I need yo draw a shape as attached in the image using Java graphics. I am struggling with the curve part. The curve part is a arc of an circle whose radius and center is known. But I have to paint the region out side of that arc. How will I do that? I was looking at Path2D.Float() and there is a guadTo function. It says it needs a control point to draw that quadratic curve. Can anybody help me understanding what this control point means. I know how to draw that arc using drawArc method but how to paint outside the arc is what I what I want to know
mKorbel 274 Veteran Poster
import java.awt.AlphaComposite;
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Component;
import java.awt.EventQueue;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.RenderingHints;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyEvent;
import java.awt.geom.Ellipse2D;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.io.InputStream;
import java.util.Properties;
import javax.swing.BorderFactory;
import javax.swing.BoxLayout;
import javax.swing.ButtonGroup;
import javax.swing.Icon;
import javax.swing.JButton;
import javax.swing.JColorChooser;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JRadioButton;
import javax.swing.JSpinner;
import javax.swing.JTextArea;
import javax.swing.SpinnerNumberModel;
import javax.swing.border.Border;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;
/**
* @see <a href="http://keithp.com/~keithp/porterduff/p253-porter.pdf">Porter-Duff</a>
* @see <a href="http://www.ibm.com/developerworks/java/library/j-mer0918/">Zukowski</a>
* @author John B. Matthews
*/
public class AlphaCompositeDemo extends JPanel {
private static final Rule defaultRule = Rule.Xor;
private static final String form = "0.00";
private static final Border border = BorderFactory.createEmptyBorder(4, 16, 4, 16);
private static final long serialVersionUID = 1L;
private AlphaView view;
private JSpinner srcSpin, dstSpin;
private JComboBox rules;
private final JTextArea text;
public AlphaCompositeDemo() {
super(true);
this.setLayout(new BorderLayout());
System.out.println(this.isOpaque());
JLabel titleLabel = new JLabel("AlphaComposite");
titleLabel.setHorizontalAlignment(JLabel.CENTER);
titleLabel.setFont(new Font("SansSerif", Font.BOLD, 24));
this.add(titleLabel, BorderLayout.NORTH);
view = new AlphaView();
view.setBorder(border);
this.add(view, BorderLayout.CENTER);
rules = new JComboBox();
for (Rule rule : Rule.values()) {
rules.addItem(rule);
}
rules.setSelectedItem(defaultRule);
view.setRule(defaultRule);
rules.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
Rule rule = (Rule) rules.getSelectedItem();
view.setRule(rule);
text.setText(rule.getDescription());
}
});
srcSpin = new JSpinner();
srcSpin.setModel(new SpinnerNumberModel(1.0, 0, 1.0, 0.1));
srcSpin.setEditor(new JSpinner.NumberEditor(srcSpin, form));
srcSpin.addChangeListener(new ChangeListener() {
@Override
public void stateChanged(ChangeEvent e) {
Number n = (Number) srcSpin.getValue();
view.setSrcAlpha(n.floatValue());
}
});
dstSpin = new JSpinner();
dstSpin.setModel(new SpinnerNumberModel(1.0, 0, 1.0, 0.1));
dstSpin.setEditor(new JSpinner.NumberEditor(dstSpin, form));
dstSpin.addChangeListener(new ChangeListener() {
@Override
public void stateChanged(ChangeEvent e) {
Number n = (Number) dstSpin.getValue();
view.setDstAlpha(n.floatValue());
}
});
JRadioButton hexButton = new JRadioButton("Hex");
hexButton.setMnemonic(KeyEvent.VK_H);
hexButton.setSelected(true);
hexButton.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
view.setRadix(16);
}
});
JRadioButton decButton = new JRadioButton("Dec");
decButton.setMnemonic(KeyEvent.VK_D);
decButton.setSelected(false);
decButton.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
view.setRadix(10);
}
});
ButtonGroup group = new ButtonGroup();
group.add(hexButton);
group.add(decButton);
JButton srcColor = new JButton("SrcColor");
srcColor.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
Color newColor = JColorChooser.showDialog(AlphaCompositeDemo.this, "Choose Src Color", view.getSrcColor());
if (newColor != null) {
view.setSrcColor(newColor);
}
}
});
JButton dstColor = new JButton("DstColor");
dstColor.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
Color newColor = JColorChooser.showDialog(AlphaCompositeDemo.this, "Choose Src Color", view.getDstColor());
if (newColor != null) {
view.setDstColor(newColor);
}
}
});
text = new JTextArea(3, 36);
text.setEditable(false);
text.setLineWrap(true);
text.setWrapStyleWord(true);
text.setBorder(border);
text.setText(defaultRule.getDescription());
JPanel controlPanel = new JPanel();
controlPanel.add(new JLabel("Src \u03b1:", JLabel.RIGHT));
controlPanel.add(srcSpin);
controlPanel.add(new JLabel("Rule:", JLabel.RIGHT));
controlPanel.add(rules);
controlPanel.add(new JLabel("Dst \u03b1:", JLabel.RIGHT));
controlPanel.add(dstSpin);
JPanel colorPanel = new JPanel();
colorPanel.add(srcColor);
colorPanel.add(hexButton);
colorPanel.add(decButton);
colorPanel.add(dstColor);
JPanel southPanel = new JPanel();
southPanel.setLayout(new BoxLayout(southPanel, BoxLayout.Y_AXIS));
southPanel.add(controlPanel);
southPanel.add(colorPanel);
southPanel.add(text);
this.add(southPanel, BorderLayout.SOUTH);
}
public static void main(String arg[]) {
EventQueue.invokeLater(new Runnable() {
@Override
public void run() {
JFrame f = new JFrame();
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.add(new AlphaCompositeDemo());
f.pack();
f.setVisible(true);
}
});
}
}
enum Rule {
Clear(AlphaComposite.CLEAR),
Dst(AlphaComposite.DST),
DstAtop(AlphaComposite.DST_ATOP),
DstIn(AlphaComposite.DST_IN),
DstOut(AlphaComposite.DST_OUT),
DstOver(AlphaComposite.DST_OVER),
Src(AlphaComposite.SRC),
SrcAtop(AlphaComposite.SRC_ATOP),
SrcIn(AlphaComposite.SRC_IN),
SrcOut(AlphaComposite.SRC_OUT),
SrcOver(AlphaComposite.SRC_OVER),
Xor(AlphaComposite.XOR);
private static final Properties glossary = new Properties();
private final int code;
private Rule(int code) {
this.code = code;
}
public int getCode() {
return this.code;
}
public String getDescription() {
return glossary.getProperty(this.name(), this.name());
}
static {
String name = "src/rule.properties";
ClassLoader loader = Rule.class.getClassLoader();
InputStream in = loader.getResourceAsStream(name);
if (in != null) {
try {
glossary.load(in);
} catch (IOException e) {
System.err.println(e.toString());
}
}
}
}
class AlphaView extends JLabel implements Icon {
private static final long serialVersionUID = 1L;
private int WIDTH1 = 500;
private int HEIGHT1 = 250;
private float srcAlpha = 1f;
private float dstAlpha = 1f;
private Rule rule = Rule.Xor;
private BufferedImage src, dst;
private Graphics2D srcG, dstG;
private Color srcColor = Color.blue;
private Color dstColor = Color.red;
private Ellipse2D.Double srcE = new Ellipse2D.Double();
private Ellipse2D.Double dstE = new Ellipse2D.Double();
private Color hiliteColor = new Color(255, 255, 168);
private int[] ia = new int[4];
private int radix = 16;
AlphaView() {
this.setIcon(this);
this.setHorizontalAlignment(AlphaView.CENTER);
int w = 2 * WIDTH1 / 3;
int h = 2 * HEIGHT1 / 3;
srcE.setFrame(0, h / 4, w, h);
dstE.setFrame(w / 2, h / 4, w, h);
src = new BufferedImage(WIDTH1, HEIGHT1, BufferedImage.TYPE_INT_ARGB);
dst = new BufferedImage(WIDTH1, HEIGHT1, BufferedImage.TYPE_INT_ARGB);
}
@Override
public void paintIcon(Component c, Graphics g, int x, int y) {
if (srcG == null) {
srcG = src.createGraphics();
srcG.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
}
if (dstG == null) {
dstG = dst.createGraphics();
dstG.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
}
srcG.setComposite(AlphaComposite.Clear);
srcG.fillRect(0, 0, WIDTH1, HEIGHT1);
srcG.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC, srcAlpha));
srcG.setPaint(srcColor);
srcG.drawString("Src", 20, 20);
srcG.fill(srcE);
dstG.setComposite(AlphaComposite.Clear);
dstG.fillRect(0, 0, WIDTH1, HEIGHT1);
dstG.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC, dstAlpha));
dstG.setPaint(dstColor);
dstG.drawString("Dst", WIDTH1 - 40, 20);
dstG.fill(dstE);
dstG.setComposite(AlphaComposite.getInstance(rule.getCode()));
dstG.drawImage(src, 0, 0, null);
g.drawImage(dst, x, y, this);
//g.drawLine(x + WIDTH / 2, y, x + WIDTH / 2, y + HEIGHT);
//g.drawLine(x, y + HEIGHT / 2, x + WIDTH, y + HEIGHT / 2);
dst.getRaster().getPixel(WIDTH1 / 2, HEIGHT1 / 2, ia);
String s = format(ia);
int a = g.getFontMetrics().getAscent();
int w = g.getFontMetrics().stringWidth(s);
int h = g.getFontMetrics().getHeight();
int bx = x + WIDTH1 / 2 - w / 2;
int by = y + HEIGHT1 / 2 + a / 2;
g.setColor(hiliteColor);
g.fillRect(bx - 2, by - a, w + 3, h + 1);
g.setColor(Color.gray);
g.drawRect(bx - 2, by - a - 1, w + 3, h + 1);
g.setColor(Color.black);
g.drawString(s, bx, by);
}
private String format(int[] ia) {
StringBuilder sb = new StringBuilder();
int length = ia.length;
for (int i = 0; i < length; i++) {
sb.append(Integer.toString(ia[i], radix).toUpperCase());
if (i < length - 1) {
sb.append(',');
}
}
return sb.toString();
}
public void setSrcAlpha(float alpha) {
this.srcAlpha = alpha;
this.repaint();
}
public void setDstAlpha(float alpha) {
this.dstAlpha = alpha;
this.repaint();
}
public void setRule(Rule rule) {
this.rule = rule;
this.repaint();
}
public void setRadix(int radix) {
this.radix = radix;
this.repaint();
}
public Color getSrcColor() {
return srcColor;
}
public void setSrcColor(Color srcColor) {
this.srcColor = srcColor;
this.repaint();
}
public Color getDstColor() {
return dstColor;
}
public void setDstColor(Color dstColor) {
this.dstColor = dstColor;
this.repaint();
}
@Override
public int getIconWidth() {
return WIDTH1;
}
@Override
public int getIconHeight() {
return HEIGHT1;
}
} mKorbel 274 Veteran Poster
back to your previous thread (animations)
again check your methods with this good & simple example, then anything is just and about timing
- but I miss there repaint();
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.GridLayout;
import java.awt.Point;
import java.awt.Polygon;
import java.awt.RenderingHints;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.ArrayList;
import java.util.Random;
import javax.swing.AbstractAction;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
import javax.swing.Timer;
public class AnimationBackground {
public AnimationBackground() {
Random random = new Random();
JFrame frame = new JFrame("Animation Background");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setResizable(false);
final MyJPanel panel = new MyJPanel();
panel.setBackground(Color.BLACK);
for (int i = 0; i < 50; i++) {
Star star = new Star(new Point(random.nextInt(490), random.nextInt(490)));
star.setColor(new Color(100 + random.nextInt(155), 100 + random.nextInt(155), 100 + random.nextInt(155)));
star.setxIncr(-3 + random.nextInt(7));
star.setyIncr(-3 + random.nextInt(7));
panel.add(star);
}
panel.setLayout(new GridLayout(10, 1));
JLabel label = new JLabel("This is a Starry background.", JLabel.CENTER);
label.setForeground(Color.WHITE);
panel.add(label);
JPanel stopPanel = new JPanel();
stopPanel.setOpaque(false);
stopPanel.add(new JButton(new AbstractAction("Stop this madness!!") {
private static final long serialVersionUID = 1L;
@Override
public void actionPerformed(ActionEvent e) {
panel.stopAnimation();
}
}));
panel.add(stopPanel);
JPanel startPanel = new JPanel();
startPanel.setOpaque(false);
startPanel.add(new JButton(new AbstractAction("Start moving...") {
private static final long serialVersionUID = 1L;
@Override
public void actionPerformed(ActionEvent e) {
panel.startAnimation();
}
}));
panel.add(startPanel);
frame.add(panel);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
@Override
public void run() {
AnimationBackground animationBackground = new AnimationBackground();
}
});
}
class Star extends Polygon {
private static final long serialVersionUID = 1L;
private Point location = null;
private Color color = Color.YELLOW;
private int xIncr, yIncr;
static final int WIDTH = 500, HEIGHT = 500;
Star(Point location) {
int x = location.x;
int y = location.y;
this.location = location;
this.addPoint(x, y + 8);
this.addPoint(x + 8, y + 8);
this.addPoint(x + 11, y);
this.addPoint(x + 14, y + 8);
this.addPoint(x + 22, y + 8);
this.addPoint(x + 17, y + 12);
this.addPoint(x + 21, y + 20);
this.addPoint(x + 11, y + 14);
this.addPoint(x + 3, y + 20);
this.addPoint(x + 6, y + 12);
}
public void setColor(Color color) {
this.color = color;
}
public void move() {
if (location.x < 0 || location.x > WIDTH) {
xIncr = -xIncr;
}
if (location.y < 0 || location.y > WIDTH) {
yIncr = -yIncr;
}
translate(xIncr, yIncr);
location.setLocation(location.x + xIncr, location.y + yIncr);
}
public void setxIncr(int xIncr) {
this.xIncr = xIncr;
}
public void setyIncr(int yIncr) {
this.yIncr = yIncr;
}
public Color getColor() {
return color;
}
}
class MyJPanel extends JPanel {
private static final long serialVersionUID = 1L;
private ArrayList<Star> stars = new ArrayList<Star>();
private Timer timer = new Timer(20, new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
for (Star star : stars) {
star.move();
}
repaint();
}
});
public void stopAnimation() {
if (timer.isRunning()) {
timer.stop();
}
}
public void startAnimation() {
if (!timer.isRunning()) {
timer.start();
}
}
@Override
public void addNotify() {
super.addNotify();
timer.start();
}
@Override
public void removeNotify() {
super.removeNotify();
timer.stop();
}
MyJPanel() {
this.setPreferredSize(new Dimension(512, 512));
}
public void add(Star star) {
stars.add(star);
}
@Override
public void paintComponent(Graphics g) {
super.paintComponent(g);
((Graphics2D) g).setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
for (Star star : stars) {
g.setColor(star.getColor());
g.fillPolygon(star);
}
}
}
} gunjannigam 28 Junior Poster
Solved using Path2D and Arc2D
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