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XXXmdf - incomplete
Name Strings
$Date: 1999/01/08 19:41:53 $ $Revision: 1.1 $
SGIX_fbconfig is required
This extension enhances the fbconfig visual selection and description
capabilities by adding support for floating-point attributes. While
SGIX_fbconfig only provides for integral attributes, some visual
attributes are best described with floating point
numbers. Applications which seek to choose visuals based on those
attributes may use the facilites described in this extension.
* There is an implicit assumption that all attribute tokens can be
cast to double and back to int without losing information. There
are currently no tokens with more than 16 significant bits so this
is almost certainly a safe assumption, however it should be noted
as a limitation.
New Procedures and Functions
int glXGetFBConfigFltAttribSGIX(Display *dpy,
GLXFBConfigSGIX config,
int attribute,
double *value);
GLXFBConfigSGIX *glXChooseFBConfigWithFltSGIX(
Display *dpy,
int screen,
const int *int_attrib_list,
const double *flt_attrib_list,
int *nelements);
New Tokens
Additions to the OpenGL 1.0 Specification
Additions to the GLX Specification
[Added following the description of glXChooseFBConfigSGIX]
Use glXChooseFBConfigWithFltSGIX in place of
glXChooseFBConfigSGIX in order to select GLXFBConfigSGIXs based on
floating point attributes.
GLXFBConfigSGIX *glXChooseFBConfigWithFltSGIX(
Display *dpy,
int screen,
const int *attrib_list,
const double *flt_attrib_list,
int *nelements);
If <flt_attrib_list> is NULL then glXChooseFBConfigWithFltSGIX behaves
identically to glXChooseFBConfigSGIX; otherwise, the attributes
listed in <flt_attrib_list> are used in conjunction with
the attributes listed in <attrib_list> to select a
matching GLXFBConfigSGIX.
All attributes have an inherent data type, listed in Table 3, such as
integer, boolean, enumerated, bitmask, XID, or floating point.
Any of these attributes may appear in <attrib_list>, although
in the case of floating point attributes the cast to integer may lose
information. Only floating point attributes may appear in
<flt_attrib_list>. Since the attribute tokens are integer constants,
they must be cast to double to appear in <flt_attrib_list>. Any
attribute which appears in both lists will take on the value from
[Added following the description of glXGetFBConfigAttribSGIX]
To get the value of a floating point GLX attribute for a
GLXFBConfigSGIX use:
int glXGetFBConfigFltAttribSGIX(Display *dpy,
GLXFBConfigSGIX config,
int attribute,
double *value);
glXGetFBConfigFltAttribSGIX has the same semantics as
glXGetFBConfigAttribSGIX, although it returns a double value
rather than an int value. Non-floating-point attributes undergo
a cast to double before they are returned.
GLX Protocol
New State
New Implementation Dependent State