我的问题:给定 x 和 y,我需要计算所需的操纵杆偏转的 x 和 y。
当没有操纵杆死区时,这很简单——我只使用 x 和 y 而不进行任何操作。
当存在死区时,我希望 x=0 为零,而 x=non-zero 是死区外该方向上的第一个值。
方形死区很简单。在下面的代码中,x 和 y 是从 -1 到 1(含)。死区是从 0 到 1(含)。
float xDeflection = 0;
if (x > 0)
xDeflection = (1 - deadzone) * x + deadzone;
else if (x < 0)
xDeflection = (1 - deadzone) * x - deadzone;
float yDeflection = 0;
if (y > 0)
yDeflection = (1 - deadzone) * y + deadzone;
else if (y < 0)
yDeflection = (1 - deadzone) * y - deadzone;
圆形死区更棘手。经过大量的鬼混之后,我想出了这个:
float xDeflection = 0, yDeflection = 0;
if (x != 0 || y != 0) {
float distRange = 1 - deadzone;
float dist = distRange * (float)Math.sqrt(x * x + y * y) + deadzone;
double angle = Math.atan2(x, y);
xDeflection = dist * (float)Math.sin(angle);
yDeflection = dist * (float)Math.cos(angle);
}
以下是极端情况下操纵杆偏转的输出(死区 = 0.25):
Non-square joystick deflection. http://n4te.com/temp/nonsquare.gif
如您所见,偏转不会延伸到角落。即,如果 x=1,y=1,那么 xDeflection 和 yDeflection 都等于 0.918。死区越大,问题就越严重,使上图中的绿线看起来越来越像一个圆圈。在死区=1 时,绿线是一个与死区匹配的圆圈。
我发现只要稍作改动,我就可以放大由绿线和剪裁值表示的形状,超出 -1 到 1:
if (x != 0 || y != 0) {
float distRange = 1 - 0.71f * deadzone;
float dist = distRange * (float)Math.sqrt(x * x + y * y) + deadzone;
double angle = Math.atan2(x, y);
xDeflection = dist * (float)Math.sin(angle);
xDeflection = Math.min(1, Math.max(-1, xDeflection));
yDeflection = dist * (float)Math.cos(angle);
yDeflection = Math.min(1, Math.max(-1, yDeflection));
}
我通过反复试验得出了常数 0.71。这个数字使形状足够大,角在实际角的几个小数位内。出于学术原因,谁能解释为什么 0.71 恰好是这样做的数字?
总的来说,我不确定我是否采取了正确的方法。有没有更好的方法来完成我对圆形死区的需求?
我编写了一个简单的基于 Swing 的程序来可视化正在发生的事情:
import java.awt.BorderLayout;
import java.awt.CardLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.Hashtable;
import javax.swing.DefaultComboBoxModel;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JSlider;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;
public class DeadzoneTest extends JFrame {
float xState, yState;
float deadzone = 0.3f;
int size = (int)(255 * deadzone);
public DeadzoneTest () {
super("DeadzoneTest");
setDefaultCloseOperation(DISPOSE_ON_CLOSE);
final CardLayout cardLayout = new CardLayout();
final JPanel centerPanel = new JPanel(cardLayout);
getContentPane().add(centerPanel, BorderLayout.CENTER);
centerPanel.setPreferredSize(new Dimension(512, 512));
Hashtable labels = new Hashtable();
labels.put(-255, new JLabel("-1"));
labels.put(-128, new JLabel("-0.5"));
labels.put(0, new JLabel("0"));
labels.put(128, new JLabel("0.5"));
labels.put(255, new JLabel("1"));
final JSlider ySlider = new JSlider(JSlider.VERTICAL, -256, 256, 0);
getContentPane().add(ySlider, BorderLayout.EAST);
ySlider.setInverted(true);
ySlider.setLabelTable(labels);
ySlider.setPaintLabels(true);
ySlider.setMajorTickSpacing(32);
ySlider.setSnapToTicks(true);
ySlider.addChangeListener(new ChangeListener() {
public void stateChanged (ChangeEvent event) {
yState = ySlider.getValue() / 255f;
centerPanel.repaint();
}
});
final JSlider xSlider = new JSlider(JSlider.HORIZONTAL, -256, 256, 0);
getContentPane().add(xSlider, BorderLayout.SOUTH);
xSlider.setLabelTable(labels);
xSlider.setPaintLabels(true);
xSlider.setMajorTickSpacing(32);
xSlider.setSnapToTicks(true);
xSlider.addChangeListener(new ChangeListener() {
public void stateChanged (ChangeEvent event) {
xState = xSlider.getValue() / 255f;
centerPanel.repaint();
}
});
final JSlider deadzoneSlider = new JSlider(JSlider.VERTICAL, 0, 100, 33);
getContentPane().add(deadzoneSlider, BorderLayout.WEST);
deadzoneSlider.setInverted(true);
deadzoneSlider.createStandardLabels(25);
deadzoneSlider.setPaintLabels(true);
deadzoneSlider.setMajorTickSpacing(25);
deadzoneSlider.setSnapToTicks(true);
deadzoneSlider.addChangeListener(new ChangeListener() {
public void stateChanged (ChangeEvent event) {
deadzone = deadzoneSlider.getValue() / 100f;
size = (int)(255 * deadzone);
centerPanel.repaint();
}
});
final JComboBox combo = new JComboBox();
combo.setModel(new DefaultComboBoxModel(new Object[] {"round", "square"}));
getContentPane().add(combo, BorderLayout.NORTH);
combo.addActionListener(new ActionListener() {
public void actionPerformed (ActionEvent event) {
cardLayout.show(centerPanel, (String)combo.getSelectedItem());
}
});
centerPanel.add(new Panel() {
public void toDeflection (Graphics g, float x, float y) {
g.drawRect(256 - size, 256 - size, size * 2, size * 2);
float xDeflection = 0;
if (x > 0)
xDeflection = (1 - deadzone) * x + deadzone;
else if (x < 0) {
xDeflection = (1 - deadzone) * x - deadzone;
}
float yDeflection = 0;
if (y > 0)
yDeflection = (1 - deadzone) * y + deadzone;
else if (y < 0) {
yDeflection = (1 - deadzone) * y - deadzone;
}
draw(g, xDeflection, yDeflection);
}
}, "square");
centerPanel.add(new Panel() {
public void toDeflection (Graphics g, float x, float y) {
g.drawOval(256 - size, 256 - size, size * 2, size * 2);
float xDeflection = 0, yDeflection = 0;
if (x != 0 || y != 0) {
float distRange = 1 - 0.71f * deadzone;
float dist = distRange * (float)Math.sqrt(x * x + y * y) + deadzone;
double angle = Math.atan2(x, y);
xDeflection = dist * (float)Math.sin(angle);
xDeflection = Math.min(1, Math.max(-1, xDeflection));
yDeflection = dist * (float)Math.cos(angle);
yDeflection = Math.min(1, Math.max(-1, yDeflection));
}
draw(g, xDeflection, yDeflection);
}
}, "round");
cardLayout.show(centerPanel, (String)combo.getSelectedItem());
pack();
setLocationRelativeTo(null);
setVisible(true);
}
private abstract class Panel extends JPanel {
public void paintComponent (Graphics g) {
g.setColor(Color.gray);
g.fillRect(0, 0, getWidth(), getHeight());
g.setColor(Color.white);
g.fillRect(0, 0, 512, 512);
g.setColor(Color.green);
if (true) {
// Draws all edge points.
for (int i = -255; i < 256; i++)
toDeflection(g, i / 255f, 1);
for (int i = -255; i < 256; i++)
toDeflection(g, i / 255f, -1);
for (int i = -255; i < 256; i++)
toDeflection(g, 1, i / 255f);
for (int i = -255; i < 256; i++)
toDeflection(g, -1, i / 255f);
} else if (false) {
// Draws all possible points (slow).
for (int x = -255; x < 256; x++)
for (int y = -255; y < 256; y++)
toDeflection(g, x / 255f, y / 255f);
}
g.setColor(Color.red);
toDeflection(g, xState, yState);
}
abstract public void toDeflection (Graphics g, float x, float y);
public void draw (Graphics g, float xDeflection, float yDeflection) {
int r = 5, d = r * 2;
g.fillRect((int)(xDeflection * 256) + 256 - r, (int)(yDeflection * 256) + 256 - r, d, d);
}
}
public static void main (String[] args) {
new DeadzoneTest();
}
}
最佳答案
这是我拼凑的。它的行为有点奇怪,但在边界上它很好:
private Point2D.Float calculateDeflection(float x, float y) {
Point2D.Float center = new Point2D.Float(0, 0);
Point2D.Float joyPoint = new Point2D.Float(x, y);
Double angleRad = Math.atan2(y, x);
float maxDist = getMaxDist(joyPoint);
float factor = (maxDist - deadzone) / maxDist;
Point2D.Float factoredPoint = new Point2D.Float(x * factor, y * factor);
float factoredDist = (float) center.distance(factoredPoint);
float finalDist = factoredDist + deadzone;
float finalX = finalDist * (float) Math.cos(angleRad);
float finalY = finalDist * (float) Math.sin(angleRad);
Point2D.Float finalPoint = new Point2D.Float(finalX, finalY);
return finalPoint;
}
编辑:错过了这个。
private float getMaxDist(Point2D.Float point) {
float xMax;
float yMax;
if (Math.abs(point.x) > Math.abs(point.y)) {
xMax = Math.signum(point.x);
yMax = point.y * point.x / xMax;
} else {
yMax = Math.signum(point.y);
xMax = point.x * point.y / yMax;
}
Point2D.Float maxPoint = new Point2D.Float(xMax, yMax);
Point2D.Float center = new Point2D.Float(0, 0);
return (float) center.distance(maxPoint);
}
它保留了角度,但将距离从 0 和边界之间的某处缩放到死区和边界之间。最大距离是变化的,因为它在边上是 1,在角落里是 sqrt(2),所以必须相应地改变缩放比例。