Introduction to the OpenGL for Solaris Software

The OpenGL for Solaris software is Sun's native implementation of the OpenGL application programming interface (API). The OpenGL API is an industry-standard, vendor-neutral graphics library. It provides a small set of low-level geometric primitives and many basic and advanced 3D rendering features, such as modeling transformations, shading, lighting, anti-aliasing, texture mapping, fog, and alpha blending.

OpenGL 1.1.1 for Solaris Product Functionality

The OpenGL 1.1.1 for Solaris software is a functionally conforming implementation based on the OpenGL 1.1, GLX 1.2, and GLU 1.2 standard specifications. The OpenGL 1.1.1 for Solaris software incorporates the new features in OpenGL and includes support for the SERVER_OVERLAY_VISUALS property.

OpenGL 1.1.1 Library

The OpenGL 1.1.1 library is a superset of OpenGL 1.1, including all OpenGL 1.1 functionality and additional features that were available as extensions to OpenGL 1.0. The added extensions, which are listed in TABLE 1-1 on page 2, have become part of base OpenGL functionality; however, the semantics or syntax may have changed

in OpenGL 1.1.1 for Solaris. For detailed information on the extensions incorporated into the OpenGL 1.1 specification, see Appendix C in The OpenGL Graphics System: A Specification, Version 1.1.

TABLE 1-1

OpenGL 1.1 Name	Extension Name	Changed Syntax or Semantics
Vertex arrays	`GL_EXT_vertex_array`	Yes
Polygon offset	`GL_EXT_polygon_offset`	Yes
RGBA logical operations	`GL_EXT_blend_logic_op`	No
Internal texture image formats	`GL_EXT_texture`	No
Texture replace environment	`GL_EXT_texture`	No
Texture proxies	`GL_EXT_texture`	Yes
Copy texture and subtexture	`GL_EXT_copy_texture` `GL_EXT_subtexture`	No
Texture objects	`GL_EXT_texture_object`	Yes

Note - Because the OpenGL 1.1.1 for Solaris software is based on a more current version of the OpenGL specifications (OpenGL 1.1, GLX 1.2, GLU 1.2) than the OpenGL 1.0 version, customers currently using the OpenGL 1.0 extensions syntax should be alert for software changes required to support the updated OpenGL specifications.

Supported OpenGL 1.1.1 Extensions

The OpenGL 1.1.1 for Solaris software supports the following OpenGL extensions:

3D texture mapping extension - GL_EXT_texture3D
ABGR reverse-order color format extension - GL_EXT_abgr
Texture color table extension - GL_SGI_texture_color_table
SGI color table extension - GL_SGI_color_table
Sun geometry compression extension - GL_SUNX_geometry_compression
Rescale normal extension - GL_EXT_rescale_normal
Histogram extension - GL_EXT_histogram

Postconvolution color table extension - GL_SGI_postconvolution_color_table
Convolution extension - GL_EXT_convolution
Blend color extension - GL_EXT_blend_color
Blend minmax extension - GL_EXT_blend_minmax
Blend suptract extension - GL_EXT_blend_subtract
Pixel transform extension - GL_EXT_pixel_transform
Multidrawarrays extension - GL_SUN_multi_draw_arrays
Convolution border mode extension - GL_HP_convolution_border_modes
Convolution border mode extension - GL_SUN_convoution_border_modes
Pixel transformation extension - GL_EXT_pixel_transform

Note - glBlendEquationEXT(GL_LOGIC_OP) is not supported. Instead of using the code sequence:

                         glLogicOpEXT(GL_XOR)
                         glBlendEquationEXT(GL_LOGIC_OP)
                         glEnable(GL_BLEND)
 use the following code sequence:
                 glLogicOp(GL_XOR)
                 /* GL_LOGIC_OP not supported
                    in glBlendEquationEXT with
                    OpenGL for Solaris */
                 #ifdef GL_VERSION_1_1
                     glEnable(GL_COLOR_LOGIC_OP)
                 #endif

The OpenGL 1.1.1 for Solaris software also supports the following GLX extensions:

Return the transparent pixel index for an overlay/underlay window pair - GLX_SUN_get_transparent_index. See the glXGetTransparentIndexSUN(3gl) man page.
fbconfig extension - GLX_SGIX_fbconfig
pbuffer extension - GLX_SGIX_pbuffer
make current read extension - GLX_SGI_make_current_read
Multithread support extension - GLX_SUN_init_threads

Note - To determine what extensions, if any, your application uses, search for command-name patterns such as glProcedureEXT(3gl). If your application uses extensions, you will need to ensure that it also handles the functionality in an OpenGL 1.1-compliant manner. To determine what extensions an OpenGL implementation supports, use glXQueryExtensionString(3gl). Because the OpenGL 1.1.1 for Solaris software is based on a more current version of the OpenGL specifications (OpenGL 1.1, GLX 1.2, GLU 1.2) than the OpenGL 1.0 version, customers currently using the OpenGL 1.0 extensions syntax should be alert for software changes required to support the updated OpenGL specifications.

Compatibility Issues

Applications compiled with the previous OpenGL for Solaris libraries will run unchanged with the Solaris OpenGL 1.1.1 implementation. However, note the following backward compatibility issues:

To reduce function call overhead and improve performance for vertex calls in immediate mode, vertex commands such as glVertex, glColor, glNormal, glTexCoord and glIndex have been redefined as macros in the OpenGL 1.1.1 for Solaris software. Therefore, by default, applications compiled with the OpenGL 1.1.1 for Solaris library will not run on the 1.0 library. To compile an application with the OpenGL 1.1.1 for Solaris library and maintain compatibility with 1.0, use the flag -DSUN_OGL_NO_VERTEX_MACROS when compiling the application. See the glVertex (3gl) man page for further information.
If your application uses the features in the OpenGL 1.1.1 for Solaris library, these are not available in the previous release for OpenGL It will not be backward compatible with the previous OpenGL libraries.

MT-Safe

The OpenGL for Solaris library is multithread safe (MT-safe). Multiple rendering threads are allowed in a single process. See man page glXInitThreadsSUN(3gl).

If an application needs only one rendering thread, MT-safe mode is not recommended. MT-safe mode incurs some performance overhead which can be avoided for single threaded rendering. Some multithread cases may contain computation or GUI threads. For these cases an application can create one OpenGL rendering thread and separate GUI or computational threads.

Multithread safe allows OpenGL parallelism. This parallelism supports single to multiple processors as well as single to multiple screens.

Multithread safe does not allow:

More than one thread using the same context
More than one current context per thread

The maximum number of OpenGL rendering threads supported is 64.

The following MT-Safe patches are required:

Solaris 2.5.1 +patch 103566-27
Solaris 2.6 +patch 105633-02 (if using Creator patch 105360-04 also needed)

Caution - When the OpenGL renderer (see glGetString(GL_RENDERER)) is a graphics accelerator (not a software renderer), multiple rendering threads to the same screen might perform slower than single threaded rendering. If possible, avoid multithreaded rendering to a single graphics accelerated screen.

Supported Platforms

The OpenGL 1.1.1 for Solaris software supports the following devices:

Creator Graphics and Creator3D Graphics - OpenGL functionality is accelerated in hardware.
SX, ZX, GX, GX+, TGX, TGX+, S24 - OpenGL functionality is performed in software.
All SMCC SPARC^TM systems equipped with the following frame buffers are supported on the OpenGL 1.1.1 for Solaris software: the TCX, SX, GX, ZX and Creator families of frame buffers. This includes Ultra^TM desktop, Ultra Enterprise^TM and all the legacy SPARCstation^TM family.

Note - The PGX frame buffer family is not supported by the OpenGL 1.1.1 for Solaris software.

Where to Look for Information on OpenGL Programming

For information on how to write an OpenGL application, see the following books:

OpenGL Programming Guide by Neider, Davis, and Woo
OpenGL Reference Manual by the OpenGL Architecture Review Board
OpenGL Programming for X Windows System by Mark Kilgard

These books are published by Addison-Wesley and are available through your local bookstore.

For more information on OpenGL, you may want to refer to "The Design of the OpenGL Interface" written by Mark Segal and Kurt Akeley. A PostScript copy of this document is included in the SUNWgldoc package or the OpenGL 1.1.1 for Solaris CD-ROM. For the complete specification of what constitutes OpenGL, see The OpenGL Graphics System: A Specification, Version 1.1, also written by Mark Segal and Kurt Akeley. An online version of this specification is located at http://

www.sgi.com/Technology/OpenGL/glspec1.1/glspec.html).

Finally, for a good source of answers to questions you may have about OpenGL, see the OpenGL information center at http://www.sgi.com/Technology/OpenGL/ opengl.html.