1991-2006
Silicon Graphics, Inc.
glXMakeContextCurrent
3G
glXMakeContextCurrent
attach a GLX context to a GLX drawable
C Specification
Bool glXMakeContextCurrent
Display * display
GLXDrawable draw
GLXDrawable read
GLXContext ctx
Parameters
display
Specifies the connection to the X server.
draw
Specifies a GLX drawable to render into.
Must be an XID representing a GLXWindow, GLXPixmap, or GLXPbuffer.
read
Specifies a GLX drawable to read from.
Must be an XID representing a GLXWindow, GLXPixmap, or GLXPbuffer.
ctx
Specifies the GLX context to be bound to read and ctx.
Description
glXMakeContextCurrent binds ctx to the current rendering thread and to the draw
and read GLX drawables. draw and read may be the same.
draw is used for all OpenGL operations except:
Any pixel data that are read based on the value of GLX_READ_BUFFER.
Note that accumulation operations use the value of GLX_READ_BUFFER,
but are not allowed unless draw is identical to read.
Any depth values that are retrieved by glReadPixels or glCopyPixels.
Any stencil values that are retrieved by glReadPixels or
glCopyPixels.
Frame buffer values are taken from draw.
If the current rendering thread has a current rendering context, that
context is flushed and replaced by ctx.
The first time that ctx is made current, the viewport and scissor
dimensions are set to the size of the draw drawable. The viewport
and scissor are not modified when ctx is subsequently made current.
To release the current context without assigning a new one,
call glXMakeContextCurrent with draw and read set to None and ctx
set to NULL.
glXMakeContextCurrent returns True if it is successful,
False otherwise.
If False is returned, the previously current rendering context
and drawable (if any) remain unchanged.
Notes
glXMakeContextCurrent is available only if the GLX version is 1.3 or greater.
If the GLX version is 1.1 or 1.0, the GL version must be 1.0.
If the GLX version is 1.2, then the GL version must be 1.1.
If the GLX version is 1.3, then the GL version must be 1.2.
Errors
BadMatch is generated if draw and read are not compatible.
BadAccess is generated if ctx is current to some other
thread.
GLXContextState is generated if there is a current rendering
context and its render mode is either GLX_FEEDBACK or
GLX_SELECT.
GLXBadContext is generated if ctx is not a valid GLX
rendering context.
GLXBadDrawable is generated if draw or read is not a valid
GLX drawable.
GLXBadWindow is generated if the underlying X window for either
draw or read is no longer valid.
GLXBadCurrentDrawable is generated if the previous context of
the calling thread has unflushed commands and the previous drawable is
no longer valid.
BadAlloc is generated if the X server does not have enough
resources to allocate the buffers.
BadMatch is generated if:
draw and read cannot fit into frame buffer memory simultaneously.
draw or read is a GLXPixmap and ctx is a direct-rendering
context.
draw or read is a GLXPixmap and ctx was previously bound to a
GLXWindow or GLXPbuffer.
draw or read is a GLXWindow or GLXPbuffer and ctx was
previously bound to a GLXPixmap.
See Also
glXCreateNewContext,
glXCreateWindow,
glXCreatePixmap,
glXCreatePbuffer,
glXDestroyContext,
glXGetCurrentContext,
glXGetCurrentDisplay,
glXGetCurrentDrawable,
glXGetCurrentReadDrawable,
glXMakeCurrent
Copyright
Copyright 1991-2006
Silicon Graphics, Inc. This document is licensed under the SGI
Free Software B License. For details, see
http://oss.sgi.com/projects/FreeB/.