C++ Programming for Games Module I e-Institute Publishing, Inc ©Copyright 2004 e-Institute, Inc All rights reserved No part of this book may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or by any information storage or retrieval system without prior written permission from e-Institute Inc., except for the inclusion of brief quotations in a review Editor: Susan Nguyen Cover Design: Adam Hoult E-INSTITUTE PUBLISHING INC www.gameinstitute.com Frank Luna, Game Institute Faculty, C++ Programming for Games All brand names and product names mentioned in this book are trademarks or service marks of their respective companies Any omission or misuse of any kind of service marks or trademarks should not be regarded as intent to infringe on the property of others The publisher recognizes and respects all marks used by companies, manufacturers, and developers as a means to distinguish their products E-INSTITUTE PUBLISHING titles are available for site license or bulk purchase by institutions, user groups, corporations, etc For additional information, please contact the Sales Department at sales@gameinstitute.com Table of Contents CHAPTER 1: INTRODUCING C++ .9 INTRODUCTION 10 CHAPTER OBJECTIVES 10 1.1 GETTING STARTED—YOUR FIRST C++ PROGRAM 10 1.1.1 Creating the Project 10 1.1.2 Adding A CPP File to the Project 12 1.1.3 Writing the Code .13 1.1.4 Compiling, Linking, and Executing .14 1.2 THE “PRINT STRING” PROGRAM EXPLAINED 16 1.2.1 Comments 16 1.2.2 White Space 17 1.2.2 Include Directives 18 1.2.3 Namespaces 18 1.2.4 The main{ } Function 20 1.2.5 std::string 20 1.2.6 Input and Output with std::cin and std::cout 20 1.3 VARIABLES 21 1.3.1 Variable Declarations and Definitions 24 1.3.2 Variable Names .25 1.3.3 The sizeof Operator 25 1.3.4 The unsigned Keyword .26 1.3.5 Literal Assignments .27 1.3.6 Type Conversions 27 1.3.7 Typedefs 30 1.3.8 Const Variables .30 1.3.9 Macros 30 1.4 ARITHMETIC OPERATIONS .31 1.4.1 Unary Arithmetic Operations 32 1.4.2 Binary Arithmetic Operations 33 1.4.3 The Modulus Operator 34 1.4.4 Compound Arithmetic Operations 35 1.4.5 Operator Precedence 36 1.5 SUMMARY 37 1.6 EXERCISES .38 1.6.1 Arithmetic Operators 38 1.6.2 Cin/Cout 38 1.6.3 Cube 38 1.6.4 Area/Circumference 39 1.6.5 Average 39 1.6.6 Bug Fixing .39 CHAPTER 2: LOGIC, CONDITIONALS, LOOPS AND ARRAYS 41 INTRODUCTION 41 CHAPTER OBJECTIVES: 42 2.1 THE RELATIONAL OPERATORS 42 2.2 THE LOGICAL OPERATORS .44 2.3 CONDITIONAL STATEMENTS: IF, IF…ELSE 48 2.3.1 The If Statement 49 2.3.2 The Else Clause .50 2.3.3 Nested If…Else Statements 51 2.3.4 The Switch Statement 53 2.3.5 The Ternary Operator .55 2.4 REPETITION 56 2.4.1 The for-loop 56 2.4.2 The while Loop 58 2.4.3 The do…while Loop 60 2.4.4 Nesting Loops 61 2.4.5 Break and Continue Keywords 62 2.5 ARRAYS 63 2.5.1 Array Initialization 64 2.5.2 Iterating Over an Array 64 2.5.3 Multidimensional Arrays 65 2.6 SUMMARY 67 2.7 EXERCISES .68 2.7.1 Logical Operator Evaluation 68 2.7.2 Navigator .68 2.7.3 Average 69 2.7.4 Factorial 69 2.7.5 Matrix Addition .70 2.7.6 ASCII .71 2.7.7 Linear Search 71 2.7.8 Selection Sort 73 CHAPTER 3: FUNCTIONS 75 INTRODUCTION 75 3.1 USER DEFINED FUNCTIONS 78 3.1.2 Functions with One Parameter .80 3.1.3 Functions with Several Parameters .82 3.2 VARIABLE SCOPE .83 3.2.1 Example 83 3.2.2 Example 85 3.2.3 Example 86 3.3 MATH LIBRARY FUNCTIONS 87 3.4 RANDOM NUMBER LIBRARY FUNCTIONS 88 3.4.1 Specifying the Range .91 3.5 FUNCTION OVERLOADING 92 3.5.1 Default Parameters 94 3.6 SUMMARY 96 3.7 EXERCISES .97 3.7.1 Factorial 97 3.7.2 ToUpper; ToLower 97 3.7.3 3D Distance 98 3.7.4 Arc Tangent 99 3.7.5 Calculator Program 100 3.7.6 Slot Machine 101 3.7.7 Binary Search 102 3.7.8 Bubble Sort 103 CHAPTER 4: REFERENCES AND POINTERS .107 INTRODUCTION 108 CHAPTER OBJECTIVES 108 4.1 REFERENCES 108 4.1.1 Constant References 110 4.2 POINTERS .111 4.2.1 Computer Memory Primer 111 4.4.2 Pointer Initialization .112 4.4.3 Dereferencing 114 4.3 ARRAYS REVISITED 117 4.3.1 Pointer to the Beginning of an Array 117 4.3.2 Pointer Arithmetic 118 4.3.1 Passing Arrays into Functions 120 4.4 RETURNING MULTIPLE RETURN VALUES 122 4.4.1 Returning Multiple Return Values with Pointers 122 4.4.2 Returning Multiple Return Values with References 124 4.5 DYNAMIC MEMORY 125 4.5.1 Allocating Memory 126 4.5.2 Deleting Memory 127 4.5.3 Memory Leaks 127 4.5.4 Sample Program 128 4.6 STD::VECTOR 132 4.7 FUNCTION POINTERS 135 4.7.1 The Uses of Function Pointers 136 4.7.2 Function Pointer Syntax 137 4.8 SUMMARY 138 4.9 EXERCISES 139 4.9.1 Essay Questions 139 4.9.2 Dice Function 140 4.9.3 Array Fill 140 4.9.4 Quadratic Equation 141 CHAPTER 5: CLASSES AND OBJECT ORIENTED PROGRAMMING 144 INTRODUCTION 144 CHAPTER OBJECTIVES 145 5.1 OBJECT ORIENTED PROGRAMMING CONCEPTS 145 5.2 CLASSES 146 5.2.1 Syntax 146 5.2.2 Class Access: The Dot Operator 148 5.2.3 Header Files; Class Definitions; Class Implementations 150 5.2.2.1 Inclusion Guards 152 5.2.4 DATA HIDING: PRIVATE VERSUS PUBLIC 153 5.2.5 Constructors and Destructors 155 5.2.6 Copy Constructors and the Assignment Operator 157 5.3 RPG GAME: CLASS EXAMPLES 158 5.3.1 The Range Structure 158 5.3.2 Random Functions 159 5.3.3 Weapon Class 159 5.3.4 Monster Class 160 5.3.5 Player Class 165 5.3.6 Map Class 173 5.4 THE GAME 177 5.4.1 Segment 179 5.4.2 Segment 180 5.4.3 Segment 180 5.4.4 Segment 182 5.5 SUMMARY 183 5.6 EXERCISES 184 5.6.1 Gold Modification 185 5.6.2 Character Races 185 5.6.3 Leveling Up 185 5.6.4 Magic Points 185 5.6.5 Random Encounters During Rest 186 5.6.6 A Store 186 5.6.7 Items 187 5.6.8 Multiple Enemies 187 CHAPTER 6: STRINGS AND OTHER TOPICS 188 INTRODUCTION 189 CHAPTER OBJECTIVES 189 6.1 CHAR STRINGS 189 6.1 STRING LITERALS 191 6.2 ESCAPE CHARACTERS 192 6.2 C-STRING FUNCTIONS 193 6.2.1 Length 193 6.2.2 Equality 194 6.2.3 Copying 195 6.2.4 Addition 195 6.2.7 Formatting 196 6.3 STD::STRING 199 6.3.1 Length 199 6.3.2 Relational Operators 200 6.3.3 Addition 201 6.3.4 Empty Strings 201 6.3.5 Substrings 202 6.3.6 Insert 203 6.3.7 Find .204 6.3.8 Replace 204 6.3.9 Bracket Operator 205 6.3.10 C-String Equivalent 205 6.3.11 getline 206 6.4 THE THIS POINTER 208 6.5 FRIENDS 211 6.5.1 Friend Functions 211 6.5.2 Friend Classes .212 6.6 THE STATIC KEYWORD 212 6.6.1 Static Variables in Functions 212 6.6.2 Static Data Members .213 6.6.3 Static Methods .214 6.7 NAMESPACES 215 6.7.1 Variations of the “using” Clause 217 6.8 ENUMERATED TYPES .218 6.9 SUMMARY 219 6.10 EXERCISES 220 6.10.1 String Reverse 220 6.10.2 To-Upper .220 6.10.3 To-Lower .220 6.10.4 Palindrome 221 CHAPTER 7: OPERATOR OVERLOADING 222 INTRODUCTION 223 CHAPTER OBJECTIVES 224 7.1 VECTOR MATHEMATICS 224 7.2 A VECTOR CLASS 232 7.2.1 Constructors 233 7.2.2 Equality 233 7.2.3 Addition and Subtraction .234 7.2.4 Scalar Multiplication 234 7.2.5 Length 235 7.2.6 Normalization 235 7.2.7 The Dot Product 235 7.2.8 Conversion to float Array 236 7.2.9 Printing 237 7.2.10 Inputting 237 7.2.11 Example: Vector3 in Action 237 7.3 OVERLOADING ARITHMETIC OPERATORS 240 7.3.1 Operator Overloading Syntax 241 7.3.2 Overloading the Other Arithmetic Operators 242 7.3.3 Example using our Overloaded Operators 243 7.4 OVERLOADING RELATIONAL OPERATORS 244 7.5 OVERLOADING CONVERSION OPERATORS 246 7.6 OVERLOADING THE EXTRACTION AND INSERTION OPERATORS 247 7.7 A STRING CLASS; OVERLOADING THE ASSIGNMENT OPERATOR, COPY CONSTRUCTOR, AND BRACKET OPERATOR 250 7.7.1 Construction and Destruction 250 7.7.2 Assignment Operator 251 7.7.3 Copy Constructor 253 7.7.4 Overloading the Bracket Operator 254 7.8 SUMMARY 254 7.9 EXERCISES 255 7.9.1 Fraction Class 255 7.9.2 Simple float Array Class 256 CHAPTER 8: FILE INPUT AND OUTPUT 259 INTRODUCTION 260 CHAPTER OBJECTIVES 260 8.1 STREAMS 260 8.2 TEXT FILE I/O 261 8.2.1 Saving Data 261 8.2.2 Loading Data 262 8.2.3 File I/O Example 263 8.3 BINARY FILE I/O 268 8.3.1 Saving Data 268 8.3.2 Loading Data 269 8.3.3 Examples 270 8.4 SUMMARY 273 8.5 EXERCISES 274 8.5.1 Line Count 274 8.5.2 REWRITE 274 CHAPTER 9: INHERITANCE AND POLYMORPHISM 275 INTRODUCTION 276 CHAPTER OBJECTIVES 276 9.1 INHERITANCE BASICS 277 9.2 INHERITANCE DETAILS 284 9.2.1 Repeated Inheritance 284 9.2.2 isa versus hasa 284 9.2.3 Moving Between the Base Class and Derived Class 285 9.2.4 Public versus Private Inheritance 287 9.2.5 Method Overriding 288 9.3 CONSTRUCTORS AND DESTRUCTORS WITH INHERITANCE 290 9.4 MULTIPLE INHERITANCE 292 9.5 POLYMORPHISM 292 9.5.1 First Attempt (Incorrect Solution) 293 9.5.2 Second Attempt (Correct Solution) 296 9.6 HOW VIRTUAL FUNCTIONS WORK 300 9.7 THE COST OF VIRTUAL FUNCTIONS 302 9.8 ABSTRACT CLASSES 303 9.9 INTERFACES 305 9.10 SUMMARY 307 9.11 EXERCISES 308 9.11 Employee Database 308 C++ MODULE I CONCLUSION .313 Chapter Introducing C++ Introduction C++ is a powerful language that unifies high-level programming paradigms, such as object oriented programming, with low-level efficiencies, such as the ability to directly manipulate memory For these reasons, C++ has been embraced as the language of choice among game developers C++ fulfills the need for high-level language constructs which aid in the organization of building complex virtual worlds, but is also able to perform low-level optimizations in order to squeeze out extra performance for such things as sophisticated special effects, realistic physics, and complex artificial intelligence Chapter Objectives • • • • • • Create, compile, link and execute C++ programs Find out how C++ code is transformed into machine code Learn some of the basic C++ features necessary for every C++ program Discover how to output and input text information to and from the user Understand the concept of variables Perform simple arithmetic operations in C++ 1.1 Getting Started—Your First C++ Program A program is a list of instructions that directs the computer to perform a series of operations An operation could be adding two numbers together or outputting some data to the screen In this section you will learn, step-by-step, how to create, compile, link and execute a C++ program using Visual C++ NET (either the 2002 or 2003 edition) We recommend that you actually perform these steps as you read them in order to fully understand and absorb all that you are learning If you are not using Visual C++ NET, consult your particular C++ development tool’s documentation for information on how to create, compile, link and execute a C++ program 1.1.1 Creating the Project After you launch Visual C++ NET, go to the menu and select File->New->Project The following dialog box appears: 10 Figure 1.4: The “Add New Item” dialog box Select the file type you wish to add to the project In this case we want to add a C++ File (.cpp) 1.1.3 Writing the Code You should now see a blank CPP file where we can begin to write our code Type or copy the following C++ code, exactly as it is, into your CPP file Program 1.1: Print String //=================================================================== // print_string.cpp By Frank Luna //=================================================================== #include #include int main() { std::string firstName = ""; std::cout > firstName; std::cout