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/*
*
* Copyright (C) 2000 Silicon Graphics, Inc. All Rights Reserved.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* Further, this software is distributed without any warranty that it is
* free of the rightful claim of any third person regarding infringement
* or the like. Any license provided herein, whether implied or
* otherwise, applies only to this software file. Patent licenses, if
* any, provided herein do not apply to combinations of this program with
* other software, or any other product whatsoever.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* Contact information: Silicon Graphics, Inc., 1600 Amphitheatre Pkwy,
* Mountain View, CA 94043, or:
*
* http://www.sgi.com
*
* For further information regarding this notice, see:
*
* http://oss.sgi.com/projects/GenInfo/NoticeExplan/
*
*/
// -*- C++ -*-
/*
* Copyright (C) 1990,91 Silicon Graphics, Inc.
*
_______________________________________________________________________
______________ S I L I C O N G R A P H I C S I N C . ____________
|
| $Revision: 1.1.1.1 $
|
| Description:
| This file defines the SoGLLightIdElement class.
|
| Author(s) : Paul S. Strauss
|
______________ S I L I C O N G R A P H I C S I N C . ____________
_______________________________________________________________________
*/
#ifndef _SO_GL_LIGHT_ID_ELEMENT
#define _SO_GL_LIGHT_ID_ELEMENT
#include <Inventor/elements/SoInt32Element.h>
//////////////////////////////////////////////////////////////////////////////
//
// Class: SoGLLightIdElement
//
// Element that stores the id of the current light. The first light
// active in a scene has id 0, the next has 1, and so on. This
// element can be used to determine how many lights are currently
// active. The initial value of this element is -1 to indicate that
// there are no lights active.
//
// Note that even though the effects of this element accumulate (each
// light source increments the id), it is derived from
// SoInt32Element. This is because each call to increment()
// effectively does a "get" of the current top instance, so caching
// knows about the dependency of each instance on the previous one.
//
//////////////////////////////////////////////////////////////////////////////
SoEXTENDER class SoGLLightIdElement : public SoInt32Element {
SO_ELEMENT_HEADER(SoGLLightIdElement);
public:
// Initializes element
virtual void init(SoState *state);
// Increments the current light id. This should be called when a
// light source becomes active. This returns the new id, or -1 if
// the maximum number of GL light sources has been exceeded.
// Otherwise, enables light source.
static int increment(SoState *state);
#ifndef IV_STRICT
static int increment(SoState *state, SoNode *)
{ return increment(state); }
#endif
// Returns current light id from the state
static int get(SoState *state)
{ return (int)SoInt32Element::get(classStackIndex, state); }
// Returns the default light id
static int getDefault() { return -1; }
// Returns the maximum number of concurrent light sources
// supported by GL implementation
static int getMaxGLSources();
// Overrides push() method to copy values from next instance in the stack
virtual void push(SoState *state);
// Override pop() method so side effects can occur in GL
virtual void pop(SoState *state, const SoElement *prevTopElement);
// Prints element (for debugging)
virtual void print(FILE *fp) const;
SoINTERNAL public:
// Initializes the SoGLLightIdElement class
static void initClass();
protected:
virtual ~SoGLLightIdElement();
private:
static int maxGLSources; // Holds max number of GL sources
};
#endif /* _SO_GL_LIGHT_ID_ELEMENT */
|
