Building a 2D Game Physics Engine: Using HTML5 and JavaScript

Contents at a Glance......Page 5
Contents......Page 6
About the Authors......Page 10
About the Technical Reviewer......Page 12
Acknowledgments......Page 13
Introduction......Page 14
Chapter 1: Introduction to 2D Game Physics Engine Development......Page 16
 Setting Up Your Development Environment......Page 17
 Working in the NetBeans Development Environment......Page 18
  Creating an HTML5 Project in NetBeans......Page 19
 HTML5 Canvas Project......Page 23
 Drawing Core......Page 24
  Creating the Core Script......Page 25
  Creating User Control Script......Page 27
  Using the User Control Script......Page 28
 Summary......Page 29
Chapter 2: Implementing the 2D Physics Engine Core......Page 30
  Creating the Library......Page 31
 Physics Engine and Rigid Shapes......Page 32
  The Rigid Shape Project......Page 33
   The Rigid Shape Base Class......Page 34
   The Rigid Rectangle Class......Page 35
   The Rigid Circle Class......Page 37
   Modify the User Control Script......Page 38
   Integrate into the Core......Page 39
   Define the Initial Scene......Page 40
   Modify the index.html File......Page 41
 The Core Engine Loop......Page 42
  Engine Loop Implementations......Page 43
   Implement the Engine Loop Component......Page 44
    Rigid Shape Base Class......Page 46
    The Rectangle Class......Page 47
   Modify User Control Script......Page 49
  Observation......Page 50
 Summary......Page 51
Chapter 3: Incorporating Collision Detection......Page 52
 Interpenetration of Colliding Objects......Page 53
  The Broad Phase Method Project......Page 55
   Define the Physics Engine Component......Page 56
   Invoke the Physics Collision and Update the UI......Page 57
   Modify Rigid Shape Classes......Page 58
 Collision Information......Page 60
  The Circle Collision Detection Project......Page 61
   Define Collision Information Object......Page 62
   Compute Collision Information Between Two Circles......Page 63
   Case for Collision with a Rectangle......Page 65
   Modify Physics Engine Component......Page 66
 Separating Axis Theorem......Page 67
  A Simple SAT-based Algorithm......Page 69
   Support Point May Not Exist for a Face Normal......Page 71
   The Axis of Least Penetration and Collision Information......Page 72
  The Rectangle Collision Project......Page 73
   Modify Rectangle Collision......Page 74
 Collision Between Rectangles and Circles......Page 77
  The Rectangle Circle Collision Project......Page 78
   Modify Rectangle Collision......Page 79
 Summary......Page 84
Chapter 4: Completing the Physics Engine and Rigid Shape Component......Page 85
 Movement......Page 86
  Explicit Euler Integration......Page 87
  The Rigid Shape Movement Project......Page 88
    Modify the Engine Core......Page 89
    Implement Symplectic Euler Integration......Page 90
    Modify the RigidShape Class......Page 91
    Modify the Circle and Rectangle Classes......Page 93
    Modify the updateUIEcho Function......Page 94
   Modify the userControl function......Page 95
  Observation......Page 96
 Resolving Interpenetrations......Page 97
  The Positional Correction Project......Page 98
   Update the Physics Engine......Page 99
 Resolving Collisions......Page 101
   Decomposing the Velocity in a Collision......Page 102
   Relative Velocity of Colliding Shapes......Page 103
   Approximating the Impulse Response......Page 105
  The Steps for Resolving Collisions......Page 106
  The Collision Impulse Project......Page 107
   Modify the Physics Engine Component......Page 108
   Defining an Initial Rectangle in Mygame.js......Page 109
 Supporting Rotation in Collision Response......Page 110
  Formulating Impulse Method with Rotation......Page 111
  The Angular Impulse Project......Page 114
  Observation......Page 116
 Summary......Page 117
 The Concepts and Theories......Page 118
 The Engine Source Code......Page 119
  Modifying Simulation Scene......Page 121
  Observation......Page 122
  Physics Topics......Page 123
  Collision Detection Topics......Page 124
 Reference......Page 125
Index......Page 126