The OpenGL Graphics System: A Specification (Version 1.1)

Mark Segal
Kurt Akeley

Editor: Chris Frazier

Copyright © 1992-1997 Silicon Graphics, Inc.

This document contains unpublished information of
Silicon Graphics, Inc.

This document is protected by copyright, and contains information proprietary to Silicon Graphics, Inc. Any copying, adaptation, distribution, public performance, or public display of this document without the express written consent of Silicon Graphics, Inc. is strictly prohibited. The receipt or possession of this document does not convey any rights to reproduce, disclose, or distribute its contents, or to manufacture, use, or sell anything that it may describe, in whole or in part. U.S. Government Restricted Rights Legend

Use, duplication, or disclosure by the Government is subject to restrictions set forth in FAR 52.227.19(c)(2) or subparagraph (c)(1)(ii) of the Rights in Technical Data and Computer Software clause at DFARS 252.227-7013 and/or in similar or successor clauses in the FAR or the DOD or NASA FAR Supplement. Unpublished rights reserved under the copyright laws of the United States. Contractor/manufacturer is Silicon Graphics, Inc., 2011 N. Shoreline Blvd., Mountain View, CA 94039-7311. OpenGL is a trademark of Silicon Graphics, Inc.

• Contents
• List of Figures
• List of Tables
• 1 Introduction
  • 1.1 What is the OpenGL Graphics System?
  • 1.2 Programmer's View of OpenGL
  • 1.3 Implementor's View of OpenGL
  • 1.4 Our View
• 2 OpenGL Operation
  • 2.1 OpenGL Fundamentals
    • Floating-Point Computation
  • 2.2 GL State
  • 2.3 GL Command Syntax
  • 2.4 Basic GL Operation
  • 2.5 GL Errors
  • 2.6 Begin/End Paradigm
    • 2.6.1 Begin and End Objects
    • 2.6.2 Polygon Edges
    • 2.6.3 GL Commands within Begin/ End
  • 2.7 Vertex Specification
  • 2.8 Vertex Arrays
  • 2.9 Rectangles
  • 2.10 Coordinate Transformations
    • 2.10.1 Controlling the Viewport
    • 2.10.2 Matrices
    • 2.10.3 Normal Transformation
    • 2.10.4 Generating texture coordinates
  • 2.11 Clipping
  • 2.12 Current Raster Position
  • 2.13 Colors and Coloring
    • 2.13.1 Lighting
      • Lighting Operation
    • 2.13.2 Lighting Parameter Specification
    • 2.13.3 ColorMaterial
    • 2.13.4 Lighting State
    • 2.13.5 Color Index Lighting
    • 2.13.6 Clamping or Masking
    • 2.13.7 Flatshading
    • 2.13.8 Color and Texture Coordinate Clipping
    • 2.13.9 Final Color Processing
• 3 Rasterization
  • 3.1 Invariance
  • 3.2 Antialiasing
  • 3.3 Points
    • 3.3.1 Point Rasterization State
  • 3.4 Line Segments
    • 3.4.1 Basic Line Segment Rasterization
    • 3.4.2 Other Line Segment Features
      • Line Stipple
      • Wide Lines
      • Antialiasing
    • 3.4.3 Line Rasterization State
  • 3.5 Polygons
    • 3.5.1 Basic Polygon Rasterization
    • 3.5.2 Stippling
    • 3.5.3 Antialiasing
    • 3.5.4 Options Controlling Polygon Rasterization
    • 3.5.5 Depth Offset
    • 3.5.6 Polygon Rasterization State
  • 3.6 Pixel Rectangles
    • 3.6.1 Pixel Storage Modes
    • 3.6.2 Pixel Transfer Modes
    • 3.6.3 Rasterization of Pixel Rectangles
      • Unpacking
      • Conversion to floating-point
      • Conversion to RGB
      • Final Expansion to RGBA
      • Pixel Transfer Operations
      • Final Conversion
      • Conversion to Fragments
    • 3.6.4 Pixel Transfer Operations
      • Arithmetic on Components
      • Arithmetic on Indices
      • RGBA to RGBA Lookup
      • Color Index Lookup
      • Stencil Index Lookup
  • 3.7 Bitmaps
  • 3.8 Texturing
    • Texture Image Specification
    • Alternate Texture Image Specification Commands
    • Texture Parameters
    • Texture Wrap Modes
    • 3.8.1 Texture Minification
      • Mipmapping
    • 3.8.2 Texture Magnification
    • 3.8.3 Texture State and Proxy State
    • 3.8.4 Texture Objects
    • 3.8.5 Texture Environments and Texture Functions
    • 3.8.6 Texture Application
  • 3.9 Fog
  • 3.10 Antialiasing Application
• Per-Fragment Operations and the Framebuffer
  • 4.1 Per-Fragment Operations
    • 4.1.1 Pixel Ownership Test
    • 4.1.2 Scissor test
    • 4.1.3 Alpha test
    • 4.1.4 Stencil test
    • 4.1.5 Depth buffer test
    • 4.1.6 Blending
    • 4.1.7 Dithering
    • 4.1.8 Logical Operation
  • 4.2 Whole Framebuffer Operations
    • 4.2.1 Selecting a Buffer for Writing
    • 4.2.2 Fine Control of Buffer Updates
    • 4.2.3 Clearing the Buffers
    • 4.2.4 The Accumulation Buffer
  • 4.3 Drawing, Reading, and Copying Pixels
    • 4.3.1 Writing to the Stencil Buffer
    • 4.3.2 Reading Pixels
      • Obtaining Pixels from the Framebuffer
      • Conversion of RGBA values
      • Conversion of Depth values
      • Pixel Transfer Operations
      • Conversion to L
      • Final Conversion
      • Placement in Client Memory
    • 4.3.3 Copying Pixels
    • 4.3.4 Pixel draw/read state
• 5 Special Functions
  • 5.1 Evaluators
  • 5.2 Selection
  • 5.3 Feedback
  • 5.4 Display Lists
  • 5.5 Flush and Finish
  • 5.6 Hints
• 6 State and State Requests
• A Invariance
  • A.1 Repeatability
  • A.2 Multi-pass Algorithms
  • A.3 Invariance Rules
  • A.4 What All This Means
• B Corollaries
• C Version 1.1
  • C.1 Vertex Array
  • C.2 Polygon Offset
  • C.3 Logical Operation
  • C.4 Texture Image Formats
  • C.5 Texture Replace Environment
  • C.6 Texture Proxies
  • C.7 Copy Texture and Subtexture
  • C.8 Texture Objects
  • C.9 Other Changes
  • C.10 Acknowledgements
• Index
• About this document ...