I'm doing a Java Project that consists of making a "Space Invaders" clone. I'm starting with the ship movement, searching on stackOverflow I found this code:
if(Gdx.input.isKeyPressed(Input.Keys.LEFT) )
x -= Gdx.graphics.getDeltaTime() * PlayerSpeed;
if(Gdx.input.isKeyPressed(Input.Keys.RIGHT) )
x += Gdx.graphics.getDeltaTime() * PlayerSpeed;
I use it to the playerShip(the class below):
public class PlayerShip extends Ship {
private Animator animator;
private float PlayerSpeed = 20.0f;
private int x,y;
public PlayerShip(SpriteBatch batch){
this.animator=new Animator(batch,"ship.png", 5, 2);
}
public void create(){
animator.create();
}
public void render(){
this.animator.render(this.x,this.y);
if(Gdx.input.isKeyPressed(Input.Keys.LEFT) )
x -= Gdx.graphics.getDeltaTime() * PlayerSpeed;
if(Gdx.input.isKeyPressed(Input.Keys.RIGHT) )
x += Gdx.graphics.getDeltaTime() * PlayerSpeed;
}
public void setX(int x) {
this.x = x;
}
public void setY(int y) {
this.y = y;
}
}
Game(main):
public class Game extends ApplicationAdapter {
private SpriteBatch batch;
private BackgroundManagement backgroundManagement;
private BitmapFont font;
private PlayerShip player;
private SmallShip smallShip;
#Override
public void create() {
Gdx.graphics.setWindowedMode(600, 800);
batch = new SpriteBatch();
player = new PlayerShip(batch);
smallShip = new SmallShip(batch);
player.create();
player.setX(300);
player.setY(100);
smallShip.create();
smallShip.setX(200);
smallShip.setY(400);
font = new BitmapFont(Gdx.files.internal("gamefont.fnt"),
Gdx.files.internal("gamefont.png"), false);
backgroundManagement = new BackgroundManagement(batch);
}
#Override
public void render() {
Gdx.gl.glClearColor(0, 0, 0.2f, 1);
Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT);
batch.begin();
backgroundManagement.render();
player.render();
smallShip.render();
batch.end();
}
#Override
public void dispose() {
batch.dispose();
}
}
When trying on my code, the ship didn't move to the right, I had tried various solutions but i didn't found any, Any help is appreciated, thanks!
The position of the ship is an integer. Your increment is a float. You maybe have a decent graphics card which can render a simple game at e.g. 200+ fps continuous render (or more even could be crazy). In 200fps case the increment would be (1/200)*20 = 1/10 float.
integer += .1f
won't change the original integer.
Change your position to a float as well, then cast (or convert) to an integer when you need to actually render so x can increment very small values.
Class FirstTower:
public class FirstTower extends Sprite {
private Map map;
private Texture texture;
private float transfer = 1000;
private float hp;
private float radius;
public FirstTower(Map map) {
this.texture = new Texture("square.png");
this.map = map;
this.hp = 100;
radius = 40;
}
#Override
public void render(SpriteBatch batch) {
batch.draw(texture, Gdx.input.getX() - radius, transfer - Gdx.input.getY() - radius);
}
#Override
public void updade(float dt) {
}
}
I need simple to create example of this class (object of FirstTower) with mouse click on gamefield.
How can I do this?
Try to search, but not find anything useful.
Image of object follow with my cursor.
Here is screen when app is running:
You need to set the GDX InputProcessor. This is done by executing the following:
Replace MyClass with the class you wish to create (FirstTower I believe)
Gdx.input.setInputProcessor(new InputProcessor() {
public boolean touchDown(int x, int y, int point, int button) {
if (button == Input.Buttons.LEFT) {
new MyClass();
return true;
}
return false;
}
});
Note: I have excluded the other methods when creating a new InputProcessor to keep this answer tidy, but you will need to implement those methods.
I'm trying to write a program that states the color and area of a circle using String color and int radius using sets and gets. Using green & 10 as an example. Here's what I have so far:
public class Circle
{
private String color;
private int radius;
public Circle () {
color = "null";
radius = 0;
}
public Circle (String setColor, int setRadius) {
}
public void setRadius (int radius) {
this.radius = radius;
}
public void setColor(String color) {
this.color = color;
}
public int getRadius(){
return radius;
}
public String getColor(){
return color;
}
public void printInfo(String setColor, int setRadius) {
double area = Math.PI * this.radius * this.radius;
System.out.printf("The " + "%s" + " circle has area " + "%.2f",
this.radius, area);
}
}
public class Main
{
public static void main(String [] args)
{
Circle circle = new Circle("green", 10);
circle.printInfo();
}
}
"circle.printInfo();" has an error and I'm not sure why. Still pretty new to this so any help is appreciated. Thanks!
In the constructor which takes arguments, you forgot to include code which defines the Circle. Right now, you create a circle with undefined variable, even though you passed it information. How to fix:
public Circle (String color, int radius) {
this.setRadius(radius);
this.setColor(color);
}
I believe you thought the arguments in the constructor took the place of the methods you created, but you are creating and defining local variables with the same name as the methods instead.
Hope this helps! Comment on anything that confuses you.
I'm trying to draw isometric tiles in Java and implement a tile picking system using the mouse cursor. I draw the tiles using these math formulas I found and adapted to my tile textures which you can find below. Tiles are 64x64px but flat tiles are only 32px height even if I draw them using the 64x64 sprite.
The map is a simple 2d array where my tiles are represented by their id.
Here is the class I use to convert map coordinates to screen coordinates using the toIso() function. I pass my screen coordinates which represent the cursor position on the screen to the toGrid() function to convert them to map coordinates.
public class Utils {
private static int TILE_WIDTH = Tile.TILE_WIDTH;
private static int TILE_HEIGHT = Tile.TILE_HEIGHT;
private static int TILE_WIDTH_HALF = TILE_WIDTH/2;
private static int TILE_HEIGHT_HALF = TILE_HEIGHT/2;
private static int TILE_WIDTH_QUARTER = TILE_WIDTH_HALF/2;
private static int TILE_HEIGHT_QUARTER = TILE_HEIGHT_HALF/2;
public static int[] toIso(int x, int y){
int i = (x - y) * TILE_WIDTH_HALF;
int j = (x + y) * TILE_HEIGHT_QUARTER;
//800 and 100 are temporary offsets I apply to center the map.
i+=800;
j+=100;
return new int[]{i,j};
}
public static int[] toGrid(int x, int y){
//800 and 100 are temporary offsets I apply to center the map.
x-=800;
y-=100;
int i = ( x / ( TILE_WIDTH_HALF ) + y / ( TILE_HEIGHT_QUARTER )) / 2;
int j = ( y / ( TILE_HEIGHT_QUARTER ) - ( x / ( TILE_WIDTH_HALF ))) / 2;
return new int[]{i,j};
}}
I currently render my tiles by using two for loops and converting the map coordinates to screen coordinates using the toIso() function.
public void render(Graphics g){
for(int x = 0;x<width;x++){
for(int y = 0;y<height;y++){
int[] isoCoords = Utils.toIso(x, y);
int fx = isoCoords[0];//
int fy = isoCoords[1];//
if(world[x][y] == 0){
Tile grass = new GrassTile(0);
grass.render(g, grass.getId(), fx, fy);
}else if(world[x][y] == 1){
Tile water = new WaterTile(1);
water.render(g, water.getId(), fx, fy);
}
}
}
}
I get a diamond shape as I wanted rendered on the screen.
I finally update each tick which are the actual mouse coordinates on screen.
int[] coords = Utils.toGrid(mouseManager.getMouseX(), mouseManager.getMouseY());
tileX = coords[0];
tileY = coords[1];
The selected tile is finally rendered:
BufferedImage selectedTexture = Assets.selected;
int[] coordsIsoSelected = Utils.toIso(this.tileX, this.tileY);
g.drawImage(selectedTexture, coordsIsoSelected[0], coordsIsoSelected[1], Tile.TILE_WIDTH, Tile.TILE_HEIGHT, null);
g.drawRect(Utils.toIso(tileX, tileY)[0], Utils.toIso(tileX, tileY)[1]+Tile.TILE_HEIGHT/2, Tile.TILE_WIDTH, Tile.TILE_HEIGHT/2);//I draw a rectangle to visualize what's happening.
Finally, my tile detection isn't working as expected, it isn't fitting the tiles perfectly, however it seems to be in relation with the rectangle I draw. I can't figure out the solution to this problem, I thank you in advance for reading or any advice you could give to me. If you need more precisions, I would be glad to give you more informations.
Here is a video showing what is actually happening: youtu.be/baCVIfJz2Wo
EDIT:
Here is some of my code you could use to run an application like mine. Sorry for this very messy code, but I tried to make it as short as possible without disturbing the behavior of the "game".
You will need to put the sheet provided before into a "textures" folder created into the ressource folder of the project.
The gfx package:
package fr.romainimberti.isometric.gfx;
import java.awt.image.BufferedImage;
public class Assets {
private static final int width = 64, height = 64;
public static BufferedImage grass, water, selected;
public static void init(){
//Temp
SpriteSheet tileSheet = new SpriteSheet(ImageLoader.loadImage("/textures/sheet.png"));
grass = tileSheet.crop(width*2, 0, width, height);
water = tileSheet.crop(width*9, height*5, width, height);
selected = tileSheet.crop(0, height*5, width, height);
//
}
}
package fr.romainimberti.isometric.gfx;
import java.awt.image.BufferedImage;
import java.io.IOException;
import javax.imageio.ImageIO;
public class ImageLoader {
public static BufferedImage loadImage(String path){
try {
return ImageIO.read(ImageLoader.class.getResource(path));
} catch (IOException e) {
e.printStackTrace();
System.exit(1);
}
return null;
}
}
package fr.romainimberti.isometric.gfx;
import java.awt.image.BufferedImage;
public class SpriteSheet {
private BufferedImage sheet;
public SpriteSheet(BufferedImage sheet){
this.sheet = sheet;
}
public BufferedImage crop(int x, int y, int width, int height){
return sheet.getSubimage(x, y, width, height);
}
}
The rest of the project:
package fr.romainimberti.isometric;
public class Launcher {
public static void main(String args[]){
System.setProperty("sun.awt.noerasebackground", "true");
Game game = new Game("Isometric", 1280, 720);
game.start();
}
}
package fr.romainimberti.isometric;
import java.awt.Canvas;
import java.awt.Dimension;
import javax.swing.JFrame;
public class Display {
private JFrame frame;
private Canvas canvas;
private String title;
private int width, height;
public Display(String title, int width, int height){
this.title = title;
this.width = width;
this.height = height;
createDisplay();
}
private void createDisplay(){
frame = new JFrame(title);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setResizable(true);
frame.setLocationRelativeTo(null);
frame.setVisible(true);
canvas = new Canvas();
canvas.setPreferredSize(new Dimension(width, height));
canvas.setMaximumSize(new Dimension(width, height));
canvas.setMinimumSize(new Dimension(width, height));
canvas.setFocusable(true);
frame.add(canvas);
frame.pack();
}
public Canvas getCanvas(){
return canvas;
}
public JFrame getFrame(){
return frame;
}
}
package fr.romainimberti.isometric;
import java.awt.Graphics;
import java.awt.image.BufferStrategy;
import java.util.concurrent.ThreadLocalRandom;
import javax.swing.JFrame;
import fr.romainimberti.isometric.gfx.Assets;
public class Game implements Runnable {
private Display display;
private int width, height;
public JFrame frame;
private boolean running = false;
private Thread thread;
public String title;
private BufferStrategy bs;
private Graphics g;
public int x, y;
public int[][] world;
public static final int TILE_WIDTH = 64;
public static final int TILE_HEIGHT = 64;
public static final int TILE_WIDTH_HALF = 32;
public static final int TILE_HEIGHT_HALF = 32;
public static final int TILE_WIDTH_QUARTER = 16;
public static final int TILE_HEIGHT_QUARTER = 16;
public int xOffset;
//Input
private MouseManager mouseManager;
public Game(String title, int width, int height){
this.width = width;
this.height = height;
this.mouseManager = new MouseManager(this);
this.world = new int[10][10];
}
private void init(){
display = new Display(title, width, height);
display.getFrame().addMouseListener(mouseManager);
display.getFrame().addMouseMotionListener(mouseManager);
display.getCanvas().addMouseListener(mouseManager);
display.getCanvas().addMouseMotionListener(mouseManager);
this.frame = display.getFrame();
Assets.init();
xOffset = frame.getWidth()/2;
//Fill the world
for(int i = 0;i<world.length;i++){
for(int j=0;j<world[0].length;j++){
int r = ThreadLocalRandom.current().nextInt(0,1+1);
if(r == 0)
world[i][j] = 0;
else
world[i][j] = 1;
}
}
}
private void tick(){
mouseManager.tick();
xOffset = frame.getWidth()/2;
}
private void render(){
bs = display.getCanvas().getBufferStrategy();
if(bs == null){
display.getCanvas().createBufferStrategy(3);
return;
}
g = bs.getDrawGraphics();
//Clear Screen
g.clearRect(0, 0, frame.getWidth(), frame.getHeight());
//Draw Here
//World render
for(int x = 0;x<world.length;x++){
for(int y = 0;y<world[0].length;y++){
int[] isoCoords = toIso(x, y);
int fx = isoCoords[0];//
int fy = isoCoords[1];//
if(world[x][y] == 0){
g.drawImage(Assets.grass, fx, fy, null);
}else if(world[x][y] == 1){
g.drawImage(Assets.water, fx, fy, null);
}
}
}
//Selected tile render
int[] coordsIsoSelected = toIso(x, y);
g.drawImage(Assets.selected, coordsIsoSelected[0], coordsIsoSelected[1], TILE_WIDTH, TILE_HEIGHT, null);
//End Drawing
bs.show();
g.dispose();
}
public void run(){
init();
int fps = 120;
double timePerTick = 1000000000 / fps;
double delta = 0;
long now;
long lastTime = System.nanoTime();
while(running){
now = System.nanoTime();
delta += (now - lastTime) / timePerTick;
lastTime = now;
if(delta >= 1){
tick();
render();
delta--;
}
}
stop();
}
public MouseManager getMouseManager(){
return mouseManager;
}
public int getWidth(){
return width;
}
public int getHeight(){
return height;
}
public synchronized void start(){
if(running)
return;
running = true;
thread = new Thread(this);
thread.start();
}
public synchronized void stop(){
if(!running)
return;
running = false;
try {
thread.join();
} catch (InterruptedException e) {
e.printStackTrace();
}
}
public static int[] toIso(int x, int y){
int i = (x - y) * TILE_WIDTH_HALF;
int j = (x + y) * TILE_HEIGHT_QUARTER;
i+=xOffset;
return new int[]{i,j};
}
public static int[] toGrid(int x, int y){
x-=xOffset;
int i = ( x / ( TILE_WIDTH_HALF ) + y / ( TILE_HEIGHT_QUARTER )) / 2;
int j = ( y / ( TILE_HEIGHT_QUARTER ) - ( x / ( TILE_WIDTH_HALF ))) / 2;
return new int[]{i,j};
}
}
package fr.romainimberti.isometric;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.awt.event.MouseMotionListener;
public class MouseManager implements MouseListener, MouseMotionListener {
private boolean leftPressed, rightPressed;
private int mouseX, mouseY;
private Game game;
public MouseManager(Game game){
this.game = game;
}
public void tick(){
game.x = game.toGrid(mouseX, mouseY)[0];
game.y = game.toGrid(mouseX, mouseY)[1];
}
// Getters
public boolean isLeftPressed(){
return leftPressed;
}
public boolean isRightPressed(){
return rightPressed;
}
public int getMouseX(){
return mouseX;
}
public int getMouseY(){
return mouseY;
}
// Implemented methods
#Override
public void mousePressed(MouseEvent e) {
if(e.getButton() == MouseEvent.BUTTON1)
leftPressed = true;
else if(e.getButton() == MouseEvent.BUTTON3)
rightPressed = true;
}
#Override
public void mouseReleased(MouseEvent e) {
if(e.getButton() == MouseEvent.BUTTON1)
leftPressed = false;
else if(e.getButton() == MouseEvent.BUTTON3)
rightPressed = false;
}
#Override
public void mouseMoved(MouseEvent e) {
mouseX = e.getX();
mouseY = e.getY();
}
#Override
public void mouseDragged(MouseEvent e) {
// TODO Auto-generated method stub
}
#Override
public void mouseClicked(MouseEvent e) {
// TODO Auto-generated method stub
}
#Override
public void mouseEntered(MouseEvent e) {
// TODO Auto-generated method stub
}
#Override
public void mouseExited(MouseEvent e) {
// TODO Auto-generated method stub
}
}
If you need it, you can find here my project architecture so you can organize all the files correctly.
Again, sorry for this very, very messy code but I had to split all the usefull parts of my game to reduce it's size. Also don't forget to download and place correctly the sheet file. Hope this will help.
128*64 tiles
just wanted to say that I finally solved it. It was just a conversion to int issue. These are the final methods that I use. Hope it will help people who are trying to work with isometric tiles. Thank you !
public static int[] toIso(int x, int y){
int i = (x - y) * TILE_WIDTH_HALF;
int j = (x + y) * TILE_HEIGHT_QUARTER;
i += xOffset-TILE_WIDTH_HALF;
j+=yOffset;
return new int[]{i,j};
}
public static int[] toGrid(double i, double j){
i-=xOffset;
j-=yOffset;
double tx = Math.ceil(((i / TILE_WIDTH_HALF) + (j / TILE_HEIGHT_QUARTER))/2);
double ty = Math.ceil(((j / TILE_HEIGHT_QUARTER) - (i / TILE_WIDTH_HALF))/2);
int x = (int) Math.ceil(tx)-1;
int y = (int) Math.ceil(ty)-1;
return new int[]{x, y};
}
After replacing the spritesheet with the new one with 128x64 pixels' tiles, I've been able to achieve the desired output partially...
Why I say "partially"? Because I've managed to get the desired result only from the half right part of the map.
I believe it could have something to do with how the map is being painted, I'm not a native English speaker so I might be misunderstanding what the "Notes" section says in OP's link:
Notice that the "origin" of the isometric tile is the top corner. But usually when we draw a sprite it's from the top-left corner
I've called the methods toGrid() and toIso() at the beginning of the program as follows:
int[] coordinates = Game.toIso(2, 1);
System.out.println(coordinates[0] + "-" + coordinates[1]);
int[] coordinates2 = Game.toGrid(coordinates[0], coordinates[1]);
System.out.println(coordinates2[0] + "-" + coordinates2[1]);
And got the following results, (Which indeed are what we were expecting), so we know the methods work correctly:
64-96
2-1
I was sure to modify the Assets file:
public static final int WIDTH = 128, HEIGHT = 64;
Where I also changed the variable names following the Java naming conventions (ALL_WORDS_UPPER_CASE_CONSTANTS) and made it public instead of private
I also changed the Game file:
public static final int TILE_WIDTH = Assets.WIDTH;
public static final int TILE_HEIGHT = Assets.HEIGHT;
public static final int TILE_WIDTH_HALF = TILE_WIDTH / 2;
public static final int TILE_HEIGHT_HALF = TILE_HEIGHT / 2;
public static final int TILE_WIDTH_QUARTER = TILE_WIDTH / 4;
public static final int TILE_HEIGHT_QUARTER = TILE_HEIGHT / 4;
To use those constants on the Assets file and calculate the HALF and QUARTER instead of hardcoding it.
I also believe xOffset shouldn't be public but private as well as some other variables on the program...
The tick() method, doesn't need to calculate the xOffset everytime, so we can get rid of this line inside it:
xOffset = frame.getWidth() / 2 - 65;
I also changed the way you paint the tile you're selecting as:
// Selected tile render
int[] coordsIsoSelected = toIso(x, y);
g.drawImage(Assets.selected, coordsIsoSelected[0], coordsIsoSelected[1], TILE_WIDTH, TILE_HEIGHT, null);
And for the Tolso equations, I changed them to:
public static int[] toIso(int x, int y) {
int i = (x - y) * TILE_WIDTH_HALF;
int j = (x + y) * TILE_HEIGHT_HALF;
i += xOffset;
return new int[] { i, j };
}
Below I adjusted the parenthesis locations:
public static int[] toGrid(int x, int y) {
x -= xOffset;
int i = ((x / TILE_WIDTH_HALF) + (y / TILE_HEIGHT_HALF)) / 2;
int j = ((y / TILE_HEIGHT_HALF) - (x / TILE_WIDTH_HALF)) / 2;
return new int[] { i, j };
}
This is my first time working with extends and stuff like that :)
In mt most recent program, I have BasicTile extending Tile.
I construct the basic tile with a Bitmap.
The bitmap is not an actual bitmap, its a class that I wrote that contains an array of integers (holding color values).
When I render with the bitmap, I get a black screen. This goes away when I make the bitmap static (I do not want that because I want multiple basic tiles like grass, bushes, etc.)
It also goes away if I set the texture right in the render method (I don't want to do that either bc it would load 60*256 bitmaps a second).
I tested some and in the constructor of the BasicTile the array in the bitmap contains the right values. In the render method it changed to only be the number -16777216 though.
The information seems to get lost somewhere in between. I am having problems finding where it gets lost because I do not do anything to the bitmap in between the constructor and the render method.
This is my Tile, BasicTile, and Bitmap classes:
public abstract class Tile {
public static final Tile[] tiles = new Tile[576];
public static final Tile VOID = new BasicTile(0, Art.spritesheet[0][0]);
public static final Tile STONE = new BasicTile(1, Art.spritesheet[1][0]);
public static final Tile GRASS = new BasicTile(2, Art.spritesheet[3][0]);
protected byte id;
protected boolean solid;
protected boolean emitter;
public Tile(int id, boolean isSolid, boolean isEmitter){
this.solid = isSolid;
this.emitter = isEmitter;
tiles[id] = this;
}
public byte getId(){
return id;
}
public boolean isSolid(){
return solid;
}
public boolean isEmitter(){
return emitter;
}
public abstract void render(Screen screen, int x, int y);
}
public class BasicTile extends Tile{
protected int tileId;
protected Bitmap texture;
public BasicTile(int id, Bitmap bitmap) {
super(id, false, false);
texture = bitmap;
}
public void render(Screen screen, int x, int y) {
/*for(int i = 0; i < texture.h; i++){
for(int j = 0; j < texture.w; j++){
System.out.println(texture.pixels[j + i * texture.w]);
}
}*/ //the algorithm I used to debug (getting the values of the int array)
screen.render(texture, x, y);
}
}
public class Bitmap {
public int w, h;
public int[] pixels;
public Bitmap(int w, int h){
this.w = w;
this.h = h;
this.pixels = new int[w * h];
}
}
when I render to the screen, it renders it to another bigger array of ints :)
Added examples:
normal code: see above (sorry I can only post 2 links)
result: black screen
making bitmap static: in the BasicTile change "protected Bitmap texture;" to "protected static Bitmap texture;"
result
set it in the render method
result: same as the one with the bricks (so it works)
P.S.: If you need anything else to solve this issue please tell me :)
I figured out it was not displaying a black screen but instead the void tile...
I don't know why (I'm working on a fix and it will be posted here) but if I change the
public static final Tile VOID = new BasicTile(0, Art.spritesheet[0][0])
to
public static final Tile VOID = new BasicTile(0, Art.spritesheet[3][0])
it renders the bricks :)