I am working on a project and i have already made a menu and a JPanel but now i want to draw over the JPanel and add some HUD to my game.
I am providing a picture with the final panel of my game and i want to add at the left a blue rectangle with the player heads and at the right another rectangle with actions, money etc but i want to construct them outside my Window class where i construct the frame and all of the JPanels. Generally now that the player has chosen to play a local game i want to be able to draw and erase on this panel as the game continues.
private void render() {
BufferStrategy bs = this.getBufferStrategy();
if (bs == null) {
this.createBufferStrategy(1);
return;
}
Graphics g = null;
window.render();
if (gameState == STATE.MultiPlay) {
handler.render(g);
hud.render(g);
}
if (gameState == STATE.LocalPlay) {
handler.render(g);
hud.render(g);
}
}
The code i provided is the render method i am using at my game engine class. With my game engine i have made this method circles 10 times per second and i wanted from here to instantiate the Graphics class and then go on with the other class and rendering everything i want to draw over that JPanel.
How can i draw over that JPanel using Graphics or something like that?
You must use Graphics object like that:
Graphics g= bs.getDrawGraphics();
I think it will be usefull, have a nice day.
PD: If you don't want to do that, you can also override the method paint(Graphcis g) and use the parameter.
Related
I'm pretty new to Java and the GUI world. Right now I'm trying to create a really basic space shooter. To create it I started creating a JFrame, in which I've later on put a personal extension of a JPanel called GamePanel, on which I'm now trying to display all my components. Until here it's all pretty clear, the problem comes now: I have my GamePanel in which I display my player, and on the KeyEvent of pressing S the player should shoot the Bullets. I've managed the bullets as an Array, called Shooter[], of Bullet Objects, created by myself this way:
public class Bullet implements ActionListener{
Timer Time = new Timer(20, this);
private int BulletY = 430;
public int PlayerX;
public Rectangle Bound = new Rectangle();
public Bullet(int playerx) {
this.PlayerX = playerx;
Time.start();
}
public void draw(Graphics g){
g.setColor(Color.RED);
g.fillRect(PlayerX + 2, BulletY, 3, 10);
g.dispose();
}
#Override
public void actionPerformed(ActionEvent e) {
if (Time.isRunning()) {
BulletY = BulletY - 5;
Bound = new Rectangle (PlayerX + 2, BulletY, 3, 10);
}
}
}
I thought that calling the draw method in the GamePanel's paint() method would have allowed me to display both all the bullets shot and the player. What actually happens is that at the start it seems allright, but when I press S the player disappears and just one bullet is shot. Can you explain me why? This is how my paint() method looks like:
public void paint(Graphics g) {
g.setColor(Color.BLACK);
g.fillRect(0, 0, 500, 500);
for(int i = 0; i < BulletsCounter; i++) {
Shooter[i].draw(g);
}
g.setColor(Color.RED);
g.fillRect(PlayerX, PlayerY, 20, 20);
//System.out.println("Here I should have painted the player...");
g.dispose();
}
BulletsCounter is a counter I've created to avoid any NullPointerExceptions in painting the whole array, it increases when S is pressed and so another bullet of the array is initialized and shot.
Thank you for your patience, I'm new to the site, so warn me for any mistake.
You've several significant problems, the biggest given first:
You're disposing a Graphics object given to you by the JVM. Never do this as this will break the painting chain. Instead, only dispose of a Graphics object that you yourself have created.
You're drawing within paint which is not good for several reasons, but especially bad for animation since you don't have automatic double buffering of the image
You don't call the super painting method within your override and thus don't allow the JPanel to do house-keeping painting.
Recommendations:
Don't dispose of the Graphics object, not unless you, yourself, create it, for example if you extract one from a BufferedImage.
Override the JPanel's paintComponent method, not its paint method to give you double buffering and smoother animation.
And call super.paintComponent(g) first thing in your override to allow for housekeeping painting
I am trying to make a snake game in java but the thing i am trying to make is not a normal snake game. I want to make a snake game which is snake (player) can go to every direction (like in slither.io game).
And i am trying to make a snake from circles.
I am trying to use Graphics2D for it and I successfully draw a circle.
But I couldnt make it lot of circles which is attached to eachothers. (I tryed to use arrayList).
Also like in classical snake game i want to make snake grow when it eats food.
But instead of making it longer i need to add more circles.
Code i wrote for the circle (script name is also "Circle");
public void drawToScreen(Graphics2D g)
{
g.setColor(GameConstants.BORDER_COLOR);
BasicStroke stroke = new BasicStroke(5);
g.setStroke(stroke);
Ellipse2D border = new Ellipse2D.Double(getX()-getSize()/2, getY()-getSize()/2, getSize(), getSize());
g.draw(border);
g.setColor(getColor());
Ellipse2D shape = new Ellipse2D.Double(getX()-getSize()/2, getY()-getSize()/2, getSize(), getSize());
g.fill(shape);
setBounds(shape.getBounds());
// Here is for the username
g.setColor(Color.BLACK);
g.setFont(new Font("Arial", Font.PLAIN, 14));
int width = g.getFontMetrics().stringWidth(getName());
g.drawString(getName(), (int)(getX()-width/2), (int)(getY()+5));
}
I have another script ("GamePanel") which I set up game, in that script I call some function whit this codes.
private Circle player;
player = new Circle(GameConstants.START_SIZE, spawnPoint.getX(), spawnPoint.getY(), randomColor(), GameConstants.START_VELOCITY, name);
player.drawToScreen(g2);
g2.translate(viewX, viewY);
I have zero clue what a "Script" is in Java.
But here is the source code to a game with very similar aspects that you can draw lessons from.
I made the Enemy ai a tad to intelligent, but you you will see how to do what you are asking in this code.
The Great Escape
Following a guide that was released in Nov, 2015. I have copied his code verbatim at this point and it still won't work for me. Has something been deprecated?
I have 3 buffers (call them 1,2, and 3). When 2 and 3 are drawn to the screen they have black lines on the top and left sides of the screen. This same code works fine with two buffers.
Bug footage: https://gfycat.com/gifs/detail/GraveCompetentArmyworm
package field;
import javax.swing.JFrame;
import java.awt.*;
import java.awt.image.BufferStrategy;
public class Main extends JFrame{
private Canvas canvas=new Canvas();
public Main() {
setDefaultCloseOperation(EXIT_ON_CLOSE);
setBounds(0,0,1000,1000);
setLocationRelativeTo(null);
add(canvas);
setVisible(true);
canvas.createBufferStrategy(3);
BufferStrategy buffert = canvas.getBufferStrategy();
int p=0;
int ap=0;
while(p<1000) {
if (ap==100){
p++;
ap=0;
}
ap++;
buffert=canvas.getBufferStrategy();
Graphics g = buffert.getDrawGraphics();
super.paint(g);
g.setColor(Color.GREEN);
g.fillOval(p+100, 200, 50, 50);
buffert.show();
}
}
// public void paint(Graphics graphics) {
// super.paint(graphics);
// graphics.setColor(Color.RED);
// graphics.fillOval(100, 100, 100, 100);
//
// }
public static void main(String[] args){
new Main();
}
}
You need to go read the JavaDocs for BufferStrategy and Full-Screen Exclusive Mode API, which a number of important tutorials and examples on BufferStrategy
A BufferStrategy is a means to perform "page flipping", which is independent of the regular painting system. This provides you with "active" control over the painting process. Each buffer is updated off screen and the pushed onto the screen when it's ready.
This generally does not involve the component's own painting system and the intention is to avoid it.
This means you should NOT be calling super.paint(g) on the JFrame or canvas.paint. In fact, as a general rule, you should NEVER call paint manually.
Each time you want to update a buffer, you will be required to "prepare" it. This typically means filling it with some base color
So, based on the example from the JavaDocs, you could do something like...
// Check the capabilities of the GraphicsConfiguration
...
// Create our component
Window w = new Window(gc);
// Show our window
w.setVisible(true);
// Create a general double-buffering strategy
w.createBufferStrategy(2);
BufferStrategy strategy = w.getBufferStrategy();
// Main loop
while (!done) {
// Prepare for rendering the next frame
// ...
// Render single frame
do {
// The following loop ensures that the contents of the drawing buffer
// are consistent in case the underlying surface was recreated
do {
// Get a new graphics context every time through the loop
// Determine the current width and height of the
// output
int width = ...;
int height = ...l
// to make sure the strategy is validated
Graphics graphics = strategy.getDrawGraphics();
graphics.setColor(Color.WHITE);
graphics.fillRect(0, 0, width, height);
// Render to graphics
// ...
// Dispose the graphics
graphics.dispose();
// Repeat the rendering if the drawing buffer contents
// were restored
} while (strategy.contentsRestored());
// Display the buffer
strategy.show();
// Repeat the rendering if the drawing buffer was lost
} while (strategy.contentsLost());
}
// Dispose the window
w.setVisible(false);
w.dispose();
Now, personally, I'd prefer to use Canvas as the base, as it gives a more re-usable solution and it's easier to determine dimensions from
As the title suggests, my problem is that I want to be able to drag an image.
In this specific case, I want to drag an image from one JPanel (or rather my own subclass) into another (different) subclass of JPanel. Therefore, I added an MouseListener to my JPanel subclass, so that upon clicking a certain area in the panel, an image is chosen to be painted on the JFrame (subclass). Here's some code so you'll understand my problem:
public void mousePressed(MouseEvent e) {
int x = e.getX();
int y = e.getY();
if (x >= 10 && x < 42 && y >= 10 && y < 42) {
image = barracks; //barracks is a predefined image, created in the constructor
dragBuilding = true;
PixelMain.pixelMain.repaint(); //pixelMain is an instance of the JFrame subclass
}
}
//irrelevant code, e.g mouseMoved, ...
public void mouseDragged(MouseEvent e) {
if (dragBuilding) {
//System.out.println("GPanel mouseDragged");
PixelMain.pixelMain.repaint();
}
}
the JFrame subclass only contains the constructor and the following code:
public void paint(Graphics g) { //i would have used paintComponent, but it seems like JFrame does not have this method ...?
super.paint(g);
if (PixelMain.panelOffense.getDragBuilding()) { //panelOffense is an instance of the JPanel subclass, getDragBuilding returns a boolean that depends on whether the mouse is held down at the moment
Graphics2D g2 = (Graphics2D) g;
Rectangle2D tr = new Rectangle2D.Double((int)getMousePosition().getX(), (int)getMousePosition().getY(), 16, 16); //size of the texture
TexturePaint tp = new TexturePaint(PixelMain.panelOffense.getImg(), tr);
g2.setPaint(tp);
Rectangle2D r = (Rectangle2D) new Rectangle((int)getMousePosition().getX(), (int)getMousePosition().getY(), 16, 16); //area to fill with texture
g2.fill(r);
System.out.println("test");
}
}
Before you ask - I did move some code to other classes so it's called less often, but that's not the problem. Even if the paint method only draws a rectangle (directly on Graphics g, not Graphics2D), the rectangle flickers.
If anyone could help me figure out a solution, I'd be very thankful!
Note: I know it's probably not very elegant to draw on a JFrame or a subclass of JFrame, but I personally don't know an alternative.
Note 2: According to google/stackoverflow results or threads that I read, I should use a JPanel, which seems to be double-buffered (whatever that is, I didn't really understand that. but then again, it's almost 11 pm here). Hence, I could probably move all my components to a JPanel to solve the issue, but I wanted to try to solve the problem without doing that.
Note 3: Yes, the code belongs to a (strategy) game I'm writing, but considering that the problem is not really related to game development exclusively, I decided to post it here and not at game development stack exchange.
Ok dear folks, i've got this question and i don't really know a certain way to solve it.
I'm doing like a "Paint application" in java, i know everything is ready, but I need to paint the shapes with Computer Graphics Algorithms.
So, the thing is, once the shape is painted in the container how could I convert it like sort of an "Object" to be able to select the shape and move it around (I have to move it with another algorithm) I just want to know how could I know that some random point clicked in the screen belongs to an object, knowing that, I would be able to fill it(with algorithm).
I was thinking that having a Point class, and a shape class, if i click on the screen, get the coordinates and look within all the shapes and their points, but this may not be very efficient.
Any ideas guys ?
Thanks for the help.
Here is some of my code:
public class Windows extends JFrame{
private JPanel panel;
private JLabel etiqueta,etiqueta2;
public Windows() {
initcomp();
}
public void initcomp()
{
panel = new JPanel();
panel.setBounds(50, 50, 300, 300);
etiqueta = new JLabel("Circulo Trigonometrico");
etiqueta.setBounds(20, 40, 200, 30);
etiqueta2 = new JLabel("Circulo Bresenham");
etiqueta2.setBounds(150, 110, 200, 30);
panel.setLayout(null);
panel.add(etiqueta);
panel.add(etiqueta2);
panel.setBackground(Color.gray);
this.add(panel);
this.setLayout(null);
this.setVisible(true);
this.setSize(400,400);
this.setDefaultCloseOperation(EXIT_ON_CLOSE);
}
public void paint(Graphics g){
super.paint(g);
Graphics2D g2d = (Graphics2D) g;
g2d.setColor(Color.red);
g2d.setStroke(new BasicStroke(2));
dibujarCirculo_bresenham(g2d, 50, 260, 260);
dibujarCirculo_trigonometrico(g2d, 50, 130, 200);
}
/*This functions paints a Circle*/
public void dibujarCirculo_trigonometrico(Graphics g,int R,int xc,int yc)
{
int x,y;
for (int i = 0; i < 180; i++) {
double angulo = Math.toRadians(i);
x = (int) (Math.cos(angulo)*R);
y = (int) (Math.sin(angulo)*R);
g.drawLine(x+xc, y+yc, x+xc, y+yc);
g.drawLine((-x+xc), (-y+yc), (-x+xc), (-y+yc));
}
}
I assume that any image is a valid (isn't constrained to a particular set of shapes). To get an contiguous area with similar properties, try using a flood fill.
To colour in or move a particular shape around, you can use flood fill to determine the set of pixels and manipulate the set accordingly. You can set a tolerance for similar hue, etc so that it's not as rigid as in Paint, and becomes more like the magic selection tool in Photoshop.
There are a couple of approaches to take here depending on what precisely you want.
1) is to have objects, one for each drawn thing on screen, with classes like Circle and Rectangle and Polygon so on. They would define methods like paint (how to draw them on screen), isCLickInsideOf (is a click at this point on screen contained by this shape, given size/position/etc?) and so on. Then, to redraw the screen draw each object, and to test if an object is being clicked on ask each object what it thinks.
2) is, if objects have the property of being uniform in colour, you can grab all pixels that make up a shape when the user clicks on one of the pixels by using a floodfill algorithm. Then you can load these into some kind of data structure, move them around as the user moves the mouse around, etc. Also, if every object is guaranteed to have a unique colour, you can test which object is being clicked on by just looking at colour. (Libraries like OpenGL use a trick like this sometimes to determine what object you have clicked on - drawing each object as a flat colour on a hidden frame and testing what pixel colour under the mouse pointer is)