.\" Copyright (c) 1994 The Board of Trustees of The Leland Stanford
.\" Junior University.  All rights reserved.
.\" 
.\" Permission to use, copy, modify and distribute this software and its
.\" documentation for any purpose is hereby granted without fee, provided
.\" that the above copyright notice and this permission notice appear in
.\" all copies of this software and that you do not sell the software.
.\" Commercial licensing is available by contacting the author.
.\" 
.\" THE SOFTWARE IS PROVIDED "AS IS" AND WITHOUT WARRANTY OF ANY KIND,
.\" EXPRESS, IMPLIED OR OTHERWISE, INCLUDING WITHOUT LIMITATION, ANY
.\" WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
.\" 
.\" Author:
.\"    Phil Lacroute
.\"    Computer Systems Laboratory
.\"    Electrical Engineering Dept.
.\"    Stanford University
.\" 
.\" $Date: 1994/12/31 19:49:53 $
.\" $Revision: 1.1 $
.\"
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.TH vpStoreRawVolume 3 "" VolPack
.SH NAME
vpStoreRawVolume, vpStoreMinMaxOctree, vpStoreClassifiedVolume,
vpStoreContext \- store volume data structures to a file
.SH SYNOPSIS
#include <volpack.h>
.sp
.FS vpResult
\fBvpStoreRawVolume(\fIvpc, fd\fB)\fR
.FA
vpContext *\fIvpc;\fR
.FA
int \fIfd;\fR
.FE
.sp
.FS vpResult
\fBvpStoreMinMaxOctree(\fIvpc, fd\fB)\fR
.FA
vpContext *\fIvpc;\fR
.FA
int \fIfd;\fR
.FE
.sp
.FS vpResult
\fBvpStoreClassifiedVolume(\fIvpc, fd\fB)\fR
.FA
vpContext *\fIvpc;\fR
.FA
int \fIfd;\fR
.FE
.sp
.FS vpResult
\fBvpStoreContext(\fIvpc, fd\fB)\fR
.FA
vpContext *\fIvpc;\fR
.FA
int \fIfd;\fR
.FE
.SH ARGUMENTS
.IP \fIvpc\fR
VolPack context from \fBvpCreateContext.\fR
.IP \fIfd\fR
File descriptor from \fBopen\fR(2), open for writing.
.SH DESCRIPTION
These functions are used to store volume data structures from a
rendering context into files in the format read by the VolPack file
reading routines (see vpLoadRawVolume(3)).
.PP
\fBvpStoreRawVolume\fR creates a 3D voxel array file.  The file
includes information about the size of the volume and the layout of
the voxels as well as the volume data itself.
.PP
\fBvpStoreMinMaxOctree\fR creates a min-max octree file.  The file
includes information about the size of the volume and the layout of
the voxels as well as the octree itself.
.PP
\fBvpStoreClassifiedVolume\fR creates a preclassified volume data
file.  The file includes information about the size of the volume and the
layout of the voxels as well as the volume data itself.
.PP
\fBvpStoreContext\fR creates a rendering context file.  The file
includes all rendering parameters except volume data and callback
functions.  The contents of any lookup tables for shading and
classification are also stored.
.PP
The function used to write data to the files can be set by calling
\fBvpSetCallback\fR with the VP_WRITE_FUNC option.  This could be used
to implement a file-compression system, for example.
.SH "STATE VARIABLES"
The current file I/O parameters can be retrieved with the following
state variable codes (see vpGeti(3)): VP_WRITE_FUNC.
.SH ERRORS
The normal return value is VP_OK.  The following error return values
are possible:
.IP VPERROR_IO
The file writing function returned an error value (in which case the
external variable \fBerrno\fR should contain an operating-system
specific error code), or the file system is full.
.IP VPERROR_BAD_VOLUME
The volume dimensions are invalid, or there is no voxel data in the
context.
.IP VPERROR_BAD_SIZE
There is no min-max octree in the volume (\fBvpStoreMinMaxOctree\fR only).
.IP VPERROR_BAD_VOXEL
The voxel fields in the rendering context have not been properly defined.
.SH SEE ALSO
VolPack(3), vpCreateContext(3), vpLoadRawVolume(3)