Projecting mouse coordinates - java

This question has probably been answered but from the ones i have found they don't seem to work, others actually not making any changes.
I'm creating a game, the game has a screen (Canvas) that is inside of the window (JFrame). In this game i would like to use a mouse, as well as allowing the user to maximize the window. The game screen stays the same size no matter what, but if the window is re-sized, so i scale the game image to the size of the window.
My problem is that i cannot find a suitable way to project the coordinates of the the mouse, as when the window is maximized, its coordinates are still being read as if the window were still normal sized, creating an offset.
I've tried:
#Override public void mouseMoved(MouseEvent e){
MOUSE_X = Math.round((float) e.getX() / (float) RenderableCanvas.oldSizeX * (float) f.getWidth());
MOUSE_Y = Math.round((float) e.getY() / (float) RenderableCanvas.oldSizeY * (float) f.getHeight());
}
Where MOUSE_X/MOUSE_Y are static variables that can be referenced anywhere in the program to get the mouse location.
and RenderableCanvas is the game window, containing an embedded canvas object, this class also keeps track of the original size of the window stated as oldSizeX and oldSizeY
and finally f.getHeight() and f.getWidth() are the current size of the frame, as f is a reference to the JFrame inside of the RenderableCanvas class.
but all that does the same as:
#Override public void mouseMoved(MouseEvent e){
MOUSE_X = e.getX();
MOUSE_Y = e.getY();
}
Thank you for any help in advance.

The basic idea is you need to be able to convert between the two coordinate systems, in this case, the "world" which is the space getting scaled and the "view" which is what the user sees (or something like that)
The basic maths is to use the default value and the current value to generate a percentage value, by which you can then multiple the target value by, for example convert from the view to the world might look like...
pointInView * (staticSize / currentSize)
So, given a point in "world" coordinates, you need to scale back to "view" coordinates...
protected Point toView(int x, int y) {
return toView(new Point(x, y));
}
protected Point toView(Point p) {
Point scaled = new Point(p);
scaled.x = Math.round(p.x * ((float) getWidth() / (float) DEFAULT_WIDTH));
scaled.y = Math.round(p.y * ((float) getHeight() / (float) DEFAULT_HEIGHT));
return scaled;
}
And given "view" coordinates, you need to scale up to the "world" coordinates...
protected Point toWorld(int x, int y) {
return toWorld(new Point(x, y));
}
protected Point toWorld(Point p) {
Point scaled = new Point(p);
scaled.x = Math.round(p.x * ((float) DEFAULT_WIDTH) / (float) getWidth());
scaled.y = Math.round(p.y * ((float) DEFAULT_HEIGHT) / (float) getHeight());
return scaled;
}
So, for example, when the mouse is moved or clicked on your "view", you could use
Point world = toWorld(e.getPoint());
to convert the mouse point into world coordinates
... please feel free to rename those to suit your own needs, but basically, view is the physical view that the user sees and is your virtual concept of that view...
The basic concept will work for Dimension and by extension, Rectangle as well...
import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.GridBagLayout;
import java.awt.Point;
import java.awt.Rectangle;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.event.MouseMotionAdapter;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
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 {
protected static final int DEFAULT_WIDTH = 200;
protected static final int DEFAULT_HEIGHT = 200;
private Dimension preferredSize = new Dimension(DEFAULT_WIDTH, DEFAULT_HEIGHT);
private JLabel properties;
private boolean highlighted = false;
private Rectangle hoverRect = new Rectangle(10, 10, 50, 50);
public TestPane() {
setLayout(new GridBagLayout());
properties = new JLabel("...");
add(properties);
addMouseMotionListener(new MouseMotionAdapter() {
#Override
public void mouseMoved(MouseEvent e) {
int x = e.getX();
int y = e.getY();
Point world = toWorld(e.getPoint());
highlighted = hoverRect.contains(world);
repaint();
properties.setText("<html>#" + format(e.getPoint())
+ "<br>world = " + format(world)
+ "<br>view = " + format(toView(world)));
}
});
addMouseListener(new MouseAdapter() {
#Override
public void mouseClicked(MouseEvent e) {
preferredSize = new Dimension(DEFAULT_WIDTH * 2, DEFAULT_HEIGHT * 2);
SwingUtilities.windowForComponent(TestPane.this).pack();
}
});
}
protected String format(Point p) {
return p.x + "x" + p.y;
}
protected Point toView(int x, int y) {
return toView(new Point(x, y));
}
protected Point toView(Point p) {
Point scaled = new Point(p);
scaled.x = Math.round(p.x * ((float) getWidth() / (float) DEFAULT_WIDTH));
scaled.y = Math.round(p.y * ((float) getHeight() / (float) DEFAULT_HEIGHT));
return scaled;
}
protected Point toWorld(int x, int y) {
return toWorld(new Point(x, y));
}
protected Point toWorld(Point p) {
Point scaled = new Point(p);
scaled.x = Math.round(p.x * ((float) DEFAULT_WIDTH) / (float) getWidth());
scaled.y = Math.round(p.y * ((float) DEFAULT_HEIGHT) / (float) getHeight());
return scaled;
}
protected Rectangle toWorld(Rectangle bounds) {
return toWorld(bounds.x, bounds.y, bounds.width, bounds.height);
}
protected Rectangle toWorld(int x, int y, int width, int height) {
Rectangle scaled = new Rectangle();
scaled.setLocation(toWorld(x, y));
scaled.width = Math.round(width * ((float) DEFAULT_WIDTH / (float) getWidth()));
scaled.height = Math.round(height * ((float) DEFAULT_HEIGHT / (float) getHeight()));
return scaled;
}
protected Rectangle toView(Rectangle bounds) {
return toView(bounds.x, bounds.y, bounds.width, bounds.height);
}
protected Rectangle toView(int x, int y, int width, int height) {
Rectangle scaled = new Rectangle();
scaled.setLocation(toView(x, y));
scaled.width = Math.round(width * ((float) getWidth() / (float) DEFAULT_WIDTH));
scaled.height = Math.round(height * ((float) getHeight() / (float) DEFAULT_HEIGHT));
return scaled;
}
#Override
public Dimension getPreferredSize() {
return preferredSize;
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g.create();
Rectangle bounds = toView(hoverRect);
if (highlighted) {
g2d.setColor(Color.BLUE);
g2d.fill(bounds);
}
g2d.setColor(Color.BLACK);
g2d.draw(bounds);
}
}
}

So i think I've got it, i did some old Pen and Paper math and realized that i had part of my equation flipped from what i thought i should have.
This seems to work:
#Override public void mouseMoved(MouseEvent e){
MOUSE_X = (int) ((float) e.getX() / (float) f.getWidth() * (float) RenderableCanvas.oldSizeX);
MOUSE_Y = (int) ((float) e.getY() / (float) f.getHeight() * (float) RenderableCanvas.oldSizeY);
}

Related

How do I manipulate shapes within a zoomed panel in Java?

I have some code I found on the internet that allows me to control zooming and panning of a scrollable panel in Java but I want to be able to manipulate the shapes within this area and having trouble translating the x and y coordinates back to the original (unzoomed) dimensions ..
There are a few things I would like to do with these shapes but to start, how can I paint the two entity rectangles red when the mouse moves within them?
Here is code I have so far:
import java.awt.BasicStroke;
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Point;
import java.awt.Rectangle;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.awt.event.MouseMotionListener;
import java.awt.event.MouseWheelEvent;
import java.awt.event.MouseWheelListener;
import java.awt.geom.Point2D;
import java.awt.geom.Rectangle2D;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
public class CanvasPane extends JPanel {
private static Canvas canvas;
public CanvasPane(boolean isDoubleBuffered) {
super(isDoubleBuffered);
setLayout(new BorderLayout());
canvas = new Canvas(1.0);
JScrollPane pane = new JScrollPane(canvas);
pane.getViewport().setBackground(Color.DARK_GRAY);
add(pane, BorderLayout.CENTER);
}
public static void main(String[] args) {
JFrame frame = new JFrame("Test Graphics");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new BorderLayout());
frame.add(new CanvasPane(true), BorderLayout.CENTER);
frame.pack();
frame.setSize(800, 600);
frame.setLocationRelativeTo(null);
frame.setVisible(true);
//Initial scrolling of the canvas to its center
Rectangle canvasRectangle = canvas.getBounds();
Rectangle visibleRectangle = canvas.getVisibleRect();
double tx = (canvasRectangle.getWidth() - visibleRectangle.getWidth())/2;
double ty = (canvasRectangle.getHeight() - visibleRectangle.getHeight())/2;
visibleRectangle.setBounds((int)tx, (int)ty, visibleRectangle.width, visibleRectangle.height);
canvas.scrollRectToVisible(visibleRectangle);
}
}
class Canvas extends JComponent implements MouseWheelListener, MouseMotionListener, MouseListener {
private static final long serialVersionUID = 1L;
private double zoom = 1.0;
public static final double SCALE_STEP = 0.1d;
private Dimension initialSize;
private Point origin;
private double previousZoom = zoom;
private double scrollX = 0d;
private double scrollY = 0d;
private Rectangle2D workspace = new Rectangle2D.Double(0,0, 1024, 768);
private Rectangle entity1 = new Rectangle(10, 10, 100, 100);
private Rectangle entity2 = new Rectangle(300, 300, 100, 100);
public Canvas(double zoom) {
this.zoom = zoom;
addMouseWheelListener(this);
addMouseMotionListener(this);
addMouseListener(this);
setAutoscrolls(true);
setPreferredSize(new Dimension((int)workspace.getWidth(), (int)workspace.getHeight()));
}
#Override public void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g;
//Zoom graphics
g2d.scale(zoom, zoom);
//translate graphics to be always in center of the canvas
Rectangle size = getBounds();
double tx = ((size.getWidth() - workspace.getWidth() * zoom) / 2) / zoom;
double ty = ((size.getHeight() - workspace.getHeight() * zoom) / 2) / zoom;
g2d.translate(tx, ty);
//Draw
g2d.setColor(Color.LIGHT_GRAY);
g2d.fill(workspace);
g2d.setColor(Color.DARK_GRAY);
g2d.setStroke(new BasicStroke(5.0f));
g2d.draw(workspace);
g2d.draw(entity1);
g2d.draw(entity2);
}
#Override public void setSize(Dimension size) {
super.setSize(size);
if (initialSize == null) {
this.initialSize = size;
}
}
#Override public void setPreferredSize(Dimension preferredSize) {
super.setPreferredSize(preferredSize);
if (initialSize == null) {
this.initialSize = preferredSize;
}
}
public void mouseWheelMoved(MouseWheelEvent e) {
double zoomFactor = -SCALE_STEP * e.getPreciseWheelRotation() * zoom;
zoom = Math.abs(zoom + zoomFactor);
//Here we calculate new size of canvas relative to zoom.
Dimension d = new Dimension(
(int)(initialSize.width * zoom),
(int)(initialSize.height * zoom));
setPreferredSize(d);
setSize(d);
validate();
followMouseOrCenter(e.getPoint());
previousZoom = zoom;
}
public void followMouseOrCenter(Point2D point) {
Rectangle size = getBounds();
Rectangle visibleRect = getVisibleRect();
scrollX = size.getCenterX();
scrollY = size.getCenterY();
if (point != null) {
scrollX = point.getX() / previousZoom * zoom - (point.getX() - visibleRect.getX());
scrollY = point.getY() / previousZoom * zoom - (point.getY() - visibleRect.getY());
}
visibleRect.setRect(scrollX, scrollY, visibleRect.getWidth(), visibleRect.getHeight());
scrollRectToVisible(visibleRect);
}
public void mouseDragged(MouseEvent e) {
if (origin != null) {
int deltaX = origin.x - e.getX();
int deltaY = origin.y - e.getY();
Rectangle view = getVisibleRect();
view.x += deltaX;
view.y += deltaY;
scrollRectToVisible(view);
}
}
public void mousePressed(MouseEvent e) {
origin = new Point(e.getPoint());
}
public void mouseMoved(MouseEvent e) {
}
public void mouseClicked(MouseEvent e) {}
public void mouseReleased(MouseEvent e) {}
public void mouseEntered(MouseEvent e) {}
public void mouseExited(MouseEvent e) {}
}
I have tried to calculate using following code but this isn't quite right
public void mouseMoved(MouseEvent e) {
double x = e.getX() / zoom;
double y = e.getY() / zoom;
double x2 = getWidth() - workspace.getWidth() * zoom;
double y2 = getHeight() - workspace.getHeight() * zoom;
if(x2 > 0) x -= x2;
if(y2 > 0) y -= y2;
Point p = new Point((int)x, (int)y);
if(entity1.contains(p)) {
intersects = true;
}
else {
intersects = false;
}
repaint();
}
This seems to work even better but I am not sure if its the cleanest solution ...
public void mouseMoved(MouseEvent e) {
double x = e.getX() / zoom;
double y = e.getY() / zoom;
// double x2 = getWidth() - workspace.getWidth() * zoom;
// double y2 = getHeight() - workspace.getHeight() * zoom;
double x2 = ((getWidth() - workspace.getWidth() * zoom) / 2) / zoom;
double y2 = ((getHeight() - workspace.getHeight() * zoom) / 2) / zoom;
if(x2 > 0) x -= x2;
if(y2 > 0) y -= y2;
Point p = new Point((int)x, (int)y);
if(entity1.contains(p)) {
intersects = true;
}
else {
intersects = false;
}
repaint();
}

make image point toward specific location in java

BEFORE YOU MARK IT AS DUPLICATE
I have searched a lot in the internet for that and tried every solution, but no one does it the same way I do it. In my case the rotation is in a sperate class.
I have created a java class that inherits JLabel class, in my class I have an arrow BufferedImage which I draw using the paintComponent(Graphics g) method.
I am trying to make the arrow point to a specific point (which I get from a different method) but something goes wrong and the arrow rotates to the wrong direction.
I THINK: it doesn't calculate correctly because the imageLocation is relative to the label.
Here is my code:
package pkg1;
import java.awt.*;
import java.awt.event.*;
import java.awt.image.*;
import java.io.*;
import javax.imageio.*;
import javax.swing.*;
public final class ImageLabel extends JLabel {
private float angle = 0.0f; // in radians
private Point imageLocation = new Point();
private File imageFile = null;
private Dimension imageSize = new Dimension(50, 50);
private BufferedImage bi;
private BufferedImage resizeImage(BufferedImage originalImage, int img_width, int img_height) {
int type = originalImage.getType() == 0 ? BufferedImage.TYPE_INT_ARGB : originalImage.getType();
BufferedImage resizedImage = new BufferedImage(img_width, img_height, type);
Graphics2D g = resizedImage.createGraphics();
g.drawImage(originalImage, 0, 0, img_width, img_height, null);
g.dispose();
return resizedImage;
}
#Override
public void paintComponent(Graphics g) {
super.paintComponent(g);
if (bi == null) {
return;
}
imageLocation = new Point(getWidth() / 2 - bi.getWidth() / 2, getHeight() / 2 - bi.getHeight() / 2);
Graphics2D g2 = (Graphics2D) g;
g2.rotate(angle, imageLocation.x + bi.getWidth() / 2, imageLocation.y + bi.getHeight() / 2);
g2.drawImage(bi, imageLocation.x, imageLocation.y, null);
}
public void rotateImage(float angle) { // rotate the image to specific angle
this.angle = (float) Math.toRadians(angle);
repaint();
}
public void pointImageToPoint(Point target) {
calculateAngle(target);
repaint();
}
private void calculateAngle(Point target) {
// calculate the angle from the center of the image
float deltaY = target.y - (imageLocation.y + bi.getHeight() / 2);
float deltaX = target.x - (imageLocation.x + bi.getWidth() / 2);
angle = (float) Math.atan2(deltaY, deltaX);
if (angle < 0) {
angle += (Math.PI * 2);
}
}
}
Okay, so two things jump out at me...
If you take a Point from outside the context of the label, you will have to translate the point into the components coordinate context
The calculateAngle seems wrong
So starting with...
private void calculateAngle(Point target) {
// calculate the angle from the center of the image
float deltaY = target.y - (imageLocation.y + bi.getHeight() / 2);
float deltaX = target.x - (imageLocation.x + bi.getWidth() / 2);
angle = (float) Math.atan2(deltaY, deltaX);
if (angle < 0) {
angle += (Math.PI * 2);
}
}
angle = (float) Math.atan2(deltaY, deltaX); should be angle = (float) Math.atan2(deltaX, deltaY); (swap the deltas)
You will find that you need to adjust the result by 180 degrees in order to get the image to point in the right direction
angle = Math.toRadians(Math.toDegrees(angle) + 180.0);
Okay, I'm an idiot, but it works :P
I'd also make use of a AffineTransform to translate and rotate the image - personally, I find it easier to deal with.
In the example, I've cheated a little. I set the translation of the AffineTransform to the centre of the component, I then rotate the context around the new origin point (0x0). I then paint the image offset by half it's height/width, thus making it appear as the if the image is been rotated about it's centre - It's late, I'm tired, it works :P
import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.GridBagLayout;
import java.awt.Point;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.geom.AffineTransform;
import java.awt.image.BufferedImage;
import java.io.File;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
import javax.swing.border.LineBorder;
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 ImageLabel label;
public TestPane() {
setLayout(new GridBagLayout());
label = new ImageLabel();
add(label);
addMouseMotionListener(new MouseAdapter() {
#Override
public void mouseMoved(MouseEvent e) {
label.pointImageToPoint(e.getPoint(), TestPane.this);
}
});
}
#Override
public Dimension getPreferredSize() {
return new Dimension(200, 200);
}
}
public final class ImageLabel extends JLabel {
private double angle = 0;
private Point imageLocation = new Point();
private File imageFile = null;
private Dimension imageSize = new Dimension(50, 50);
private BufferedImage bi;
public ImageLabel() {
setBorder(new LineBorder(Color.BLUE));
bi = new BufferedImage(50, 50, BufferedImage.TYPE_INT_ARGB);
Graphics2D g2d = bi.createGraphics();
g2d.setColor(Color.RED);
g2d.drawLine(25, 0, 25, 50);
g2d.drawLine(25, 0, 0, 12);
g2d.drawLine(25, 0, 50, 12);
g2d.dispose();
}
#Override
public Dimension getPreferredSize() {
return new Dimension(bi.getWidth(), bi.getHeight());
}
protected Point centerPoint() {
return new Point(getWidth() / 2, getHeight() / 2);
}
#Override
public void paintComponent(Graphics g) {
super.paintComponent(g);
if (bi == null) {
return;
}
Graphics2D g2d = (Graphics2D) g.create();
AffineTransform at = g2d.getTransform();
Point center = centerPoint();
at.translate(center.x, center.y);
at.rotate(angle, 0, 0);
g2d.setTransform(at);
g2d.drawImage(bi, -bi.getWidth() / 2, -bi.getHeight() / 2, this);
g2d.dispose();
}
public void rotateImage(float angle) { // rotate the image to specific angle
this.angle = (float) Math.toRadians(angle);
repaint();
}
public void pointImageToPoint(Point target, JComponent fromContext) {
calculateAngle(target, fromContext);
repaint();
}
private void calculateAngle(Point target, JComponent fromContext) {
// calculate the angle from the center of the image
target = SwingUtilities.convertPoint(fromContext, target, this);
Point center = centerPoint();
float deltaY = target.y - center.y;
float deltaX = target.x - center.x;
angle = (float) -Math.atan2(deltaX, deltaY);
angle = Math.toRadians(Math.toDegrees(angle) + 180.0);
repaint();
}
}
}
I just want to add that using a JLabel for this purpose is overkill, a simple JPanel or JComponent would do the same job and carry a lot less overhead with it, just saying

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

Simple circle rotation (simulate motion)

I have a simple animation in Java that consists of a wheel moving across a window. It is just a plain circle that starts off of the screen from the left, enters and continues to the right until it goes off of the screen. Then it loops and repeats this process.
X is a variable that contains the position of the wheel. It can be between -(wheel width) and the window size + the wheel width.
I would like to simulate rotation by drawing a circle within this wheel, that rotates around the circle as if it were attached.
Imagine a bike wheel in real life with a red flag on the wheel. As the wheel rotates, the red flag would be on the edge on the wheel moving as the wheel progresses. This is the behavior I want.
I am getting a percentage to pass into my wheel class like this:
int percentage = x/windowWidth;
Each frame that the wheel moves, I call wheel.rotate(percentage).
This is the implementation:
private int diameter = 50;
private final int SPOKE_DIAMETER = diameter/5;
public void rotate(double percent){
this.percent = percent;
this.theta = percent*(PI*2);
System.out.println(percent*PI);
}
public void paintComponent(Graphics canvas)
{
// wheel
canvas.setColor(Color.gray);
canvas.fillOval(0, 0, diameter, diameter);
// spinning flag
canvas.setColor(Color.red);
canvas.fillOval((int)(percent*diameter),(int)((sin((percent*(PI*2)))*diameter)), SPOKE_DIAMETER,SPOKE_DIAMETER);
}
The x location works more or less how I wanted, but the y does not. It wiggles like a sin wave, which is expected (I did use sin...), however, I'm not sure how to alter my math to follow the circle around.
What is wrong with my implementation? (I'm not very good with drawing with trigonometric functions)
Basically, you need to calculate the point on the circle, based on an angle that the object should appear...
Like most things, I stole this off the internet somewhere, but it works...
protected Point getPointOnCircle(float degress, float radius) {
int x = Math.round(getWidth() / 2);
int y = Math.round(getHeight() / 2);
double rads = Math.toRadians(degress - 90); // 0 becomes the top
// Calculate the outter point of the line
int xPosy = Math.round((float) (x + Math.cos(rads) * radius));
int yPosy = Math.round((float) (y + Math.sin(rads) * radius));
return new Point(xPosy, yPosy);
}
Based on an angel (in degrees) and the radius of the circle, this will return the x/y position along the circumference of the circle...
import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Point;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.Timer;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class RotateWheel {
public static void main(String[] args) {
new RotateWheel();
}
public RotateWheel() {
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 float degrees = 0;
public TestPane() {
Timer timer = new Timer(40, new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
degrees += 0.5f;
repaint();
}
});
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();
int diameter = Math.min(getWidth(), getHeight());
int x = (getWidth() - diameter) / 2;
int y = (getHeight() - diameter) / 2;
g2d.setColor(Color.GREEN);
g2d.drawOval(x, y, diameter, diameter);
g2d.setColor(Color.RED);
float innerDiameter = 20;
Point p = getPointOnCircle(degrees, (diameter / 2f) - (innerDiameter / 2));
g2d.drawOval(x + p.x - (int) (innerDiameter / 2), y + p.y - (int) (innerDiameter / 2), (int) innerDiameter, (int) innerDiameter);
g2d.dispose();
}
protected Point getPointOnCircle(float degress, float radius) {
int x = Math.round(getWidth() / 2);
int y = Math.round(getHeight() / 2);
double rads = Math.toRadians(degress - 90); // 0 becomes the top
// Calculate the outter point of the line
int xPosy = Math.round((float) (x + Math.cos(rads) * radius));
int yPosy = Math.round((float) (y + Math.sin(rads) * radius));
return new Point(xPosy, yPosy);
}
}
}

How do I zoom inside JScrollPane with AffineTransform without shifting[EDITED]

I am trying to implement a zoom tool for my game editor. I am using a Color[] to store all the "Colors/tiles" and I want to be able to zoom inside my JPanel to view all the tiles upclose or from far away i.e zoomed in or zoomed out. These are some requirements that I would like to have(Any examples are appreciated and they don't need to include all or any of the requirements. They are there to help you understand what I am aiming for):
Zooming should be determined by a zoom variable that can be changed dynamicly(prefferably mouseWheel)
When zoomed(in or out) you should be able to navigate horisontaly and vertically with as little as possible tearing or other graphical glitches(using the JScrollBar s in the example)
The zooming should be based on where the mouse cursor is and zoom towards that point
The zooming can use anything inside normal Java which means no external libraries.
This is a very simple version of my editor. I added some test code for zooming but it doesn't work. I am giving you this code so you have something to start from if neccesary. See the PaintComponent method and the mouseWheel listener.
EDITED: Thanks to #trashgod you can now place colors at the right position. See MouseTest class!
The tearing is gone.
package stuff;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Rectangle;
import java.awt.RenderingHints;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.event.MouseWheelEvent;
import java.awt.event.MouseWheelListener;
import java.awt.geom.AffineTransform;
import java.awt.geom.NoninvertibleTransformException;
import java.util.Random;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.Scrollable;
import javax.swing.SwingUtilities;
public class ZoomPane extends JPanel implements MouseWheelListener, Scrollable {
private int width, height, screenWidth, screenHeight, tileSize;
private Color[] colorMap;
private double scale = 1.0;
// Zooming
AffineTransform at;
class MouseTest extends MouseAdapter {
public void mousePressed(MouseEvent e) {
try {
int newX = (int) at.inverseTransform(e.getPoint(), null).getX();
int newY = (int) at.inverseTransform(e.getPoint(), null).getY();
colorMap[(newX / tileSize) + ((newY / tileSize) * width)] = getRandomColor();
} catch (NoninvertibleTransformException e1) {
e1.printStackTrace();
}
repaint();
}
#Override
public void mouseDragged(MouseEvent e) {
super.mouseDragged(e);
try {
System.out.println("Dragging");
int newX = (int) at.inverseTransform(e.getPoint(), null).getX();
int newY = (int) at.inverseTransform(e.getPoint(), null).getY();
colorMap[(newX / tileSize) + ((newY / tileSize) * width)] = getRandomColor();
} catch (NoninvertibleTransformException e1) {
e1.printStackTrace();
}
repaint();
}
}
public ZoomPane(int width, int height, int tileSize) {
super();
this.width = width;
this.height = height;
this.screenWidth = width * tileSize;
this.screenHeight = height * tileSize;
this.tileSize = tileSize;
this.colorMap = new Color[width * height];
addMouseWheelListener(this);
addMouseListener(new MouseTest());
addMouseMotionListener(new MouseTest());
}
public void paintComponent(Graphics g) {
super.paintComponents(g);
final Graphics2D g2d = (Graphics2D) g.create();
g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
// Scale
at = null;
at = g2d.getTransform();
// Translate code here?
at.scale(scale, scale);
g2d.setTransform(at);
final Rectangle clip = g2d.getClipBounds();
g2d.setColor(Color.DARK_GRAY);
g2d.fill(clip);
int topX = clip.x / tileSize;
int topY = clip.y / tileSize;
int bottomX = clip.x + clip.width / tileSize + 1 + (int) (tileSize * scale);
int bottomY = clip.y + clip.height / tileSize + 1;
// Draw colors
for (int y = topY; y < bottomY; y++) {
for (int x = topX; x < bottomX; x++) {
Rectangle r = new Rectangle(width, height);
if (r.contains(x, y) && colorMap[x + y * width] != null) {
g2d.setColor(colorMap[x + y * width]);
g2d.fillRect(x * tileSize, y * tileSize, tileSize, tileSize);
}
}
}
g2d.dispose();
}
private Color getRandomColor() {
Random rand = new Random();
return new Color(rand.nextInt(255), rand.nextInt(255), rand.nextInt(255));
}
#Override
public Dimension getPreferredSize() {
return new Dimension((int) (screenWidth), (int) (screenHeight));
}
#Override
public void mouseWheelMoved(MouseWheelEvent e) {
double delta = 0.05 * e.getPreciseWheelRotation();
if (scale + delta > 0)
scale += delta;
revalidate();
repaint();
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
JFrame frame = new JFrame("Zoom test");
// Frame settings
frame.setVisible(true);
frame.setPreferredSize(new Dimension(800, 600));
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JScrollPane pane = new JScrollPane(new ZoomPane(50, 50, 32));
frame.add(pane);
frame.pack();
}
});
}
#Override
public Dimension getPreferredScrollableViewportSize() {
repaint();
return null;
}
#Override
public int getScrollableBlockIncrement(Rectangle visibleRect, int orientation, int direction) {
repaint();
return 0;
}
#Override
public boolean getScrollableTracksViewportHeight() {
repaint();
return false;
}
#Override
public boolean getScrollableTracksViewportWidth() {
repaint();
return false;
}
#Override
public int getScrollableUnitIncrement(Rectangle visibleRect, int orientation, int direction) {
repaint();
return 0;
}
}
If you try to run the program you will see these problems:
When you move the JScrollBars it seams that the mouse position gets an offset when you try to place a color.
If you zoom/scroll the mouse whell everything shifts up/down and left/right. I would like to zoom at the mouse cursor/point or atleast not shift everything sideways.
This is what works at the moment:
Placing of colors works correctly now.
Moving verticaly or horizontaly doesnt tear anymore.
As you see most of the requirements I mentioned at the top can be found in articles here on SO and most of them are really good and well described but I don't know/ can't implement them so that I can solve the problems above.
My goal with this zoom would be something like the example in here with the exception of drawing my "Colors/tiles" instead of the rectangles he draws and that I am using AffineTransform. Otherwise that example is really what I am aiming for.
It doesn't have to use any of the code he uses. I would preffer to use AffineTransform. If any of you knows how to implement what I am looking for in another way I am all ears. I thought that the example might make it easier for you guys to understand what I am aiming for.
I accept any changes or comments about the code or the implementaion and I will respond as quickly as I can and change the post.
Many thanks,
Towni0

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