Im working on a simple game engine using java.
Im want to make some light in the game and I want to use RadialGradientPaint.
Here is my light class
package engine.graphics;
import java.awt.AlphaComposite;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.RadialGradientPaint;
import java.awt.geom.Point2D;
import engine.Main;
import engine.maths.Vector2f;
public class Light
{
private Vector2f pos;
private int radius;
public Light(Vector2f pos, int radius)
{
this.pos = pos;
this.radius = radius;
}
public void render(Graphics g)
{
Graphics2D g2d = (Graphics2D)g;
Point2D center = new Point2D.Float(pos.x, pos.y);
float[] dist = {0.9f, 1.0f};
Color[] color = {new Color(0.0f, 0.0f, 0.0f, 0.1f), new Color(0, 0, 0, 255)};
RadialGradientPaint p = new RadialGradientPaint(center, radius, dist, color);
g2d.setPaint(p);
g2d.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_OVER, .95f));
g2d.fillRect(0, 0, Main.WIDTH, Main.HEIGHT);
g2d.dispose();
}
}
The problem that i found is that i cant draw more than one light.
How can i modify my code to make more lights?
Thank you..
I propose you this :
package solamda;
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.RadialGradientPaint;
import java.awt.geom.Point2D;
import javax.swing.JFrame;
import javax.swing.JLabel;
public class Main {
private static final Color transparency = new Color(0, 0, 0, 0);
private static final int WIDTH = 500;
private static final int HEIGHT = 500;
public static void main(String[] args) {
JFrame f = new JFrame();
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.setMinimumSize(new Dimension(WIDTH, HEIGHT));
f.setLayout(new BorderLayout());
f.add(new JLabel() {
#Override
public void paint(Graphics g) {
super.paint(g);
render(g);
}
});
f.pack();
f.setVisible(true);
}
public static void render(Graphics g) {
Graphics2D g2d = (Graphics2D) g;
Point[] lights = { new Point(WIDTH / 2, HEIGHT / 2), new Point(0,0),
new Point(WIDTH / 2+10, HEIGHT / 2), new Point(WIDTH / 2-10, HEIGHT / 2) };
for (Point center : lights) {
paintlight(g2d, center);
}
g2d.dispose();
}
private static void paintlight(Graphics2D g2d, Point center) {
float[] dist = { 0.2f, 1.0f };
Color[] color = { Color.white, transparency };
RadialGradientPaint p = new RadialGradientPaint(center, 10, dist, color);
g2d.setPaint(p);
g2d.fillRect(center.x - 20, center.y - 20, 40, 40);
}
}
You don need to fill whole rect just the part where the light is . So from your code i just extract a method where center is a parameter (call paintlight) then in your method render, i can draw as many ligh as i want ; i simply paint a white hallo arround this point and i keep the transparency in the pattern when i paint it
Related
I have created a JPanel and add it on a JFrame. JPanel has TitledBorder, but when I use the method translate(), e.g.,
g2.translate(getWidth() / 2, getHeight() / 2);
the whole component, including the border is translated. The effect is presented on Figure 1.
The desired result is depicted on the figure below.
Code is pasted below.
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import javax.swing.BorderFactory;
import javax.swing.JFrame;
import javax.swing.JPanel;
class GPanel extends JPanel {
private void doDrawing(Graphics g) {
Graphics2D g2 = (Graphics2D) g;
g2.translate(getWidth() / 2, getHeight() / 2);
}
#Override
public void paintComponent(Graphics g) {
super.paintComponent(g);
doDrawing(g);
}
}
class Main extends JFrame {
public Main() {
}
public static void main(String[] args) {
Main ex = new Main();
ex.setSize(new Dimension(400, 400));
GPanel panel = new GPanel();
panel.setBorder(BorderFactory.createTitledBorder("Title"));
ex.add(panel);
ex.setLocationRelativeTo(null);
ex.setVisible(true);
}
}
You have invoked setBorder() on an instance of GPanel and then modified the graphics context's transform in the latter's implementation of paintComponent(). The border doesn't know about this, so the result shown is entirely expected. Instead, follow the parent JComponent implementation advice for setBorder(): "put the component in a JPanel and set the border on the JPanel." A related example is shown here.
In the variation below,
The enclosing bPanel now has the Border, and the enclosed gPanel can safely manipulate the graphics context.
Before translate(), the red dot is centered on the origin; after translate(), the blue dot is centered on the origin, but the origin has moved.
Don't use setPreferredSize() when you really mean to override getPreferredSize().
Don't extend JFrame needlessly.
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import javax.swing.BorderFactory;
import javax.swing.JFrame;
import javax.swing.JPanel;
class GTest {
public static void main(String[] args) {
JFrame f = new JFrame();
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
GPanel gPanel = new GPanel();
JPanel bPanel = new JPanel();
bPanel.setBorder(BorderFactory.createTitledBorder("Title"));
bPanel.add(gPanel);
f.add(bPanel);
f.pack();
f.setLocationRelativeTo(null);
f.setVisible(true);
}
private static class GPanel extends JPanel {
private static final int N = 16;
private void doDrawing(Graphics g) {
Graphics2D g2 = (Graphics2D) g;
g2.setPaint(Color.red);
g.fillOval(-N, -N, 2 * N, 2 * N);
g2.translate(getWidth() / 2, getHeight() / 2);
g2.setPaint(Color.blue);
g.fillOval(-N, -N, 2 * N, 2 * N);
}
#Override
public void paintComponent(Graphics g) {
super.paintComponent(g);
doDrawing(g);
}
#Override
public Dimension getPreferredSize() {
return new Dimension(256, 256);
}
}
}
You might need to restore the move made by executing g2.translate(x, y); with g2.translate(-x, -y);:
Graphics2D g2 = (Graphics2D) g;
double x = getWidth() / 2d;
double y = getHeight() / 2d;
g2.translate(x, y);
g2.setPaint(Color.BLUE);
g2.fill(s);
g2.translate(-x, -y);
Another common way is to use a new Graphics object which is a copy of GPanel's Graphics object:
Graphics#create(), Graphics#dispose()
Graphics2D g2 = (Graphics2D) g.create();
g2.translate(getWidth() / 2, getHeight() / 2);
g2.setPaint(Color.BLUE);
g2.fill(s);
g2.dispose();
Main2.java
import java.awt.*;
import java.awt.geom.*;
import javax.swing.*;
class GPanel extends JPanel {
private final Rectangle s = new Rectangle(0, 0, 16, 16);
private void doDrawing(Graphics g) {
g.setColor(Color.RED);
g.fillRect(s.x, s.y, s.width, s.height);
// Graphics2D g2 = (Graphics2D) g;
// double x = getWidth() / 2d;
// double y = getHeight() / 2d;
// g2.translate(x, y);
// g2.setPaint(Color.BLUE);
// g2.fill(s);
// g2.translate(-x, -y);
Graphics2D g2 = (Graphics2D) g.create();
g2.translate(getWidth() / 2, getHeight() / 2);
g2.setPaint(Color.BLUE);
g2.fill(s);
g2.dispose();
}
#Override
public void paintComponent(Graphics g) {
super.paintComponent(g);
doDrawing(g);
}
}
public class Main2 extends JFrame {
public static void main(String[] args) {
EventQueue.invokeLater(() -> {
GPanel panel = new GPanel();
panel.setBorder(BorderFactory.createTitledBorder("Title"));
JFrame ex = new JFrame();
ex.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
ex.getContentPane().add(panel);
ex.setSize(400, 400);
ex.setLocationRelativeTo(null);
ex.setVisible(true);
});
}
}
try this code:
private void doDrawing(Graphics g) {
Graphics2D g2 = (Graphics2D) g;
g2.translate(0, 0);
}
Using Graphics2D, how can I take a black and white image, and use to define what should and what shouldn't rendered on another image?
E.g if I had an image of say, a field, and on that field is a cow, and on another image of the same dimensions I draw a white box on a black background, at the same coordinates of the cow, when rendered in Java the image would be all black, apart from the cow where I had the white box?
EDIT: Based on a long discussion in the chat, it became clear that there was a misunderstanding about the intention, and the original question suffered from the XY-Problem: The question of how to compose an image with a masking image was only about one solution attempt for the actual problem - namely painting some shadow/light effects on a tile map. The original versions of the post can be seen in the revision history.
The actual goal was obviously to add a "light effect" over the image. Here is an example of how this can be achieved:
The original image is painted in the background
A "shadow image" is painted over the image.
The "shadow image" is initially a nearly opaqe, nearly black image. The lights are painted into this image, with a RadialGradientPaint. The colors for this paint are chosen so that they make the shadow image less opaque and less black at the places where the lights should be. This causes these areas to appear lighted, while the other parts remain dark.
import java.awt.AlphaComposite;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.MultipleGradientPaint.CycleMethod;
import java.awt.Point;
import java.awt.RadialGradientPaint;
import java.awt.event.MouseEvent;
import java.awt.event.MouseMotionListener;
import java.awt.geom.Point2D;
import java.awt.image.BufferedImage;
import java.util.Random;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
public class LightEffectTest2
{
public static void main(String args[])
{
SwingUtilities.invokeLater(new Runnable()
{
public void run()
{
new LightEffectTest2();
}
});
}
public LightEffectTest2()
{
JFrame f = new JFrame();
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.getContentPane().add(new LightEffectPanel2());
f.setSize(600,600);
f.setVisible(true);
}
}
class LightEffectPanel2 extends JPanel implements MouseMotionListener
{
private Point point = new Point(0,0);
private BufferedImage image;
private BufferedImage shadow;
public LightEffectPanel2()
{
image = createExampleImage(600,600);
shadow = new BufferedImage(image.getWidth(), image.getHeight(),
BufferedImage.TYPE_INT_ARGB);
addMouseMotionListener(this);
}
private static BufferedImage createExampleImage(int w, int h)
{
BufferedImage image = new BufferedImage(w, h,
BufferedImage.TYPE_INT_ARGB);
Graphics g = image.getGraphics();
Random random = new Random(0);
for (int i=0; i<200; i++)
{
int x = random.nextInt(w);
int y = random.nextInt(h);
Color c = new Color(
random.nextInt(255),
random.nextInt(255),
random.nextInt(255));
g.setColor(c);
g.fillOval(x-20, y-20, 40, 40);
}
g.dispose();
return image;
}
#Override
protected void paintComponent(Graphics gr)
{
super.paintComponent(gr);
Graphics2D g = (Graphics2D)gr;
g.drawImage(image, 0,0,null);
drawLights();
g.drawImage(shadow, 0,0, null);
}
private void drawLights()
{
Graphics2D g = shadow.createGraphics();
g.setComposite(AlphaComposite.Src);
g.setColor(new Color(0,0,16,240));
g.fillRect(0,0,getWidth(),getHeight());
drawLight(g, new Point(100,100));
drawLight(g, point);
g.dispose();
}
private void drawLight(Graphics2D g, Point pt)
{
float radius = 100;
g.setComposite(AlphaComposite.DstOut);
Point2D center = new Point2D.Float(pt.x, pt.y);
float[] dist = {0.0f, 1.0f};
Color[] colors = {new Color(255,255,255,255), new Color(0,0,0,0) };
RadialGradientPaint p =
new RadialGradientPaint(
center, radius, dist, colors, CycleMethod.NO_CYCLE);
g.setPaint(p);
g.fillOval(pt.x-(int)radius,pt.y-(int)radius,(int)radius*2,(int)radius*2);
}
#Override
public void mouseDragged(MouseEvent e) {
}
#Override
public void mouseMoved(MouseEvent e) {
point = e.getPoint();
repaint();
}
}
(late) EDIT For the request in the comments:
To add another shadow (regardless of the existing lights), one can create a drawShadow method that re-applies the shadows after the lights have been drawn. It basically uses another RadialGradientPaint that partially "restores" the original, opaqe, dark shadow image.
(The shadow is given a somewhat sharper border here, to make the effect more visible)
import java.awt.AlphaComposite;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.MultipleGradientPaint.CycleMethod;
import java.awt.Point;
import java.awt.RadialGradientPaint;
import java.awt.event.MouseEvent;
import java.awt.event.MouseMotionListener;
import java.awt.geom.Point2D;
import java.awt.image.BufferedImage;
import java.util.Random;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
public class LightEffectTest3
{
public static void main(String args[])
{
SwingUtilities.invokeLater(new Runnable()
{
public void run()
{
new LightEffectTest3();
}
});
}
public LightEffectTest3()
{
JFrame f = new JFrame();
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.getContentPane().add(new LightEffectPanel3());
f.setSize(600,600);
f.setVisible(true);
}
}
class LightEffectPanel3 extends JPanel implements MouseMotionListener
{
private Point point = new Point(0,0);
private BufferedImage image;
private BufferedImage shadow;
public LightEffectPanel3()
{
image = createExampleImage(600,600);
shadow = new BufferedImage(image.getWidth(), image.getHeight(),
BufferedImage.TYPE_INT_ARGB);
addMouseMotionListener(this);
}
private static BufferedImage createExampleImage(int w, int h)
{
BufferedImage image = new BufferedImage(w, h,
BufferedImage.TYPE_INT_ARGB);
Graphics g = image.getGraphics();
Random random = new Random(0);
for (int i=0; i<200; i++)
{
int x = random.nextInt(w);
int y = random.nextInt(h);
Color c = new Color(
random.nextInt(255),
random.nextInt(255),
random.nextInt(255));
g.setColor(c);
g.fillOval(x-20, y-20, 40, 40);
}
g.dispose();
return image;
}
#Override
protected void paintComponent(Graphics gr)
{
super.paintComponent(gr);
Graphics2D g = (Graphics2D)gr;
g.drawImage(image, 0,0,null);
drawLights();
g.drawImage(shadow, 0,0, null);
}
private void drawLights()
{
Graphics2D g = shadow.createGraphics();
g.setComposite(AlphaComposite.Src);
g.setColor(new Color(0,0,16,240));
g.fillRect(0,0,getWidth(),getHeight());
drawLight(g, new Point(200,200));
drawLight(g, point);
drawShadow(g, new Point(250,250));
g.dispose();
}
private void drawLight(Graphics2D g, Point pt)
{
float radius = 150;
g.setComposite(AlphaComposite.DstOut);
Point2D center = new Point2D.Float(pt.x, pt.y);
float[] dist = {0.0f, 1.0f};
Color[] colors = {new Color(255,255,255,255), new Color(0,0,0,0) };
RadialGradientPaint p =
new RadialGradientPaint(
center, radius, dist, colors, CycleMethod.NO_CYCLE);
g.setPaint(p);
g.fillOval(pt.x-(int)radius,pt.y-(int)radius,
(int)radius*2,(int)radius*2);
}
private void drawShadow(Graphics2D g, Point pt)
{
float radius = 75;
g.setComposite(AlphaComposite.DstOver);
Point2D center = new Point2D.Float(pt.x, pt.y);
float[] dist = {0.0f, 0.7f, 1.0f};
Color[] colors = {
new Color(0,0,0,200),
new Color(0,0,0,150),
new Color(255,255,255,0) };
RadialGradientPaint p =
new RadialGradientPaint(
center, radius, dist, colors, CycleMethod.NO_CYCLE);
g.setPaint(p);
g.fillOval(pt.x-(int)radius,pt.y-(int)radius,
(int)radius*2,(int)radius*2);
}
#Override
public void mouseDragged(MouseEvent e) {
}
#Override
public void mouseMoved(MouseEvent e) {
point = e.getPoint();
repaint();
}
}
Okay, this seems like a really simple task but I can't seem to get it. All I want is to have an image (jpg) as the background to my breakout game. Here is my code:
Main Class:
import java.awt.BorderLayout;
import java.awt.Color;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JLabel;
public class Breakout extends JFrame {
public Breakout()
{
add(new BreakBoard());
setTitle("Breakout");
setSize(BreakCommons.WIDTH, BreakCommons.HEIGTH);
setLocationRelativeTo(null);
setIgnoreRepaint(true);
setResizable(false);
setVisible(true);
}
public static void main(String[] args) {
new Breakout();
}
}
Board Class:
import java.awt.Color;
import java.awt.Font;
import java.awt.FontMetrics;
import java.awt.Graphics;
import java.awt.Point;
import java.awt.Toolkit;
import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;
import java.util.Timer;
import java.util.TimerTask;
import javax.swing.ImageIcon;
import javax.swing.JLabel;
import javax.swing.JPanel;
public class BreakBoard extends JPanel implements BreakCommons {
ImageIcon icon = new ImageIcon("../pacpix/love.jpg");
Timer timer;
String message = "Game Over";
BreakBall ball;
BreakPaddle paddle;
BreakBrick bricks[];
boolean ingame = true;
int timerId;
public BreakBoard() {
setOpaque(false);
addKeyListener(new TAdapter());
setFocusable(true);
//setBackground(Color.white);
bricks = new BreakBrick[30];
setDoubleBuffered(true);
timer = new Timer();
timer.scheduleAtFixedRate(new ScheduleTask(), 1000, 10);
}
public void paint(Graphics g) {
super.paint(g);
g.drawImage(icon.getImage(), 10, 10, this);
if (ingame) {
g.drawImage(ball.getImage(), ball.getX(), ball.getY(),
ball.getWidth(), ball.getHeight(), this);
g.drawImage(paddle.getImage(), paddle.getX(), paddle.getY(),
paddle.getWidth(), paddle.getHeight(), this);
for (int i = 0; i < 30; i++) {
if (!bricks[i].isDestroyed())
g.drawImage(bricks[i].getImage(), bricks[i].getX(),
bricks[i].getY(), bricks[i].getWidth(),
bricks[i].getHeight(), this);
}
} else {
Font font = new Font("Verdana", Font.BOLD, 18);
FontMetrics metr = this.getFontMetrics(font);
g.setColor(Color.BLACK);
g.setFont(font);
g.drawString(message,
(BreakCommons.WIDTH - metr.stringWidth(message)) / 2,
BreakCommons.WIDTH / 2);
}
Toolkit.getDefaultToolkit().sync();
g.dispose();
}
So the image is stored in variable icon and is located in my source files (along with my classes) so I know that the path is right. I tried setting the frame and panel to setOpaque(false) but that just changed the background to default grey. I can easily set the background color by setBackground(Color.white);, but how do I set an image?
I tried putting the image in a JLabel and then adding it to the JPanel, but that produced no results. I would appreciate any help, and thanks in advance! I can provide more information as needed.
easy way first create a separate class for jpane
import java.awt.Color;
import java.awt.GradientPaint;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.Paint;
import javax.swing.ImageIcon;
import javax.swing.JPanel;
public class JPanelDemo extends JPanel {
/**
*
*/
private static final long serialVersionUID = 1L;
private static final Color BACKGROUND = Color.black;
private static final Color BACKGROUND_2 = Color.WHITE;
String path="/img/background.jpg";
#Override
protected void paintComponent(Graphics g) {
Graphics2D graphics = (Graphics2D) g.create();
int midY = 100;
Paint topPaint = new GradientPaint(0, 0, BACKGROUND,0, midY, BACKGROUND_2);
graphics.setPaint(topPaint);
graphics.fillRect(0, 0, getWidth(), midY);
Paint bottomPaint = new GradientPaint(0, midY + 1, BACKGROUND_2,0, getHeight(), BACKGROUND);
graphics.setPaint(bottomPaint);
graphics.fillRect(0, midY, getWidth(), getHeight());
Image img = new ImageIcon(getClass().getResource(path)).getImage();
int imgX = img.getWidth(null);
int imgY = img.getHeight(null);
graphics.drawImage(img, (getWidth() - imgX) / 2, (getHeight() - imgY) / 2, imgX, imgY, null);
// graphics.dispose();
}
}
how use it
JPanelDemo contentPane = new JPanelDemo();
This is a JPanel with a background image. Use IPanel in place of JPanel in your code. Tweak as necessary to suit your needs.
public class IPanel extends JPanel {
private static final long serialVersionUID = 1L;
private Image imageOrg = null;
private Image image = null;
{
addComponentListener(new ComponentAdapter() {
#Override
public void componentResized(final ComponentEvent e) {
final int w = IPanel.this.getWidth();
final int h = IPanel.this.getHeight();
image = w > 0 && h > 0 ? imageOrg.getScaledInstance(w, h, Image.SCALE_SMOOTH) : imageOrg;
IPanel.this.repaint();
}
});
}
public IPanel(final Image i) {
imageOrg = i;
image = i;
}
#Override
public void paintComponent(final Graphics g) {
super.paintComponent(g);
if (image != null)
g.drawImage(image, 0, 0, null);
}
}
Example:
final JPanel j = new IPanel(image);
j.setLayout(new FlowLayout());
j.add(new JButton("YoYo"));
j.add(new JButton("MaMa"));
j.add(new JLabel(icon));
Produces:
I got it to work finally!
public class BreakBoard extends JPanel implements BreakCommons {
Image love;
public BreakBoard() {
ImageIcon icon = new ImageIcon(this.getClass().getResource("../pacpix/love.jpg"));
love = icon.getImage();
}
public void paint(Graphics g) {
super.paint(g);
Graphics2D g2d = (Graphics2D) g;
g2d.drawImage(love, 10, 10, null);
}
}
For future searches or those that are curious, I used http://zetcode.com/tutorials/javagamestutorial/basics/. Great site for beginners! (Or those that need dumbing-down to understand)
JPanel panel = new JPanel()
{
#Override
public void paintComponent(Graphics g)
{
g.drawImage(ImageObject, 0, 0, null);
}
};
I have written a code that draws grids and a triangle inside one grid cell. The grid size is increased/decreased when the window is maximized or minimized.
My requirement is that the triangle size should also increase/decrease to fit the grid cell each time the grid size is increased/decreased.
My code is as follows:
import java.awt.BasicStroke;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Polygon;
import java.awt.RenderingHints;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class Grid extends JPanel {
/**
* #param args
*/
public static void main(String[] args) {
Grid g = new Grid();
JFrame f = new JFrame("Application GUI Window");
f.addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent e) {System.exit(0);}
});
f.getContentPane().add("Center", g);
f.pack();
f.setSize(new Dimension(450,400));
f.show();
}
public void paint(Graphics g) {
Graphics2D g2d = (Graphics2D) g;
Dimension d = getSize();
g2d.setBackground(getBackground());
g2d.clearRect(0, 0, d.width, d.height);
g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
RenderingHints.VALUE_ANTIALIAS_ON);
drawGrid(d.width, d.height, g2d);
int[] xPoints = {20,15,25};
int[] yPoints = {15,25,25};
int n = 3;
Polygon triangle = new Polygon(xPoints, yPoints, n);
g.fillPolygon(triangle);
}
private void drawGrid(int width, int height, Graphics2D g2d) {
/* BasicStroke border = new BasicStroke(3, BasicStroke.CAP_SQUARE, BasicStroke.JOIN_ROUND, 0, new float[]{0,1,0,1}, 0);
g2d.setStroke(border);
g2d.drawRect(3,3,width-6,height-6);*/
//horizontal lines
int cellheight = height/10;
int cellwidth = width/5;
for (int j=0;j<height;j=j+cellheight)
{
BasicStroke line = new BasicStroke(1, BasicStroke.CAP_SQUARE, BasicStroke.JOIN_ROUND, 0, new float[]{0,1,0,1}, 0);
g2d.setStroke(line);
g2d.drawLine(0, j, cellwidth*5, j);
}
//vertical lines
for (int i=0;i<width;i=i+cellwidth)
{
BasicStroke line = new BasicStroke(1, BasicStroke.CAP_SQUARE, BasicStroke.JOIN_ROUND, 0, new float[]{0,1,0,1}, 0);
g2d.setStroke(line);
g2d.drawLine(i, 0, i, cellheight*10);
}
}
}
Thanks in advance for your help.
You can tie the coordinates of the triangle to the dimensions of a grid cell. Here is a snippet based on your example:
int cellHeight = d.height/10;
int cellWidth = d.width/5;
int xOffset = cellWidth/6;
int yOffset = cellHeight/6;
int[] xPoints = {cellWidth/2, xOffset, cellWidth - xOffset};
int[] yPoints = {yOffset, cellHeight - yOffset, cellHeight - yOffset};
Polygon triangle = new Polygon(xPoints, yPoints, xPoints.length);
Note that in Swing you usually should override paintComponent() rather than paint(), unless in some special cases. See A Closer Look at the Paint Mechanism for more details.
Also note that show() is deprecated in favor of setVisible(). You can replace it with: setVisible(true)
I am writing a test app. To set Alpha for image I use paintComponent method. Watch next snippet...
public class TestImage extends JLabel{
public void paintComponent( Graphics g ) {
super.paintComponent( g );
Graphics2D g2d=(Graphics2D)g;
g2d.drawImage(this.bImage, rop, 0, 0);
}
public void setRescaleOp(RescaleOp rop){this.rop=rop;}
}
As you can see,
g2d.drawImage(this.bImage, rop, 0, 0);
does not allow to set width and height as if I use g.drawImage(bImage, 0, 0,width,height, null);
So the question is... How to set width and height for bImage in this case?
Any useful comment is appreciated
Andrew
First filter(), as shown here, and then scale using drawImage() or AffineTransformOp, as shown here.
Addendum: Alternatively, you can scale the image first (using either approach above) and then use your RescaleOp in drawImage().
As an aside, RescaleOp scales the image's color bands; it does not change the image's dimensions. To avoid confusion, dimensional scaling is sometimes called resampling.
Addendum: Here's an example of using drawImage() to resample and RescaleOp to adjust the alpha of an image.
import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.image.BufferedImage;
import java.awt.image.RescaleOp;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JSlider;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;
/**
* #see https://stackoverflow.com/questions/5838842
* #see https://stackoverflow.com/questions/5864490
*/
public class AlphaTest {
private static void display() {
JFrame f = new JFrame("AlphaTest");
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
ImageIcon icon = new ImageIcon("image.jpg");
final AlphaPanel ip = new AlphaPanel(icon, 0.75);
final JSlider slider = new JSlider();
slider.addChangeListener(new ChangeListener() {
#Override
public void stateChanged(ChangeEvent e) {
int v = slider.getValue();
ip.setAlpha((float) v / slider.getMaximum());
ip.repaint();
}
});
f.add(ip, BorderLayout.CENTER);
f.add(slider, BorderLayout.SOUTH);
f.pack();
f.setLocationRelativeTo(null);
f.setVisible(true);
}
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
display();
}
});
}
}
class AlphaPanel extends JPanel {
private BufferedImage bi;
private float[] scales = {1f, 1f, 1f, 0.5f};
private float[] offsets = new float[4];
private RescaleOp rop;
public AlphaPanel(ImageIcon icon, double scale) {
int width = (int) (scale * icon.getIconWidth());
int height = (int) (scale * icon.getIconHeight());
this.setPreferredSize(new Dimension(width, height));
this.bi = new BufferedImage(
width, height, BufferedImage.TYPE_INT_ARGB);
this.bi.createGraphics().drawImage(
icon.getImage(), 0, 0, width, height, null);
rop = new RescaleOp(scales, offsets, null);
}
#Override
public void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g;
g2d.drawImage(bi, rop, 0, 0);
}
public void setAlpha(float alpha) {
this.scales[3] = alpha;
this.rop = new RescaleOp(scales, offsets, null);
}
}