dmFXGetDMBuffer(3dm)					  dmFXGetDMBuffer(3dm)

NAME    [Toc]    [Back]

     dmFXGetDataPtr, dmFXGetRowLength -	return a pointer to the	pixels stored
     in	a DMfxbuffer

SYNOPSIS    [Toc]    [Back]

     #include <dmedia/fx_buffer.h>

     void* dmFXGetDataPtr
	   ( DMfxbuffer* fxbuffer )

     int dmFXGetRowLength
	   ( DMfxbuffer* fxbuffer )

PARAMETERS    [Toc]    [Back]

     fxbuffer	A buffer that was created with dmFXAllocateImageBuffers.

DESCRIPTION    [Toc]    [Back]

     These functions are used to access	the pixels stored in a DMfxbuffer.
     Before calling them, you must first set up	the buffer.  To	read pixels
     from the buffer, call dmFXSetupInputImageBufferWithUsage, and specify
     bufInputDirect.  To write pixels into a buffer, call
     dmFXSetupOutputImageBuffer	and specify bufOutputDirect.


     After the buffer has been set up for input	or output access,
     dmFXGetDataPtr will return	a pointer to the first pixel in	the buffer,
     the one at	the upper-left corner of the image.


     When DMfxbuffers are allocated, they may be bigger	than necessary to hold
     the requested images.  dmFXGetRowLength will return the number of pixels
     to	skip to	get from the beginning of one row to the beginning of the
     next.


     If	the buffer has not been	set up correctly for direct access,
     dmFXGetDataPtr will return	NULL and dmFXGetRowLength will return 0.


     Under normal circumstances, dmFXGetRowLength will return the width	of the
     buffer, as	requested when it was created.	Applications that use
     DMfxbuffers can count on this.  It	can be useful, when debugging plugins,
     to	create buffers that have a larger internal width.  If you are using
     the debug version of libfxplugutils, setting the environment variable
     FX_STRANGE_ROWBYTES to YES	will cause it to create	buffers	where the
     width of the storage area is greater than is needed.






									Page 1






dmFXGetDMBuffer(3dm)					  dmFXGetDMBuffer(3dm)

SEE ALSO    [Toc]    [Back]

     dmFXAllocateImageBuffers(3dm), dmFXSetupInputImageBuffer(3dm),
     dmFXSetupOutputImageBuffer(3dm), DMbuffer(4).


									PPPPaaaaggggeeee 2222