BlackJack Algorithm - c++

Question

What is the general alogirthm for a BlackJack game ?
I'm writing one in c++ and end up having WAY too many if statements which ruin the whole thing.
The project is a win32 GUI application, and Im posting the message loop as well as the part of the program that checks the game's status
Posting the complete code will make it humongous, so here are the links to all the files:
Full Source Code
Message Loop
LRESULT CALLBACK WndProc( HWND hWnd, UINT Msg, WPARAM wParam, LPARAM lParam ){
switch(Msg)
{
case WM_PAINT:
{
PAINTSTRUCT PS;
HDC hDC = BeginPaint(hWnd, &PS);
You.Draw(hDC);
Dealer.Draw(hDC);
EndPaint(hWnd, &PS);
if(Bet.Enabled){
Bet.GetFocus();
Bet.Select(0,Bet.Length());
}
}
return 0;
case WM_CTLCOLORSTATIC:
{
SetBkMode((HDC)wParam, TRANSPARENT);
}
return (INT_PTR)(HBRUSH)GetStockObject(NULL_BRUSH);
case WM_CREATE:
{
//Create edit control
Bet.Create(hWnd, 10, 550, 100, 25, "0");
//Create labels
char Buffer[30];
sprintf(Buffer, "%d", You.HandValue());
BetLabel.Create(hWnd, 10, 500, 100, 40, "Enter Bet Amount");
GameControls.Create(hWnd, 10, 375, 100, 40, "Game Controls");
PlayerLabels.Create(hWnd, 10, 10, 100, 20, "You:");
PlayerLabels.Create(hWnd, 10, 150, 100, 20, "Dealer:");
HandValueLabel.Create(hWnd, (int)You.x[You.cards] + 85, (int)You.y[You.cards] + 25, 100, 20, Buffer);
YourMoney.Create(hWnd, 125, 500, 100, 40, "Your money: ");
sprintf(Buffer, "%d", You.money);
MoneyValue.Create(hWnd, 125, 525, 100, 40, Buffer);
//Create buttons
Ok.Create(hWnd, 10, 600, 100, 50, "Ok");
Hit.Create(hWnd, 10, 425, 100, 50, "Hit");
Stand.Create(hWnd, 120, 425, 100, 50, "Stand");
//Select Text
Bet.Select(0,3);
}
return 0;
case WM_CLOSE:
exit(0);
break;
case WM_COMMAND:
{
switch(HIWORD(wParam))
{
case BN_CLICKED:
{
switch(LOWORD(wParam))
{
case ID_OK:
{
//Place bet
int bet = 0;
bet = StringToNumber(Bet.Text());
You.money -= bet;
char Buffer[30];
sprintf(Buffer, "%d", You.money);
MoneyValue.SetText(Buffer);
//Update the window
InvalidateRect(hWnd, 0, TRUE);
You.Bet = YES;
Ok.Disable();
Bet.Disable();
You.DealCard();
You.DealCard();
Dealer.DealCard();
Dealer.DealCard();
You.win = false;
You.bust = false;
You.playing = YES;
Dealer.win = NO;
Dealer.bust = NO;
Dealer.playing = YES;
}
break;
case ID_HIT:
{
if(You.HandValue() < 21 && You.playing && !You.bust){
//Deal a card to the player, if he hasn't won or lost
You.DealCard();
}
if((Dealer.HandValue() <= 17 || Dealer.HandValue() < You.HandValue()) && Dealer.playing)
{
Dealer.DealCard();
}
//Update Hand Value
char Buffer[30];
sprintf(Buffer, "%d", You.HandValue());
HandValueLabel.SetText(Buffer);
InvalidateRect(hWnd,0,TRUE);
MoveWindow(HandValueLabel.Handle, (int)You.x[You.cards] + 80, (int)You.y[You.cards] + 25, 100, 20, TRUE);
RedrawWindow(hWnd, NULL, NULL, RDW_INVALIDATE | RDW_INTERNALPAINT);
}
break;
case ID_STAND:
if(Hit.Enabled){
//Don't deal more cards
Hit.Disable();
You.playing = false;
}
if((Dealer.HandValue() <= 17 || Dealer.HandValue() < You.HandValue()) && Dealer.playing){
//Deal a card to the dealer
Dealer.DealCard();
}
}
StatusChecker
void ProcessStatus(HWND hWnd){
if(Dealer.HandValue() > 17){
if(Dealer.HandValue() > You.HandValue() && Dealer.playing){
Dealer.playing = false;
}
else if(!You.playing && Dealer.HandValue() <= You.HandValue() && Dealer.playing){
Dealer.DealCard();
}
}
else if(Dealer.HandValue() <= 17 && Dealer.HandValue() <= You.HandValue() && !You.playing && Dealer.playing){
Dealer.DealCard();
}
if(EvaluateStatus() != 0){
status = OVER;
}
if(EvaluateStatus() == -1){
switch(MessageBoxA(hWnd, "You Lost! \n Keep Playing ?", "You Lost!", MB_YESNO | MB_ICONQUESTION))
{
case IDYES:
Reset();
break;
case IDNO:
exit(0);
break;
}
}
else if(EvaluateStatus() == 1){
switch(MessageBoxA(hWnd, "You Won! \n Keep Playing ?", "You Won!", MB_YESNO | MB_ICONQUESTION))
{
case IDYES:
Reset();
break;
case IDNO:
exit(0);
break;
}
}
}
int EvaluateStatus()
{
if(You.HandValue() > 21 && You.playing)
{
You.bust = true;
Dealer.win = true;
You.playing = NO;
return -1;
}
if(You.HandValue() == 21)
{
You.win = true;
return 1;
}
if(Dealer.HandValue() > 21)
{
Dealer.bust = true;
You.win = true;
return 1;
}
if(Dealer.HandValue() == 21)
{
Dealer.win = true;
return -1;
}
if(!You.playing && Dealer.HandValue() > You.HandValue() &&!Dealer.bust)
{
Dealer.win = true;
return -1;
}
if(You.HandValue() > Dealer.HandValue() && (!You.playing && (!Dealer.playing || Dealer.bust)))
{
You.win = true;
return 1;
}
if(You.HandValue() == Dealer.HandValue() && (!You.playing || !Dealer.playing))
{
You.win = true;
return 1;
}

Answer 1

As a first step: I probably wouldn't mix game logic and your GUI logic.. separate them into different modules.
And if you only have two players, you only need a bool to decide which one won. You don't need for both of the players Bust and Won variables.

Answer 2

A google search revealed this PDF paper on BlackJack algorithms. I'm sure if you did some more research using Google, you could find things too.
To figure out how to work out the actual steps needing to be done to play the game, work out on paper the different steps of the game, then decide how you can create classes that represent parts of the game and functions in these classes to execute the different steps of the game.'
This could be an iterative thing, where you go through it, then create some classes, functions, etc, now you can go back and see if what you've done makes sense, improve on the design etc.
Perhaps also play the game and see what is done, how that could be translated into code.

Answer 3

I have modified the way the program handles messages, and am posting it as a seperate answer.
It is still broken because of a minor hiccup, but i think the general idea is solid. comments would be appreciated
cards.h
/*
* cards.h
*
* Created on: Aug 31, 2011
* Author: Viraj
*/
#ifndef CARDS_H_
#define CARDS_H_
#include <iostream>
#include <algorithm>
#define STARTED true
#define OVER false
#define YES true
#define NO false
using namespace std;
HINSTANCE hApplication;
HBITMAP Bitmap;
char Buffer[30];
class Deck{
public:
int deck[53];
Deck(){
for(int suit = 1; suit <= 4; suit++){
for(int card = 1; card <= 13; card++){
deck[((suit-1)*13)+card] = card;
}
}
deck[0] = 0;
}
};
Deck deck;
class Cards{
private:
int card_seed;
int suit_seed;
public:
int card[11];
int cards;
int value[11];
Cards(){
fill(card, card + 10, 0);
fill(value, value + 10, 0);
cards = 0;
}
void DealCard()
{
cards++;
while(!deck.deck[card[cards]]){
card_seed = rand()%13 + 1;
suit_seed = rand()%4 + 1;
card[cards] = (suit_seed - 1)*13 + card_seed;
}
deck.deck[card[cards]] = 0;
if(card_seed > 1 && card_seed < 11){
value[cards] = card_seed;
}
else if(card_seed >= 11 && card_seed <= 13){
value[cards] = 10;
}
else if(card_seed == 1){
value[cards] = 11;
}
}
};
class Player : public Cards {
public:
float x[11];
float y[11];
bool playing;
bool bust;
bool win;
int money;
Player(const char* Type){
srand(time(NULL));
playing = true;
if(Type == "Dealer"){
for(int card = 1; card <= 10; card++){
x[card] = 10 + (card-1)*75;
y[card] = 200;
}
}
else{
for(int card = 1; card <= 10; card++){
x[card] = 10 + (card-1)*75;
y[card] = 35;
money = 1000;
}
}
}
void Reset(){
cards = 0;
fill(card, card + 10, 0);
fill(value, value + 10, 0);
playing = true;
}
int HandValue(){
int sum = 0;
for(int current_card = 1; current_card <= cards; current_card++){
sum += value[current_card];
}
if(sum > 21){
for(int current_card = 1; current_card <= cards; current_card++){
if(value[current_card] == 11 && sum > 21){
value[current_card] = 1;
sum = HandValue();
break;
}
}
}
return sum;
}
void Draw(HDC hDC){
HDC MemoryDevice;
for(int CardToLoad = 1; CardToLoad <= cards; CardToLoad++){
Bitmap = LoadBitmap(hApplication, MAKEINTRESOURCE(card[CardToLoad]));
MemoryDevice = CreateCompatibleDC(hDC);
SelectObject(MemoryDevice, Bitmap);
BitBlt(hDC, (int)x[CardToLoad], (int)y[CardToLoad], 75, 100, MemoryDevice, 0, 0, SRCCOPY);
}
DeleteDC(MemoryDevice);
}
};
class CONTROL{
public:
HWND Handle;
char* ClassName;
char* Caption;
DWORD ClassStyle;
DWORD ExtendedStyle;
int x;
int y;
int Width;
int Height;
int ID;
bool Enabled;
void Create(HWND ParentHandle, int x, int y, int Width, int Height, char* Caption){
Handle = CreateWindowExA(ExtendedStyle, ClassName, Caption, ClassStyle, x, y, Width, Height, ParentHandle, (HMENU)ID, NULL, NULL);
Enabled = true;
CONTROL::Caption = Caption;
CONTROL::x = x;
CONTROL::y = y;
CONTROL::Width = Width;
CONTROL::Height = Height;
}
void GetFocus(){
SetFocus(Handle);
}
void Disable(){
EnableWindow(Handle, FALSE);
Enabled = false;
}
void Enable(){
EnableWindow(Handle, TRUE);
Enabled = true;
}
void SetText(char* String){
SetWindowTextA(Handle, String);
}
};
class BUTTON : public CONTROL {
public:
BUTTON(int Identifier){
ClassStyle = BS_PUSHBUTTON | WS_VISIBLE | WS_CHILD;
ID = Identifier;
ClassName = "BUTTON";
ExtendedStyle = 0;
}
};
class EDIT : public CONTROL {
public:
EDIT(int Identifier){
ClassStyle = ES_NUMBER | WS_VISIBLE | ES_CENTER | WS_CHILD | ES_NOHIDESEL;
ExtendedStyle = WS_EX_CLIENTEDGE;
ID = Identifier;
ClassName = "EDIT";
}
void Select(int first, int last){
Edit_SetSel(Handle, first, last);
}
int Length(){
return Edit_GetTextLength(Handle);
}
const char* Text(){
char Buffer[Length() + 1];
Edit_GetText(Handle, (LPTSTR)&Buffer, Length() + 1);
string String = Buffer;
return String.c_str();
}
};
class STATIC : public CONTROL {
public:
STATIC() {
ClassStyle = WS_VISIBLE | SS_CENTER | WS_CHILD;
ID = 0;
ClassName = "STATIC";
ExtendedStyle = 0;
}
};
Player You("You"), Dealer("Dealer");
BUTTON Ok(ID_OK), Hit(ID_HIT), Stand(ID_STAND);
EDIT Bet(ID_BET);
STATIC BetLabel, GameControls, PlayerLabels, HandValueLabel, YourMoney, MoneyValue, Bust;
class Game{
public:
bool started;
Game(){
started = false;
}
void Stop(){
started = false;
}
void ResetGame(HWND hWnd){
//Reset Players
You.Reset();
Dealer.Reset();
//Reset Controls
Ok.Enable();
Bet.Enable();
Hit.Enable();
//Reset Hand value
sprintf(Buffer, "%d", You.HandValue());
HandValueLabel.SetText(Buffer);
//Reset deck
deck = Deck();
//Stop the game
started = false;
//Update the Display
InvalidateRect(hWnd, 0, TRUE);
RedrawWindow(hWnd, NULL, NULL, RDW_INVALIDATE | RDW_INTERNALPAINT);
}
int SendMessage(HWND hWnd, int ButtonID, unsigned int MESSAGE, int Information, char* _Information){
return ProcessMessage(hWnd, ButtonID, MESSAGE, Information, _Information);
}
int ProcessMessage(HWND hWnd, int ButtonID, unsigned int MESSAGE, int Information, char* _Information){
switch(MESSAGE)
{
case START_GAME:
//Place Bet
You.money -= Information;
started = YES;
sprintf(Buffer, "%d", You.money);
//Update Controls
MoneyValue.SetText(Buffer);
Ok.Disable();
Bet.Disable();
//Deal two cards to player and dealer
You.DealCard();
You.DealCard();
Dealer.DealCard();
Dealer.DealCard();
//Update the Hand Value Label
sprintf(Buffer, "%d", You.HandValue());
HandValueLabel.SetText(Buffer);
//Move the label
MoveWindow(HandValueLabel.Handle, (int)You.x[You.cards] + 80, (int)You.y[You.cards] + 25, 100, 20, TRUE);
//Send PAINT message
InvalidateRect(hWnd,0, TRUE);
RedrawWindow(hWnd, NULL, NULL, RDW_INVALIDATE | RDW_INTERNALPAINT);
//Check for BlackJacks
if(You.HandValue() == 21){
SendMessage(hWnd, 0, INTERNAL, YOU_WIN, "");
}
else if(Dealer.HandValue() == 21){
SendMessage(hWnd, 0, INTERNAL, DEALER_WIN, "");
}
break;
case STAND:
if(started){
Hit.Disable();
You.playing = false;
}
break;
case INTERNAL:
switch(Information)
{
case DEALER_WIN:
return MessageBoxA(hWnd, "You Loose! \n Play Again ?", "Game Over", MB_YESNO | MB_ICONINFORMATION);
case YOU_WIN:
return MessageBoxA(hWnd, "You Win! \n Keep Playing ?", "Game Over", MB_YESNO | MB_ICONINFORMATION);
}
break;
case IDLE:
if(started){
//Check for BlackJacks
if(Dealer.HandValue() == 21){
started = false;
switch(SendMessage(hWnd, 0, INTERNAL, DEALER_WIN, ""))
{
case IDYES:
ResetGame(hWnd);
return 0;
case IDNO:
exit(0);
return 0;
}
}
if(!You.playing && Dealer.playing && Dealer.HandValue() < You.HandValue())
Dealer.DealCard();
//Update the Window
InvalidateRect(hWnd,0, TRUE);
RedrawWindow(hWnd, NULL, NULL, RDW_INVALIDATE | RDW_INTERNALPAINT);
//Check for a Bust
if(Dealer.HandValue() > 21){
switch(SendMessage(hWnd, 0, INTERNAL, YOU_WIN, ""))
{
case IDYES:
ResetGame(hWnd);
return 0;
case IDNO:
exit(0);
return 0;
}
}
if(Dealer.HandValue() == 21){
switch(SendMessage(hWnd, 0, INTERNAL, YOU_WIN, ""))
{
case IDYES:
ResetGame(hWnd);
return 0;
case IDNO:
exit(0);
return 0;
}
}
}
break;
case HIT:
//Check to see who's still playing and deal a card to them
if(started){
if(You.playing){
You.DealCard();
//Update the Hand Value Label
sprintf(Buffer, "%d", You.HandValue());
HandValueLabel.SetText(Buffer);
//Move the label and update the screen
MoveWindow(HandValueLabel.Handle, (int)You.x[You.cards] + 80, (int)You.y[You.cards] + 25, 100, 20, TRUE);
InvalidateRect(hWnd, 0, TRUE);
RedrawWindow(hWnd, NULL, NULL, RDW_INVALIDATE | RDW_INTERNALPAINT);
//Check for a BlackJack
if(You.HandValue() == 21){
started = false;
switch(SendMessage(hWnd, 0, INTERNAL, YOU_WIN, ""))
{
case IDYES:
ResetGame(hWnd);
return 0;
case IDNO:
exit(0);
return 0;
}
}
//Check for a bust
if(You.HandValue() > 21){
started = false;
switch(SendMessage(hWnd, 0, INTERNAL, YOU_WIN, ""))
{
case IDYES:
ResetGame(hWnd);
return 0;
case IDNO:
exit(0);
return 0;
}
}
}
if(Dealer.playing){
Dealer.DealCard();
InvalidateRect(hWnd, 0, TRUE);
RedrawWindow(hWnd, NULL, NULL, RDW_INVALIDATE | RDW_INTERNALPAINT);
//Check for BlackJack
if(Dealer.HandValue() == 21){
started = false;
switch(SendMessage(hWnd, 0, INTERNAL, DEALER_WIN, ""))
{
case IDYES:
ResetGame(hWnd);
return 0;
case IDNO:
exit(0);
return 0;
}
}
//Check for Bust
if(Dealer.HandValue() > 21){
started = false;
switch(SendMessage(hWnd, 0, INTERNAL, YOU_WIN, ""))
{
case IDYES:
ResetGame(hWnd);
return 0;
case IDNO:
exit(0);
return 0;
}
}
}
}
break;
}
return 0;
}
};
Game game;
#endif
Message Loop
switch(Msg)
{
case WM_PAINT:
{
PAINTSTRUCT PS;
HDC hDC = BeginPaint(hWnd, &PS);
You.Draw(hDC);
Dealer.Draw(hDC);
EndPaint(hWnd, &PS);
if(Bet.Enabled){
Bet.GetFocus();
Bet.Select(0,Bet.Length());
}
}
return 0;
case WM_CTLCOLORSTATIC:
{
SetBkMode((HDC)wParam, TRANSPARENT);
}
return (INT_PTR)(HBRUSH)GetStockObject(NULL_BRUSH);
case WM_CREATE:
{
//Create edit control
Bet.Create(hWnd, 10, 550, 100, 25, "0");
//Create labels
char Buffer[30];
sprintf(Buffer, "%d", You.HandValue());
BetLabel.Create(hWnd, 10, 500, 100, 40, "Enter Bet Amount");
GameControls.Create(hWnd, 10, 375, 100, 40, "Game Controls");
PlayerLabels.Create(hWnd, 10, 10, 100, 20, "You:");
PlayerLabels.Create(hWnd, 10, 175, 100, 20, "Dealer:");
HandValueLabel.Create(hWnd, (int)You.x[You.cards] + 85, 60, 100, 20, Buffer);
YourMoney.Create(hWnd, 125, 500, 100, 40, "Your money: ");
sprintf(Buffer, "%d", You.money);
MoneyValue.Create(hWnd, 125, 525, 100, 40, Buffer);
//Create buttons
Ok.Create(hWnd, 10, 600, 100, 50, "Ok");
Hit.Create(hWnd, 10, 425, 100, 50, "Hit");
Stand.Create(hWnd, 120, 425, 100, 50, "Stand");
//Select Text
Bet.Select(0,3);
}
return 0;
case WM_CLOSE:
exit(0);
break;
case WM_COMMAND:
{
switch(HIWORD(wParam))
{
case BN_CLICKED:
{
switch(LOWORD(wParam))
{
case ID_OK:
{
//Place bet
int bet = 0;
bet = StringToNumber(Bet.Text());
game.SendMessage(hWnd, ID_OK, START_GAME, bet, "");
}
break;
case ID_HIT:
{
//Tell the game that the player wants another card
game.SendMessage(hWnd, ID_HIT, HIT, 0, "");
}
break;
case ID_STAND:
game.SendMessage(hWnd, ID_STAND, STAND, 0, "");
}
}
break;
}
}
break;
default:
//Default:
game.SendMessage(hWnd, 0, IDLE, 0, "");
return DefWindowProcA(hWnd, Msg, wParam, lParam);
}
return 0;
}