These are some notes I took at the Siggraph 2008 OpenGL BOF, where the final specs for OpenGL 3.0 were announced. Note that these notes are of course biased by what I found interesting/useful to note.

I just put these here in the hope some will find it useful. We can always delete/archive this page when OpenGL 3 becomes a part of our everyday lives.

-- [wiki:Community/People/Jean-SebastienGuay Jean-Sebastien Guay]

== OpenGL 3.0 Summary ==

 * Deprecation based on profiles, in the hope of streamlining future releases.
 * GLSL 1.3
 * Support for most 2.x ARB extensions in the core of OpenGL 3.0
 * Some features were kept as ARB/EXT extensions for lack of time

== More in-depth list of new/updated features ==

 * '''Requires programmable hardware'''
 * Expanded FBO in the core :
   * Multisampling of FBOs
   * Blitting
   * sRGB FBOs
   * Packed formats
   * Depth and stencil in FBOs
 * Enhanced vertex arrays (!MapBufferRange to specify what range of a buffer changed and just re-upload that)
 * Capture transformed vertex data in buffer objects (sends result of vertex/geometry shader back to CPU for further processing)
 * Int and float texture formats without clamping
 * Array texture (array of 1D/2D textures)
 * Conditional rendering based on occlusion queries
 * Control over blending
 * New pixel/texel formats
 * GLSL 1.3 (more detail in GLSL 1.3 section below)
 * 3.0 ARB extensions (lack of time):
   * Geometry shader
   * Texture buffer object
   * Draw instanced
   * Create context (to specify a 3.0 context and forward-compatible context)
 * 2.x ARB extensions (backported from 3.0)
   * FBO
   * sRGB Framebuffer
   * Most of the above too, see slides
 * Deprecation model (more detail in Ecosystem section below):
   * 3.0 does not remove features
   * 3.0 marks some features deprecated:
     * Fixed function vertex and fragment pipelines
     * Color index mode
     * Display lists, selection and feedback modes
     * GLSL 1.1 and 1.2

== GLSL 1.3 ==

 * `#version 1.30`
 * 32-bit `int` and `unsigned int`
 * Texture array samplers (ex: `sampler1DArray`, `sampler1DShadowArray`)
 * Perspective interpolation and smoothing specified per sampler
 * New operators for int types (bitwise `&`, `|`, etc.)
 * `switch` statement
 * Vectors for `int`, `unsigned int`
 * Hyperbolic sine, cosine and tangent

=== Deprecated ===

 * `attribute`
 * `varying`
 * `centroid varying`

Use instead:
 * `varying` in vertex shader: `out` (at global scope)
 * `varying` in fragment shader: `in` (at global scope)

 * Built-in `attribute`, `uniform` and `varying` variables are also deprecated
 * `ftransform()` also deprecated

=== Missed 1.3 ===

 * `#include`
 * `uniform a = { /*...*/ }`
 * row-major qualifier for matrices (just change the order of operations...)

== Blizzard ==

 * Blizzard develops most of their games cross-platform for Windows and Mac OS X (which means they could probably port them to Linux too for minimal effort, don't know why they don't)
   * Past games: Warcraft 3, World of Warcraft
   * Upcoming games: Starcraft 2, Diablo 3
 * In their opinion, 3.0 unifies and integrates what was essentially an extension "forest" in 2.x

== Transgaming ==

 * Explained the new extensions in more detail

== Ecosystem ==

 * Update man pages for 3.0
   * Leverage OpenGL ES 2.0 work
 * Bring the conformance tests into the shader era
   * Use the OpenGL ES 2.0 tests as a starting point

=== Deprecation model ===

Terms:
 * core for version X : in a particular version of the OpenGL spec
 * deprecated : reduced support for a given feature
 * profile : ARB-defined subset of the spec. Hopefully there will be as few as possible but as many as necessary. 
   * 3.0 : only one profile.
   * Possibilities: entertainment, content creation profiles; desktop versus mobile profiles.

Process:
 * Step 0 : core
 * Step 1 : deprecated (will possibly be removed in the next release)
 * Step 2 : extension (considered for exclusion, query in extension string)
 * Step 3 : removed (maybe still available as a vendor extension if the vendor caters to a specific area)








==> Mirrors extension approval process:

 * Step -3 : vendor-specific extension
 * Step -2 : EXT extension (considered for inclusion, query in extension string)

 * Step -1 : ARB extension (accepted, will possibly be included in the next release)
 * Step  0 : core
 * Step  1 : deprecated (will possibly be removed in the next release)
 * Step  2 : extension (considered for exclusion, query in extension string)
 * Step  3 : removed (maybe still available as a vendor extension if the vendor caters to a specific area)

This image shows the relationship between the deprecation model and the profiles in a visual way:

[[Image(OpenGL3DeprecationProcess.png, 400)]]

 * GLSL will deprecate in the same way

Contexts:
 * Full context: all features of release and profile
 * Forward-compatible context: only non-deprecated features
 * Create Context:
   * Past: driver gives whatever it wants, most likely a context compatible with the latest release it supports.
   * Now: specify parameters to get what you want.
   * `wgl_ARB_CREATE_CONTEXT` / `xgl_ARB_CREATE_CONTEXT`
   * Takes `const int* attribList` parameter
     * `MAJOR_VERSION`
     * `MINOR_VERSION`
     * `ATTRIB_FLAGS`
   * version <= 2.1 --> current behavior (get what the driver wants to give, most likely the most recent 2.x version it supports)
   * version >= 3.0 --> version you want if the driver supports it, most recent if not.
   * `attribList`: specify forward-compatible, debug context, profile.
   * To reiterate: the old context creation process will not return a 3.0+ context.
   * Can create a surface-less context for rendering without a window

== Vendor support (2008/08/13) ==

 * AMD / ATI
   * Ramping up support for 3.0 in drivers, starting now
   * Full 3.0 support expected Q1 2009

 * Intel
   * Soon is all they could say.

 * NVIDIA
   * Beta drivers are out now for XP and Vista
   * Please file bug reports
   * [http://developer.nvidia.com/object/opengl_3_driver OpenGL 3 driver] (see page for features it does not support yet)

== OpenCL ==

 * Hybrid computational library to use all computational resources, be they task-parallel (CPUs) or data-parallel (GPUs). Can use X CPUs and Y GPUs transparently.
 * Low-level abstraction
   * Need domain-specific middleware/languages/tools
 * C-based
 * Desktop/mobile profiles
 * Interoperable with OpenGL (data sharing - no need to copy back and forth)
 * Efficient inter-API communication (select whether to compute with OpenGL or OpenCL)
 * Normal Khronos process (same as OpenGL)
 * Draft specification done, fast track schedule, no date announced.
 * Based on initial proposal by Apple
 * Open : vendor-neutral, royalty-free

=== Language spec ===

 * C99-based + parallelism
 * IEEE precision 
 * Platform API
 * Runtime API

== gDebugger ==

 * OpenGL debugger, profiler
 * OpenGL ES and OpenGL 3.0 supported
 * Linux, Windows
 * Different performance counters:
   * Their OpenGL implementation
   * Windows/Linux kernel counters
   * Vendor-specific counters (NVIDIA, ATI)
 * Find bottlenecks by disabling different pipeline stages, replacing textures by 2x2 textures, etc.

== SPECgpc ==

 * Graphics performance characterization
 * Unbiased benchmarks
 * SPECviewperf 10.1
   * Updated data sets for 3dsMax, Maya, etc.
   * OpenGL 2 shaders
   * VBOs (ex: CATIA - mix of VBOs and display lists)
 * Application performance characterization (updated applications)

== !TechSoup ==

 * Training in 3D Computer Graphics
 * OpenGL 3.0 courses in Q4 2008
 * !OpenSceneGraph courses
 * OpenGL ES 2.0 courses
 * Paul Martz, Bob Kuehne, Alan Millman
 * [http://www.techsoupcorp.com/ Official web site]

== Documentation ==

 * Updates for OpenGL 3.0 in the Addison-Wesley OpenGL books
   * Programming Guide
   * Shading Language
   * SuperBible
   * Academic Series
 * Upcoming electronic books for the above and more.

== More information ==

 * [http://www.khronos.org/library/detail/2008_siggraph_opengl_bof_slides/ Siggraph 2008 OpenGL BOF slides]
 * [http://www.khronos.org/news/press/releases/khronos_releases_opengl_30_specifications_to_support_latest_generations_of/ Press release]
 * [http://www.opengl.org/registry/doc/glspec30.20080811.withchanges.pdf OpenGL 3.0 spec]
 * [http://www.opengl.org/registry/doc/GLSLangSpec.Full.1.30.08.withchanges.pdf GLSL 1.3 spec]
 * [http://www.opengl.org/registry/ Registry]
 * [http://thread.gmane.org/gmane.comp.graphics.openscenegraph.user/32185/focus=32186 ARB chairman talks about Longs Peak and other things]