diff -r 000000000000 -r 7f656887cf89 commands/snake/snake.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/commands/snake/snake.cpp	Wed Jun 23 15:52:26 2010 +0100
@@ -0,0 +1,473 @@
+// snake.cpp
+// 
+// Copyright (c) 2009 - 2010 Accenture. All rights reserved.
+// This component and the accompanying materials are made available
+// under the terms of the "Eclipse Public License v1.0"
+// which accompanies this distribution, and is available
+// at the URL "http://www.eclipse.org/legal/epl-v10.html".
+// 
+// Initial Contributors:
+// Accenture - Initial contribution
+//
+
+#include <fshell/ioutils.h>
+#include <e32math.h>
+
+using namespace IoUtils;
+
+_LIT(KSnakeSeg, "*");
+_LIT(KBait, "$");
+
+class CKeyWatcher;
+
+class CCmdSnake : public CCommandBase
+	{
+public:
+	static CCommandBase* NewLC();
+	~CCmdSnake();
+	
+	void Up();
+	void Down();
+	void Left();
+	void Right();
+	void Exit();
+	void OnTimer();
+private:
+	CCmdSnake();
+private: // From CCommandBase.
+	virtual const TDesC& Name() const;
+	virtual void DoRunL();
+	virtual void ArgumentsL(RCommandArgumentList& aArguments);
+	virtual void OptionsL(RCommandOptionList& aOptions);
+	
+	void ConstructL();
+	void InitBoardL();
+	void SetBoard(TInt aX, TInt aY, TBool aSet);
+	TBool GetBoard(TInt aX, TInt aY);
+	void DrawBoardL();
+	void InitSnakeL(TInt aLen, TPoint aPos);
+	void DrawSnakeL();
+	void DrawScore();
+	void PlaceBait();
+	void Grow();
+	
+	void Dead();
+private:
+	RIoConsoleWriteHandle iCons;
+	RIoConsoleReadHandle iConsIn;
+	TSize iBoardSize;
+	RArray<TPoint> iSnake;
+	TInt iSnakeHead;
+	RArray<TUint32> iBoard;
+	TInt iBoardWidthWords;
+	TPoint iDirection;
+	TPoint iBait;
+	TInt iScore;
+	TInt iSpeed;
+	
+	CKeyWatcher* iKeys;
+	CPeriodic* iTimer;
+	TInt64 iRandomSeed;
+	TBool iInCollisionGracePeriod;
+	};
+
+class CKeyWatcher : public CActive
+	{
+public:
+	CKeyWatcher(CCmdSnake& aOwner, RIoConsoleReadHandle& aCons);
+	~CKeyWatcher();
+	void Request();
+
+private:
+	virtual void RunL();
+	virtual void DoCancel();
+private:
+	CCmdSnake& iOwner;
+	RIoConsoleReadHandle& iCons;
+	};
+
+
+CCommandBase* CCmdSnake::NewLC()
+	{
+	CCmdSnake* self = new(ELeave) CCmdSnake();
+	CleanupStack::PushL(self);
+	self->ConstructL();
+	return self;
+	}
+
+CCmdSnake::~CCmdSnake()
+	{
+	delete iKeys;
+	delete iTimer;
+	iSnake.Close();
+	iBoard.Close();
+	}
+
+CCmdSnake::CCmdSnake()
+	: CCommandBase(EManualComplete), iSpeed(50000)
+	{
+	}
+
+const TDesC& CCmdSnake::Name() const
+	{
+	_LIT(KName, "snake");	
+	return KName;
+	}
+	
+TInt OnTimerS(TAny* aSnake)
+	{
+	((CCmdSnake*)aSnake)->OnTimer();
+	return KErrNone;
+	}
+
+void CCmdSnake::DoRunL()
+	{
+	if (!Stdout().AttachedToConsole())
+		{
+		LeaveIfErr(KErrNotSupported, _L("Stdout must be connected to a console"));
+		}
+	iCons = Stdout();
+	if (!Stdin().AttachedToConsole())
+		{
+		LeaveIfErr(KErrNotSupported, _L("Stdin must be connected to a console"));
+		}
+	iConsIn = Stdin();
+	iKeys = new(ELeave)CKeyWatcher(*this, iConsIn);
+	iCons.SetCursorHeight(0);
+	
+	User::LeaveIfError(iCons.GetScreenSize(iBoardSize));
+	iBoardSize.iHeight--; // space for status bar, plus to ensure that the console doesn't scroll when we draw the bottom line
+	iBoardWidthWords = iBoardSize.iWidth / 32;
+	if (iBoardSize.iWidth % 32) ++iBoardWidthWords;
+	InitBoardL();
+	
+	DrawBoardL();
+	
+	TPoint centre;
+	centre.iX = iBoardSize.iWidth / 2;
+	centre.iY = iBoardSize.iHeight / 2;
+	InitSnakeL(10, centre);	
+	DrawSnakeL();
+	PlaceBait();
+	DrawScore();
+	
+	iTimer = CPeriodic::NewL(CActive::EPriorityStandard);
+	iTimer->Start(iSpeed, iSpeed, TCallBack(OnTimerS, this));
+	}
+
+void CCmdSnake::ArgumentsL(RCommandArgumentList& /*aArguments*/)
+	{
+	}
+
+void CCmdSnake::OptionsL(RCommandOptionList& aOptions)
+	{
+	_LIT(KOptSpeed, "speed");
+	aOptions.AppendIntL(iSpeed, KOptSpeed);
+	}
+	
+void CCmdSnake::ConstructL()
+	{
+	BaseConstructL();
+	TTime now;
+	now.HomeTime();
+	iRandomSeed = now.Int64();
+	}
+
+void CCmdSnake::InitBoardL()
+	{
+	// first, zero the whole board
+	iBoard.Reset();
+	for (TInt y=0; y<iBoardSize.iHeight; ++y)
+		{
+		for (TInt x=0; x<iBoardWidthWords; ++x)
+			{
+			iBoard.AppendL(0);
+			}
+		}
+	// draw a box around the edge
+	for (TInt i=0; i<iBoardSize.iWidth; ++i)
+		{
+		SetBoard(i, 0, ETrue);
+		SetBoard(i, iBoardSize.iHeight-1, ETrue);
+		}
+	for (TInt i=0; i<iBoardSize.iHeight; ++i)
+		{
+		SetBoard(0, i, ETrue);
+		SetBoard(iBoardSize.iWidth-1, i, ETrue);
+		}
+	}
+	
+void CCmdSnake::SetBoard(TInt aX, TInt aY, TBool aSet)
+	{
+	TInt word = (aY * iBoardWidthWords) + (aX / 32);
+	TInt bit = 1 << (aX % 32);
+	if (aSet)
+		{
+		iBoard[word] |= bit;
+		}
+	else
+		{
+		iBoard[word] &= (~bit);
+		}
+	}
+	
+TBool CCmdSnake::GetBoard(TInt aX, TInt aY)
+	{
+	TInt word = (aY * iBoardWidthWords) + (aX / 32);
+	TInt bit = 1 << (aX % 32);
+	return iBoard[word] & bit;
+	}
+	
+void CCmdSnake::DrawBoardL()
+	{
+	User::LeaveIfError(iCons.ClearScreen());
+	
+	RBuf line;
+	line.CreateMaxL(iBoardSize.iWidth);
+	CleanupClosePushL(line);
+	
+	for (TInt y=0; y<iBoardSize.iHeight; ++y)
+		{
+		for (TInt x=0; x<iBoardSize.iWidth; ++x)
+			{
+			line[x] = GetBoard(x,y) ? '#' : ' ';
+			}
+		User::LeaveIfError(iCons.SetCursorPosAbs(TPoint(0, y)));
+		User::LeaveIfError(iCons.Write(line));
+		}
+	
+	
+	CleanupStack::PopAndDestroy();
+	}
+	
+void CCmdSnake::InitSnakeL(TInt aLen, TPoint aPos)
+	{
+	iSnake.Reset();
+	for (TInt i=0; i<aLen; ++i)
+		{
+		iSnake.AppendL(aPos);
+		}
+	iSnakeHead = 0;
+	}
+	
+void CCmdSnake::DrawSnakeL()
+	{
+	for (TInt i=0; i<iSnake.Count(); ++i)
+		{
+		User::LeaveIfError(iCons.SetCursorPosAbs(iSnake[i]));
+		User::LeaveIfError(iCons.Write(KSnakeSeg));
+		}
+	}
+
+void CCmdSnake::Up()
+	{
+	if (iDirection.iY != 1)
+		{
+		iDirection.SetXY(0, -1);
+		}
+	}
+	
+void CCmdSnake::Down()
+	{
+	if (iDirection.iY != -1)
+		{
+		iDirection.SetXY(0, 1);
+		}
+	}
+	
+void CCmdSnake::Left()
+	{
+	if (iDirection.iX != 1)
+		{
+		iDirection.SetXY(-1, 0);
+		}
+	}
+	
+void CCmdSnake::Right()
+	{
+	if (iDirection.iX != -1)
+		{
+		iDirection.SetXY(1, 0);
+		}
+	}
+	
+_LIT(KQuitFmt, "Quit; score: %d\n");
+
+void CCmdSnake::Exit()
+	{
+	iCons.SetCursorPosAbs(TPoint(0, iBoardSize.iHeight));
+	iCons.SetCursorHeight(20);
+	TBuf<0x20> buf;
+	buf.AppendFormat(KQuitFmt, iScore);
+	iCons.Write(buf);
+	Complete(iScore);
+	}
+	
+_LIT(KDeadFmt, "Game over; score: %d\n");
+
+void CCmdSnake::Dead()
+	{
+	iKeys->Cancel();
+	iCons.SetCursorPosAbs(TPoint(0, iBoardSize.iHeight));
+	iCons.SetCursorHeight(20);
+	TBuf<0x20> buf;
+	buf.AppendFormat(KDeadFmt, iScore);
+	iCons.Write(buf);
+	Complete(iScore);
+	}
+	
+void CCmdSnake::OnTimer()
+	{
+	iKeys->Request();
+	if (!(iDirection.iX || iDirection.iY)) return;
+	TPoint newHead = iSnake[iSnakeHead] + iDirection + iBoardSize;
+	newHead.iX %= iBoardSize.iWidth;
+	newHead.iY %= iBoardSize.iHeight;
+	
+	// check for obstacles
+	if (GetBoard(newHead.iX, newHead.iY))
+		{
+		if (iInCollisionGracePeriod)
+			{
+			Dead();
+			}
+		else
+			{
+			iInCollisionGracePeriod = ETrue;
+			}
+		return;
+		}
+	iInCollisionGracePeriod = EFalse;
+	for (TInt i=0; i<iSnake.Count(); ++i)
+		{
+		if (newHead == iSnake[i])
+			{
+			Dead();
+			return;
+			}
+		}
+	
+	TInt tail = (iSnakeHead+1) % iSnake.Count();
+	// overwrite the tail if it's not in the same position as the segment before it
+	if (iSnake[tail] != iSnake[(tail+1)%iSnake.Count()])
+		{
+		iCons.SetCursorPosAbs(iSnake[tail]);
+		iCons.Write(_L(" "));
+		}
+	iCons.SetCursorPosAbs(newHead);
+	iCons.Write(KSnakeSeg);
+	iSnakeHead = (iSnakeHead+1) % iSnake.Count();
+	iSnake[iSnakeHead] = newHead;
+	
+	if (iSnake[iSnakeHead] == iBait)
+		{
+		// Yummy!
+		iScore++;
+		DrawScore();
+		PlaceBait();
+		Grow();
+		}
+	}
+	
+_LIT(KScoreFormat, "Score: %d");
+	
+void CCmdSnake::DrawScore()
+	{
+	iCons.SetCursorPosAbs(TPoint(0, iBoardSize.iHeight));
+	TBuf<0x20> score;
+	score.AppendFormat(KScoreFormat, iScore);
+	iCons.Write(score);
+	}
+
+void CCmdSnake::PlaceBait()
+	{
+	TBool ok;
+	do
+		{
+		ok = ETrue;
+		iBait.iX = Math::Rand(iRandomSeed) % iBoardSize.iWidth;
+		iBait.iY = Math::Rand(iRandomSeed) % iBoardSize.iHeight;
+		
+		if (GetBoard(iBait.iX, iBait.iY)) ok = EFalse;
+		if (ok)
+			{
+			for (TInt i=0; i<iSnake.Count(); ++i)
+				{
+				if (iSnake[i] == iBait) ok = EFalse;
+				}
+			}
+		} while (!ok);
+	iCons.SetCursorPosAbs(iBait);
+	iCons.Write(KBait);
+	}
+
+void CCmdSnake::Grow()
+	{
+	TInt tail = (iSnakeHead+1)% iSnake.Count();
+	iSnake.Insert(iSnake[tail], tail);
+	if (tail < iSnakeHead) iSnakeHead++;
+	}
+
+
+
+EXE_BOILER_PLATE(CCmdSnake)
+
+
+//______________________________________________________________________________
+//						CKeyWatcher
+CKeyWatcher::CKeyWatcher(CCmdSnake& aOwner, RIoConsoleReadHandle& aCons)
+	: CActive(EPriorityHigh), iOwner(aOwner), iCons(aCons)
+	{
+	CActiveScheduler::Add(this);
+	Request();
+	}
+
+CKeyWatcher::~CKeyWatcher()
+	{
+	Cancel();
+	}
+
+void CKeyWatcher::RunL()
+	{
+	User::LeaveIfError(iStatus.Int());
+	TKeyCode key = (TKeyCode)iCons.KeyCode();
+	switch (key)
+		{
+	case EKeyUpArrow:
+	case '2':
+		iOwner.Up();
+		break;
+	case EKeyDownArrow:
+	case '8':
+		iOwner.Down();
+		break;
+	case EKeyLeftArrow:
+	case '4':
+		iOwner.Left();
+		break;
+	case EKeyRightArrow:
+	case '6':
+		iOwner.Right();
+		break;
+	case EKeyEscape:
+	case EKeyBackspace:
+		iOwner.Exit();
+		break;
+	default:
+		break;
+		}
+	}
+
+void CKeyWatcher::DoCancel()
+	{
+	iCons.WaitForKeyCancel();
+	}
+
+void CKeyWatcher::Request()
+	{
+	if (!IsActive())
+		{
+		iCons.WaitForKey(iStatus);
+		SetActive();
+		}
+	}