OpenGL SUPERBIBLE. Fifth Edition. Comprehensive Tutorial and Reference. Richard S. Wright, Jr. Nicholas Haemel Graham Sellers Benjamin Lipchak

Transcription

1 OpenGL SUPERBIBLE Fifth Edition Comprehensive Tutorial and Reference Richard S. Wright, Jr. Nicholas Haemel Graham Sellers Benjamin Lipchak AAddison-Wesley Upper Saddle River, NJ Boston Indianapolis San Francisco New York Toronto Montreal London Munich Paris Madrid Cape Town Sydney Tokyo Singapore Mexico City

2 Table of Contents Preface to the Fifth Edition xxi Preface to the Fourth Edition xxiii Preface to the Third Edition xxvi Introduction 1 What's New in This Edition 1 How This Book Is Organized 2 Part I: Basic Concepts 2 Part II: Intermediate to Advanced Ideas 3 Part III: Platform-Specific Notes 4 Conventions Used in This Book 4 About the Companion Web Site 5 PART I Basic Concepts 7 1 Introduction to 3D Graphics and OpenGL 9 A Brief History of Computer Graphics 9 Going Electric 10 Going 3D 11 3D Graphics Techniques and Terminology 14 Transformations and Projections 14 Rasterization 14 Shading 16 Texture Mapping 16 Blending 17 Connecting the Dots 18 Common Uses for 3D Graphics 18 Real-Time 3D 18 Non-Real-Time 3D 22 Shaders 22

3 x OpenGL SuperBible Basic 3D Programming Principles 23 Not a Toolbox 23 Coordinate Systems 24 Projections: Getting 3D to 2D 28 Summary 30 2 Getting Started 33 What Is OpenGL? 33 Evolution of a Standard 34 Licensing and Conformance 38 The Future of OpenGL 38 Deprecated Functionality 40 Using OpenGL 42 Our Supporting Cast 42 OpenGL API Specifics 44 OpenGL Errors 46 Identifying the Version 47 Getting a Clue with glhint 47 The OpenGL State Machine 48 Setting Up Windows Projects 49 Including Paths 50 Creating the Project 52 Adding Our Files 53 Setting Up Mac OS X Projects 55 Custom Build Settings 55 Creating a New Project 56 Frameworks, Headers, and Libraries 59 Your First Triangle 61 What to "Include" 64 Starting GLUT 65 Coordinate System Basics 67 Setting Things Up 70 Getting Down to Business 73 Putting a Little Life into It! 73 Special Keys 74 Refreshing the Display 75 Simple Automated Animation 76 Summary 77

4 Contents xi 3 Basic Rendering 79 The Basic Graphics Pipeline 80 Client-Server 81 Shaders 82 Setting Up Your Coordinate System 84 Orthographic Projections 85 Perspective Projections 85 Using the Stock Shaders 86 Attributes 87 Uniforms 87 Connecting The Dots 89 Points and Lines 90 Drawing Triangles in 3D 94 Individual Triangles 95 A Simple Batch Container 100 Unwanted Geometry 101 Polygon Offset 108 Cutting It Out with Scissors Ill Blending 113 Combining Colors 114 Changing the Blending Equation 116 Antialiasing 117 Multisampling 121 Summary Basic Transformations: A Vector/Matrix Primer 125 Is This the Dreaded Math Chapter? 126 A Crash Course in 3D Graphics Math 126 Vectors, or Which Way Is Which? 127 The Matrix 130 Understanding Transformations 132 Eye Coordinates 132 Viewing Transformations 133 Modeling Transformations 134 The Modelview Duality 135 Projection Transformations 136 Viewport Transformations 137

5 xii OpenGL SuperBible The Modelview Matrix 138 Matrix Construction 138 Applying a Modelview Matrix 144 More Objects 145 Using the Triangle Batch Class 146 Making a Sphere 146 Making a Torus 147 Making a Cylinder or a Cone 148 Making a Disk 150 Projection Matrix 150 Orthographic Projections 151 Perspective Projection 153 The ModelviewProjection Matrix 155 The Transformation Pipeline 159 Using a Matrix Stack 159 Managing Your Pipeline 161 Spicing It Up! 165 Moving Around Using Cameras and Actors 167 An Actor Frame 168 Euler Angles: "Use the Frame, Luke!" 169 Camera Management 170 Adding More Actors 173 What About Lights? 175 Summary Basic Texturing 179 Raw Image Data 180 Pixel Packing 181 Pixmaps 183 Packed Pixel Formats 185 Saving Pixels 186 Reading Pixels 188 Loading Textures 192 Using the Color Buffer 193 Updating Textures 194 Texture Objects 195 Texture Application 196 Texture Coordinates 196 Texture Parameters 199 Putting It All Together 202

6 Contents xiii Mipmapping 207 Mipmap Filtering 209 Generating Mip Levels 210 Mipmaps in Action 210 Anisotropie Filtering 221 Texture Compression 223 Compressing Textures 224 Loading Compressed Textures 225 A Final Example 226 Summary Thinking Outside the Box, Nonstock Shaders 229 GLSL Variables and Data Types 231 Storage Qualifiers 234 ARealShader 236 Compiling, Binding, and Linking 240 Using the Shader 247 Provoking Vertex 248 Shader Uniforms 249 Finding Your Uniforms 249 Setting Scalars and Vector Uniforms 250 Setting Uniform Arrays 251 Setting Uniform Matrices 252 The Flat Shader 252 Built-in Functions 255 Trigonometry Functions 256 Exponential Functions 256 Geometric Functions 257 Matrix Functions 257 Vector Relational Functions 258 Common Functions 259 Simulating Light 262 Simple Diffuse Lighting 262 The Point Light Diffuse Shader 264 The ADS Light Model 269 Phong Shading 273

7 xiv OpenGL SuperBible Accessing Textures 277 Just the Texels Please 277 Light the Texels 279 Discarding Fragments 281 Cell Shading Texels as Light 284 Summary More Advanced Texture Topics 289 Rectangle Textures 289 Loading a Rectangle Texture 290 Using a Rectangle Texture 291 Cube Maps 294 Loading Cube Maps 295 Making a Skybox 297 Making a Reflection 299 Multitexture 301 Multiple Texture Coordinates 301 A Multitextured Example 302 Point Sprites 304 Texturing Points 305 Point Sizes 306 Putting This All Together 307 Point Parameters 310 Shaped Points 311 Rotating Points 312 Texture Arrays 314 Loading a 2D Texture Array 314 Indexing the Texture Array 316 Accessing Texture Arrays 317 Texture Proxies 318 Summary 320 PART II Intermediate to Advanced Ideas Buffer Objects: Storage Is Now in Your Hands 323 Buffers 324 Creating Your Very Own Buffers 324 Filling Buffers 325 Pixel Buffer Objects 326 Texture Buffer Objects 334

8 Contents xv Framebuffer Objects, Going Beyond the Window 336 HowtoUseFBOs 336 Renderbuffer Objects 337 Draw Buffers 339 Framebuffer Completeness 342 Copying Data in Framebuffers 345 Putting It All Together Using FBOs 346 Rendering to Textures 351 Summary Advanced Buffers: Beyond the Basics 359 Getting at Your Data 359 Mapping Buffers 360 Copying Buffers 361 Controlling the Destiny of Your Pixel Shaders; Mapping Fragment Outputs 361 New Formats for a New Hardware Generation 364 Floats True Precision at Last! 364 Multisampling 380 Integers 385 srgb 386 Texture Compression 387 Summary Fragment Operations: The End of the Pipeline 391 Scissoring Cutting Your Geometry Down To Size 392 Multisampling 392 Sample Coverage 393 Sample Mask 394 Putting It All Together 394 Stencil Operations 399 Depth Testing 402 Depth Clamp 402 Blending Everything Together 402 Blend Equation 402 Blend Function 403 Putting It All Together 404 Dithering 406 Logic Ops 407

9 xvi OpenGL SuperBible Masking Output 408 Color 408 Depth 408 Stencil 408 Usage 409 Summary Advanced Shader Usage 411 Advanced Vertex Shaders 412 Physical Simulation in the Vertex Shader 412 Geometry Shaders 419 The Pass-Through Geometry Shader 420 Using Geometry Shaders in an Application 422 Discarding Geometry in the Geometry Shader 426 Modifying Geometry in the Geometry Shader 429 Generating Geometry in the Geometry Shader 430 Changing the Primitive Type in the Geometry Shader 434 New Primitive Types Introduced by the Geometry Shader 438 Advanced Fragment Shaders 441 Post-Processing in the Fragment Shader Color Correction 442 Post-Processing in the Fragment Shader Convolution 444 Generating Image Data in the Fragment Shader 448 Discarding Work in the Fragment Shader 451 Controlling Depth Per Fragment 453 More Advanced Shader Functions 454 Interpolation and Storage Qualifiers 454 Other Advanced Built-in Functions 458 Uniform Buffer Objects 460 Building Uniform Blocks 461 Summary Advanced Geometry Management 471 Gathering Information about the OpenGL Pipeline Queries 472 Preparing a Query 472 Issuing a Query 473 Retrieving Query Results 474 Using the Results of a Query 475 Getting OpenGL to Make Decisions for You 478 Measuring Time Taken to Execute Commands 480

10 Contents xvii Storing Data in GPU Memory 483 Using Buffers to Store Vertex Data 484 Storing Vertex Indices in Buffers 489 Using Vertex Array Objects to Organize Your Buffers 490 Drawing a lot of Geometry Efficiently 492 Combining Drawing Functions 492 Combining Geometry Using Primitive Restart 494 Instanced Rendering 496 Getting Your Data Automatically 503 Storing Transformed Vertices Transform Feedback 508 Transform Feedback 509 Turning Off Rasterization 514 Counting Vertices Using Primitive Queries 515 Using the Results of a Primitive Query 516 Example Uses for Transform Feedback 517 Clipping and Determining What Should Be Drawn 528 Clip Distances Defining Your Own Custom Clip Space 528 Synchronizing When OpenGL Begins to Draw 532 Summary 537 PART III Platform-Specific Notes OpenGL on Windows 541 OpenGL Implementations on Windows 542 Microsoft's OpenGL 542 Modern Graphics Drivers 542 Extended OpenGL 544 WGL Extensions 545 Basic Windows Rendering 547 GDI Device Contexts 547 Pixel Formats 548 The OpenGL Rendering Context 556 Putting It All Together 559 Creating the Window 560 Full-Screen Rendering 565 Double Buffering 567 Eliminating Visual Tearing 567 Summary 568

11 xviii OpenGL SuperBible 14 OpenGL on OS X 569 The Four Faces of OpenGL on the Mac 569 OpenGL with Cocoa 570 Creating a Cocoa Program 571 Wiring It All Together 578 Double or Single Buffered? 580 SphereWorld 580 Full-Screen Rendering 585 Going Full-Screen with Cocoa 586 CGL 593 Sync Frame Rate 593 Increasing Fill Performance 594 Multithreaded OpenGL 595 Summary OpenGL on Linux 597 The Basics 597 Brief History 598 What Is X? 598 Getting Started 598 Checking for OpenGL 599 Setting Up Mesa 599 Setting Up Hardware Drivers 600 Setting Up GLUT and GLEW 600 Building OpenGL Apps 601 GLX Interfacing with X Windows 602 Displays and X Windows 603 Config Management and Visuals 603 Windows and Render Surfaces 607 Extending OpenGL and GLX 608 Context Management 609 Synchronization 612 GLX Queries 613 Putting It All Together 614 Summary 617

12 16 OpenGL ES on Mobile Devices 619 OpenGL on a Diet 619 What's the ES For? 620 A Brief History 620 Which Version Is Right for You? 622 ES The ES Environment 627 Application Design Considerations 627 Dealing with a Limited Environment 628 Fixed-Point Math 629 EGL: A New Windowing Environment 630 EGL Displays 631 Creating a Window 632 Context Management 636 Presenting Buffers and Rendering Synchronization 636 More EGL Stuff 637 Negotiating Embedded Environments 638 Popular Operating Systems 638 Vendor-Specific Extensions 639 For the Home Gamer 639 Apple Handheld Platforms 639 Setting Up An iphone Project 640 Moving to the iphone 644 Summary 652 Appendix A Further Reading 653 Other Good OpenGL Books 653 3D Graphics Books 653 WebSites 654 Appendix В Glossary 655 Appendix С OpenGL Man Pages for (Core) OpenGL Index 939