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/*
* Copyright 1997-2008 Sun Microsystems, Inc. All Rights Reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
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* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Sun designates this
* particular file as subject to the "Classpath" exception as provided
* by Sun in the LICENSE file that accompanied this code.
*
* This code 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 General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
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* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
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package javax.media.j3d;
/**
* Class specifying a wakeup when a specific number of frames have
* elapsed. The wakeup criterion can either be passive or
* non-passive. If any behavior uses a non-passive
* WakeupOnElapsedFrames, the rendering system will run continuously.
*
*
* In general, applications cannot count on behavior execution being
* synchronized with rendering. Behaviors that use
* WakeupOnElapsedFrames with a frame count of 0 are an exception to
* this general rule. Such behaviors will be executed every frame.
* Further, all modifications to scene graph objects (not including
* geometry by-reference or texture by-reference) made from the
* processStimulus methods of such behaviors are
* guaranteed to take effect in the same rendering frame.
*/
public final class WakeupOnElapsedFrames extends WakeupCriterion {
// different types of WakeupIndexedList that use in BehaviorStructure
static final int COND_IN_BS_LIST = 0;
// total number of different IndexedUnorderedSet types
static final int TOTAL_INDEXED_UNORDER_SET_TYPES = 1;
// Indicates whether the wakeup condition is passive or
// non-passive. Only behaviors using a non-passive
// WakeupOnElapsedFrames will force a continuous traversal.
boolean passive;
// Number of frames before wakeup
int frameCount;
// When this reaches 0, this criterion is met.
int countdown;
/**
* Constructs a non-passive WakeupOnElapsedFrames criterion.
*
* @param frameCount the number of frames that Java 3D should draw
* before awakening this behavior object; a value of N means
* wakeup at the end of frame N, where the current frame is zero,
* a value of zero means wakeup at the end of the current frame.
*
* @exception IllegalArgumentException if frameCount is less than zero
*/
public WakeupOnElapsedFrames(int frameCount) {
this(frameCount, false);
}
/**
* Constructs a WakeupOnElapsedFrames criterion.
*
* @param frameCount the number of frames that Java 3D should draw
* before awakening this behavior object; a value of N means
* wakeup at the end of frame N, where the current frame is zero,
* a value of zero means wakeup at the end of the current frame.
*
* @param passive flag indicating whether this behavior is
* passive; a non-passive behavior will cause the rendering system
* to run continuously, while a passive behavior will only run
* when some other event causes a frame to be run.
*
* @exception IllegalArgumentException if frameCount is less than zero
*
* @since Java 3D 1.2
*/
public WakeupOnElapsedFrames(int frameCount, boolean passive) {
if (frameCount < 0)
throw new IllegalArgumentException(J3dI18N.getString("WakeupOnElapsedFrames0"));
this.frameCount = frameCount;
this.passive = passive;
WakeupIndexedList.init(this, TOTAL_INDEXED_UNORDER_SET_TYPES);
}
/**
* Retrieves the elapsed frame count that was used when
* constructing this object.
*
* @return the elapsed frame count specified when constructing
* this object
*/
public int getElapsedFrameCount() {
return frameCount;
}
/**
* Retrieves the state of the passive flag that was used when
* constructing this object.
*
* @return true if this wakeup criterion is passive, false otherwise
*
* @since Java 3D 1.2
*/
public boolean isPassive() {
return passive;
}
/**
* decrement the frame count, and set trigger if 0
*/
void newFrame() {
if (this.countdown == 0) {
this.setTriggered();
} else {
this.countdown--;
}
}
/**
* This is a callback from BehaviorStructure. It is
* used to add wakeupCondition to behavior structure.
*/
@Override
void addBehaviorCondition(BehaviorStructure bs) {
this.countdown = this.frameCount;
bs.wakeupOnElapsedFrames.add(this);
if (!passive && (behav != null) && behav.enable) {
bs.activeWakeupOnFrameCount++;
}
// This is necessary to invoke this condition next time
// Otherwise jftc won't work for static scene.
VirtualUniverse.mc.sendRunMessage(bs.universe,
J3dThread.UPDATE_BEHAVIOR);
}
/**
* This is a callback from BehaviorStructure. It is
* used to remove wakeupCondition from behavior structure.
*/
@Override
void removeBehaviorCondition(BehaviorStructure bs) {
bs.wakeupOnElapsedFrames.remove(this);
if (!passive && (behav != null) && behav.enable) {
bs.activeWakeupOnFrameCount--;
}
}
/**
* Perform task in addBehaviorCondition() that has to be
* set every time the condition met.
*/
@Override
void resetBehaviorCondition(BehaviorStructure bs) {
this.countdown = this.frameCount;
}
}