C++ Workshop - Project 1 - CPP Workshop

Jeromy Walsh · 2009-11-08T13:28:06

Project 1 – Overview Welcome all to the first project of the C++ Workshop. This project will be a combat simulator following very simple combat logic, roughly equivalent to that found in Dungeons & Dragons 3.5 Edition. Participants will have 1 month (ending September 15) to complete the project. In the mean time, feel free to post your questions and ideas here on the thread. In order to complete this project you may find you need to draw upon not only what you’ve already learned, but also what WILL be learned during the course of the next 4 weeks. As we have already covered the chapter on Object-Oriented Analysis and Design the remainder of this post will follow the guidelines provided. I will provide the conceptualization and the analysis of the project. It will be up to each participant to do the design and implementation of the project, though design and implementation questions may be posted here if you get stuck. Project 1 - Conceptualization The program will be a console application consisting of various menus and submenus. The primary functionality will be the ability to create a character, purchase equipment, view your character’s stats, and enter the arena for combat. Once in the arena the character can select which level of opponent he wishes to face (from 1 to 20). After the level of opponent is chosen the opponent will be randomly generated and then him and the player will exchange blows until someone “dies.” Blows will be exchanged on the rate of one attack every 2 seconds and each attack/defense will be displayed on the screen. If the player is the winner he will receive experience points and money which can be used to purchase better equipment. Once a player receives the required experience he will automatically “level up,” resulting in an increase in stats at the end of a fight. The user may continue to buy equipment and fight in the arena until he loses a battle. At that point the character is dead and the user must create a new character. Finally, output should be color-coded. Menus, status information, and lists should all be in white, damage received should be shown in red, and damage given should be in another suitable color. Feel free to add other colors as you feel inclined. Project 1 - General AnalysisUse Cases: 1. When the user first executes the program they will be shown a main menu similar to that displayed below. When the user makes a choice the screen will be cleared and the user will be shown a new menu or screen depending upon which choice was made. ============================== Main Menu ============================== Menu Options: a. Create Character b. Purchase Equipment c. View Stats d. Fight! Q. Quit ============================== Choice: 2. When the user selects the option to create a character they will be shown a menu similar to that shown below. If the user selects “Name Character” they will receive a prompt allowing them to enter a name for the character. If the user selects roll for stats, then he will enter a loop where he can continue to “roll for stats” until he finds a suitable distribution. Returning to the previous menu clears the screen and then once again shows the main menu. 2a. If the user has already created a character by previously entering this submenu then entering the “Create Character” menu additional times should first prompt the user that they have already created a character, and that continuing will result in the removal of the old character to make room for the new. If the user opts to continue to “Create a Character” then the menu below is shown. If they decide NOT to create a new character, they will simply be returned to the main menu and their previously created character will remain. 2b. If the user had created a character but the character died in the arena, entering this menu does not prompt the user with a warning as described in 2b. ============================== Create Character ============================== Menu Options: a. Name Character b. Roll for Stats R. Return to previous menu ============================== Choice: 3. If the user selects Purchase Equipment they will be shown a menu similar to that shown below. From this screen the user can opt to purchase either armor or weapons. Depending upon which submenu the user selects he will be shown a new menu listing the items available, their cost, and benefits. See the Armor and Weapons table below for information about what should be displayed and what items are available. The meaning of the fields in the tables below will be explained later. For now, just use it as a reference of what should be displayed in the item lists. ============================== Purchase Equipment ============================== Menu Options: a. Purchase Armor b. Purchase Weapon R. Return to previous menu ============================== Choice: Table 3.1 - Weapons Unarmed Strike 1d3 (20/x2) Brass Knuckles 1d4 (20/x2) 1g Dagger 1d4 (19-20/x2) 2g Mace 1d6 (20/x2) 5g Handaxe 1d6 (20/x3) 6g Shortsword 1d6 (19-20/x2) 6.5g Scimitar 1d6 (18-20/x2) 7g Morningstar 1d8 (20/x2) 8g Spear 1d8 (20/x3) 9g Longsword 1d8 (19-20/x2) 9.5g Greatclub 1d10 (20/x2) 11g Halberd 1d10 (20/x3) 12g Bastard Sword 1d10 (19-20/x2) 12.5g Greataxe 1d12 (20/x3) 16.0g Greatsword 2d6 (19-20/x2) 20.0g Table 3.2 - Armor Unarmored AC: +0 Max Dex: INF Padded Armor AC: +1 Max Dex: +8 5g Leather Armor AC: +2 Max Dex: +6 10g Hide Armor AC: +3 Max Dex: +4 15g Studded Leather AC: +3 Max Dex: +5 25g Scale Mail AC: +4 Max Dex: +3 50g Chain Shirt AC: +4 Max Dex: +4 100g Chainmail AC: +5 Max Dex: +2 150g Breastplate AC: +5 Max Dex: +3 200g Splint Mail AC: +6 Max Dex: +0 225g Banded Mail AC: +6 Max Dex: +1 250g Half-Plate AC: +7 Max Dex: +0 600g Full Plate AC: +8 Max Dex: +1 1000g 4. If the user selects “View Stats” he will be shown a screen that displays the character’s stats. If no character has been created or if the character was killed in the arena, the output is simply “No Character Found.” After the stats or ‘no character’ message is displayed the player will be prompted to press any key. Doing so clears the screen and returns the player to the main menu. How the stats are displayed are up to the developer, but the following stats should be shown: Name // Name of the Character Level // Level of the Character (1-20) Strength // Strength of the Character (8-20) Dexterity // Dexterity of the Character (8-20) Constitution // Constitution of the Character (8-20) Hit Point // The hit points of the character Experience // How many experience points the character has earned Gold // The amount of gold the character has earned through victorious battles 5. If the user selects “Fight!” at the main menu he will be taken to another menu which allows the user to select which level of opponent he wants to fight, in the range of 1 to 20, depending on whether or not he’s defeated an opponent of the previous level. For example, the first time the user enters the menu, “Level 1” will be the only choice. After he defeats a “Level 1” opponent and returns to the menu, “Level 1” and “Level 2” will both be options. Similarly, after the player defeats a level 15 opponent, the level 16 opponent will become available…and the pattern continues with level 20 being the most difficult opponent. Since the user can decide whether to fight an opponent of his level or less difficult, the choice he makes will determine how much experience and gold the player will get if he wins the battle. Listed below is a table that shows how much gold and experience a character gets for fighting mobs – relative to his own level. Table 5.1 – Experience Rewards based on Opponent Level Character Level: 300xp Character Level - 1: 150xp Character Level - 2: 75xp Character Level – 3: 35xp Character Level – 4: 15xp Character Level – 5: 5xp More than 5 levels below is 5xp Table 5.2 – Treasure Rewards based on Opponent Level Character Level: 25g Character Level – 1: 12g Character Level – 2 : 6g Character Level – 3 : 3g Character Level – 4 : 1g Character Level – 5 : 0.5g More than 5 levels below is 0.5g Table 5.3 – Total Experience Points Required at each level Level 1 - 0 Level 2 – 1,000 Level 3 – 3,000 Level 4 – 6,000 Level 5 – 10,000 …. To compute the remaining entries in the table up to level 20, simply take the previous level, multiply it by 1,000 and add it to the experience required for the previous level. Example: Level 11 = (10 * 1,000) + 45,000 = 55,000 Level 12 = (11 * 1,000) + 55,000 = 66,000 If a character dies and the player returns to the “Fight” menu a “No Character Found” message will be shown, and the user will be returned to the main menu after pressing a key. If the character has died and a new character was created, the possible opponents are reset back to Level 1 and the character’s experience and gold are reset to 0. 6. Once the user has chosen an opponent, combat begins. Who attacks first is referred to as “Initiative” and is calculated based on the formula below. Once initiative is calculated for both the player and his opponent the scores are compared. Whoever has the higher initiative attack first. From then on the player’s character and his opponent alternate attacking each other every 2 seconds until someone dies. Initiative: d20 + (Dexterity Modifier) Each attack the success or failure of an attack and how much damage it does will be output to the screen, scrolling down. As an Example: … Round 3 (Caspian vs. Level 4); 25hp remaining > Caspian swings his Shortsword at his opponent and misses. > The level 4 opponent swings his Scimitar and strikes Caspian for 4 damage. …2 second pause … // don’t display this…just note it in your mind Round 4 (Caspian vs. Level 4); 21hp remaining > Caspian swings his Shortsword at his opponent and critically hits him for 12 damage! > The level 4 opponent dies. > Caspian earns 300xp and 25g > Press any key to continue…. When the combat finally ends one of two things will happen. If the player won, he will receive an amount of gold and experience according to the above table, and the additions will be output to the screen. If the player earned enough experience to be promoted to a new level then this too will be output to the screen, along with his new level number and his new hit points. If the player’s character died, however, then a message indicating the character died will be displayed, along with a message letting them know they must create a new combatant. Project 1 - Discussion of Combat and Modifiers Each round of combat we must determine a few things: We must determine whether or not an attack was successful (and if so was it critical) and then we need to determine how much damage was done to the opponent. This process is done for both the player and his opponent, depending on who’s currently attacking whom. Step 1: Determining Attack Role Whenever a character attempts to strike another an “Attack Roll” is performed. This is essentially calculating a random number between 1 and 20 (d20), and then adding on to the random number two values: the level of the attacker, and the attacker’s Strength Modifier. The attacker’s Strength Modifier is determined the same way as determining his Dexterity Modifier and his Constitution Modifier. You simply take the particular score, subtract 10 from it, and then divide the result by 2 (using integer truncation). As an example, lets assume my Strength is 15. Attack Role: d20 + (Level + StrMod) Strength: 15 Strength Bonus: (15 – 10) / 2 = 2.5 = 2 So the final result is 2, after integer truncation. This value, plus the attacker’s level (1-20) is added to the random number that was calculated, and that becomes the attacker’s “Attack Role.” Step 2: Determining Success of Attack Now that we know what the attacker “rolled” we must determine whether or not it was high enough to successfully penetrate his opponents’ armor and fast reflexes. To do this simply compare the attack role with his opponents Armor Check. If the Attack Role was greater than or equal to his opponent’s armor check, the hit was successful. If it was lower, the hit was a ….miss. Successful Attack: Attack Role >= Armor Check To determine the opponent’s Armor Check, simply take 10, add onto it the opponent’s Armor Value (determined by equipment), and then add on to it the character’s Dexterity Modifier (calculated as the Strength Modifier above). Note that some armor limits the maximum value the Dexterity Modifier can contribute to the Armor Check. Scale Mail, for example, has a maximum Dexterity Bonus of +3…which means even if the person has a Dexterity Modifier of +4, only +3 of it counts towards the Armor Check. As an Example: My character is equipped with Scale Mail, and has a Dexterity of 14. Armor Value: +4 Dexterity Modifier: +2 Armor Check: 10 + 4 + 2 = 16 So based upon my Armor Check above, any Attack Role of 16 or higher would result in a successful attack. Step 4: Determining Damage If a successful attack role is made, then the next step is to determine how much damage will be subtracted from the opponent’s hit points. To determine the amount of damage, compute a random value based upon the weapon carried, and then add to it the Strength Modifier of the Attacker. For example lets assume my character has a Strength of 14 and is wielding a Shortsword (1d6). My damage would be a random value between 1 and 6, and then I would add to that value 2 (My computed Strength Modifier). The minimum damage would then be 3, and the maximum would be 8. You can also see in the weapon list above, the Greatsword has a damage of 2d6. This means a random number between 1 and 6, twice. (ie the value from two 6-sided dice). So the actual range of values is from 2 to 12. In general you can determine the range of a roll by looking at the two numbers. The first number is the minimum, and the first number multiplied by the second number is the maximum value. Step 5: Critical Strikes By default if the random component of the Attack Role was 20 (called a natural 20), then a critical strike was made. By default this means that rather than computing the damage done once, it is computed twice. The addition of BOTH damage calculations are applied to the opponent’s hit points. So for example if I were still using my Shortsword (1d6) and I rolled a natural 20, I would then get to apply 1d6 damage, twice (x2). Now, above I said that the default was a natural 20 (the random value came up 20), and the default was a x2 damage roll. Depending upon the weapon the attacker is carrying, this can be different. In the weapon list above you can see that some weapons say 18-20, 19-20, and also x2 or x3. These are critical strike modifiers. A 18-20 means that a natural roll of 18, 19, or 20 will result in the application of a critical strike (additional damage rolls). The x2 and x3 tell you how many damage rolls will actually be applied. So by default (non critical strike) you apply a x1 damage modifier. If the weapon says x2, you apply an extra damage roll. If the weapon says x3 you apply TWO extra damage rolls. Project 1 - Hit points and Leveling Whenever a character is first created they have hit points equal to 10 + their Constitution Modifier. Any time a character levels they receive additional hit points equal to 1d10 (random value between 1 and 10), plus their Constitution Modifier. Starting HP : 10 + ConModAdditional HP: 1d10 + ConMod For example, I just created a new character with a Constitution of 14. Total starting hit points is 12. (10+2). The next time I level I roll a 10-sided dice (range: 1-10) and I add to it 2. So any time I level I can gain a possible 3 to 12 hit points. After every battle, hit points should be restored back to the total value. So this means characters have a “maximum hit points” and then while fighting they have a “current hit points.” If current hit points ever drops to 0…the character is dead. Project 1 - Conclusion I’ve tried to give you a reasonable overview of how the menus should look, what kinds of items and treasures should be available and how combat should proceed. If you have any questions about the logistics of the program, please feel free to post your questions on the forums. I encourage all people participating in the C++ Workshop to complete this project, as you can be assured it will be used again in later projects.

Twisol

468

October 03, 2006 01:42 AM

No, it's telling you to #define it before you even include windows.h. That way, it sees a definition of _WIN32_WINNT (or WINVER) already, so it doens't re-define. System headers are always (hopefully!) implemented in such a way that the end user never needs to modify them.

me_minus

126

October 03, 2006 01:57 PM

popcorn:

Be consistent with #include and file names (upper/lower case)
For the include guard to work it must have the same name in both #ifndef and #define

iostream should almost never be included into a .h file.

You can place a struct or class inside a class. This is good since you can control the visibility.

dont do:

class Menu {  public:    Menu::Menu();}

The Menu:: part is bad.

don't use #define to create constants and enums. (Game.h)

I think this would be clearer (untested):

void Menu::addOptions(vector<Option> optionItem){        copy(optionItem.begin(),optionItem.end(),back_inserter(options));}

popcorn

151

October 03, 2006 07:53 PM

Thanks for all the feedback me_minus.

Quote:
Original post by me_minus
popcorn:

Be consistent with #include and file names (upper/lower case)
For the include guard to work it must have the same name in both #ifndef and #define

I knew I had done something stupid but yeah it works now without the pragma's.

Quote:
Original post by me_minus
You can place a struct or class inside a class. This is good since you can control the visibility.

You couldn't give me any examples of this could you or links to websites/pages with info on this subject?

Quote:
Original post by me_minus
don't use #define to create constants and enums. (Game.h)

Fair point, I am just used to using #define for constants now but I do know you can use const int etc which would be a better way of doing things. I will try to do this in future.

Quote:
Original post by me_minus
I think this would be clearer (untested):
void Menu::addOptions(vector<Option> optionItem){        copy(optionItem.begin(),optionItem.end(),back_inserter(options));}

Just tested this quickly and it compiles and works fine - doesn't seem to cause any problems so yeah it is a lot clearer.

How about them apples?

me_minus

126

October 04, 2006 03:37 AM

This is not the best example...
I hope it works, this computer/network do not have any compilers on it.

The MenuItem implementaion is hidden from the user.

If you change the first private: to public: it is possible to create
MenuItem's by doing this:

  Menu::MenuItem item('a',"wakeup","Ring the bell of wakeup.");  std::cout << item << std::endl;

The example:

#include <iostream>#include <map>#include <string>class Menu{ private:  class MenuItem   {   public:    MenuItem(const char shortcut, const std::string& text, const std::string& explanation): shortcut_(shortcut), text_(text), explanation_(explanation) {;}   private:      char shortcut_;     std::string text_;     std::string explanation_;     friend std::ostream& operator<<(std::ostream& s,const MenuItem& item);  }; public:  Menu();  void add(int number,const std::string& text,const std::string& explantaion)  { items.insert(make_pair(number,MenuItem(text[0],text,explanation))); }  void draw(std::ostream& s)  {     for (iter=items.begin(); iter!=items.end(); ++iter) {       s << (*iter).first << ": " << (*iter).second << endl;    }  private:  std::map<int,MenuItem> items;  };std::ostream& operator<<(std::ostream& s,const MenuItem& item){  // could be extended by marking the shortcut letter in the text  s << item.text_ << " : " << item.explanation_;   return s;}

popcorn

151

October 04, 2006 07:17 PM

me_minus I can see from your code that it is possible to declare a class within a class but what I don't understand is how can menu access MenuItem's private data without accessor functions. Also don't you have to declare the type of iterator you want before using it inside the for loops draw member function.

How about them apples?

me_minus

126

October 05, 2006 03:11 AM

You are right about the iterator stuff, I forgot to fix it.

Why should Menu need to access MenuItem's internal state?

operator<< is overloaded to print a MenuItem in 'global' scope.
Even if it is in 'global' scope it can access MenuItems internals
by beeing friend to it.

popcorn

151

October 05, 2006 07:22 PM

Ok I've had another look at the code now and I think I understand how it works. I can see why you have no need for accessor functions now. The add member function in Menu creates the the new item using the MenuItem class constructor.
From what I understand everything looks correct, however when I put the code into Visual C++ 2005 it came up with some compiler errors. Here is the code:

#include <iostream>#include <map>#include <string>class Menu{private:	class MenuItem 	{	public:		MenuItem(const char shortcut, const std::string &text, const std::string &explanation): shortcut_(shortcut), text_(text), explanation_(explanation) {}	private: 		char shortcut_;		std::string text_;		std::string explanation_;		friend std::ostream& operator<<(std::ostream &s, const MenuItem &item);	};public:	Menu();	void add(int number, const std::string &text, const std::string &explanation)	{ 		items.insert(std::make_pair(number, MenuItem(text[0], text, explanation))); 	}	void draw(std::ostream &s)	{ 		std::map<int, MenuItem>::const_iterator iter;		for(iter = items.begin(); iter != items.end(); ++iter)		{ 			s << (*iter).first << ": " << (*iter).second << std::endl;		} 	} private:  std::map<int, MenuItem> items;  };std::ostream& operator<<(std::ostream &s, const MenuItem &item){  // could be extended by marking the shortcut letter in the text  s << item.text_ << " : " << item.explanation_;   return s;}

I've reformatted it for my own preferences. The problem seems to be caused by the overloaded operator friend function, however I don't understand why - It looks correct to me.

The errors I get are:
--
Compiling...
test.cpp
error C4430: missing type specifier - int assumed. Note: C++ does not support default-int

error C2143: syntax error : missing ',' before '&'

error C2065: 'item' : undeclared identifier

error C2228: left of '.text_' must have class/struct/union
type is ''unknown-type''

error C2228: left of '.explanation_' must have class/struct/union
type is ''unknown-type''

test - 5 error(s), 0 warning(s)
========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========

Any ideas on why this happens?

I tried the following and it works

class MenuItem 	{	public:		MenuItem(const char shortcut, const std::string &text, const std::string &explanation): shortcut_(shortcut), text_(text), explanation_(explanation) {}	private: 		char shortcut_;		std::string text_;		std::string explanation_;		friend std::ostream& operator<<(std::ostream &s, const MenuItem &item)		{			// could be extended by marking the shortcut letter in the text			s << item.text_ << " : " << item.explanation_; 			return s;		}	};

But I don't understand why this works and the other way doesn't.

[Edited by - popcorn on October 5, 2006 7:22:00 PM]

How about them apples?

me_minus

126

October 06, 2006 03:38 AM

std::ostream& operator<<(std::ostream &s, const MenuItem &item)
is the faulty line. Change it to
std::ostream& operator<<(std::ostream &s, const Menu::MenuItem &item)
and it might work.

I dont know if there will be trouble with MenuItem is private.

popcorn

151

October 06, 2006 07:42 AM

Quote:
Original post by me_minus
std::ostream& operator<<(std::ostream &s, const MenuItem &item)
is the faulty line. Change it to
std::ostream& operator<<(std::ostream &s, const Menu::MenuItem &item)
and it might work.

I dont know if there will be trouble with MenuItem is private.

Sorry it doesn't, you get the following error:

error C2248: 'Menu::MenuItem' : cannot access private class declared in class 'Menu'

It works if you change private to a public though I'm not sure if this would be considered a good thing or not.

oops..reread one of your earlier posts and thats what you said I should do the first time round. I think I understand what's going on now. Thanks for all your help.

[Edited by - popcorn on October 6, 2006 8:42:43 PM]

How about them apples?

Akusei

226

October 17, 2006 04:29 PM

I'm hoping that someone is still watching this thread, as I have stumbled across this just last week. I have completed, to some degree, this project and would like some opinions and criticisms. So, if anyone is reading this thread, please take a look and let me know what you think. Hopefully I will begin Project 2 shortly.

Download: Arena.zip

-akusei

C++ Workshop - Project 1

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