Develop Reference

Measure pixel height of rotated string Java

I am attempting to calculate the pixel height of a rotated string in Java. At the moment, I am creating an affine transformation and rotating it by the desired amount.
Then, I create a font derived form this affine transformation. I also create a FontRenderContect and a GlyphVector.
When I attempt to get the pixel bounds from the glyph vector, it gives me the height of the text as if it weren't rotated
AffineTransform affineTransform = new AffineTransform();
affineTransform.rotate(Math.toRadians(45),0,0);
Font rotatedFont = font.deriveFont(affineTransform);
FontRenderContext frc = new FontRenderContext(affineTransform, true, false);
GlyphVector gv = rotatedFont.createGlyphVector(frc, "i");
System.out.println(gv.getPixelBounds(frc, 0, 0).getBounds());
gv = rotatedFont.createGlyphVector(frc, "iiiiiiiiiiii");
System.out.println(gv.getPixelBounds(frc, 0, 0).getBounds());
Results in:
java.awt.Rectangle[x=0,y=1,width=9,height=2]
java.awt.Rectangle[x=0,y=1,width=31,height=2]
The height should be much greater as it is rotated at a 45 degree angle (the width should equal the height).
Any help is appreciated.

Determining the bounding box is made easy by using a Shape & applying the AffineTransform directly to that shape.
import java.awt.*;
import java.awt.geom.*;
import java.awt.font.*;
import java.awt.image.BufferedImage;
import javax.swing.*;
import javax.swing.border.EmptyBorder;
public class BoundingBoxRotatedText {
private JComponent ui = null;
JLabel output = new JLabel();
Font font = new Font(Font.SERIF, Font.PLAIN, 20);
String string = "The quick brown fox jumps over the lazy dog";
Shape textShape = getShapeOfText(font, string);
Rectangle2D rectangle = textShape.getBounds2D();
BoundingBoxRotatedText() {
initUI();
}
public final void initUI() {
if (ui!=null) return;
ui = new JPanel(new BorderLayout(4,4));
ui.setBorder(new EmptyBorder(4,4,4,4));
ui.add(output);
output.setIcon(new ImageIcon(getImage()));
}
public static Shape getShapeOfText(Font font, String msg) {
BufferedImage bi = new BufferedImage(
1, 1, BufferedImage.TYPE_INT_RGB);
Graphics2D g = bi.createGraphics();
FontRenderContext frc = g.getFontRenderContext();
GlyphVector gv = font.createGlyphVector(frc, msg);
return gv.getOutline();
}
public static Shape moveShapeToCenter(Shape shape, int w, int h) {
Rectangle2D b = shape.getBounds2D();
double xOff = -b.getX() + ((w - b.getWidth()) / 2d);
double yOff = -b.getY() + ((h - b.getHeight()) / 2d);
AffineTransform move = AffineTransform.getTranslateInstance(xOff, yOff);
return move.createTransformedShape(shape);
}
private BufferedImage getImage() {
int sz = (int)(rectangle.getBounds().width*1.2);
BufferedImage bi = new BufferedImage(
sz, sz, BufferedImage.TYPE_INT_RGB);
Graphics2D g = bi.createGraphics();
g.setColor(Color.WHITE);
g.fillRect(0, 0, sz, sz);
Shape shape = moveShapeToCenter(textShape, sz, sz);
g.setColor(Color.GREEN);
g.fill(shape);
g.draw(shape);
g.draw(shape.getBounds());
AffineTransform rotate45 = AffineTransform.
getRotateInstance(Math.PI/4, sz/2, sz/2);
shape = rotate45.createTransformedShape(shape);
g.setColor(Color.BLUE);
g.fill(shape);
g.draw(shape);
g.draw(shape.getBounds());
shape = rotate45.createTransformedShape(shape);
g.setColor(Color.RED);
g.fill(shape);
g.draw(shape);
g.draw(shape.getBounds());
g.dispose();
return bi;
}
public JComponent getUI() {
return ui;
}
public static void main(String[] args) {
Runnable r = () -> {
try {
UIManager.setLookAndFeel(
UIManager.getSystemLookAndFeelClassName());
} catch (Exception ex) {
ex.printStackTrace();
}
BoundingBoxRotatedText o = new BoundingBoxRotatedText();
JFrame f = new JFrame(o.getClass().getSimpleName());
f.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
f.setLocationByPlatform(true);
f.setContentPane(o.getUI());
f.pack();
f.setMinimumSize(f.getSize());
f.setVisible(true);
};
SwingUtilities.invokeLater(r);
}
}

Drawing Line from Specific Angle in Java [duplicate]

I want to make the pacman open/close mouth animation using the easiest method.
Here is my recent code: The problem is, nothing is happening?
package ordner;
import java.awt.Color;
import java.awt.Graphics;
import javax.swing.JFrame;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
public class PacMan implements ActionListener {
private JFrame frame;
private DrawPanel panel;
private void initGui() {
frame = new JFrame("Pacman");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
panel = new DrawPanel();
frame.add(panel);
panel.setBackground(Color.BLACK);
frame.setSize(300, 300);
frame.setVisible(true);
}
public static void main(String[] args) {
PacMan pm = new PacMan();
pm.initGui();
}
#Override
public void actionPerformed(ActionEvent e) {
panel.repaint();
}
}
and here is my draw panel:
import java.awt.Color;
import java.awt.Graphics;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class DrawPanel extends JPanel {
#Override
public void paintComponent(Graphics g) {
super.paintComponent(g);
g.setColor(Color.yellow);
g.fillArc(70,50,150,150,30,300);
int i = 0;
while ( i <= 60) {
g.fillArc(70,50,150,150,30-i,300+i+i);
try {
Thread.sleep(25);
}
catch (Exception e) {
Thread.currentThread().interrupt();
}
i++;
}
}
}
The while loop doesn't affect anything, what could be the reason for that?

Something like this might work for PacMan images. It uses a Java 2D based Shape instance to represent the form, and an AffineTransform to produce the different orientations.
import java.awt.*;
import java.awt.event.*;
import java.awt.geom.*;
import java.awt.image.BufferedImage;
import javax.swing.*;
import java.io.*;
import javax.imageio.ImageIO;
class PacManShape {
private double size;
private double rotation;
final int maxSize = 4;
static File home = new File(System.getProperty("user.home"));
static File images = new File(home, "images");
PacManShape(int size, double rotation) {
this.size = size;
this.rotation = rotation;
}
public Area getPacManShape(double jaws) {
Area area = new Area(new Ellipse2D.Double(0d, 0d, size, size));
double x1 = size / 2 + (2d * size * Math.cos(jaws / 2d));
double y1 = size / 2 + (2d * size * Math.sin(jaws / 2d));
double x2 = x1;
double y2 = size / 2 - (2d * size * Math.sin(jaws / 2d));
Polygon mouth = new Polygon();
mouth.addPoint((int) (size / 2), (int) (size / 2));
mouth.addPoint((int) x1, (int) y1);
mouth.addPoint((int) x2, (int) y2);
mouth.addPoint((int) (size / 2), (int) (size / 2));
area.subtract(new Area(mouth));
return area;
}
public BufferedImage getPacManImage(double angle, Color color) {
BufferedImage bi = new BufferedImage(
(int) size, (int) size, BufferedImage.TYPE_INT_ARGB);
Graphics2D g2 = bi.createGraphics();
g2.setColor(color);
g2.fillRect(0, 0, (int) size, (int) size);
AffineTransform rotate = AffineTransform.getRotateInstance(
rotation, size / 2, size / 2);
g2.setTransform(rotate);
Area pacMan = getPacManShape(angle);
g2.setRenderingHint(
RenderingHints.KEY_ANTIALIASING,
RenderingHints.VALUE_ANTIALIAS_ON);
g2.setColor(Color.YELLOW);
float[] dist = {.15f, .9f};
Color[] colors = {Color.YELLOW, Color.ORANGE};
Point2D center = new Point2D.Double(size / 2, size / 2);
RadialGradientPaint radial = new RadialGradientPaint(
center, (float) ((size / 2) - 2f), dist, colors);
g2.setPaint(radial);
g2.fill(pacMan);
GradientPaint gradient = new GradientPaint(
0, 0, new Color(255, 255, 225, 220),
(int) (size / 3), 0, new Color(255, 255, 255, 0));
g2.setPaint(gradient);
g2.fill(pacMan);
g2.dispose();
return bi;
}
public void savePacManImage(int q, int num) throws IOException {
double angle = Math.PI*2 / 3d * ((double) num / (double) maxSize);
BufferedImage bi = getPacManImage(angle, Color.WHITE);
images.mkdirs();
File img = new File(images, "PacMan-" + q + "x" + num + ".gif");
ImageIO.write(bi, "gif", img);
}
public static void main(String[] args) {
try {
for (int ii = 0; ii < 4; ii++) {
PacManShape pms = new PacManShape(100, (double) ii * Math.PI / 2d);
for (int jj = 0; jj <= pms.maxSize; jj++) {
pms.savePacManImage(ii, jj);
}
}
Desktop.getDesktop().open(images);
} catch (IOException ex) {
ex.printStackTrace();
}
Runnable r = new Runnable() {
#Override
public void run() {
JPanel gui = new JPanel(new BorderLayout());
gui.add(new PacManComponent());
JOptionPane.showMessageDialog(null, gui);
}
};
// Swing GUIs should be created and updated on the EDT
// http://docs.oracle.com/javase/tutorial/uiswing/concurrency/initial.html
SwingUtilities.invokeLater(r);
}
}
class PacManComponent extends JPanel {
double angle = 0d;
int preferredSize = 100;
double diff = Math.PI / 8;
boolean chomp = true;
Timer timer;
PacManComponent() {
ActionListener listener = new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
repaint();
}
};
timer = new Timer(180, listener);
timer.start();
}
#Override
public Dimension getPreferredSize() {
return new Dimension(preferredSize, preferredSize);
}
#Override
public void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2 = (Graphics2D) g.create();
//double size = (getWidth() < getHeight() ? getWidth() : getHeight());
if (angle > 2 * Math.PI / 3) {
chomp = true;
} else if (angle < 0.01) {
chomp = false;
}
if (chomp) {
angle -= diff;
} else {
angle += diff;
}
PacManShape pms = new PacManShape(100, 0d);
Image image = pms.getPacManImage(angle, new Color(0, 0, 0, 0));
g2.drawImage(image, 0, 0, this);
g2.dispose();
}
}
If you wanted to transform & render images at run-time, try starting with this series of PNG format images that uses partial transparency to soften the edges.

For the animation, you could use a Swing Timer to move the Pacman graphic as well as adjusting the angle by which the "mouth" opens, by varying the parameters used by fillArc.
Interaction with KeyEvents for movement control can be acheived using Key Bindings.
Also, I would move the paint functionality to a paintComponent method in a sub-classed JComponent for better paint performance.
Related: Painting with Swing
Edit:
As youre starting Java there are a number of tasks to get working first
Create the JComponent based class with a static Pacman graphic. Move your painting logic to paintComponent
Get the Swing Timer functionality working. Follow the Oracle guide for Timers.
Implement the Key Bindings
Other functionality such as score keeping, etc.

2d animation:
http://en.wikipedia.org/wiki/File:The_Horse_in_Motion.jpg
Pseudocode:
while programActive:
deltatime = get_time_since_last_call()
update_animation_frame(deltatime)
image = get_animation_frame()
draw_background()
draw(image)
enforce_framerate(24)
To learn and do this sort of thing in Pygame would be easy compared to Java, but unsuitable for larger projects

How to draw and rotate square inside center of other square?

I need to draw some squares inside other square but I don't know how to rotate my squares by center of them and make them smaller?
Here is a picture how it should looks like at the end:
Now I have some code which draw squares which make circle.
class MySquare extends JComponent {
public void paint(Graphics g) {
Graphics2D g2d = (Graphics2D) g;
for (int i = 0; i < 20; i++) {
g2d = (Graphics2D) g.create();
g2d.rotate(Math.toRadians(45 - (i * 10)), 100, 100);
// Difrent colors:
if (i % 2 == 0)
g2d.setColor(Color.black);
else
g2d.setColor(Color.green);
g2d.fillRect(50, 50, 100, 100);
}
}
}
public class DrawRect {
public static void main(String[] a) {
JFrame window = new JFrame();
window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
window.setBounds(30, 30, 800, 800);
window.getContentPane().add(new MySquare());
window.setVisible(true);
}
}

You could first draw your figure around the origin (that's easy) and then translate:
import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class Test {
public static void main(String[] args) {
JFrame frame = new JFrame();
frame.setSize(400, 400);
frame.setVisible(true);
frame.add(new JPanel() {
#Override
protected void paintComponent(Graphics g) {
Graphics2D g2d = (Graphics2D) g;
double alpha = Math.toRadians(5);
double factor = 1 / (Math.sin(alpha) + Math.cos(alpha));
double size = 200;
g2d.translate(size, size);
for (int i = 0; i < 20; i++) {
g2d.setColor(i % 2 == 0 ? Color.black : Color.green);
int intSize = (int) Math.round(size);
g2d.fillRect(-intSize / 2, -intSize / 2, intSize, intSize);
size = size * factor;
g2d.rotate(alpha);
}
}
});
}
}

Pacman open/close mouth animation

I want to make the pacman open/close mouth animation using the easiest method.
Here is my recent code: The problem is, nothing is happening?
package ordner;
import java.awt.Color;
import java.awt.Graphics;
import javax.swing.JFrame;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
public class PacMan implements ActionListener {
private JFrame frame;
private DrawPanel panel;
private void initGui() {
frame = new JFrame("Pacman");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
panel = new DrawPanel();
frame.add(panel);
panel.setBackground(Color.BLACK);
frame.setSize(300, 300);
frame.setVisible(true);
}
public static void main(String[] args) {
PacMan pm = new PacMan();
pm.initGui();
}
#Override
public void actionPerformed(ActionEvent e) {
panel.repaint();
}
}
and here is my draw panel:
import java.awt.Color;
import java.awt.Graphics;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class DrawPanel extends JPanel {
#Override
public void paintComponent(Graphics g) {
super.paintComponent(g);
g.setColor(Color.yellow);
g.fillArc(70,50,150,150,30,300);
int i = 0;
while ( i <= 60) {
g.fillArc(70,50,150,150,30-i,300+i+i);
try {
Thread.sleep(25);
}
catch (Exception e) {
Thread.currentThread().interrupt();
}
i++;
}
}
}
The while loop doesn't affect anything, what could be the reason for that?

Something like this might work for PacMan images. It uses a Java 2D based Shape instance to represent the form, and an AffineTransform to produce the different orientations.
import java.awt.*;
import java.awt.event.*;
import java.awt.geom.*;
import java.awt.image.BufferedImage;
import javax.swing.*;
import java.io.*;
import javax.imageio.ImageIO;
class PacManShape {
private double size;
private double rotation;
final int maxSize = 4;
static File home = new File(System.getProperty("user.home"));
static File images = new File(home, "images");
PacManShape(int size, double rotation) {
this.size = size;
this.rotation = rotation;
}
public Area getPacManShape(double jaws) {
Area area = new Area(new Ellipse2D.Double(0d, 0d, size, size));
double x1 = size / 2 + (2d * size * Math.cos(jaws / 2d));
double y1 = size / 2 + (2d * size * Math.sin(jaws / 2d));
double x2 = x1;
double y2 = size / 2 - (2d * size * Math.sin(jaws / 2d));
Polygon mouth = new Polygon();
mouth.addPoint((int) (size / 2), (int) (size / 2));
mouth.addPoint((int) x1, (int) y1);
mouth.addPoint((int) x2, (int) y2);
mouth.addPoint((int) (size / 2), (int) (size / 2));
area.subtract(new Area(mouth));
return area;
}
public BufferedImage getPacManImage(double angle, Color color) {
BufferedImage bi = new BufferedImage(
(int) size, (int) size, BufferedImage.TYPE_INT_ARGB);
Graphics2D g2 = bi.createGraphics();
g2.setColor(color);
g2.fillRect(0, 0, (int) size, (int) size);
AffineTransform rotate = AffineTransform.getRotateInstance(
rotation, size / 2, size / 2);
g2.setTransform(rotate);
Area pacMan = getPacManShape(angle);
g2.setRenderingHint(
RenderingHints.KEY_ANTIALIASING,
RenderingHints.VALUE_ANTIALIAS_ON);
g2.setColor(Color.YELLOW);
float[] dist = {.15f, .9f};
Color[] colors = {Color.YELLOW, Color.ORANGE};
Point2D center = new Point2D.Double(size / 2, size / 2);
RadialGradientPaint radial = new RadialGradientPaint(
center, (float) ((size / 2) - 2f), dist, colors);
g2.setPaint(radial);
g2.fill(pacMan);
GradientPaint gradient = new GradientPaint(
0, 0, new Color(255, 255, 225, 220),
(int) (size / 3), 0, new Color(255, 255, 255, 0));
g2.setPaint(gradient);
g2.fill(pacMan);
g2.dispose();
return bi;
}
public void savePacManImage(int q, int num) throws IOException {
double angle = Math.PI*2 / 3d * ((double) num / (double) maxSize);
BufferedImage bi = getPacManImage(angle, Color.WHITE);
images.mkdirs();
File img = new File(images, "PacMan-" + q + "x" + num + ".gif");
ImageIO.write(bi, "gif", img);
}
public static void main(String[] args) {
try {
for (int ii = 0; ii < 4; ii++) {
PacManShape pms = new PacManShape(100, (double) ii * Math.PI / 2d);
for (int jj = 0; jj <= pms.maxSize; jj++) {
pms.savePacManImage(ii, jj);
}
}
Desktop.getDesktop().open(images);
} catch (IOException ex) {
ex.printStackTrace();
}
Runnable r = new Runnable() {
#Override
public void run() {
JPanel gui = new JPanel(new BorderLayout());
gui.add(new PacManComponent());
JOptionPane.showMessageDialog(null, gui);
}
};
// Swing GUIs should be created and updated on the EDT
// http://docs.oracle.com/javase/tutorial/uiswing/concurrency/initial.html
SwingUtilities.invokeLater(r);
}
}
class PacManComponent extends JPanel {
double angle = 0d;
int preferredSize = 100;
double diff = Math.PI / 8;
boolean chomp = true;
Timer timer;
PacManComponent() {
ActionListener listener = new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
repaint();
}
};
timer = new Timer(180, listener);
timer.start();
}
#Override
public Dimension getPreferredSize() {
return new Dimension(preferredSize, preferredSize);
}
#Override
public void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2 = (Graphics2D) g.create();
//double size = (getWidth() < getHeight() ? getWidth() : getHeight());
if (angle > 2 * Math.PI / 3) {
chomp = true;
} else if (angle < 0.01) {
chomp = false;
}
if (chomp) {
angle -= diff;
} else {
angle += diff;
}
PacManShape pms = new PacManShape(100, 0d);
Image image = pms.getPacManImage(angle, new Color(0, 0, 0, 0));
g2.drawImage(image, 0, 0, this);
g2.dispose();
}
}
If you wanted to transform & render images at run-time, try starting with this series of PNG format images that uses partial transparency to soften the edges.

For the animation, you could use a Swing Timer to move the Pacman graphic as well as adjusting the angle by which the "mouth" opens, by varying the parameters used by fillArc.
Interaction with KeyEvents for movement control can be acheived using Key Bindings.
Also, I would move the paint functionality to a paintComponent method in a sub-classed JComponent for better paint performance.
Related: Painting with Swing
Edit:
As youre starting Java there are a number of tasks to get working first
Create the JComponent based class with a static Pacman graphic. Move your painting logic to paintComponent
Get the Swing Timer functionality working. Follow the Oracle guide for Timers.
Implement the Key Bindings
Other functionality such as score keeping, etc.

2d animation:
http://en.wikipedia.org/wiki/File:The_Horse_in_Motion.jpg
Pseudocode:
while programActive:
deltatime = get_time_since_last_call()
update_animation_frame(deltatime)
image = get_animation_frame()
draw_background()
draw(image)
enforce_framerate(24)
To learn and do this sort of thing in Pygame would be easy compared to Java, but unsuitable for larger projects

Shapes combination in Java?

Does java Shape interface contract and library routines allow combining multiple shapes into one object extending Shape interface?
For example, may I define class Flower which will consist of several ovals for petals and core?
Or the Shape supposes only one continuous outline? If so then is there any class in Java for holding multiple shapes, may be some class for vectorized graphics?

To manipulate shapes in Java like you're describing, you want to use the Area class, which has these operations. Just convert a Shape to an Area with new Area(Shape).

Here is my attempt - using a rotate transform anchored on the center of the flower shape.
import java.awt.*;
import java.awt.geom.*;
import java.awt.image.BufferedImage;
import javax.swing.*;
public class DaisyDisplay {
DaisyDisplay() {
BufferedImage daisy = new BufferedImage(
200,200,BufferedImage.TYPE_INT_RGB);
Graphics2D g = daisy.createGraphics();
g.setColor(Color.GREEN.darker());
g.fillRect(0, 0, 200, 200);
Daisy daisyPainter = new Daisy();
daisyPainter.paint(g);
g.dispose();
JOptionPane.showMessageDialog(null, new JLabel(new ImageIcon(daisy)));
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
new DaisyDisplay();
}
});
}
}
class Daisy {
public void paint(Graphics2D g) {
Area daisyArea = getDaisyShape();
g.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
RenderingHints.VALUE_ANTIALIAS_ON);
paintDaisyPart(g,daisyArea);
g.setTransform(AffineTransform.getRotateInstance(
Math.PI*1/8,
100,100));
paintDaisyPart(g,daisyArea);
g.setTransform(AffineTransform.getRotateInstance(
Math.PI*3/8,
100,100);
paintDaisyPart(g,daisyArea);
g.setTransform(AffineTransform.getRotateInstance(
Math.PI*2/8,
100,100));
paintDaisyPart(g,daisyArea);
}
public void paintDaisyPart(Graphics2D g, Area daisyArea) {
g.setClip(daisyArea);
g.setColor(Color.YELLOW);
g.fillRect(0, 0, 200, 200);
g.setColor(Color.YELLOW.darker());
g.setClip(null);
g.setStroke(new BasicStroke(3));
g.draw(daisyArea);
}
public Area getDaisyShape() {
Ellipse2D.Double core = new Ellipse2D.Double(70,70,60,60);
Area area = new Area(core);
int size = 200;
int pad = 10;
int petalWidth = 50;
int petalLength = 75;
// left petal
area.add(new Area(new Ellipse2D.Double(
pad,(size-petalWidth)/2,petalLength,petalWidth)));
// right petal
area.add(new Area(new Ellipse2D.Double(
(size-petalLength-pad),(size-petalWidth)/2,petalLength,petalWidth)));
// top petal
area.add(new Area(new Ellipse2D.Double(
(size-petalWidth)/2,pad,petalWidth,petalLength)));
// bottom petal
area.add(new Area(new Ellipse2D.Double(
(size-petalWidth)/2,(size-petalLength-pad),petalWidth,petalLength)));
return area;
}
}