Figures ..................................................... xxiii
Tables ....................................................... xxix
Examples ................................................... xxxiii
About This Guide .............................................. xli
What This Guide Contains ...................................... xli
What's New in This Edition .................................. xliii
What You Should Know Before Reading This Guide .............. xliii
How to Obtain the Sample Code .................................xliv
Errata ........................................................ xlv
Style Conventions ............................................. xlv
1 Introduction to OpenGL ....................................... 1
What Is OpenGL? .............................................. 2
Your First Look at an OpenGL Program ......................... 3
OpenGL Syntax ................................................ 8
OpenGL's Rendering Pipeline ................................. 10
Preparing to Send Data to OpenGL ......................... 11
Sending Data to OpenGL ................................... 11
Vertex Shading ........................................... 12
Tessellation Shading ..................................... 12
Geometry Shading ......................................... 12
Primitive Assembly ....................................... 12
Clipping ................................................. 13
Rasterization ............................................ 13
Fragment Shading ......................................... 13
Per-Fragment Operations .................................. 13
Our First Program: A Detailed Discussion .................... 14
Entering main() .......................................... 14
OpenGL Initialization .................................... 16
Our First OpenGL Rendering ............................... 28
2 Shader Fundamentals ......................................... 33
Shaders and OpenGL .......................................... 34
OpenGL's Programmable Pipeline .............................. 35
An Overview of the OpenGL Shading Language .................. 37
Creating Shaders with GLSL ............................... 37
Storage Qualifiers ....................................... 45
Statements ............................................... 49
Computational Invariance ................................. 54
Shader Preprocessor ...................................... 56
Compiler Control ......................................... 58
Global Shader-Compilation Option ......................... 59
Interface Blocks ............................................ 60
Uniform Blocks ........................................... 61
Specifying Uniform Blocks in Shaders ..................... 61
Accessing Uniform Blocks from Your Application ........... 63
Buffer Blocks ............................................ 69
In/Out Blocks ............................................ 70
Compiling Shaders ........................................... 70
Our LoadShaders() Function ............................... 76
Shader Subroutines .......................................... 76
GLSL Subroutine Setup .................................... 77
Selecting Shader Subroutines ............................. 78
Separate Shader Objects ..................................... 81
3 Drawing with OpenGL ......................................... 85
OpenGL Graphics Primitives .................................. 86
Points ................................................... 87
Lines, Strips, and Loops ................................. 88
Triangles, Strips, and Fans .............................. 89
Data in OpenGL Buffers ...................................... 92
Creating and Allocating Buffers .......................... 92
Getting Data into and out of Buffers ..................... 95
Accessing the Content of Buffers ........................ 100
Discarding Buffer Data .................................. 107
Vertex Specification ....................................... 108
Vertex Attrib Pointer in Depth .......................... 108
Static Vertex-Attribute Specification ................... 112
OpenGL Drawing Commands .................................... 115
Restarting Primitives ................................... 124
Instanced Rendering ........................................ 128
Instanced Vertex Attributes ............................. 129
Using the Instance Counter in Shaders ................... 136
Instancing Redux ........................................ 139
4 Color, Pixels, and Framebuffers ............................ 141
Basic Color Theory ......................................... 142
Buffers and Their Uses ..................................... 144
Clearing Buffers ........................................ 146
Masking Buffers ......................................... 147
Color and OpenGL ........................................... 148
Color Representation and OpenGL ......................... 149
Vertex Colors ........................................... 150
Rasterization ........................................... 153
Multisampling .............................................. 153
Sample Shading .......................................... 155
Testing and Operating on Fragments ......................... 156
Scissor Test ............................................ 157
Multisample Fragment Operations ......................... 158
Stencil Test ............................................ 159
Stencil Examples ........................................ 161
Depth Test .............................................. 163
Blending ................................................ 166
Blending Factors ........................................ 167
Controlling Blending Factors ............................ 167
The Blending Equation ................................... 170
Dithering ............................................... 171
Logical Operations ...................................... 171
Occlusion Query ......................................... 173
Conditional Rendering ................................... 176
Per-Primitive Antialiasing ................................. 178
Antialiasing Lines ...................................... 179
Antialiasing Polygons ................................... 180
Framebuffer Objects ........................................ 180
Renderbuffers ........................................... 183
Creating Renderbuffer Storage ........................... 185
Framebuffer Attachments ................................. 187
Framebuffer Completeness ................................ 190
Invalidating Framebuffers ............................... 192
Writing to Multiple Renderbuffers Simultaneously ........... 193
Selecting Color Buffers for Writing and Reading ......... 195
Dual-Source Blending .................................... 198
Reading and Copying Pixel Data ............................. 200
Copying Pixel Rectangles ................................... 203
5 Viewing Transformations, Clipping, and Feedback ............ 205
Viewing .................................................... 206
Viewing Model ........................................... 207
Camera Model ............................................ 207
Orthographic Viewing Model .............................. 212
User Transformations ....................................... 212
Matrix Multiply Refresher ............................... 214
Homogeneous Coordinates ................................. 215
Linear Transformations and Matrices ..................... 219
Transforming Normals .................................... 231
OpenGL Matrices ......................................... 232
OpenGL Transformations ..................................... 236
Advanced: User Clipping ................................. 238
Transform Feedback ......................................... 239
Transform Feedback Objects .............................. 239
Transform Feedback Buffers .............................. 241
Configuring Transform Feedback Varyings ................. 244
Starting and Stopping Transform Feedback ................ 250
Transform Feedback Example—Particle System .............. 252
6 Textures ................................................... 259
Texture Mapping ............................................ 261
Basic Texture Types ........................................ 262
Creating and Initializing Textures ......................... 263
Texture Formats ......................................... 270
Proxy Textures ............................................. 276
Specifying Texture Data .................................... 277
Explicitly Setting Texture Data ......................... 277
Using Pixel Unpack Buffers .............................. 280
Copying Data from the Framebuffer ....................... 281
Loading Images from Files ............................... 282
Retrieving Texture Data ................................. 287
Texture Data Layout ..................................... 288
Sampler Objects ............................................ 292
Sampler Parameters ...................................... 294
Using Textures ............................................. 295
Texture Coordinates ..................................... 298
Arranging Texture Data .................................. 302
Using Multiple Textures ................................. 303
Complex Texture Types ...................................... 306
3D Textures ............................................. 307
Array Textures .......................................... 309
Cube-Map Textures ....................................... 309
Shadow Samplers ......................................... 317
Depth-Stencil Textures .................................. 318
Buffer Textures ......................................... 319
Texture Views .............................................. 321
Compressed Textures ........................................ 326
Filtering .................................................. 329
Linear Filtering ........................................ 330
Using and Generating Mipmaps ............................ 333
Calculating the Mipmap Level ............................ 338
Mipmap Level-of-Detail Control .......................... 339
Advanced Texture Lookup Functions .......................... 340
Explicit Level of Detail ................................ 340
Explicit Gradient Specification ......................... 340
Texture Fetch with Offsets .............................. 341
Projective Texturing .................................... 342
Texture Queries in Shaders .............................. 343
Gathering Texels ........................................ 345
Combining Special Functions ............................. 345
Point Sprites .............................................. 346
Textured Point Sprites .................................. 347
Controlling the Appearance of Points .................... 350
Rendering to Texture Maps .................................. 351
Discarding Rendered Data ................................ 354
Chapter Summary ............................................ 356
Texture Redux ........................................... 356
Texture Best Practices .................................. 357
7 Light and Shadow ........................................... 359
Lighting Introduction ...................................... 360
Classic Lighting Model ..................................... 361
Fragment Shaders for Different Light Styles ............. 362
Moving Calculations to the Vertex Shader ................ 373
Multiple Lights and Materials ........................... 376
Lighting Coordinate Systems ............................. 383
Limitations of the Classic Lighting Model ............... 383
Advanced Lighting Models ................................... 384
Hemisphere Lighting ..................................... 384
Image-Based Lighting .................................... 389
Lighting with Spherical Harmonics ....................... 395
Shadow Mapping ............................................. 400
Creating a Shadow Map ................................... 401
8 Procedural Texturing ....................................... 411
Procedural Texturing ....................................... 412
Regular Patterns ........................................ 414
Toy Ball ................................................ 422
Lattice ................................................. 431
Procedural Shading Summary .............................. 432
Bump Mapping ............................................... 433
Application Setup ....................................... 436
Vertex Shader ........................................... 438
Fragment Shader ......................................... 439
Normal Maps ............................................. 441
Antialiasing Procedural Textures ........................... 442
Sources of Aliasing ..................................... 442
Avoiding Aliasing ....................................... 444
Increasing Resolution ................................... 445
Antialiasing High Frequencies ........................... 447
Frequency Clamping ...................................... 457
Procedural Antialiasing Summary ......................... 459
Noise ...................................................... 460
Definition of Noise ..................................... 461
Noise Textures .......................................... 468
Trade-offs .............................................. 471
A Simple Noise Shader ................................... 472
Turbulence .............................................. 475
Marble .................................................. 477
Granite ................................................. 478
Wood .................................................... 478
Noise Summary ........................................... 483
Further Information ........................................ 483
9 Tessellation Shaders ....................................... 485
Tessellation Shaders ....................................... 486
Tessellation Patches ....................................... 487
Tessellation Control Shaders ............................... 488
Generating Output-Patch Vertices ........................ 489
Tessellation Control Shader Variables ................... 490
Controlling Tessellation ................................ 491
Tessellation Evaluation Shaders ............................ 496
Specifying the Primitive Generation Domain .............. 497
Specifying the Face Winding for Generated Primitives .... 497
Specifying the Spacing of Tessellation Coordinates ...... 498
Additional Tessellation Evaluation Shader layout
Options ................................................. 498
Specifying a Vertex's Position .......................... 498
Tessellation Evaluation Shader Variables ................ 499
A Tessellation Example: The Teapot ......................... 500
Processing Patch Input Vertices ......................... 501
Evaluating Tessellation Coordinates for the Teapot ...... 501
Additional Tessellation Techniques ......................... 504
View-Dependent Tessellation ............................. 504
Shared Tessellated Edges and Cracking ................... 506
Displacement Mapping .................................... 507
10 Geometry Shaders ........................................... 509
Creating a Geometry Shader ................................. 510
Geometry Shader Inputs and Outputs ......................... 514
Geometry Shader Inputs .................................. 514
Special Geometry Shader Primitives ...................... 517
Geometry Shader Outputs ................................. 523
Producing Primitives .................................... 525
Culling Geometry ........................................ 525
Geometry Amplification .................................. 527
Advanced Transform Feedback ................................ 532
Multiple Output Streams ................................. 533
Primitive Queries ....................................... 537
Using Transform Feedback Results ........................ 539
Geometry Shader Instancing ................................. 549
Multiple Viewports and Layered Rendering ................... 550
Viewport Index .......................................... 550
Layered Rendering ....................................... 556
Chapter Summary ............................................ 559
Geometry Shader Redux ................................... 560
Geometry Shader Best Practices .......................... 561
11 Memory ..................................................... 563
Using Textures for Generic Data Storage .................... 564
Binding Textures to Image Units ......................... 569
Reading from and Writing to Images ...................... 572
Shader Storage Buffer Objects .............................. 576
Writing Structured Data ................................. 577
Atomic Operations and Synchronization ...................... 578
Atomic Operations on Images ............................. 578
Atomic Operations on Buffers ............................ 587
Sync Objects ............................................ 589
Image Qualifiers and Barriers ........................... 593
High Performance Atomic Counters ........................ 605
Example .................................................... 609
Order-Independent Transparency .......................... 609
12 Compute Shaders ............................................ 623
Overview ................................................... 624
Workgroups and Dispatch .................................... 625
Knowing Where You Are ................................... 630
Communication and Synchronization .......................... 632
Communication ........................................... 633
Synchronization ......................................... 634
Examples ................................................... 636
Physical Simulation ..................................... 636
Image Processing ........................................ 642
Chapter Summary ............................................ 647
Compute Shader Redux .................................... 647
Compute Shader Best Practices ........................... 648
A Basics of GLUT: The OpenGL Utility Toolkit ................ 651
Initializing and Creating a Window ......................... 652
Accessing Functions ........................................ 654
Handling Window and Input Events ........................... 655
Managing a Background Process .............................. 658
Running the Program ........................................ 658
B OpenGL ES and WebGL ........................................ 659
OpenGL ES .................................................. 660
WebGL ...................................................... 662
Setting up WebGL within an HTML5 page ................... 662
Initializing Shaders in WebGL ........................... 664
Initializing Vertex Data in WebGL ....................... 667
Using Texture Maps in WebGL ............................. 668
C Built-in GLSL Variables and Functions ...................... 673
Built-in Variables ......................................... 674
Built-in Variable Declarations .......................... 674
Built-in Variable Descriptions .......................... 676
Built-in Constants ......................................... 684
Built-in Functions ......................................... 686
Angle and Trigonometry Functions ........................ 688
Exponential Functions ................................... 690
Common Functions ........................................ 692
Floating-Point Pack and Unpack Functions ................ 698
Geometric Functions ..................................... 700
Matrix Functions ........................................ 702
Vector Relational Functions ............................. 703
Integer Functions ....................................... 705
Texture Functions ....................................... 708
Atomic-Counter Functions ................................ 722
Atomic Memory Functions ................................. 723
Image Functions ......................................... 725
Fragment Processing Functions ........................... 729
Noise Functions ......................................... 731
Geometry Shader Functions ............................... 732
Shader Invocation Control Functions ..................... 734
Shader Memory Control Functions ......................... 734
D State Variables ............................................ 737
The Query Commands ......................................... 738
OpenGL State Variables ..................................... 745
Current Values and Associated Data ...................... 746
Vertex Array Object State ............................... 747
Vertex Array Data ....................................... 749
Buffer Object State ..................................... 750
Transformation State .................................... 751
Coloring State .......................................... 752
Rasterization State ..................................... 753
Multisampling ........................................... 755
Textures ................................................ 756
Textures ................................................ 759
Textures ................................................ 762
Textures ................................................ 764
Texture Environment ..................................... 766
Pixel Operations ........................................ 767
Framebuffer Controls .................................... 770
Framebuffer State ....................................... 771
Framebuffer State ....................................... 772
Frambuffer State ........................................ 773
Renderbuffer State ...................................... 775
Renderbuffer State ...................................... 776
Pixel State ............................................. 778
Shader Object State ..................................... 781
Shader Program Pipeline Object State .................... 782
Shader Program Object State ............................. 783
Program Interface State ................................. 793
Program Object Resource State ........................... 794
Vertex and Geometry Shader State ........................ 797
Query Object State ...................................... 797
Image State ............................................. 798
Transform Feedback State ................................ 799
Atomic Counter State .................................... 800
Shader Storage Buffer State ............................. 801
Sync Object State ....................................... 802
Hints ................................................... 803
Compute Dispatch State .................................. 803
Implementation-Dependent Values ......................... 804
Tessellation Shader Implementation-Dependent Limits ..... 810
Geometry Shader Implementation-Dependent Limits ......... 813
Fragment Shader Implementation-Dependent Limits ......... 815
Implementation-Dependent Compute Shader Limits .......... 816
Implementation-Dependent Shader Limits .................. 818
Implementation-Dependent Debug Output State ............. 823
Implementation-Dependent Values ......................... 824
Internal Format-Dependent Values ........................ 826
Implementation-Dependent Transform Feedback Limits ...... 826
Framebuffer-Dependent Values ............................ 827
Miscellaneous ........................................... 827
E Homogeneous Coordinates and Transformation Matrices ........ 829
Homogeneous Coordinates .................................... 830
Transforming Vertices ................................... 830
Transforming Normals .................................... 831
Transformation Matrices .................................... 831
Translation ............................................. 832
Scaling ................................................. 832
Rotation ................................................ 832
Perspective Projection .................................. 834
Orthographic Projection ................................. 834
F OpenGL and Window Systems .................................. 835
Accessing New OpenGL Functions ............................. 836
GLEW: The OpenGL Extension Wrangler ..................... 837
GLX: OpenGL Extension for the X Window System .............. 838
Initialization .......................................... 839
Controlling Rendering ................................... 840
GLX Prototypes .......................................... 842
WGL: OpenGL Extensions for Microsoft Windows ............... 845
Initialization .......................................... 846
Controlling Rendering ................................... 846
WGL Prototypes .......................................... 848
OpenGL in Mac OS X: The Core OpenGL (CGL) API and the
NSOpenGL Classes ........................................ 850
Mac OS X's Core OpenGL Library ............................. 851
Initialization .......................................... 851
Controlling Rendering ................................... 852
CGL Prototypes .......................................... 852
The NSOpenGL Classes ....................................... 854
Initialization .......................................... 854
G Floating-Point Formats for Textures, Framebuffers, and
Renderbuffers .............................................. 857
Reduced-Precision Floating-Point Values .................... 858
16-bit Floating-Point Values ............................... 858
10- and 11-bit Unsigned Floating-Point Values .............. 860
H Debugging and Profiling OpenGL ............................. 865
Creating a Debug Context ................................... 866
Debug Output ............................................... 868
Debug Messages .......................................... 869
Filtering Messages ...................................... 872
Application-Generated Messages .......................... 874
Debug Groups ............................................... 875
Naming Objects .......................................... 877
I Profiling .................................................. 879
Profiling Tools ......................................... 879
In-Application Profiling ................................ 881
Buffer Object Layouts ...................................... 885
Using Standard Layout Qualifiers ........................... 886
The stdl40 Layout Rules .................................... 886
The std430 Layout Rules .................................... 887
Glossary ...................................................... 889
Index ......................................................... 919
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