OpenGL Sl I I ICPPIPI JE?

UrCIIDIDLC

Fourth Edition Comprehensive Tutorial and Reference

Richard S. Wright, Jr. Benjamin Lipchak Nicholas Haemel

AAddison-Wesley Upper Saddle River, NJ • Boston • Indianapolis • San Francisco

New York • Toronto • Montreal • London • Munich • Paris • Madrid Capetown • Sydney • Tokyo • Singapore • Mexico City

Contents xi

Table of Contents

Preface xxvii

About the Authors xxxv

Introduction 1

What's New in This Edition 1 How This Book Is Organized 2

Part I: The Old Testament 2 Part II: The New Testament 4 Part III: The Apocrypha 4

Conventions Used in This Book 5 About the Companion Web Site 5

Part I The Old Testament 7

1 Introduction to 3D Graphics and OpenGL 9

A Brief History of Computer Graphics 9 Going Electric 10 Going 3D 11

A Survey of 3D Effects 14 Perspective 14 Color and Shading 15 Light and Shadows 15 Texture Mapping 16 Fog 17 Blending and Transparency 18 Antialiasing 18

Common Uses for 3D Graphics 19 Real-Time 3D 19 Non-Real-Time 3D 22 Shaders 22

Basic 3D Programming Principles 23 Immediate Mode and Retained Mode 23 Coordinate Systems 24 Projections: Getting 3D to 2D 28

Summary 30

xii OpenGL SuperBible, Fourth Edition

2 Using OpenGL 33

What Is OpenGL? 33 Evolution of a Standard 34 The API Wars 36 The Future of OpenGL 37

How Does OpenGL Work? 38 Generic Implementations 38 Hardware Implementations 39 The Pipeline 40

OpenGL: An API, Not a Language 41 Standard Libraries and Headers 41 Some Header Customizations 42

APISpecifics 43 Data Types 44 Function-Naming Conventions 45

Platform Independence 46 Using GLUT 47 Your First Program 48 Drawing Shapes with OpenGL 53

Animation with OpenGL and GLUT 61 Double Buffering 64

The OpenGL State Machine 65 Saving and Restoring States 66

OpenGL Errors 67 When Bad Things Happen to Good Code 67

Identifying the Version 68 Getting a Clue with glHint 69 Using Extensions 69

Checking for an Extension 69 Whose Extension Is This? 71

Summary 71

3 Drawing in Space: Geometrie Primitives and Büffers 73

Drawing Points in 3D 74 Setting Up a 3D Canvas 74 A 3D Point: The Vertex 76 Draw Something! 77

Drawing Points 78 Our First Example 78

Contents xiii

Setting the Point Size 81 Drawing Lines in 3D 85

Line Strips and Loops 87 Approximating Curves with Straight Lines 88 Setting the Line Width 89 Line Stippling 91

Drawing Triangles in 3D 94 Triangles: Your First Polygon 94 Winding 95 Triangle Strips 96 Triangle Fans 97

Building Solid Objects 98 Setting Polygon Colors 101 Hidden Surface Removal 102 Culling: Hiding Surfaces for Performance 104 Polygon Modes 107

Other Primitives 107 Four-Sided Polygons: Quads 108 Quad Strips 108 General Polygons 108 Filling Polygons, or Stippling Revisited 109 Polygon Construction Rules 113 Subdivision and Edges 114

Other Buffer Tricks 117 Using Buffer Targets 117 Manipulating the Depth Buffer 119 Cutting It Out with Scissors 119 Using the Stencil Buffer 121 Creating the Stencil Pattern 122

Summary 126

4 Geometrie Transformations: The Pipeline 127

Is This the Dreaded Math Chapter? 127 Understanding Transformations 128

Eye Coordinates 129 Viewing Transformations 130 Modeling Transformations 130 The Modelview Duality 132 Projection Transformations 132 Viewport Transformations 134

xiv OpenGL SuperBible, Fourth Edition

The Matrix: Mathematical Currency for 3D Graphics 134 What Is a Matrix? 134 The Transformation Pipeline 135 The Modelview Matrix 136 The Identity Matrix 140 The Matrix Stacks 142 A Nuclear Example 143

Using Projections 146 Orthographie Projections 147 Perspective Projections 148 A Far-Out Example 151

Advanced Matrix Manipulation 154 Loading a Matrix 156 Performing Your Own Transformations 157 Adding Transformations Together 160

Moving Around in OpenGL Using Cameras and Actors 161 An Actor Frame 161 Euler Angles: "Use the Frame, Luke!" 163 Camera Management 164

Bringing It All Together 165 Summary 171

5 Color, Materials, and Lighting: The Basics 173

What Is Color? 174 Light as a Wave 174 Light as a Particle 175 Your Personal Photon Detector 176 The Computer as a Photon Generator 176

PC Color Hardware 177 PC Display Modes 179

Screen Resolution 179 Color Depth 179

Using Color in OpenGL 180 The Color Cube 180 Setting the Drawing Color 182 Shading 183 Setting the Shading Model 185

Color in the Real World 186 Ambient Light 187 Diffuse Light 188 Specular Light 188 Putting It All Together 189

Materials in the Real World 190 Material Properties 190 Adding Light to Materials 190 Calculating Ambient Light Effects 190 Diffuse and Specular Effects 191

Adding Light to a Scene 192 Enabling the Lighting 192 Setting Up Cosmic Background Radiation 192 Setting Material Properties 193

Using a Light Source 196 Which Way Is Up? 197 Surface Normals 197 Specifying a Normal 198 Unit Normals 201 Finding a Normal 202 Setting Up a Source 203 Setting the Material Properties 205 Specifying the Polygons 205

Lighting Effects 207 Specular Highlights 207 Specular Light 208 Specular Reflectance 208 Specular Exponent 209 Normal Averaging 211

Putting It All Together 213 Creating a Spotlight 214 Drawing a Spotlight 216

Shadows 221 What Is a Shadow? 222 SquishCode 223 A Shadow Example 223 Sphere World Revisited 227

Summary 227

xvi OpenGL SuperBible, Fourth Edition

6 More on Colors and Materials 229

Blending 229 Combining Colors 230 Changing the Blending Equation 234 Antialiasing 234 Multisample 238

Applying Fog 240 Fog Equations 242 Fog Coordinates 244

Accumulation Buffer 244 Other Color Operations 248

Color Masking 248 Color Logical Operations 248 Alpha Testing 249 Dithering 250

Summary 250

7 Imaging with OpenGL 251

Bitmaps 252 Bitmapped Data 253 The Raster Position 256

Pixel Packing 257 Pixmaps 258

Packed Pixel Formats 260 A More Colorful Example 261 Moving Pixels Around 265 Saving Pixels 266

More Fun with Pixels 268 Pixel Zoom 275 Pixel Transfer 277 Pixel Mapping 281

The Imaging "Subset" and Pipeline 283 Color Matrix 288 Color Lookup 289 Proxies 290 Other Operations 291 Convolutions 292 Histogram 297 Minmax Operations 301

Summary 301

Contents xvii

8 Texture Mapping: The Basics 303

Loading Textures 304 Using the Color Buffer 307 Updating Textures 307 Mapping Textures to Geometry 308 Texture Matrix 311

A Simple 2D Example 311 Texture Environment 316 Texture Parameters 318

Basic Filtering 318 Texture Wrap 320 Cartoons with Texture 321 Mipmapping 325

Texture Objects 330 Managing Multiple Textures 331

Summary 339

9 Texture Mapping: Beyond the Basics 341

Secondary Color 341 Anisotropie Filtering 344 Texture Compression 347

Compressing Textures 348 Loading Compressed Textures 349

Texture Coordinate Generation 350 Object Linear Mapping 354 Eye Linear Mapping 355 Sphere Mapping 356 Cube Mapping 357

Multitexture 362 Multiple Texture Coordinates 363 A Multitextured Example 364

Texture Combiners 369 Point Sprites 371

Using Points 372 Texture Application 374 Point Parameters 374

Summary 375

xviii OpenGL SuperBible, Fourth Edition

10 Curves and Surfaces 377

Built-in Surfaces 378 Setting Quadric States 379 Drawing Quadrics 381 Modeling with Quadrics 385

Bezier Curves and Surfaces 388 Parametric Representation 388 Evaluators 391

NURBS 401 From Bezier to B-Splines 402 Knots 402 Creating a NURBS Surface 403 NURBS Properties 404 Defining the Surface 404 Trimming 406 NURBS Curves 409

Tessellation 409 The Tessellator 411 Tessellator Callbacks 412 Specifying Vertex Data 413 Putting It All Together 414

Summary 419

11 It's All About the Pipeline: Faster Geometry Throughput 421

Display Lists 422 Batch Processing 423 Preprocessed Batches 424 Display List Caveats 426 Converting to Display Lists 426

Vertex Arrays 428 Loading the Geometry 432 Enabling Arrays 432 Where's the Data? 433 Pull the Data and Draw 434 Indexed Vertex Arrays 435

Vertex Buffer Objects 450 Managing and Using Buffer Objects 450 Back to the Thunderbird! 452

Summary 455

Contents xix

12 Interactive Graphics 457

Selection 458 Naming Your Primitives 458 Working with Selection Mode 460 The Selection Buffer 461 Picking 464 Hierarchical Picking 466 Feedback 471 The Feedback Buffer 471 Feedback Data 472 Passthrough Markers 473

A Feedback Example 473 Label the Objects for Feedback 473 Step 1: Select the Object 476 Step 2: Get Feedback on the Object 478

Summary 480

13 Occiusion Queries: Why Do More Work Than You Need To? 481

The World Before Occiusion Queries 482 Bounding Boxes 485 Querying the Query Object 490 Best Practices 492 Summary 493

14 Depth Textures and Shadows 495

BeThat Light 496 Fit the Scene to the Window 496 No Beils or Whistles, Please 497

A New Kind of Texture 498 Size Matters 499

Draw the Shadows First?! 500 And Then There Was Light 501

Projecting Your Shadow Map: The "Why" 501 Projecting Your Shadow Map: The "How" 503 The Shadow Comparison 505

Two Out of Three Ain't Bad 509 A Few Words About Polygon Offset 510 Summary 511

xx OpenGL SuperBible, Fourth Edition

Part II The New Testament 513

15 Programmable Pipeline: This Isn't Your Father's OpenGL 515

Out with the Old 516 Fixed Vertex Processing 518 Fixed Fragment Processing 520

In with the New 521 Programmable Vertex Shaders 523 Fixed Functionality Glue 524 Programmable Fragment Shaders 525

OpenGL Shading Language: A First Glimpse 526 Managing GLSL Shaders 528

Shader Objects 528 Program Objects 530

Variables 532 Basic Types 532 Structures 534 Arrays 534 Qualifiers 535 Built-In Variables 536

Expressions 537 Operators 537 Array Access 538 Constructors 538 Component Selectors 540

ControlFlow 541 Loops 541 if/else 542 discard 542 Functions 542

Summary 545

16 Vertex Shading: Do-It-Yourself Transform, L ight ing, and Texgen 547

Getting Your Feet Wet 548 Diffuse Lighting 549 Specular Lighting 551 Improved Specular Lighting 553 Per-Vertex Fog 557 Per-Vertex Point Size 560

Customized Vertex Transformation 561 Vertex Blending 563 Summary 566

17 Fragment Shading: Empower Your Pixel Processing 567

Color Conversion 568 Grayscale 568 Sepia Tone 569 Inversion 570 Heat Signature 571 Per-Fragment Fog 572

Image Processing 574 Blur 575 Sharpen 577 Dilation and Erosion 578 Edge Detection 580

Lighting 582 Diffuse Lighting 582 Multiple Specular Lights 585

Procedural Texture Mapping 587 Checkerboard Texture 588 Beach Ball Texture 592 Toy Ball Texture 595

Summary 600

18 Advanced Buffers 601

Pixel Buffer Objects 601 HowtoUsePBOs 602 The Benefits of PBOs 603 PBOs in Action 604 Oh, Where Is the Home Where the PBOs Roam? 608

Framebuffer Objects 608 HowtoUseFBOs 609 Offscreen Rendering 613 Rendering to Textures 615 Multiple Render Targets 619

Floating-Point Textures 622 High Dynamic Range 622 OpenEXR File Format 623 Tone Mapping 626

xxii OpenGL SuperBible, Fourth Edition

Making Your Whites Whiter and Your Brights Brighter 630 Drawing the Scene 630 Bright Pass 633 Gaussian Blur with a Little Help 634 The Sum Is Greater Than Its Parts 636 PBOs Make a Comeback 638

Summary 638

Part III The Apocrypha 639

19 Wiggle: OpenGL on Windows 641

OpenGL Implementations on Windows 642 Generic OpenGL 642 Installable Client Driver 642 Mini-Client Driver 643 Mini-Driver 643 OpenGL on Vista 644 Extended OpenGL 644

Basic Windows Rendering 645 GDI Device Contexts 646 Pixel Formats 647 The OpenGL Rendering Context 654

Putting It All Together 655 Creating the Window 655 Using the OpenGL Rendering Context 660 Other Windows Messages 664

OpenGL and Windows Fonts 666 3D Fonts and Text 666 2D Fonts and Text 669

Full-Screen Rendering 671 Creating a Frameless Window 672 Creating a Full-Screen Window 672

Multithreaded Rendering 675 OpenGL and WGL Extensions 676

Simple Extensions 677 Using New Entrypoints 678 Auto-Magic Extensions 679 WGL Extensions 680

Summary 684

Con

20 OpenGL on Mac OS X 685

GLUT 686 Setting Up a GLUT Project 686 Application Frameworks 687 Ditching Cocoa 688

OpenGL with Carbon 689 Setting Up for OpenGL 689 Bitmap Fonts 697

OpenGL with Cocoa 699 Creating a Cocoa Program 699 Wiring It All Together 703 Hang on a Second There! 705

Full-Screen Rendering 706 Managing the Display 706 AGL Full-Screen Support 708

Summary 711

21 OpenGL on Linux 713

The Basics 713 Setup 714

Setting Up Mesa 715 Setting Up Hardware Drivers 715 More Setup Details 715 Setting Up GLUT 716 Building OpenGL Apps 716

GLUT 717 GLX—Dealing with the X Windows Interface 718

Displays and X 718 Config Management and Visuals 719 Windows and Render Surfaces 723 Context Management 724 Synchronization 726 GLXStrings 727 The Rest of GLX 727

Putting It All Together 729 Summary 734

xxiv OpenGL SuperBible, Fourth Edition

22 OpenGL ES: OpenGL on the Small 735

OpenGL on a Diet 735 What's the ES For? 735 A Brief History 736

Which Version Is Right for You? 738 ES 1.0 739 ES 1.1 742 ES 2.0 746 ES SC 752

The ES Environment 754 Application Design Considerations 754 Dealing with a Limited Environment 755 Fixed-Point Math 756

EGL: A New Windowing Environment 757 EGL Displays 758 Creating a Window 759 Context Management 763 Presenting Buffers and Rendering Synchronization 764 MoreEGLStuff 765

Negotiating Embedded Environments 766 Populär Operating Systems 766 Embedded Hardware 766 Vendor-Specific Extensions 767 For the Home Gamer 767

Putting OpenGL ES into Action 767 Setting Up the Environment 768 Setting Up OpenGL ES State 769 Rendering 770 Cleaning Up 771

Summary 772

A Further Reading/References 773

Other Good OpenGL Books 773 3D Graphics Books 773 WebSites 774

Contents xxv

B Glossary 777

C API Reference 783

Overview of Appendix C 783

Index 1141