Java 如何使用线程实现轻松功能
我试图找到一种高效、正常或简单的方法来在java程序中实现easing函数。我得到了缓解功能,但我觉得有一个更有效的方法来实现它;一个我看不见的,可能是因为隧道视觉。这是我的密码;有人能告诉我应该做些什么,或者给我指出我需要去研究的方向吗Java 如何使用线程实现轻松功能,java,eclipse,Java,Eclipse,我试图找到一种高效、正常或简单的方法来在java程序中实现easing函数。我得到了缓解功能,但我觉得有一个更有效的方法来实现它;一个我看不见的,可能是因为隧道视觉。这是我的密码;有人能告诉我应该做些什么,或者给我指出我需要去研究的方向吗 public class slide extends JPanel implements Runnable { Thread ease = new Thread(this); float total = 0; float dur;
public class slide extends JPanel implements Runnable {
Thread ease = new Thread(this);
float total = 0;
float dur;
slide() {
ease.start();
setLayout(null);
}
public float calc(float t, float b, float c, float d) {
return c * t / d + b;
}
public void run() {
while (true) {
try {
if (total < 50) {
total += 1;
} else {
ease.stop();
}
setBounds(400, Math.round(200 * total / 50 + 0), 250, 150);
repaint();
System.out.println(total + " " + dur);
ease.sleep(10);
} catch (Exception e) {
}
}
}
}
公共类幻灯片扩展JPanel实现可运行{
螺纹松动=新螺纹(此);
浮动总数=0;
浮动dur;
幻灯片(){
ease.start();
setLayout(空);
}
公共浮动计算(浮动t、浮动b、浮动c、浮动d){
返回c*t/d+b;
}
公开募捐{
while(true){
试一试{
如果(总数<50){
总数+=1;
}否则{
放松。停止();
}
挫折(400,数学四舍五入(200*total/50+0)、250、150);
重新油漆();
系统输出打印项次(总计+“”+dur);
放松睡眠(10);
}捕获(例外e){
}
}
}
}
我试着为我在网上找到的线性缓和函数实现calc()方法,但实际上毫无用处,因为我被迫将方程直接插入到中,否则无法使其工作。好吧,因此动画是一个相当复杂和深入的主题,我不打算在这里介绍,它还涉及到很多我不太懂的数学,所以我们不会深入到大量的细节,有比我更好的人可以解释它,你可以在网上阅读 首先,我们做一些假设 动画是随时间的变化,其中时间是可变的。地役权是(在本例中)速度随时间的变化。这意味着动画的速度在任何给定的时间点都是可变的 基本上,我们要做的是“正常化”一切。也就是说,在动画开始时,时间为0,在动画结束时,时间为1,介于这两个值之间的所有其他值都是这两个值之间的分数 如果你能这样想,事情就容易多了。因此,根据时间轴上的给定点,您可以决定应该做什么。例如,在50%的时间里,你应该处于起点和终点之间的一半 好吧,但这些对我们有什么帮助?如果我们要绘制一个易入易出动画,它看起来会像
SplineInterpolator si = new SplineInterpolator(1, 0, 0, 1);
for (double t = 0; t <= 1; t += 0.1) {
System.out.println(si.interpolate(t));
}
0.0
0.011111693284790492
0.057295031944523504
0.16510933001160544
0.3208510585798438
0.4852971690762217
0.6499037832761319
0.8090819765428142
0.9286158775101805
0.9839043020410436
0.999702
其中,x轴为时间,y轴为速度(在两个轴上都在0和1之间)。所以,在x(时间)上的任意给定点,我们应该能够计算速度
现在,我们可以使用一些Bézier脊椎/曲线的数学来计算物体在时间轴上给定点的速度
现在,我直接从计时框架中借用了大部分代码,但是如果您真的感兴趣,还可以查看
(注意:我确实写了这样的东西,然后两天后,发现计时框架已经实现了……这是一个有趣的练习……)
现在,关于这个实现需要注意的是,它实际上不会返回对象的速度,但它会返回沿时间轴(0-1)的时间进度,好吧,听起来很奇怪,但它允许您计算起点和终点之间的当前位置(startValue+((endValue-startValue)*进度))
沿时间线
我不想详细讨论这个问题,因为我真的不懂数学,我只知道如何应用它,但基本上,我们计算曲线上的点(x/y),然后对这些值(0-1)进行规格化,以便于查找
interpolate
方法使用二进制搜索来查找给定时间段内最近的匹配点,然后计算该点的速度/y位置
public class SplineInterpolator {
private final double points[];
private final List<PointUnit> normalisedCurve;
public SplineInterpolator(double x1, double y1, double x2, double y2) {
points = new double[]{ x1, y1, x2, y2 };
final List<Double> baseLengths = new ArrayList<>();
double prevX = 0;
double prevY = 0;
double cumulativeLength = 0;
for (double t = 0; t <= 1; t += 0.01) {
Point2D xy = getXY(t);
double length = cumulativeLength
+ Math.sqrt((xy.getX() - prevX) * (xy.getX() - prevX)
+ (xy.getY() - prevY) * (xy.getY() - prevY));
baseLengths.add(length);
cumulativeLength = length;
prevX = xy.getX();
prevY = xy.getY();
}
normalisedCurve = new ArrayList<>(baseLengths.size());
int index = 0;
for (double t = 0; t <= 1; t += 0.01) {
double length = baseLengths.get(index++);
double normalLength = length / cumulativeLength;
normalisedCurve.add(new PointUnit(t, normalLength));
}
}
public double interpolate(double fraction) {
int low = 1;
int high = normalisedCurve.size() - 1;
int mid = 0;
while (low <= high) {
mid = (low + high) / 2;
if (fraction > normalisedCurve.get(mid).getPoint()) {
low = mid + 1;
} else if (mid > 0 && fraction < normalisedCurve.get(mid - 1).getPoint()) {
high = mid - 1;
} else {
break;
}
}
/*
* The answer lies between the "mid" item and its predecessor.
*/
final PointUnit prevItem = normalisedCurve.get(mid - 1);
final double prevFraction = prevItem.getPoint();
final double prevT = prevItem.getDistance();
final PointUnit item = normalisedCurve.get(mid);
final double proportion = (fraction - prevFraction) / (item.getPoint() - prevFraction);
final double interpolatedT = prevT + (proportion * (item.getDistance() - prevT));
return getY(interpolatedT);
}
protected Point2D getXY(double t) {
final double invT = 1 - t;
final double b1 = 3 * t * invT * invT;
final double b2 = 3 * t * t * invT;
final double b3 = t * t * t;
final Point2D xy = new Point2D.Double((b1 * points[0]) + (b2 * points[2]) + b3, (b1 * points[1]) + (b2 * points[3]) + b3);
return xy;
}
protected double getY(double t) {
final double invT = 1 - t;
final double b1 = 3 * t * invT * invT;
final double b2 = 3 * t * t * invT;
final double b3 = t * t * t;
return (b1 * points[2]) + (b2 * points[3]) + b3;
}
public class PointUnit {
private final double distance;
private final double point;
public PointUnit(double distance, double point) {
this.distance = distance;
this.point = point;
}
public double getDistance() {
return distance;
}
public double getPoint() {
return point;
}
}
}
好吧,现在你可能会想,“等一下,这是一个线性过程!”,但事实并非如此,如果你画出它,你会发现前三个值和后三个值非常接近,其他值以不同的程度分布,这是我们的“进展”值,我们应该沿着时间线走多远
所以现在,你的头应该要爆炸了(我的是)-这就是为什么我说,使用一个框架
但你会如何使用它?!这是有趣的部分,现在记住,一切都是可变的,动画的持续时间,对象随时间的速度,滴答声或更新的数量,都是可变的
这一点很重要,因为这就是这样的功能所在!例如,如果动画由于某些外部因素而暂停,此实现可以简单地跳过这些“帧”这听起来可能是件坏事,但相信我,这一切都是为了愚弄人们的眼睛,让他们“思考”某些事情正在发生变化;)
(以下是8fps,所以非常糟糕)
瞧,我们有一个轻松进出的动画
现在,开始使用动画框架!只是简单多了:P
- 对于“快进/慢出”,您可以使用
0,0,1,1
- 对于“慢进/快出”,您可以使用
0,1,0,0
- 对于“慢入”,您可以使用
1,0,1,1
- 对于“慢出”,您可以使用
0,0,0,1
实验,看看你得到了什么好的,所以动画是一个相当复杂和深入的主题,我不打算在这里讨论,它还涉及很多数学,我不太懂,所以我们不会深入到大量的细节,有比我更好的人可以解释它,你可以在网上看到 首先,我们做一些假设<
import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.geom.Point2D;
import java.util.ArrayList;
import java.util.List;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.Timer;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class Test {
public static void main(String[] args) {
new Test();
}
public Test() {
EventQueue.invokeLater(new Runnable() {
@Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
ex.printStackTrace();
}
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(new TestPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class TestPane extends JPanel {
private int startAt = 0;
private int endAt;
private int x = startAt;
private Timer timer;
private SplineInterpolator splineInterpolator;
private long startTime = -1;
private long playTime = 5000; // 5 seconds
public TestPane() {
splineInterpolator = new SplineInterpolator(1, 0, 0, 1);
timer = new Timer(5, new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
if (startTime < 0) {
startTime = System.currentTimeMillis();
}
long now = System.currentTimeMillis();
long duration = now - startTime;
double t = (double) duration / (double) playTime;
if (duration >= playTime) {
t = 1;
}
double progress = splineInterpolator.interpolate(t);
x = startAt + ((int) Math.round((endAt - startAt) * progress));
repaint();
}
});
timer.setInitialDelay(0);
addMouseListener(new MouseAdapter() {
@Override
public void mouseClicked(MouseEvent e) {
if (!timer.isRunning()) {
startTime = -1;
startAt = 0;
endAt = getWidth() - 10;
timer.start();
}
}
});
}
@Override
public Dimension getPreferredSize() {
return new Dimension(200, 200);
}
@Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g.create();
g2d.setColor(Color.RED);
g2d.fillRect(x, (getHeight() / 2) - 5, 10, 10);
g2d.dispose();
}
}
public static class SplineInterpolator {
private final double points[];
private final List<PointUnit> normalisedCurve;
public SplineInterpolator(double x1, double y1, double x2, double y2) {
points = new double[]{x1, y1, x2, y2};
final List<Double> baseLengths = new ArrayList<>();
double prevX = 0;
double prevY = 0;
double cumulativeLength = 0;
for (double t = 0; t <= 1; t += 0.01) {
Point2D xy = getXY(t);
double length = cumulativeLength
+ Math.sqrt((xy.getX() - prevX) * (xy.getX() - prevX)
+ (xy.getY() - prevY) * (xy.getY() - prevY));
baseLengths.add(length);
cumulativeLength = length;
prevX = xy.getX();
prevY = xy.getY();
}
normalisedCurve = new ArrayList<>(baseLengths.size());
int index = 0;
for (double t = 0; t <= 1; t += 0.01) {
double length = baseLengths.get(index++);
double normalLength = length / cumulativeLength;
normalisedCurve.add(new PointUnit(t, normalLength));
}
}
public double interpolate(double fraction) {
int low = 1;
int high = normalisedCurve.size() - 1;
int mid = 0;
while (low <= high) {
mid = (low + high) / 2;
if (fraction > normalisedCurve.get(mid).getPoint()) {
low = mid + 1;
} else if (mid > 0 && fraction < normalisedCurve.get(mid - 1).getPoint()) {
high = mid - 1;
} else {
break;
}
}
/*
* The answer lies between the "mid" item and its predecessor.
*/
final PointUnit prevItem = normalisedCurve.get(mid - 1);
final double prevFraction = prevItem.getPoint();
final double prevT = prevItem.getDistance();
final PointUnit item = normalisedCurve.get(mid);
final double proportion = (fraction - prevFraction) / (item.getPoint() - prevFraction);
final double interpolatedT = prevT + (proportion * (item.getDistance() - prevT));
return getY(interpolatedT);
}
protected Point2D getXY(double t) {
final double invT = 1 - t;
final double b1 = 3 * t * invT * invT;
final double b2 = 3 * t * t * invT;
final double b3 = t * t * t;
final Point2D xy = new Point2D.Double((b1 * points[0]) + (b2 * points[2]) + b3, (b1 * points[1]) + (b2 * points[3]) + b3);
return xy;
}
protected double getY(double t) {
final double invT = 1 - t;
final double b1 = 3 * t * invT * invT;
final double b2 = 3 * t * t * invT;
final double b3 = t * t * t;
return (b1 * points[2]) + (b2 * points[3]) + b3;
}
public class PointUnit {
private final double distance;
private final double point;
public PointUnit(double distance, double point) {
this.distance = distance;
this.point = point;
}
public double getDistance() {
return distance;
}
public double getPoint() {
return point;
}
}
}
}
if (startTime < 0) {
startTime = System.currentTimeMillis();
}
long now = System.currentTimeMillis();
long duration = now - startTime;
double t = (double) duration / (double) playTime;
if (duration >= playTime) {
t = 1;
}
double progress = splineInterpolator.interpolate(t);
x = startAt + ((int) Math.round((endAt - startAt) * progress));
repaint();