From 27474060e1287a67c45cd790d29b9095b35b2bdf Mon Sep 17 00:00:00 2001 From: ShizZy Date: Thu, 29 Aug 2013 23:35:09 -0400 Subject: adding initial project layout --- externals/glew-1.10.0/doc/advanced.html | 272 ++++++++++++++++++++++++++++++++ 1 file changed, 272 insertions(+) create mode 100644 externals/glew-1.10.0/doc/advanced.html (limited to 'externals/glew-1.10.0/doc/advanced.html') diff --git a/externals/glew-1.10.0/doc/advanced.html b/externals/glew-1.10.0/doc/advanced.html new file mode 100644 index 000000000..a3cb7db90 --- /dev/null +++ b/externals/glew-1.10.0/doc/advanced.html @@ -0,0 +1,272 @@ + + + + + + +GLEW: The OpenGL Extension Wrangler Library + + + + + + + + +

+ + + + + + + + +

+ + + + + + + +

Latest Release: 1.10.0

+ + + + + + + + + + + +

Source Generation

+ + + + + +

Last Update: 07-22-13

+ +

The OpenGL Extension Wrangler Library

+ + + + +

Automatic Code Generation

+ +

+Starting from release 1.1.0, the source code and parts of the +documentation are automatically generated from the extension +specifications in a two-step process. In the first step, +specification files from the OpenGL registry are downloaded and +parsed. Skeleton descriptors are created for each extension. These +descriptors contain all necessary information for creating the source +code and documentation in a simple and compact format, including the +name of the extension, url link to the specification, tokens, function +declarations, typedefs and struct definitions. In the second step, +the header files as well as the library and glewinfo source are +generated from the descriptor files. The code generation scripts are +located in the auto subdirectory. +

+ +

+The code generation scripts require GNU make, wget, and perl. On +Windows, the simplest way to get access to these tools is to install +Cygwin, but make sure that the +root directory is mounted in binary mode. The makefile in the +auto directory provides the following build targets: +

+ + + + + + + + + + + + +

`make`	Create the source files from the descriptors. If the +descriptors do not exist, create them from the spec files. If the spec +files do not exist, download them from the OpenGL repository.
`make clean`	Delete the source files.
`make clobber`	Delete the source files and the descriptors.
`make destroy`	Delete the source files, the descriptors, and the spec files.
`make custom`	Create the source files for the extensions +listed in `auto/custom.txt`. See "Custom Code +Generation" below for more details.

+ +

Adding a New Extension

+ +

+To add a new extension, create a descriptor file for the extension in +auto/core and rerun the code generation scripts by typing +make clean; make in the auto directory. +

+ +

+The format of the descriptor file is given below. Items in +brackets are optional. +

+ +

+<Extension Name>
+[<URL of Specification File>]
+    [<Token Name> <Token Value>]
+    [<Token Name> <Token Value>]
+    ...
+    [<Typedef>]
+    [<Typedef>]
+    ...
+    [<Function Signature>]
+    [<Function Signature>]
+    ...
+ +

+ + + +

+Take a look at one of the files in auto/core for an +example. Note that typedefs and function signatures should not be +terminated with a semicolon. +

+ +

Custom Code Generation

+Starting from GLEW 1.3.0, it is possible to control which extensions +to include in the libarary by specifying a list in +auto/custom.txt. This is useful when you do not need all the +extensions and would like to reduce the size of the source files. +Type make clean; make custom in the auto directory +to rerun the scripts with the custom list of extensions. +

+ +

+For example, the following is the list of extensions needed to get GLEW and the +utilities to compile. +

+ +

+WGL_ARB_extensions_string
+WGL_ARB_multisample
+WGL_ARB_pixel_format
+WGL_ARB_pbuffer
+WGL_EXT_extensions_string
+WGL_ATI_pixel_format_float
+WGL_NV_float_buffer
+

+ +

Multiple Rendering Contexts (GLEW MX)

+ +

Starting with release 1.2.0, thread-safe support for multiple +rendering contexts, possibly with different capabilities, is +available. Since this is not required by most users, it is not added +to the binary releases to maintain compatibility between different +versions. To include multi-context support, you have to do the +following:

Compile and use GLEW with the GLEW_MX preprocessor token +defined.
For each rendering context, create a GLEWContext object +that will be available as long as the rendering context exists.
Define a macro or function called glewGetContext() that +returns a pointer to the GLEWContext object associated with +the rendering context from which OpenGL/WGL/GLX calls are issued. This +dispatch mechanism is primitive, but generic. +
Make sure that you call glewInit() after creating the +GLEWContext object in each rendering context. Note, that the +GLEWContext pointer returned by glewGetContext() has +to reside in global or thread-local memory. +

+ +

Note that according to the MSDN +WGL documentation, you have to initialize the entry points for +every rendering context that use pixel formats with different +capabilities For example, the pixel formats provided by the generic +software OpenGL implementation by Microsoft vs. the hardware +accelerated pixel formats have different capabilities. GLEW by +default ignores this requirement, and does not define per-context +entry points (you can however do this using the steps described +above). Assuming a global namespace for the entry points works in +most situations, because typically all hardware accelerated pixel +formats provide the same entry points and capabilities. This means +that unless you use the multi-context version of GLEW, you need to +call glewInit() only once in your program, or more precisely, +once per process.

+ +

Separate Namespace

+ +

+To avoid name clashes when linking with libraries that include the +same symbols, extension entry points are declared in a separate +namespace (release 1.1.0 and up). This is achieved by aliasing OpenGL +function names to their GLEW equivalents. For instance, +glFancyFunction is simply an alias to +glewFancyFunction. The separate namespace does not effect +token and function pointer definitions. +

+ +

Known Issues

+ +

+GLEW requires GLX 1.2 for compatibility with GLUT. +

+ + +

+ + -- cgit v1.2.3