.\" 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 vpEnable 3 "" VolPack
.SH NAME
vpEnable \- enable or disable options
.SH SYNOPSIS
#include <volpack.h>
.sp
.FS vpResult
\fBvpEnable(\fIvpc, option, value\fB)\fR
.FA
vpContext *\fIvpc;\fR
.FA
int \fIoption;\fR
.FA
int \fIvalue;\fR
.FE
.SH ARGUMENTS
.IP \fIvpc\fR
VolPack context from \fBvpCreateContext.\fR
.IP \fIoption\fR
Constant that specifies the option to be adjusted.
.IP \fIvalue\fR
New value for the option (boolean: 0 or 1).
.SH DESCRIPTION
\fBvpEnable\fR is used to enable or disable boolean options in a rendering
context.  If the \fIvalue\fR option is 0 then the option is disabled;
otherwise it is enabled.  The following list summarizes all available
options:
.IP VP_LIGHT0
.PD 0
.IP VP_LIGHT1
.IP VP_LIGHT2
.IP VP_LIGHT3
.IP VP_LIGHT4
.IP VP_LIGHT5
Enable the corresponding light source (see vpSetLight(3)).
Default: VP_LIGHT0 is enabled, and all others are disabled.
.PD
.IP VP_LIGHT_BOTH_SIDES
Enable two-sided lighting (see vpSetLight(3)).
Default: disabled
.IP VP_REVERSE_SURFACE_SIDES
Reverse the definition of interior and exterior surfaces (see
vpSetMaterial(3)).
Default: disabled
.IP VP_DEPTH_CUE
Enable depth cueing (see vpSetDepthCueing(3)).
Default: disabled
.IP VP_VIEW_X_AXIS
.PD 0
.IP VP_VIEW_Y_AXIS
.IP VP_VIEW_Z_AXIS
Enable computing a preclassified volume for the corresponding major
viewing axis (see vpClassifyVolume(3)).
Default: enabled
.PD
.IP VP_SHADOW
Enable rendering shadows (see vpSetShadowLookupShader(3)).
Default: disabled
.IP VP_CLAMP_SHADE_TABLE
Enable clamping the color components in a shade table to the range
0.0-255.0.  This option affects vpShadeTable().  Default: enabled
.SH ERRORS
The normal return value is VP_OK.  The following error return value is
possible:
.IP VPERROR_BAD_VALUE
The \fIoption\fR argument is invalid.
.SH SEE ALSO
VolPack(3), vpCreateContext(3)