this._frame < 24)
{
target.DrawString("O", AlienFont.Instance, Brushes.Lime, _posT0);
target.DrawString(Title1, Fonts.Fixed5x7, Brushes.Lime, _posT1);
}
else if (this._frame < 24 + 8)
{
target.DrawString("O", AlienFont.Instance, Brushes.Lime, _posT0);
target.DrawString(Title1, Fonts.Fixed5x7, Brushes.Lime, _posT1);
_posT0.X++;
_posT1.X++;
}
else if (this._frame < 32 + 34)
{
string alien = string.Empty + (char)(0x50 + (this._frame & 1));
target.DrawString(alien, AlienFont.Instance, Brushes.Yellow, _posAlien);
target.DrawString("O", AlienFont.Instance, Brushes.Lime, _posT0);
target.DrawString(Title1, Fonts.Fixed5x7, Brushes.Lime, _posT1);
_posAlien.X++;
}
else if (this._frame < 66 + 34)
{
string alien = string.Empty + (char)(0x50 + (this._frame & 1));
target.DrawString(alien, AlienFont.Instance, Brushes.Yellow, _posAlien);
target.DrawString("O", AlienFont.Instance, Brushes.Lime, _posT0);
target.DrawString(Title1, Fonts.Fixed5x7, Brushes.Lime, _posT1);
_posAlien.X--;
_posT0.X--;
}
else if (this._frame < 100 + 34)
{
string alien = string.Empty + (char)(0x50 + (this._frame & 1));
target.DrawString(alien, AlienFont.Instance, Brushes.Yellow, _posAlien);
target.DrawString("N", AlienFont.Instance, Brushes.Lime, _posT0);
target.DrawString(Title1, Fonts.Fixed5x7, Brushes.Lime, _posT1);
_posAlien.X++;
_posT0.X++;
}
else if (this._frame < 134 + 100)
{
string alien = string.Empty + (char)(0x50 + (this._frame & 1));
target.DrawString(alien, AlienFont.Instance, Brushes.Yellow, _posAlien);
target.DrawString("N", AlienFont.Instance, Brushes.Lime, _posT0);
target.DrawString(Title1, Fonts.Fixed5x7, Brushes.Lime, _posT1);
_posAlien.X--;
_posT0.X--;
_posT1.X--;
}
else if (this._frame < 234 + 60)
{
if (this._frame == 234)
{
this._posT0.X = 15;
this._posT0.Y = 0;
this._posT1.X = -15;
this._posT1.Y = 8;
}
//alien #2 is wider and yields less points
string alien2 = flasher ? "RS" : "TU";
target.DrawString(alien2, AlienFont.Instance, Brushes.Yellow, this._posT0);
target.DrawString(AlienLarge.Score + "p", Fonts.Fixed5x7, Brushes.Lime, this._posT0.X + 12, this._posT0.Y);
//alien #1 worth more
string alien1 = flasher ? "P" : "Q";
target.DrawString(alien1, AlienFont.Instance, Brushes.Yellow, this._posT1.X + 19, this._posT1.Y);
target.DrawString(AlienSmall.Score + "p", Fonts.Fixed5x7, Brushes.Lime, this._posT1.X, this._posT1.Y + 1);
if (this.Context.IsEvenClock)
{
this._posT0.X--;
this._posT1.X++;
}
}
else if (this._frame < 294 + 80)
{
if (flasher)
{
target.DrawString("In ert", Fonts.Fixed5x7, Brushes.Lime, new Point(-1, 0));
target.DrawString("$", Fonts.Fixed5x7, Brushes.Red, new Point(11, 0));
target.DrawString("coin", Fonts.Fixed5x7, Brushes.Yellow, new Point(4, 9));
}
}
else
{
this._frame = -1;
}
this._frame++;
return(result);
}