Cg Core Runtime API                                cgMapBuffer(3)



NAME
     cgapBuffer - map buffer into application's address space

SYNOPSIS
       #include 

       void * cgMapBuffer( CGbuffer buffer,
                           CGbufferaccess access );


PARAMETERS
     buffer  The buffer which will be mapped into the
             application's address space.

     access  An enumerant indicating the operations the client
             may perform on the data store through the pointer
             while the buffer data is mapped.

             The following enumerants are allowed:

             CGMAPREAD
                 The application can read but not write through
                 the data pointer.

             CGMAPWRITE
                 The application can write but not read through
                 the data pointer.

             CGMAPREADWRITE
                 The application can read and write through the
                 data pointer.

             CGMAPWRITEDISCARD
                 Same as CGMAPREADWRITE if using a GL buffer.

             CGMAPWRITENOVERWRITE
                 Same as CGMAPREADWRITE if using a GL buffer.

RETURN VALUES
     Returns a pointer through which the application can read or
     write the buffer's data store.

     Returns NUL if an error occurs.

DESCRIPTION
     cgapBuffer maps a buffer into the application's address
     space for memory-mapped updating of the buffer's data.  The
     application should call cgUnmapBuffercgUnmapBuffer when
     it's done updating or querying the buffer.

EXAMPLES




Cg Toolkit 2.1            Last change:                          1






Cg Core Runtime API                                cgMapBuffer(3)



         unsigned char *bufferPtr = cgMapBuffer( myBuffer, CGMAPREADWRITE );
         memcpy( ptr, bufferPtr, size );
         cgUnmapBuffer( myBuffer );


ERORS
     CGINVALIDBUFERHANDLEROR is generated if buffer is not
     a valid buffer.

     CGINVALIDENUMERANTEROR is generated if access is not
     CGREADONLY, CGWRITEONLY, or CGREADWRITE.

     CGBUFERALREADYMAPEDEROR is generated if buffer is
     already mapped.

HISTORY
     cgapBuffer was introduced in Cg 2.0.

SEE ALSO
     cgUnmapBuffer, cgSetBufferData, cgSetBufferSubData,
     cgSetParameter


































Cg Toolkit 2.1            Last change:                          2