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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 SoState 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_STATE_
#define _SO_STATE_
//////////////////////////////////////////////////////////////////////////////
//
// Class: SoState
//
// An SoState collects and holds state while traversing a scene
// graph. A state is composed of a variety of elements, each of which
// holds some specific information, such as coordinates or diffuse
// color of the surface material.
//
// Each element is stored in its own stack so that save and restore
// can be implemented as push and pop. These stack operations are
// performed lazily, so that pushing of a value occurs only when the
// value would be overwritten, for efficiency.
//
//////////////////////////////////////////////////////////////////////////////
#define SO_STATE_GET_CONST_ELEMENT(stackIndex)\
return stack[stackIndex];
#include <Inventor/SoLists.h>
class SoAction;
class SoElement;
SoEXTENDER class SoState {
public:
// Constructor. Takes pointer to action instance this state is
// part of and a list of type-ids of elements that are enabled.
SoState(SoAction *action, const SoTypeList &enabledElements);
// Destructor
~SoState();
// Returns the action instance the state is part of
SoAction * getAction() const { return action; }
// Returns a writable instance of the element on the top of the
// stack with the given index.
SoElement * getElement(int stackIndex);
// Returns the top (read-only) instance of the given element stack
const SoElement * getConstElement(int stackIndex) const
{ return stack[stackIndex]; }
// Pushes (saves) the current state until a pop() restores it. The
// push is done lazily: this just increments the depth in the
// state. When an element is accessed with getElement() and its
// depth is less than the current depth, it is then pushed
// individually.
void push()
{ depth++; }
// Pops the state, restoring the state to just before the last push().
void pop();
// Prints state to file (for debugging)
void print(FILE *fp);
SoINTERNAL public:
// Returns TRUE if element with given stack index is enabled in state
SbBool isElementEnabled(int stackIndex) const
{ return (stack[stackIndex] != NULL); }
// Returns current depth of state
int getDepth() const { return depth; }
// Sets/returns flag that indicates whether a cache is open. This
// flag lets us optimize element capturing; we don't need to try
// to capture elements if the flag is FALSE.
void setCacheOpen(SbBool flag) { cacheOpen = flag; }
SbBool isCacheOpen() const { return cacheOpen; }
// Internal-only, dangerous method that returns a writeable
// element without checking for state depth and doing a push.
// Be very careful and consider the caching implications before
// using this method!
SoElement * getElementNoPush(int stackIndex) const
{ return stack[stackIndex]; }
private:
SoAction *action; // Action instance state is in
int depth; // Current depth
SoElement **stack; // Array of element stacks
int numStacks; // Number of stacks in array
SoElement * topElement; // First element in threaded stack
SbBool cacheOpen; // TRUE if a cache is open
};
#endif /* _SO_STATE_ */
|
