Volume Number: 17 (2001)
Issue Number: 08
Column Tag: Programmer's Challenge

by Bob Boonstra, Westford, MA

I love sailing. That is, most of the time I love it, in between the moments when I'm terrified in an exhilarating sort of way. I don't own a boat, which has allowed me to avoid both of the two favorite days of a boat owner's life - the day he buys the boat, and the day he sells the boat. Most years I'm a two-week-a-year sailor, renting small to medium size boats on inland lakes during summer vacations.

But this year we did something different. We decided to charter a sailboat and spend a week in the U.S. and British Virgin Islands. Thanks to Captain Jerry and Chef Christine Miller on a 51' Beneteau, the Rusty Nail II , we had a wonderful week sailing, snorkeling, (drinking - I'd forgotten how many truly excellent drinks can be made with rum) and dining our way around St John, Tortola, Norman Island, Virgin Gorda, Marina Cay, and several other islands.

So why am I telling you this? Not to arouse envy, certainly not. No, I'm telling you this because the August Challenge is based on sailing. Your task this month is to write code that will efficiently sail a simulated boat around a set of obstacles, through a specified sequence of marks.

The prototype for the code you should write is:

typedef struct Position {
   long x;   /* positive x is East */
   long y;   /* positive y is North */
} Position;

typedef double Direction;   /* clockwise from north, in radians */

typedef struct Velocity {
   Direction direction;
   double speed;
      /* x velocity is speed*sin(direction) */
      /* y velocity is speed*cos(direction) */
} Velocity;

void InitCarribeanCruise(
   short numberOfMarks,
   Position mark[],
      /* must pass through mark[i] for each i in turn */
   double tolerance,
      /* must pass within this distance of each mark */
   double integrationInterval
      /* amount of time between calls to Cruise, in seconds */
);

Boolean /* done */ Cruise(   
   Position boatLocation,   /* boat position at the start of this time segment */
   Velocity boatVelocity,   /* boat velocity at the start of this time segment */
   Velocity windVelocity,   /* true wind velocity at this location and time */
   double currentTime,         /* time since cruise start, in seconds */
   Direction *targetBoatDirection,
      /* commanded boat direction */
   Direction *sailTrim
      /* commanded sail trim, 0..PI/4, measured as angle off the stern,
         in the direction away from the source of the wind.
         Actual sail position is a function of trim and wind direction. */
);

void TermCarribeanCruise(void);

The Challenge works like this. First, your InitCarribeanCruise routine is called, providing you with a description of the course to be followed. You will need to pass through the specified marks in sequence, approaching each within a specified distance tolerance. Then your Cruise routine is called repeatedly, at time intervals of integrationInterval, until you complete the course. Finally, your TermCarribeanCruise routine is called, where you should return any dynamically allocated memory.

With each Cruise call, you are given the current boatLocation and boatVelocity, along with the current WindVelocity for your location at the currentTime. You have two controls for the boat, the helm and the sailTrim. For simplicity, we're going to treat your boat as if it has only one sail - no need to separately trim the main and the jib. Our simplified sail trim model lets you control the maximum amount the sail can be let out, from 0° off the stern (tight trim) to 90° off the stern. The sail always moves away from the stern in the direction away from the source of the wind, clockwise off the stern when the wind is from starboard (right of the boat), and counterclockwise when the wind is from port (left of the boat).

High fidelity sailing models use complicated velocity prediction programs to determine boat speed as a function of wind and sails, but we'll use something simpler. When sailing into the wind (you cannot sail directly into the wind, but you can sail up to 45° off the wind direction in our model), the greatest sailing force is provided with the sails tight, 0° off the stern. As you fall off the wind, greater thrust is provided by easing the sails out. When the wind is directly astern (behind you), letting the sail out a full 90° provides the greatest thrust.

As counterintuitive as it might seem, you actually sail faster when going upwind. This is because the motion of the boat actually increases the apparent speed of the wind. You can take my word for it, or you can do a little vector arithmetic to convince yourself. Similarly, going downwind, the force of the wind on the boat actually approaches zero as the boat speed gets closer to the true wind speed, reducing the apparent wind speed. Of course, the resistance of the water prevents the boat from actually reducing the apparent wind speed to zero.

Enough about sailing, back to what you need to do. For each call to Cruise, you need to return the direction you want the boat to move (targetBoatDirection), and how you want to trim the sail (sailTrim). There are limits on how quickly the boat can turn, so you might not actually attain the targetBoatDirection in one integration interval. As for the sailTrim, if you ease the sail too much, it will luff and provide less (or perhaps no) force. If you keep it too tight, you'll also get less force from the wind and will go more slowly. The specifics of the velocity model will be included in the test code provided with the problem - see www.mactech.com/progchallenge/ for details.

Your objective is to sail through the marks as quickly as possible. The winner will be the entry that completes the course in the minimum simulated time, after adding a penalty of one simulated second for each millisecond of execution time. The Challenge prize will be divided between the overall winner and the best scoring entry from a contestant that has not won the Challenge recently.

This will be a native PowerPC Challenge, using the CodeWarrior Pro 6 environment. Solutions may be coded in C or C++. You may provide a solution in Java instead, provided you also provide a test driver equivalent to the C code provided on the web for this problem.

Nine contestants, including many first-time participants, submitted entries for the May Klondike Challenge. This Challenge required readers to create a Klondike solitaire game using the RealBASIC development environment. Unlike most Challenges, performance played no role in evaluating the entries. Instead, the evaluation was based on features, both features specified in the problem statement, and extra features that readers were invited to add. There were several excellent solutions submitted, and it was difficult to select a winner. Congratulations to Peter Truskier (San Mateo, CA) for winning the Klondike Challenge.

Peter's solution satisfies all but one of the features specified in the problem. He provides a high quality representation of the game state; allows cards to be played by dragging them to their destination; highlights a legal destination when a card is dragged over it; provides an undo/redo capability; includes menu items for saving, replaying, and restarting games; and allows cards to be turned over in increments of one or three. As extras, he provides sound effects, including a shuffle sound at the start of a new game, a celebratory sound following victory, and feedback when a card was clicked. He displays the tableaus in staggered fashion, so it is possible to see how many cards remain to be uncovered (not all entries did this, which made play more difficult). Peter displays cards being dragged translucently, so it is possible to see what is under the card as it is dragged. He allows cards to be played to their final destinations by clicking as well as dragging. He provides extra preference options, including control over whether strict or loose rules apply to game play and scoring. And he provides preference control over the background and highlight colors. Peter's entry automatically detects a win when all cards have been uncovered and made playable, but before the cards are actually played. Finally, Peter provides a help function.

The second-place entry by Noah Desch also has some interesting features. He provides extensive preference options for controlling scoring, including subtracting points as time passes, subtracting points for multiple passes through the deck, and subtracting points as a penalty for using the undo/redo feature. His entry displays not only the score, but the elapsed time, and sound effects notify the user when a time penalty is being applied. His preference panel displays a rollover explanation of what each item does. Noah displays the top ten high scores and gives you an option to clear those scores. And he provides four choices for card deck style and three choices for the game board. Noah also provides warnings to the user when he quits a game that is in progress without saving it. Noah's entry was targeted at Mac OS X, but it ran under 9.1 as well. It could easily have been the winner.

Closely following Noah in the admittedly subjective scoring is Presidential Klondike, by Will Leshner. Will provides all of the specified features, plays sound effects during the game, and plays the U.S. national anthem as a bonus after a win. He also provides the convenience of automatically turning over the next card in a tableau when a card is played. Will provides preference control over sound, a scoring time penalty, and animation. He also provides a folder of saved games developed as his spouse became addicted to the game during testing (sorry about that. :)).

Tied in the scoring with Will, Thomas Reed also submitted an excellent entry. Thomas provides preference control over the game and scoring rules, a separate "hard *ss" option to set them all, and a slider control over the number of undo/redo levels allowed. He provides balloon help. And you can change the background by placing a gif file in a Backgrounds folder. Finally, Thomas provides a "play out" option, that will complete the game for you once all of the cards have been exposed.

Rounding out the top five entries is the submission from Jacqueline Landsman Gay. Jacque's entry would have scored even higher, but it was written in MetaCard rather than RealBASIC. Given the unusual rules for this Challenge, I decided to accept the entry, even though I couldn't rebuild the application (not having access to MetaCard), and instead withheld evaluation points for not meeting one of the problem requirements. The graphics in the game are excellent, it has a high score list, it provides options for the card back and playing surface. It also has attractive features cited for some of the earlier entries, like a shuffle sound, play by double-clicking cards, automatically detecting a win, and playing a tribute when a win is detected.

I also asked people for feedback about using RealBASIC or other non-C environments for the Challenge, and the reaction was quite positive. Many new readers decided to enter, although few traditional Challenge participants did so. I'm inclined to try this again sometime. If you have additional thoughts on the topic, let me know at progchallenge@mactech.com.

The table below lists, for each of the solutions submitted, the points earned in various categories: features specified in the problem statement, extra game play and help features, display and sound features, extra scoring and preference options, and a subjective assessment of style and quality of play. As usual, the number in parentheses after the entrant's name is the total number of Challenge points earned in all Challenges prior to this one.

Listed here are the Top Contestants for the Programmer's Challenge, including everyone who has accumulated 20 or more points during the past two years. The numbers below include points awarded over the 24 most recent contests, including points earned by this month's entrants.

In order to give some recognition to other participants in the Challenge, we also list the high scores for contestants who have accumulated points without taking first place in a Challenge during the past two years. Listed here are all of those contestants who have accumulated 6 or more points during the past two years.

There are three ways to earn points: (1) scoring in the top 5 of any Challenge, (2) being the first person to find a bug in a published winning solution or, (3) being the first person to suggest a Challenge that I use. The points you can win are:

Here is Peter's winning Klondike solution:

Klondike_ptruskier.rbp
Copyright © 2001
Peter Truskier

Window1
Window1.newGame:
Sub newGame()
  Canvas1.newGame(flip3)
  gameOver = false
  gameUnderWay = false
  pushNewState()
End Sub

Window1.Open:
Sub Open()
  dim i as integer
  
  canvas1.setDepth(32)
  canvas1.repaint
  newGame()
  showScore = true
  windowOpen = true
  aboutDialog.close
End Sub

Window1.Canvas1.MouseDrag:
Sub MouseDrag(X As Integer, Y As Integer)
  dim i,j,m,n as integer
  
  me.targetPile = nil
  me.dragX = x
  me.dragY = y
  
  //are we dragging from the deck?
  if me.theDeck.topCardDragging then
    me.dragObj.matingRect.xUL = x - me.dragObj.mouseOffsetX
    me.dragObj.matingRect.yUL = y - me.dragObj.mouseOffsetY
    me.dragObj.matingRect.xLR = me.dragObj.matingRect.xUL + w1
    me.dragObj.matingRect.yLR = me.dragObj.matingRect.yUL + h1
    n = uBound(me.theTableaus)
    for i = 0 to n
      if me.theTableaus(i).myRect.isOverlapping(me.dragObj.matingRect) then
        if me.theTableaus(i).canIDrop(me.dragObj) then
          me.targetPile = me.theTableaus(i)
          exit
        end if
      end if
    next
    n = uBound(me.theFoundations)
    for i = 0 to n
      if me.theFoundations(i).myRect.isOverlapping(me.dragObj.matingRect) then
        if me.theFoundations(i).canIDrop(me.dragObj) then
          me.targetPile = me.theFoundations(i)
          exit
        end if
      end if
    next
  end if
  
  
  //or a tableau?
  m = uBound(me.theTableaus)
  for j = 0 to m
    if me.theTableaus(j).topCardDragging then
      me.dragObj.matingRect.xUL = x - me.dragObj.mouseOffsetX
      me.dragObj.matingRect.yUL = y - me.dragObj.mouseOffsetY
      me.dragObj.matingRect.xLR = me.dragObj.matingRect.xUL + w1
      me.dragObj.matingRect.yLR = me.dragObj.matingRect.yUL + h1
      n = uBound(me.theTableaus)
      for i = 0 to n
        if me.theTableaus(i).myRect.isOverlapping(me.dragObj.matingRect) then
          if me.theTableaus(i).canIDrop(me.dragObj) then
            me.targetPile = me.theTableaus(i)
            exit
          end if
        end if
      next
      n = uBound(me.theFoundations)
      for i = 0 to n
        if me.theFoundations(i).myRect.isOverlapping(me.dragObj.matingRect) then
          if me.theFoundations(i).canIDrop(me.dragObj) then
            me.targetPile = me.theFoundations(i)
            exit
          end if
        end if
      next
    end if
  next
  
  me.repaint
End Sub

Window1.Canvas1.dealCards:
Sub dealCards()
  dim i,j,n as integer
  dim num as integer
  
  for i = 0 to 6
    for j = i to 6
      num = num + 1
      if j = i then
        me.theTableaus(j).addCard(me.theDeck.getTopCard,true)
      else
        me.theTableaus(j).addCard(me.theDeck.getTopCard,false)
      end if
    next
  next
  //initialize the score
  me.theScore = me.theScore - 52
  //save a state on the stack
  pushNewState()
End Sub

Window1.Canvas1.MouseUp:
Sub MouseUp(X As Integer, Y As Integer)
  dim success as boolean
  dim i,n as integer
  dim temp as integer
  
  if not gameOver then
    temp = me.theScore
    me.dragging = false
    me.theDeck.topCardDragging = false
    if me.deckRect1.isWithin(x,y) then
      me.theDeck.flip
      me.graphics.drawPicture dimCard,me.deckRect1.xUL,me.deckRect1.yUL
    else
      n = uBound(me.theTableaus)
      for i = 0 to n
        me.theTableaus(i).topCardDragging = false
      next
      if me.targetPile <> nil then
        success = me.targetPile.dropCards(me.dragObj,temp)
        me.dragObj.source.removeCards(me.dragObj)
        me.dragObj = nil
      elseif me.dragObj <> NIL then
              //here's where we implement playng a top card to a foundation with a click
                //in this case, me.targetPile will be nil, but me.dragObj will NOT
        for i = 0 to 3
          if me.theFoundations(i).canIDrop(me.dragObj) then
            success = me.theFoundations(i).dropCards(me.dragObj,temp)
            me.dragObj.source.removeCards(me.dragObj)
            me.dragObj = nil
            me.repaint
            exit  //the for-next loop
          end if
        next
      end if
    end if
    me.targetPile = nil
    me.theScore = temp
    me.repaint
  end if
End Sub

Window1.Canvas1.MouseDown:
Function MouseDown(X As Integer, Y As Integer) As Boolean
  dim i,n as integer
  
  if not gameOver then
    if me.deckRect2.isWithin(x,y) then
      me.dragObj = me.theDeck.getDragCard(x,y,me.deckRect2.yUL,me.deckRect2.xUL)
      me.dragging = true
    else
      for i = 0 to 6
        if me.theTableaus(i).myRect.isWithin(x,y) then
          n = uBound(me.theTableaus(i).theCards)
          if n > -1 then
            if me.theTableaus(i).theCards(n).faceUP then
              me.dragObj = me.theTableaus(i).getDragCards(x,y)
              me.dragging = true
            else
              me.theTableaus(i).theCards(uBound(me.theTableaus(i).theCards)).faceUP = true
              pushNewState()
              cardDownSound.play
            end if
          end if
        end if
      next
    end if
    return true
  end if
End Function

Window1.Canvas1.Open:
Sub Open()
  dim i as integer
  //initilaize the position of our deck rectangles
  me.deckRect1 = new aRectangle(20,220,w1,h1)
  me.deckRect2 = new aRectangle(20,320,w1,h1+44)
End Sub

Window1.Canvas1.Paint:
Sub Paint(g as Graphics)
  dim i,c,w as integer
  dim s as string
  
  if windowOpen then   //don't draw intot he window unless it ready
    g.foreColor = backGroundColor
    g.fillRect 0,0,me.width,me.height
    //draw the deck
    me.theDeck.drawSelf(g,me.deckRect1,me.deckRect2)
    //draw each fo the tableaux
    for i = 0 to 6
      me.theTableaus(i).drawSelf(g)
    next
    //and each of the foundations
    for i = 0 to 3
      me.theFoundations(i).drawSelf(g)
    next
    //if we are dragging then draw the drag object's pict
    if me.dragging then
      if me.dragObj <> NIL then 
        g.drawPicture me.dragObj.thePic,me.dragX - me.dragObj.mouseOffsetX,me.dragY - 
           me.dragObj.mouseOffsetY
      end if
    end if
    if showScore then
      me.drawScore(g,480,20)
    end if
    if gameWon then
      for i = 0 to 51
        g.drawPicture packOfCards(i).cardPic,rnd*(self.width - w1),rnd*(self.height - h1)
      next
      c = round(rnd)*255
      g.foreColor = rgb(c,0,0)
      s = "You Win !!"
      g.textSize = 110
      w = g.stringWidth(s)
      g.drawString s,(me.width - w)/2,me.height/2 + 18
    end if
  end if
End Sub

Card
// see online code

app
// see online code

CardConstants
// see online code

Globals
// see online code

deck
deck.deck:
Sub deck(f3 as boolean)
  //constructor
  dim i as integer
  
  flipThree = f3
  for i = 0 to 51
    me.theCards.append packOfCards(i)
  next
  currentCard = -1
  clearStates()
End Sub

deck.drawSelf:
Sub drawSelf(g as graphics,L as aRectangle, R as aRectangle)
  
  dim x1,y1,x2,y2 as Integer
  dim dY as integer
  dim i,n,numCards,numUP as integer
  
  x1 = L.xUL
  y1 = L.yUL
  x2 = R.xUL
  y2 = R.yUL
  if not gameOver then
    g.drawPicture cardBack, x1,y1
    g.drawPicture dimCard, x2,y2
    if currentCard > -1 then
      if flipThree then
        n = 2
      else
        n = 0
      end if
      n = min(n,currentCard )
      numCards = uBound(theCards)
      for i = 0 to numCards
        if theCards(i).faceUP then
          numUP = numUP + 1
        end if
      next
      if numUP = 0 then
        theCards(currentCard).faceUP = true
      end if
      for i = -n to 0
        if theCards(currentCard + i).faceUP then
          g.drawPicture theCards(currentCard + i).cardPic,x2,y2 + dY
          dY = dY + 19
        end if
      next
      if dY > 0 then
        dY = dY - 19
      end if
      if topCardDragging then
        g.drawPicture dimCard,x2,y2+(numUP-1)*19
      end if
    else
      g.drawPicture doneWithDeckCard, x1,y1
    end if
  else  //game over
    g.drawPicture gameOverCard, x1,y1
  end if
End Sub

deck.shuffle:
Sub shuffle()
  dim i,j as integer
  dim tempCard as card
  dim t1,t2 as double
  
  t1 = microseconds
  shuffleSound.playLooping
  do until t2 > t1 +750000
    j = rnd*52
    tempCard = theCards(j)
    theCards.remove j
    j = rnd*51
    theCards.insert j,tempCard
    t2 = microseconds
  loop
  for i = 0 to 51
    theCards(i).faceUP = false
  next
  currentCard = -1
  shuffleSound.stop
End Sub

deck.flip:
Sub flip()
  dim i,n,numCards as integer
  dim newCurrentCard as integer
  
  if not gameOver then
    numCards = uBound(theCards)
    carddownSound.play
    if not done then
      if flipThree then 
        n = 3
      else
        n = 1
      end if
      //turn them all face down
      for i = 0 to currentCard
        theCards(i).faceUp = false
      next
      newCurrentCard = min(currentCard + n,numCards)
      if newCurrentCard = numCards then
        done = true
        timesThroughDeck = timesThroughDeck + 1
        if strict then
          if flip3 then
            gameOver = (timesThroughDeck = 3)
          else
            gameOver = (timesThroughDeck = 1)
          end if
        end if
      end if
      if newCurrentCard <= numCards then
        for i = currentCard + 1 to newCurrentCard
          theCards(i).faceUP = true
        next
        currentCard = newCurrentCard
      end if
    else  // the deck IS done
      n = uBound(theCards)
      for i = 0 to n
        theCards(i).faceUp = false
      next
      currentCard = -1
      done = false
    end if
    gameUnderWay = true
    pushNewState()
  end if
  
End Sub

deck.getTopCard:
Function getTopCard() As card
  dim tempCard as card
  
  tempCard = theCards(0)
  theCards.remove 0
  return tempCard
End Function

deck.getDragCard:
Function getDragCard(x as integer,y as integer,t as integer,l as integer) As dragObject
  dim d as dragObject
  dim p as picture
  dim topCardTop as integer
  dim i,numCards,numUP as integer
  
  if currentCard > -1 then
    numCards = uBound(theCards)
    for i = 0 to numCards
      if theCards(i).faceUP then
        numUP = numUP + 1
      end if
    next
    
    topCardTop = t + (numUP-1)*19
    
    if y < topCardTop + h1 then
      d = new dragObject
      d.source = me
      p = newpicture(dragCard.width,dragCard.height,32)
      if p = nil then
        msgBox "NIL PIC IN deck.getdragcards"
      end if
      d.theCards.append me.theCards(currentCard)
      d.matingCard = me.theCards(currentCard)
      p.graphics.drawPicture dragCard,0,0
      p.graphics.drawPicture d.theCards(0).cardPic,0,0
      p.mask.graphics.drawPicture dragShadow2,0,0
      d.thePic = p
      d.mouseOffsetX = x - l
      d.mouseOffsetY = y - topCardTop
      topCardDragging = true
      flySound.play
      return d
    end if
  end if
End Function

deck.removeCards:
Sub removeCards(d As dragObject)
  me.theCards.remove currentCard
  currentCard = currentCard - 1
  pushNewState()
End Sub

deck.stateString:
Function stateString() As string
  //save a string representation of the current state of the deck
  dim s as string
  dim i,n as integer
  
  if flipThree then
    s = "3|"
  else
    s = "1|"
  end if
  
  s = s + str(currentCard) + "|"
  if gameUnderWay then 
    s = s + "gameUnderWay"+"|"
  else
    s = s + "|"
  end if
  if gameOver then 
    s = s + "gameOver"+"|"
  else
    s = s + "|"
  end if
  if done then 
    s = s + "done"+"|"
  else
    s = s + "|"
  end if
  
  n = uBound(theCards)
  for i = 0 to n
    s = s + theCards(i).stateString + ","
  next
  
  return s
End Function

deck.restoreState:
Sub restoreState(stateStr as string)
  //restore the state of the deck represented in the string saved by the stateString method
  
  dim s,cardStr as string
  dim i,n,v as integer
  
  s = nthField(stateStr,"|",1)
  me.flipThree = (s = "3")
  s = nthField(stateStr,"|",2)
  me.currentCard = val(s)
  
  gameUnderWay = (nthField(stateStr,"|",3) = "gameUnderWay")
  gameOver = (nthField(stateStr,"|",4) = "gameOver")
  done = (nthField(stateStr,"|",5) = "done")
  s = nthField(stateStr,"|",6)
  
  n = countFields(s,",")
  
  
  redim me.theCards(-1)
  for i = 1 to n
    if s <> "" then
      cardStr = nthField(s,",",i)
      if cardStr <> "" then
        v = val(cardStr)
        if v > 51 then
          v = v - 52
          packOfCards(v).faceUp = true
        else
          packOfCards(v).faceUp = false
        end if
        me.theCards.append packOfCards((v))
      end if
    end if
  next
End Sub

deck.CardCount:
Function CardCount() As integer
  return uBound(theCards) + 1
End Function

SmoothCanvas
// see online code

CardCanvas
CardCanvas.dealCards:
Sub dealCards()
  dealCards()
End Sub

CardCanvas.newGame:
Sub newGame(flip3 as boolean)
  dim i as integer
  
  redim theFoundations(-1)
  redim theTableaus(-1)
  
  me.theDeck = new deck(flip3)
  me.theDeck.shuffle
  for i = 0 to 6
    me.theTableaus.append new tableau(new aRectangle(110+65*i,120,w1,h1))
  next
  
  for i = 0 to 3
    me.theFoundations.append new foundation(new aRectangle(110+97*i,10,w1,h1))
  next
  dealCards
  timesThroughDeck = 0
  me.repaint
  
End Sub

CardCanvas.drawScore:
Sub drawScore(g as graphics,x as integer,y as integer)
  dim i,n as integer
  dim s as string
  dim neg as boolean
  
  g.forecolor = rgb(0,0,0)
  g.textSize = 12
  
  neg = (theScore < 0)
  s = "Score: "
  if neg then
    g.forecolor = rgb(255,0,0)
    s = s + " - "
  end if
  s = s + "$" + str(abs(theScore))
  g.drawString s,x,y
End Sub

CardCanvas.updateWinningGameScore:
Sub updateWinningGameScore()
  dim i,n as integer
  
  theScore = theScore + me.theDeck.cardCount * 5
  for i = 0 to 6
    theScore = theScore + me.theTableaus(i).cardCount*5
  next
End Sub

CardCanvas.stateString:
Function stateString() As string
  return str(theScore)
End Function

CardCanvas.restoreState:
Sub restoreState(stateStr as string)
  theScore = val(stateStr)
End Sub

soundGlobals
// see online code

aRectangle
// see online code

tableau
tableau.tableau:
Sub tableau(r as aRectangle)
  me.myRect = r
End Sub

tableau.addCard:
Sub addCard(c as card,fUP as boolean)
  
  
  theCards.append c
  c.faceUp = fUP
  
End Sub

tableau.drawSelf:
Sub drawSelf(g as graphics)
  dim x,y,dY,numUP as integer
  dim i,n as integer
  
  n = uBound(theCards)
  numUp = 0
  x = myRect.xUL
  y = myRect.yUL
  g.drawPicture dimCard,x,y
  for i = 0 to n
    if theCards(i).faceUp then
      g.drawPicture theCards(i).cardPic,x,y
      y = y + 19
      numUP = numUP + 1
    else
      g.drawPicture cardBack,x,y
      y = y + 3
    end if
  next
  if numUP = 0 then
    numUP = 1
  end if
  if n = -1 then 
    n = 0
  end if
  myRect.yLR = myRect.yUL + h1
  dY = (numUP - 1)*16 + (n)*3
  myRect.yLR = myRect.yLR + dY
  if me.couldAccept then
    g.drawPicture hiliteCard,myRect.xUL,myRect.yLR - h1
    couldAccept = false
  end if
  if topCardDragging then
    g.drawPicture myDimCard,myRect.xUL,myRect.yLR - myDimCard.height
  end if
  
End Sub

tableau.canIDrop:
Function canIDrop(d as dragObject) As boolean
  dim n as integer
  
  couldAccept = false
  n = uBound(me.theCards)
  if n > -1 then
    couldAccept = (d.matingCard.isRed <> me.theCards(n).isRed) and 
    (d.matingCard.cardVal = me.theCards(n).cardVal - 1)
  else
    couldAccept = (d.matingCard.cardVal = 12)
  end if
  return couldAccept
End Function

tableau.dropCards:
Function dropCards(d As dragObject,byRef theScore as integer) As Boolean
  dim i,n as integer
  
  n = uBound(d.theCards)
  cardDownSound.play
  for i = 0 to n
    d.theCards(i).faceUP = true
    me.theCards.append d.theCards(i)
  next
  gameUnderWay = true
End Function

tableau.removeCards:
Sub removeCards(d As dragObject)
  dim i,j,m,n as integer
  
  n = uBound(d.theCards)
  for i = 0 to n
    m = uBound(me.theCards)
    me.theCards.remove m
  next
  pushNewState()
End Sub

tableau.getDragCards:
Function getDragCards(x as integer,y as integer) As dragObject
  dim d as dragObject
  dim p,pMask,tempPic as picture
  dim bottomCard as integer
  dim i,numCards,numUP,curTop as integer
  dim picHt as integer
  
  if not gameOver then
    bottomCard = whichCard(y)
    d = new dragObject
    if strict then
      if bottomCard <> uBound(theCards) then  //unless it's the top card...
        for i = 0 to (bottomCard-1)
          if theCards(i).faceUP then
            return d
                       //we'll return a null object since the player cannot play a partial run...
          end if
        next
      end if
    end if
    if theCards(bottomCard).faceUP then  
            //don't even consider face down cards
      d.source = me
      numCards = uBound(theCards)
      picHt = dragCard.height + (numCards - bottomCard)*19
      p = newpicture(dragCard.width,picHt,32)
      if p = nil then
        msgBox "NIL PIC IN tableau.getdragcards"
      end if
      
      myDimCard = newpicture(w1,picHt-14,32)
      if p = nil then
        msgBox "NIL PIC IN tableau.getdragcards"
      end if
      
      pMask = newpicture(dragCard.width,picHt,8)
      if p = nil then
        msgBox "NIL PIC IN tableau.getdragcards"
      end if
      p.graphics.foreColor = rgb(0,0,0)
      p.graphics.fillrect 0,0,p.width,p.height
      
      for i = bottomCard to numCards
        d.theCards.append me.theCards(i)
        p.graphics.drawPicture me.theCards(i).cardPic,0,curTop
        p.graphics.drawPicture tempPic,0,curTop
        if i = bottomCard then
          pMask.graphics.drawPicture dragShadow2,0,curTop
        else
          pMask.graphics.drawPicture dragShadow3,0,curTop
        end if
        if i = bottomCard then
          myDimCard.mask.graphics.drawPicture dimCardMask,0,curTop
        else
          myDimCard.mask.graphics.drawPicture dimCardMask2,0,curTop
        end if
        curTop = curTop + 19
      next
      
      d.matingCard = me.theCards(bottomCard)
      d.thePic = p
      d.mouseOffsetX = x - me.myRect.xUL
      d.mouseOffsetY = y - topOfCardY(bottomCard) - myRect.yUL
      topCardDragging = true
    end if
    p.mask.graphics.drawPicture pMask,0,0
    flySound.play
    return d
  end if
End Function

tableau.whichCard:
Function whichCard(canvasY as integer) As integer
  dim i,n,testY as integer
  
  testY = 0
  n = uBound(me.theCards)
  for i = 0 to n
    if testY > canvasY-myRect.yUL then
      return i - 1
    end if
    if theCards(i).faceUP then
      testY = testY + 19
    else
      testY = testY + 3
    end if
  next
  return n 
         //if we've gotten here, it must be the top card...
End Function

tableau.topOfCardY:
Function topOfCardY(theIndex as integer) As integer
  //this function will return the top of the specified card in local coordinates
  
  dim i,n,curTop as integer
  n = uBound(theCards)
  
  for i = 0 to n
    if i = theIndex then
      exit
    end if
    if theCards(i).faceUP then
      curTop = curTop + 19
    else
      curTop = curTop + 3
    end if
  next
  return curTop
End Function

tableau.stateString:
Function stateString() As string
  //save a string representation of the current state of this tableau
  dim s as string
  dim i,n as integer
  
  s = myRect.stateString + "|"
  n = uBound(theCards)
  for i = 0 to n
    s = s + theCards(i).stateString + ","
  next
  return s
End Function

tableau.restoreState:
Sub restoreState(stateStr as string)
  //restore the state of this tableau represented in the string saved by the stateString method
  dim s,cardStr as string
  dim i,n,v as integer
  
  s = nthField(stateStr,"|",1)
  me.myRect.restoreState(s)
  s = nthField(stateStr,"|",2)
  n = countFields(s,",")
  redim me.theCards(-1)
  for i = 1 to n
    if s <> "" then
      cardStr = nthField(s,",",i)
      if cardStr <> "" then
        v = val(cardStr)
        if v > 51 then
          v = v - 52
          packOfCards(v).faceUp = true
        else
          packOfCards(v).faceUp = false
        end if
        me.theCards.append packOfCards((v))
      end if
    end if
  next
  
End Sub

tableau.allFaceUp:
Function allFaceUp() As boolean
  dim i,n as integer
  
  if uBound(me.theCards) <=0 then
    return true
  end if
  
  n = uBound(theCards)
  for i = 0 to n
    if not theCards(i).faceUP then
      return false
    end if
  next
  return true
End Function

tableau.cardCount:
Function cardCount() As integer
  return uBound(theCards) + 1
End Function

Foundation
Foundation.foundation:
Sub foundation(r as aRectangle)
  me.myRect = r
End Sub

Foundation.addCard:
Sub addCard(c as card)
  theCards.append c
End Sub

Foundation.drawSelf:
Sub drawSelf(g as graphics)
  dim x,y,dY,numUP as integer
  dim i,n as integer
  
  n = uBound(theCards)
  
  x = myRect.xUL
  y = myRect.yUL
  
  
  
  g.drawPicture dimCard,x,y
  if n > -1 then
    g.drawPicture theCards(n).cardPic,x,y
  end if
  if me.couldAccept then
    g.drawPicture hiliteCard,myRect.xUL,myRect.yUL
    couldAccept = false
  end if
End Sub

Foundation.canIDrop:
Function canIDrop(d As dragObject) As Boolean
  dim n as integer
  
  couldAccept = false
  n = uBound(d.theCards)
  if n <> 0 then //you can only move one card to a foundation
    return couldAccept
  end if
  n = uBound(me.theCards)
  if n > -1 then
    couldAccept = (d.matingCard.cardSuit = me.theCards(n).cardSuit) and 
    (d.matingCard.cardVal = me.theCards(n).cardVal + 1)
  else
    couldAccept = (d.matingCard.cardVal = 0)
  end if
  return couldAccept
End Function

Foundation.dropCards:
Function dropCards(d As dragObject,byRef theScore as integer) As boolean
  cardDownSound.play
  d.theCards(0).faceUP = true
  me.theCards.append d.theCards(0)
  theScore = theScore + 5
  gameUnderWay = true
  return true
End Function

Foundation.stateString:
Function stateString() As string
  //save a string representation of the current state of this foundation
  dim s as string
  dim i,n as integer
  
  n = uBound(theCards) 
  for i = 0 to n
    s = s + theCards(i).stateString + ","
  next
  return s
End Function

Foundation.restoreState:
Sub restoreState(stateStr as string)
  //restore the state of this foundation represented in the string saved by the stateString method
  dim i,n,v as integer
  dim s,cardStr as string
  
  n = countFields(stateStr,",")
  
  redim me.theCards(-1)
  for i = 1 to n
    cardStr = nthField(stateStr,",",i)
    if cardStr <> "" then
      v = val(cardStr)
      if v > 51 then
        v = v - 52
        packOfCards(v).faceUp = true
      else
        packOfCards(v).faceUp = false
      end if
      me.theCards.append packOfCards((v))
    end if
  next
End Sub

dragObject
dragObject.dragObject:
Sub dragObject()
       //the "matingRect" is the rectangle that we will test for overlap with each 
      // tableau and foundation
  me.matingRect = new aRectangle(0,0,w1,h1)
End Sub

DroppablePile.canIDrop:
Function canIDrop(d as dragObject) As boolean
  
End Function

DroppablePile
DroppablePile.dropCards:
Function dropCards(d as dragObject,byRef theScore as integer) As boolean
  
End Function

dropSource.removeCards:
Sub removeCards(d as dragObject)
  
End Sub

stateMachine
stateMachine.theStateString:
Function theStateString() As string
  dim i,n as integer
  dim s as string
  
  s = globalsStateString + "&"
  s = s + window1.canvas1.stateString + "&"
  s = s + window1.canvas1.theDeck.stateString + "&"
  for i = 0 to 6
    s = s + window1.canvas1.theTableaus(i).stateString + "&"
  next
  for i = 0 to 2
    s = s + window1.canvas1.theFoundations(i).stateString + "&"
  next
  s = s + window1.canvas1.theFoundations(3).stateString
  return s
End Function

stateMachine.restoreTheState:
Sub restoreTheState(stateStr as string)
  dim i,n as integer
  dim s as string
  
  restoreGlobals(nthField(stateStr,"&",1))
  window1.canvas1.restoreState(nthField(stateStr,"&",2))
  window1.canvas1.theDeck.restoreState(nthField(stateStr,"&",3))
  for i = 0 to 6
    window1.canvas1.theTableaus(i).restoreState(nthField(stateStr,"&",i+4))
  next
  for i = 0 to 3
    window1.canvas1.theFoundations(i).restoreState(nthField(stateStr,"&",i+11))
  next
  window1.canvas1.repaint
End Sub

stateMachine.initStateMachine:
Sub initStateMachine()
  currentState = -1
End Sub

stateMachine.undoAvailable:
Function undoAvailable() As boolean
  return currentState > 0
End Function

stateMachine.redoAvailable:
Function redoAvailable() As boolean
  return uBound(stateArray) > currentState
End Function

stateMachine.pushNewState:
Sub pushNewState()
  dim i,n as integer
  dim s as string
  
  //first we need to pop off anything above our current state..
  
  n = uBound(stateArray)
  for i = currentState+1 to n
    stateArray.remove (currentState+1)
  next
  s = theStateString
  stateArray.append s
  currentState = uBound(stateArray)
  if hasGameBeenWon then
    doGameWinRoutine
  end if
  //now we'll raise our flag to mark us as dirty
  gDirty = true
End Sub

stateMachine.undo:
Sub undo()
  currentState = currentState - 1
  restoreTheState(stateArray(currentState))
  undoSound.play
End Sub

stateMachine.redo:
Sub redo()
  currentState = currentState + 1
  undoSound.play
  restoreTheState(stateArray(currentState))
End Sub

stateMachine.clearStates:
Sub clearStates()
  redim stateArray(-1)
  currentState = -1
End Sub

stateMachine.startOver:
Sub startOver()
  dim i,n as integer
  
  n = uBound(stateArray)
  for i = n downto 0
    currentState = i
    restoreTheState(stateArray(i))
    undoSound.play
  next
End Sub

stateMachine.saveGameFile:
Function saveGameFile() As boolean
  dim f as folderItem
  dim tos as textOutputStream
  dim i,n as integer
  
  f = getSaveFolderItem("TEXT","myGame")
  if f <> NIL then
    tos = f.createTextFile
    if tos <> NIL then
      n = uBound(stateArray)
      for i = 0 to n
        tos.writeLine stateArray(i)
      next
      tos.close
      gDirty = false
      return true
    end if
  end if
  return false
End Function

stateMachine.openGameFile:
Function openGameFile() As boolean
  dim f as folderItem
  dim tis as textInputStream
  dim s as string
  
  f = getOpenFolderItem("TEXT")
  if f <> NIL then
    tis = f.openAsTextFile
    if tis <> NIL then
      clearStates()
      while not tis.eof
        s = tis.readLine
        stateArray.append s
        currentState = uBound(stateArray)
      wend
      restoreTheState(stateArray(currentState))
      gDirty = false
      return true
    end if
  end if
  return false
End Function

AboutDialog
// see online code

PrefsWin
// see online code

AlertWin
// see online code