com.threerings.media.animation.SparkAnimation Maven / Gradle / Ivy
//
// Nenya library - tools for developing networked games
// Copyright (C) 2002-2012 Three Rings Design, Inc., All Rights Reserved
// https://github.com/threerings/nenya
//
// 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.
//
// 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
package com.threerings.media.animation;
import java.awt.AlphaComposite;
import java.awt.Composite;
import java.awt.Graphics2D;
import java.awt.Rectangle;
import java.awt.Shape;
import com.samskivert.util.RandomUtil;
import com.threerings.media.image.Mirage;
/**
* Displays a set of spark images originating from a specified position
* and flying outward in random directions, fading out as they go, for a
* specified period of time.
*/
public class SparkAnimation extends Animation
{
/**
* Constructs a spark animation with the supplied parameters.
*
* @param bounds the bounding rectangle for the animation.
* @param x the starting x-position for the sparks.
* @param y the starting y-position for the sparks.
* @param xjog the maximum X distance by which to "jog" the initial spark
* positions, or 0 if no jogging is desired.
* @param yjog the maximum Y distance by which to "jog" the initial spark
* positions, or 0 if no jogging is desired.
* @param minxvel the minimum starting x-velocity of the sparks.
* @param minyvel the minimum starting y-velocity of the sparks.
* @param maxxvel the maximum x-velocity of the sparks.
* @param maxyvel the maximum y-velocity of the sparks.
* @param xacc the x axis acceleration, or 0 if none is desired.
* @param yacc the y axis acceleration, or 0 if none is desired.
* @param images the spark images to be animated.
* @param delay the duration of the animation in milliseconds.
* @param fade do the fade thing
*/
public SparkAnimation (Rectangle bounds, int x, int y, int xjog, int yjog,
float minxvel, float minyvel,
float maxxvel, float maxyvel,
float xacc, float yacc,
Mirage[] images, long delay, boolean fade)
{
super(bounds);
// save things off
_xacc = xacc;
_yacc = yacc;
_images = images;
_delay = delay;
_fade = fade;
// initialize various things
_icount = images.length;
_ox = new int[_icount];
_oy = new int[_icount];
_xpos = new int[_icount];
_ypos = new int[_icount];
_sxvel = new float[_icount];
_syvel = new float[_icount];
for (int ii = 0; ii < _icount; ii++) {
// initialize spark position
_ox[ii] = x +
((xjog == 0) ? 0 : RandomUtil.getInt(xjog) * randomDirection());
_oy[ii] = y +
((yjog == 0) ? 0 : RandomUtil.getInt(yjog) * randomDirection());
// Choose random X and Y axis velocities between the inputted
// bounds
_sxvel[ii] = minxvel + RandomUtil.getFloat(1) * (maxxvel - minxvel);
_syvel[ii] = minyvel + RandomUtil.getFloat(1) * (maxyvel - minyvel);
// If accelerationes were given, make the starting velocities
// move against that acceleration; otherwise pick directions
// at random
if (_xacc > 0) {
_sxvel[ii] = -_sxvel[ii];
} else if (_xacc == 0) {
_sxvel[ii] *= randomDirection();
}
if (_yacc > 0) {
_syvel[ii] = -_syvel[ii];
} else if (_yacc == 0) {
_syvel[ii] *= randomDirection();
}
}
if (_fade) {
_alpha = 1.0f;
_comp = AlphaComposite.getInstance(AlphaComposite.SRC_OVER, _alpha);
}
}
/**
* Returns at random -1 for negative direction or +1 for positive.
*/
protected int randomDirection ()
{
return RandomUtil.getBoolean() ? -1 : 1;
}
@Override
protected void willStart (long stamp)
{
super.willStart(stamp);
_start = stamp;
}
@Override
public void fastForward (long timeDelta)
{
_start += timeDelta;
}
@Override
public void tick (long timestamp)
{
// figure out the distance the chunks have travelled
long msecs = Math.max(timestamp - _start, 0);
long msecsSq = msecs * msecs;
// calculate the alpha level with which to render the chunks
if (_fade) {
float pctdone = msecs / (float)_delay;
_alpha = Math.max(0.1f, Math.min(1.0f, 1.0f - pctdone));
_comp = AlphaComposite.getInstance(AlphaComposite.SRC_OVER, _alpha);
}
// assume all sparks have moved outside the bounds
boolean allOutside = true;
// move all sparks and check whether any remain to be animated
for (int ii = 0; ii < _icount; ii++) {
// determine the travel distance
int xtrav = (int)
((_sxvel[ii] * msecs) + (0.5f * _xacc * msecsSq));
int ytrav = (int)
((_syvel[ii] * msecs) + (0.5f * _yacc * msecsSq));
// update the position
_xpos[ii] = _ox[ii] + xtrav;
_ypos[ii] = _oy[ii] + ytrav;
// check to see if any are still in. Stop looking
// when we find one
if (allOutside && _bounds.intersects(_xpos[ii], _ypos[ii],
_images[ii].getWidth(), _images[ii].getHeight())) {
allOutside = false;
}
}
// note whether we're finished
_finished = allOutside || (msecs >= _delay);
// dirty ourselves
// TODO: only do this if at least one spark actually moved
invalidate();
}
@Override
public void paint (Graphics2D gfx)
{
Shape oclip = gfx.getClip();
gfx.clip(_bounds);
Composite ocomp = gfx.getComposite();
if (_fade) {
// set the alpha composite to reflect the current fade-out
gfx.setComposite(_comp);
}
// draw all sparks
for (int ii = 0; ii < _icount; ii++) {
_images[ii].paint(gfx, _xpos[ii], _ypos[ii]);
}
// restore the original gfx settings
gfx.setComposite(ocomp);
gfx.setClip(oclip);
}
@Override
protected void toString (StringBuilder buf)
{
super.toString(buf);
buf.append(", ox=").append(_ox);
buf.append(", oy=").append(_oy);
buf.append(", alpha=").append(_alpha);
}
/** The spark images we're animating. */
protected Mirage[] _images;
/** The number of images we're animating. */
protected int _icount;
/** The x axis acceleration in pixels per millisecond. */
protected float _xacc;
/** The y axis acceleration in pixels per millisecond. */
protected float _yacc;
/** The starting x-axis velocity of each chunk. */
protected float[] _sxvel;
/** The starting y-axis velocity of each chunk. */
protected float[] _syvel;
/** The starting 'jog' positions for each spark. */
protected int[] _ox, _oy;
/** The current positions of each spark. */
protected int[] _xpos, _ypos;
/** The starting animation time. */
protected long _start;
/** Whether or not we should fade the sparks out. */
protected boolean _fade;
/** The percent alpha with which to render the images. */
protected float _alpha;
/** The alpha composite with which to render the images. */
protected AlphaComposite _comp;
/** The duration of the spark animation in milliseconds. */
protected long _delay;
}
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