icetglsetreadbuffer(3) [debian man page]

icetGLSetReadBuffer(3)						  IceT Reference					    icetGLSetReadBuffer(3)

NAME

       icetGLSetReadBuffer -- set OpenGL buffer for images

Synopsis
       #include <IceTGL.h>

       void icetGLSetReadBuffer(   GLenum   mode  );

Description
       Set the OpenGL buffer from which to read images to composite. After the draw callback (specified by icetGLDrawCallback) returns, IceT grabs
       the rendered image from the OpenGL buffer specified by mode.  This buffer is also used  to  write  back	fully  composited  images  if  the
       ICET_GL_DISPLAY option is on.

       mode  is  an OpenGL value that specifies the buffer. It is passed to glReadBuffer and glDrawBuffer.  Accepted values are GL_FRONT, GL_BACK,
       GL_LEFT, GL_RIGHT, GL_FRONT_LEFT, GL_FRONT_RIGHT, GL_BACK_LEFT, GL_BACK_RIGHT, and any of the GL_AUXi identifiers.

       The current read buffer used is stored in the ICET_GL_READ_BUFFER state variable. The default value is GL_BACK.

Errors
       ICET_INVALID_OPERATION
	       icetGLInitialize has not been called for this IceT context.

       ICET_INVALID_ENUM
	       mode is not a known OpenGL buffer identifier.

Warnings
       None.

Bugs
       The check of mode is perfunctory. It just checks mode against a list of known buffers. It does not check to  see  if  the  buffer  actually
       exists or for any other buffers that might be defined in an OpenGL extension.

Copyright
       Copyright (C)2010 Sandia Corporation

       Under the terms of Contract DE-AC04-94AL85000 with Sandia Corporation, the U.S. Government retains certain rights in this software.

       This source code is released under the New BSD License.

See Also
       icetGLDrawCallback(3)

IceT Reference							  August  9, 2010					    icetGLSetReadBuffer(3)

icetDrawFrame(3)						  IceT Reference						  icetDrawFrame(3)

NAME

       icetDrawFrame -- renders and composites a frame

Synopsis
       #include <IceT.h>

       IceTImage icetDrawFrame(
				  const IceTDouble *   projection_matrix,
				  const IceTDouble *   modelview_matrix,
				  const IceTFloat *    background_color  );

Description
       Initiates a frame draw using the given transformation matrices (modelview and projection). If you are using OpenGL ,you should probably use
       the icetGLDrawFrame function and associated icetGLDrawCallback.

       Before IceT may render an image, the tiled display needs to be defined (using icetAddTile), the drawing function needs  to  be  set  (using
       icetDrawCallback),  and	composite  strategy  must  be  set (using icetStrategy).  The single image sub-strategy may also optionally be set
       (using icetSingleImageStrategy).

       All processes in the current IceT context must call icetDrawFrame for it to complete.

       During compositing, IceT uses the given projection_matrix and modelview_matrix, as well as the bounds given in the last call to	icetBound-
       ingBox  or icetBoundingVertices, to determine onto which pixels the local geometry projects. If the given matrices are not the same used in
       the rendering or the given bounds do not contain the geometry, IceT may clip the geometry in surprising ways. Furthermore, IceT will modify
       the  projection_matrix for the drawing callback to change the projection onto (or in between) tiles. Thus, you should pass the desired pro-
       jection_matrix to icetDrawFrame and then use the version passed to the drawing callback.

Return Value
       On each .igdisplay processdisplay process (as defined by icetAddTile, icetDrawFrame returns an image of the  fully  composited  image.  The
       contents of the image are undefined for any non-display process.

       If  the	ICET_COMPOSITE_ONE_BUFFER  option is on and both a color and depth buffer is specified with icetSetColorFormatand icetSetDepthFor-
       mat,then the returned image might be missing the depth buffer. The rational behind this option is that often both the color and depth  buf-
       fer is necessary in order to composite the color buffer, but the composited depth buffer is not needed. In this case, the compositing might
       save some time by not transferring depth information at the latter stage of compositing.

       The returned image uses memory buffers that will be reclaimed the next time IceT renders a frame. Do not use this image after the next call
       to icetDrawFrame (unless you have changed the IceT context).

Errors
       ICET_INVALID_OPERATION
	       Raised if the icetGLInitialize has not been called or if the drawing callback has not been set. Also can be raised if icetDrawFrame
	      is called recursively, probably from within the drawing callback.

       ICET_OUT_OF_MEMORY
	       Not enough memory left to hold intermittent frame buffers and other temporary data.

       icetDrawFrame may also indirectly raise an error if there is an issue with the strategy or callback.

Warnings
       None.

Bugs
       If compositing with color blending on, the image returned may have a black background instead of the background_color requested.  This  can
       be  corrected  by blending the returned image over the desired background. This will be done for you if the ICET_CORRECT_COLORED_BACKGROUND
       is on.

Copyright
       Copyright (C)2003 Sandia Corporation

       Under the terms of Contract DE-AC04-94AL85000 with Sandia Corporation, the U.S. Government retains certain rights in this software.

       This source code is released under the New BSD License.

See Also
       icetAddTile(3),	 icetBoundingBox(3),   icetBoundingVertices(3),   icetDrawCallback(3),	 icetGLDrawFrame(3),   icetSingleImageStrategy(3),
       icetStrategy(3)

IceT Reference							  August  9, 2010						  icetDrawFrame(3)