Java (swing) paint only what's viewable on the screen - java

I am making a tile based platformer game in java. I render a map which is stored in a 2 dimensional array but when this array is very big my game starts to become slow. I realised that I had to only render the part of the map that is viewable, I tried to do that but i wrote very hacky code that only worked partly so I removed it. How can I do this properly? Here is my code (without the hacky stuff). Also how could I use System.nanoTime() rather than System.currentTimeMillis()?
package sexy_robot_from_another_dimension;
import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Rectangle;
import java.awt.RenderingHints;
import java.awt.TexturePaint;
import java.awt.image.BufferedImage;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.Timer;
import java.util.TimerTask;
import javax.swing.JPanel;
#SuppressWarnings("serial")
public class Game extends JPanel
{
int playerX = 50;
int playerY = 50;
static boolean up = false;
static boolean down = false;
static boolean right = false;
static boolean left = false;
int playerSpeed = 1;
String[][] map;
int blockSize = 20;
int jumpLoop = 0;
int maxJumpLoop = 280;
static BufferedImage block, player;
int playerWidth = 20;
int playerHeight = 35;
int cameraX = 0;
int cameraY = 0;
long nextSecond = System.currentTimeMillis() + 1000;
int frameInLastSecond = 0;
int framesInCurrentSecond = 0;
public Game()
{
super();
try
{
map = load("/maps/map1.txt");
}
catch (IOException e)
{
// TODO Auto-generated catch block
e.printStackTrace();
}
Timer timer = new Timer();
TimerTask task = new TimerTask()
{
#Override
public void run()
{
if(up)
{
if((!playerIsOnBlock(playerX, playerY).equals("0")) || (!playerIsOnBlock(playerX + (playerWidth - 1), playerY).equals("0")))
{
timeToJump();
}
}
if(down)
{
}
if(right)
{
if((playerIsLeftBlock(playerX, playerY).equals("0")) && (playerIsLeftBlock(playerX, playerY + (playerHeight/2 - 1)).equals("0")) && (playerIsLeftBlock(playerX, playerY + (playerHeight - 1)).equals("0")))
{
playerX += playerSpeed;
}
}
if(left)
{
if((playerIsRightBlock(playerX, playerY).equals("0")) && (playerIsRightBlock(playerX, playerY + (playerHeight/2 - 1)).equals("0")) && (playerIsRightBlock(playerX, playerY + (playerHeight - 1)).equals("0")))
{
playerX -= playerSpeed;
}
}
repaint();
}
};
timer.scheduleAtFixedRate(task, 0, 10);
Timer timerGrav = new Timer();
TimerTask taskGrav = new TimerTask()
{
#Override
public void run()
{
if((playerIsOnBlock(playerX, playerY).equals("0")) && (playerIsOnBlock(playerX + (playerWidth - 1), playerY).equals("0")))
{
playerY += playerSpeed;
repaint();
}
}
};
timerGrav.scheduleAtFixedRate(taskGrav, 0, 6);
}
void timeToJump()
{
if(jumpLoop == 0)
{
jumpLoop = 1;
Timer timer = new Timer();
TimerTask task = new TimerTask()
{
#Override
public void run()
{
if((playerIsBelowBlock(playerX, playerY).equals("0")) && (playerIsBelowBlock(playerX + (playerWidth - 1), playerY).equals("0")))
{
playerY -= playerSpeed;
jumpLoop++;
repaint();
}
else
{
jumpLoop = maxJumpLoop;
}
if(jumpLoop == maxJumpLoop)
{
jumpLoop = 0;
cancel();
}
}
};
timer.scheduleAtFixedRate(task, 0, 3);
}
}
public void paintComponent(Graphics g)
{
super.paintComponent(g);
Graphics2D g2 = (Graphics2D)g;
g2.setRenderingHint(RenderingHints.KEY_TEXT_ANTIALIASING, RenderingHints.VALUE_TEXT_ANTIALIAS_ON);
long currentTime = System.currentTimeMillis();
if (currentTime > nextSecond)
{
nextSecond += 1000;
frameInLastSecond = framesInCurrentSecond;
framesInCurrentSecond = 0;
}
framesInCurrentSecond++;
g.drawString(frameInLastSecond + " fps", 10, 20);
cameraX = -playerX + getWidth()/2;
cameraY = -playerY + getHeight()/2;
g.translate(cameraX, cameraY);
for (int x = 0; x < map.length; x++)
{
for (int y = 0; y < map[0].length; y++)
{
switch(map[x][y])
{
case "0":
break;
case "1":
if(block != null)
{
TexturePaint tp0 = new TexturePaint(block, new Rectangle(0, 0, blockSize, blockSize));
g2.setPaint(tp0);
}
g.fillRect(y*blockSize, x*blockSize, 20, 20);
break;
}
}
}
g.setColor(Color.BLACK);
if(player != null)
{
TexturePaint tp0 = new TexturePaint(player, new Rectangle(playerX, playerY, playerWidth, playerHeight));
g2.setPaint(tp0);
}
g.fillRect(playerX, playerY, playerWidth, playerHeight);
g.setColor(Color.black);
g.setFont(new Font("Droid Sans Mono", Font.PLAIN, 12));
g.drawString("Sexy!", playerX - 5, playerY - 10);
}
boolean outOfMap(int x, int y)
{
y -= blockSize - 1;
x -= blockSize - 1;
if((y/blockSize <= map.length - 2) && (y/blockSize >= 0) && (x/blockSize <= map[0].length-2) && (x/blockSize >= 0))
{
return false;
}
return true;
}
String playerIsOnBlock(int x, int y)
{
y += playerHeight;
if(!outOfMap(x, y))
{
if(map[y/blockSize][x/blockSize] != "0")
{
return map[y/blockSize][x/blockSize];
}
}
return "0";
}
String playerIsBelowBlock(int x, int y)
{
y -= playerSpeed;
if(!outOfMap(x, y))
{
if(map[y/blockSize][x/blockSize] != "0")
{
return map[y/blockSize][x/blockSize];
}
}
return "0";
}
String playerIsLeftBlock(int x, int y)
{
x += playerWidth;
if(!outOfMap(x, y))
{
if(map[y/blockSize][x/blockSize] != "0")
{
return map[y/blockSize][x/blockSize];
}
}
return "0";
}
String playerIsRightBlock(int x, int y)
{
x -= playerSpeed;
if(!outOfMap(x, y))
{
if(map[y/blockSize][x/blockSize] != "0")
{
return map[y/blockSize][x/blockSize];
}
}
return "0";
}
String[][] load(String file) throws IOException
{
BufferedReader br = new BufferedReader(new InputStreamReader(getClass().getResourceAsStream(file)));
int lines = 1;
int length = br.readLine().split(" ").length;
while (br.readLine() != null) lines++;
br.close();
br = new BufferedReader(new InputStreamReader(getClass().getResourceAsStream(file)));
String[][] map = new String[lines][length];
for (int i = 0; i < lines; i++)
{
String line = br.readLine();
String[] parts = line.split(" ");
for (int y = 0; y < length; y++)
{
map[i][y] = parts[y];
}
}
br.close();
return map;
}
}
Thank you!

It seems your camera is centered on the player, then there are two ways of doing this, I like the first way, it is a bit cleaner:
1th: Create a rectangle that bounds your cameras view, and check if the map x,y is within this view, render only if true.
Rectangle cameraView = new Rectangle(playerX - getWidth() / 2, playerY - getHeight() / 2, getWidth(), getHeight());
for (int x = 0; x < map.length; x++) {
for (int y = 0; y < map[0].length; y++) {
if (!cameraView.contains(x*blockSize, y*blockSize))
continue;
switch (map[x][y]) {
case "0":
break;
case "1":
if (block != null) {
TexturePaint tp0 = new TexturePaint(block, new Rectangle(0, 0, blockSize, blockSize));
g2.setPaint(tp0);
}
g.fillRect(y * blockSize, x * blockSize, 20, 20);
break;
}
}
}
The second option is to simply calculate the distance to the center of the screen (playerX,playerY) from each map[x][y] and skip all map[x][y] that falls outside your viewing bounds, this is a bit uglier to code and I really don't recommend this, the rectangle option above should be fast enough.
Edit:
#JasonC That is true, I didn't consider for instance when an x value is definitely outside the view, it will still go into the y loop through all the y values. One can simply create a dummy variable in the x-loop and do the following check
for (int x = 0; x < map.length; x++) {
int dummyY = playerY
if(!cameraView.contains(x,dummyY))
continue;
....
//rest of code ommitted
Another optimization you can do is considering not setting a TexturePaint (expensive operation) but instead simply drawing the image of the block:
g.fillRect(y * blockSize, x * blockSize, 20, 20);
Replaced with
g.drawImage(block, y*blockSize, x*blockSize, null);
The same with the playerimage.

Set the clipping region to the visible area with Graphics.setClip(), that will prevent most rendering operations from taking effect outside that region.
For drawing operations where this isn't sufficient (perhaps you also want to avoid doing calculations or something for objects outside the clipping area), test your objects bounds against the clipping rectangle and skip the object if it doesn't intersect.
See Graphics.setClip().
A further optimization can be done by, for example, calculating the range of blocks on your map that is definitely outside of the visible area, and excluding that from your for loop (no sense testing blocks against the clipping region if you know they are outside already). Take the clipping region, transform it to map index coordinates, then you will know where in your map the visible area is and you can just iterate over that subsection of the map.

Related

Cannot get sprite to collide with map images (java)

I am creating a 2D game which the zombie moves with WASD keys and is supposed to collide with the walls and not enter them, as well as collide with the brains and removes them. Every type of code I have used does not create collision. I am using a zombie sprite sheet i found on google as well as 2 backgroundless images for walls and brains.
After I figure out collision, I then then to implement a autorun sequence to where it bounces around like a screensaver and does the same thing just automatically until all brains are collected.
The EZ is just a library that is utilized by UH Manoa, that can be found here: EZ Graphics
Main
import java.awt.Color;
import java.io.FileReader;
import java.util.Scanner;
public class ZombieMain {
static EZImage[] walls = new EZImage[500];
static EZImage[] sideWalls = new EZImage[500];
static EZImage[] brains = new EZImage[50];
static int wallsCount = 0;
static int sideWallsCount = 0;
static int brainsCount = 0;
/*public static void addWall(EZImage wall) {
walls[wallsCount] = wall;
wallsCount++;
}
public static void addCoin(EZImage brain) {
brains[brainsCount] = brain;
brainsCount++;
}*/
/*public static void CollisingCoin(EZImage me) {
int x = me.getXCenter();
int y = me.getYCenter();
for (int i = 0; i < brainsCount; i++) {
if ((brains[i].isPointInElement(me.getXCenter() - 30, me.getYCenter() - 30))
|| (brains[i].isPointInElement(me.getXCenter() + 30, me.getYCenter() - 30))
|| (brains[i].isPointInElement(me.getXCenter() - 30, me.getYCenter() + 30))
|| (brains[i].isPointInElement(me.getXCenter() + 30, me.getYCenter() + 30))) {
brains[i].translateTo(-20, -20);
System.out.println("You ate a brain!");
}
}
}*/
public static void main(String[] args) throws java.io.IOException {
//initialize scanner
Scanner fScanner = new Scanner(new FileReader("boundaries.txt"));
int w = fScanner.nextInt();
int h = fScanner.nextInt();
String inputText = fScanner.nextLine();
//create backdrop
EZ.initialize(w*33,h*32);
EZ.setBackgroundColor(new Color(0, 0,0));
Zombie me = new Zombie("zombieSheet.png", 650, 450, 65, 63, 10);
//set reading parameters and establish results of case readings
int row = 0;
while(fScanner.hasNext()) {
inputText = fScanner.nextLine();
for (int column = 0; column < inputText.length(); column++){
char ch = inputText.charAt(column);
switch(ch){
case 'W':
walls[wallsCount] = EZ.addImage("barbwire.jpg", column*32, row*32);
wallsCount++;
break;
case 'M':
sideWalls[wallsCount] = EZ.addImage("barb.jpg", column*32, row*32);
wallsCount++;
break;
case 'B':
brains[brainsCount] = EZ.addImage("brains.png", column*32, row*32);
brainsCount++;
break;
default:
// Do nothing
break;
}
//printed count of walls, side walls, and brains
System.out.println("W = " + wallsCount);
System.out.println("M = " + sideWallsCount);
System.out.println("B = " + brainsCount);
}
row++;
}
fScanner.close();
while (true) {
// check if going to collide with wall
// we want to check this before we actually move
// otherwise, we get "stuck" in a situation where we can't move
// if no collision, we can move
/*if (EZInteraction.isKeyDown('a')) {
if (!isCollisingWall(me, -2, 0)) {
me.translateBy(-2, 0);
}
} else if (EZInteraction.isKeyDown('d')) {
if (!isCollisingWall(me, 2, 0)) {
me.translateBy(2, 0);
}
} else if (EZInteraction.isKeyDown('w')) {
if (!isCollisingWall(me, 0, -2)) {
me.translateBy(0, -2);
}
} else if (EZInteraction.isKeyDown('s')) {
if (!isCollisingWall(me, 0, 2)) {
me.translateBy(0, 2);
}
}*/
me.go();
EZ.refreshScreen();
}
}
}
Sprite
public class Zombie {
EZImage zombieSheet;
int x = 0; // Position of Sprite
int y = 0;
int zombieWidth; // Width of each sprite
int zombieHeight; // Height of each sprite
int direction = 0; // Direction character is walking in
int walkSequence = 0; // Walk sequence counter
int cycleSteps; // Number of steps before cycling to next animation step
int counter = 0; // Cycle counter
Zombie(String imgFile, int startX, int startY, int width, int height, int steps) {
x = startX; // position of the sprite character on the screen
y = startY;
zombieWidth = width; // Width of the sprite character
zombieHeight = height; // Height of the sprite character
cycleSteps = steps; // How many pixel movement steps to move before changing the sprite graphic
zombieSheet = EZ.addImage(imgFile, x, y);
setImagePosition();
}
private void setImagePosition() {
// Move the entire sprite sheet
zombieSheet.translateTo(x, y);
// Show only a portion of the sprite sheet.
// Portion is determined by setFocus which takes 4 parameters:
// The 1st two numbers is the top left hand corner of the focus region.
// The 2nd two numbers is the bottom right hand corner of the focus region.
zombieSheet.setFocus(walkSequence * zombieWidth, direction, walkSequence * zombieWidth + zombieWidth, direction + zombieHeight);
}
public void moveDown(int stepSize) {
y = y + stepSize;
direction = 0;
if ((counter % cycleSteps) == 0) {
walkSequence++;
if (walkSequence > 6)
walkSequence = 0;
}
counter++;
setImagePosition();
}
public void moveLeft(int stepSize) {
x = x - stepSize;
direction = zombieHeight * 2;
if ((counter % cycleSteps) == 0) {
walkSequence--;
if (walkSequence < 0)
walkSequence = 6;
}
counter++;
setImagePosition();
}
public void moveRight(int stepSize) {
x = x + stepSize;
direction = zombieHeight;
if ((counter % cycleSteps) == 0) {
walkSequence++;
if (walkSequence > 6)
walkSequence = 0;
}
counter++;
setImagePosition();
}
public void moveUp(int stepSize) {
y = y - stepSize;
direction = zombieHeight * 3;
if ((counter % cycleSteps) == 0) {
walkSequence--;
if (walkSequence < 0)
walkSequence = 6;
}
setImagePosition();
counter++;
}
// Keyboard controls for moving the character.
public void go() {
if (EZInteraction.isKeyDown('w')) {
moveUp(2);
} else if (EZInteraction.isKeyDown('a')) {
moveLeft(2);
} else if (EZInteraction.isKeyDown('s')) {
moveDown(2);
} else if (EZInteraction.isKeyDown('d')) {
moveRight(2);
}
}
public void translateBy(int i, int j) {
// TODO Auto-generated method stub
}
public int getXCenter() {
// TODO Auto-generated method stub
return x;
}
public int getYCenter() {
// TODO Auto-generated method stub
return y;
}
public int getWidth() {
// TODO Auto-generated method stub
return 0;
}
public int getHeight() {
// TODO Auto-generated method stub
return 0;
}
}
EZElement provides a getBounds property, which returns a java.awt.Shape object; why is this important? Because the Java 2D Graphics API already provides some hit detection.
From this, we then need to determine the player shape's intersection with any other shapes. To do this, we need to wrap both shapes in a Area and use it to make the final determinations.
Area meArea = new Area(me.getBounds());
Area checkArea = new Area(elementToCheck.getBounds());
checkArea(meArea);
if (!checkArea.isEmpty()) {
//... We have collision
}
Obviously, this should all be wrapped up in some kind of method to handle the core functionality, but you could have a helper method which simply took two EZElements and return true/false if the collide
For brevity and testing, I stripped back your example, but the basic idea should continue to work
import java.awt.Color;
import java.awt.Shape;
import java.awt.geom.Area;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
public class Test {
private List<EZImage> brains = new ArrayList<>(25);
private Zombie me;
public static void main(String[] args) throws java.io.IOException {
new Test();
}
public Test() {
int w = 10;
int h = 10;
//create backdrop
EZ.initialize(w * 33, h * 32);
EZ.setBackgroundColor(new Color(0, 0, 0));
me = new Zombie("Zombie.png", 0, 0);
brains.add(EZ.addImage("Brains.png", (w * 33) / 2, (h * 32 / 2)));
while (true) {
detectCollision();
// check if going to collide with wall
// we want to check this before we actually move
// otherwise, we get "stuck" in a situation where we can't move
// if no collision, we can move
/*if (EZInteraction.isKeyDown('a')) {
if (!isCollisingWall(me, -2, 0)) {
me.translateBy(-2, 0);
}
} else if (EZInteraction.isKeyDown('d')) {
if (!isCollisingWall(me, 2, 0)) {
me.translateBy(2, 0);
}
} else if (EZInteraction.isKeyDown('w')) {
if (!isCollisingWall(me, 0, -2)) {
me.translateBy(0, -2);
}
} else if (EZInteraction.isKeyDown('s')) {
if (!isCollisingWall(me, 0, 2)) {
me.translateBy(0, 2);
}
}*/
me.go();
EZ.refreshScreen();
}
}
public boolean doesCollide(EZElement element, EZElement with) {
Area a = new Area(element.getBounds());
Area b = new Area(with.getBounds());
a.intersect(b);
return !a.isEmpty();
}
public void detectCollision() {
Iterator<EZImage> obstacles = brains.iterator();
while (obstacles.hasNext()) {
EZElement next = obstacles.next();
if (doesCollide(me.zombieSheet, next)) {
System.out.println("Me = " + me.getBounds().getBounds());
System.out.println("next = " + next.getBounds().getBounds());
EZ.removeEZElement(next);
obstacles.remove();
}
}
}
public class Zombie {
EZImage zombieSheet;
int x = 0; // Position of Sprite
int y = 0;
Zombie(String imgFile, int startX, int startY) {
x = startX; // position of the sprite character on the screen
y = startY;
zombieSheet = EZ.addImage(imgFile, x, y);
setImagePosition();
}
public Shape getBounds() {
return zombieSheet.getBounds();
}
private void setImagePosition() {
// Move the entire sprite sheet
zombieSheet.translateTo(x, y);
}
public void moveDown(int stepSize) {
y = y + stepSize;
setImagePosition();
}
public void moveLeft(int stepSize) {
x = x - stepSize;
setImagePosition();
}
public void moveRight(int stepSize) {
x = x + stepSize;
setImagePosition();
}
public void moveUp(int stepSize) {
y = y - stepSize;
setImagePosition();
}
// Keyboard controls for moving the character.
public void go() {
if (EZInteraction.isKeyDown('w')) {
moveUp(2);
} else if (EZInteraction.isKeyDown('a')) {
moveLeft(2);
} else if (EZInteraction.isKeyDown('s')) {
moveDown(2);
} else if (EZInteraction.isKeyDown('d')) {
moveRight(2);
}
}
}
}
I would recommend that you give each entity (and block/tile) a collision box, then test if a specific entity's bounding box collided with another entity's bounding box, then make it so that the entities can't move in that direction until there isn't a bounding box in a direction, if that made any since.
Do the same for testing for the brains, though I recommend making an ArrayList of brains, and removing specific ones if that brain had been touched.

Brick breaker brick color

I am trying to have each brick in my game have a random color, however when I try to do this the whole set of bricks become the same color. How do I make each individual brick a random color? Any help is appreciated.
import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.Rectangle;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
public class Game extends JoeApplet implements KeyListener
{
String status;
int ballx = 294; // ball spawn x coordinate
int bally = 640; // ball spawn y coordinate
int batx = 294;
int baty = 654;
int brickx = 32;
int bricky = 50;
double movex = -16; // x speed of ball
double movey = -16; //y speed of ball
int count = 0;
int currentLevel=0;
int score=0; //starts score at 0
int lives=3; //lives start at 3
static boolean right = false;
static boolean left = false;
boolean ballFallDown = false;
boolean bricksOver = false;
Rectangle Ball = new Rectangle(ballx, bally, 14, 14); //creates ball
Rectangle Bat = new Rectangle(batx, baty, 100, 12); //creates bat(paddle)
Rectangle[] Brick = new Rectangle[49]; //creates desired number of bricks
public void paint(Graphics art)
{
switch(currentLevel)
{
case 0:
menuScreen(art);
break;
case 1:
game(art);
break;
}
}
public void menuScreen(Graphics art)
{
setSize(700, 700);
art.setColor(Color.BLACK);
art.fillRect(0, 0, 698, 698);
Color ballcolor=new Color(0,0,66);
art.setColor(ballcolor);
art.fillOval(Ball.x, Ball.y, Ball.width, Ball.height);
Color batcolor=new Color(0,0,66);
art.setColor(batcolor);
art.fill3DRect(Bat.x, Bat.y, Bat.width, Bat.height, true);
art.setColor(Color.green);
art.drawRect(0, 0, 698, 698);
art.setColor(Color.yellow);
Font menu = new Font("Arial", Font.BOLD, 20);
art.setFont(menu);
art.drawString("Brick Breaker", 100,400);
art.drawString("Press P to Play", 100,425);
art.drawString("Press Q to Quit game", 100,450);
for (int i = 0; i < Brick.length; i++)
{
if (Brick[i] != null)
{
Color mycolor=new Color(100,0,0);
art.setColor(mycolor);
art.fill3DRect(Brick[i].x, Brick[i].y, Brick[i].width,
Brick[i].height, true);
}
}
art.setColor(Color.YELLOW);
if (ballFallDown || bricksOver)
{
Font f = new Font("Arial", Font.BOLD, 20);
art.setFont(f);
art.drawString(status, 294, 349);
ballFallDown = false;
bricksOver = false;
}
}
public void game(Graphics art)
{
setSize(700, 700);
art.setColor(Color.BLACK);
art.fillRect(0, 0, 698, 698);
Color ballcolor=new Color(0,0,225);
art.setColor(ballcolor);
art.fillOval(Ball.x, Ball.y, Ball.width, Ball.height);
Color batcolor=new Color(0,0,139);
art.setColor(batcolor);
art.fill3DRect(Bat.x, Bat.y, Bat.width, Bat.height, true);
art.setColor(Color.green);
art.drawRect(0, 0, 698, 698);
for (int i = 0; i < Brick.length; i++)
{
if (Brick[i] != null)
{
Color mycolor=new Color(200,0,0);
art.setColor(mycolor);
art.fill3DRect(Brick[i].x, Brick[i].y, Brick[i].width,
Brick[i].height, true);
}
}
if (ballFallDown || bricksOver)
{
Font f = new Font("Arial", Font.BOLD, 20);
art.setFont(f);
art.drawString(status, 100,425);
ballFallDown = false;
bricksOver = false;
}
for (int i = 0; i < Brick.length; i++)
{
if (Brick[i] != null)
{
if (Brick[i].intersects(Ball))
{
score=score+10;
Brick[i] = null;
movey = -movey;
count++;
}
}
}
if (count == Brick.length)
{
bricksOver = true;
movex=0;
movey=0;
art.setColor(Color.green);
status = "YOU BEAT THE LEVEL!!";
art.drawString("Press E to Exit", 100,450);
art.drawString("Press N for Next Level", 100,475);
repaint();
}
repaint();
Font f = new Font("Arial", Font.BOLD, 20);
art.setFont(f);
art.setColor(Color.white);
art.drawString("Score:"+score, 600, 684);
Ball.x += movex;
Ball.y += movey;
if (left == true)
{
Bat.x -= 18;
right = false;
}
if (right == true)
{
Bat.x += 18;
left = false;
}
if (Bat.x <= 4)
{
Bat.x = 4;
}
else if (Bat.x >= 586)
{
Bat.x = 596;
}
if (Ball.intersects(Bat))
{
movey = -movey-.1;
}
if (Ball.x <= 0 || Ball.x + Ball.height >= 698)
{
movex = -movex;
}
if (Ball.y <= 0)
{
movey = -movey;
}
Font f1 = new Font("Arial", Font.BOLD, 20);
art.setFont(f1);
art.setColor(Color.white);
art.drawString("Lives:"+ lives, 5, 684);
if (Ball.y >= 698 && (bricksOver==false) && lives>0)
{
ballFallDown = true;
art.setColor(Color.red);
status = "";
art.drawString("", 100,450);
lives=lives-1;
ballx = 294;
bally = 640;
Ball = new Rectangle(ballx, bally, 14, 14);
movex = -16;
movey = -16;
repaint();
}
if(lives==0 && Ball.y >= 698)
{
art.setColor(Color.red);
art.drawString("You lost!!", 100,425);
art.drawString("Press E to Exit", 100,450);
}
}
public void init()
{
addKeyListener(this);
for (int i = 0; i < Brick.length; i++) //creates bricks
{
Brick[i] = new Rectangle(brickx, bricky, 40, 20);
if (i == 12) //1st row of bricks
{
brickx = 32;
bricky = 84;
}
if (i == 23) //2nd row of bricks
{
brickx = 82;
bricky = 118;
}
if (i == 32) //3rd row of bricks
{
brickx = 132;
bricky = 152;
}
if (i == 39) //4th row of bricks
{
brickx = 182;
bricky = 186;
}
if (i == 44) //5th row of bricks
{
brickx = 232;
bricky = 220;
}
if (i == 47) //6th row of bricks
{
brickx = 282;
bricky = 254;
}
if (i == 48) //7th row of bricks
{
brickx = 144;
bricky = 132;
}
brickx += 50; //spacing between each brick
}
}
public void restart()
{
ballx = 294;
bally = 640;
batx = 294;
baty = 654;
brickx = 32;
bricky = 50;
Ball = new Rectangle(ballx, bally, 14, 14);
Bat = new Rectangle(batx, baty, 100, 12);
movex = -16;
movey = -16;
ballFallDown = false;
bricksOver = false;
count = 0;
status = null;
for (int i = 0; i < Brick.length; i++) //recreates bricks
{
Brick[i] = new Rectangle(brickx, bricky, 40, 20);
if (i == 12)
{
brickx = 32;
bricky = 84;
}
if (i == 23)
{
brickx = 82;
bricky = 118;
}
if (i == 32)
{
brickx = 132;
bricky = 152;
}
if (i == 39)
{
brickx = 182;
bricky = 186;
}
if (i == 44)
{
brickx = 232;
bricky = 220;
}
if (i == 47)
{
brickx = 282;
bricky = 254;
}
if (i == 48)
{
brickx = 144;
bricky = 132;
}
brickx += 50;
}
repaint();
}
#Override
public void keyPressed(KeyEvent e) //allows each key to do desired action
{
int keyCode = e.getKeyCode();
if (keyCode == KeyEvent.VK_LEFT)
{
left = true;
}
if (keyCode == KeyEvent.VK_RIGHT)
{
right = true;
}
if (keyCode == e.VK_P && currentLevel == 0)
{
currentLevel = 1;
}
else if (keyCode == e.VK_E && currentLevel == 1)
{
currentLevel = 0;
score=0;
lives=3;
restart();
}
else if(keyCode == e.VK_Q)
{
System.exit(0);
}
}
#Override
public void keyReleased(KeyEvent e)
{
int keyCode = e.getKeyCode();
if (keyCode == KeyEvent.VK_LEFT)
{
left = false;
}
if (keyCode == KeyEvent.VK_RIGHT)
{
right = false;
}
}
#Override
public void keyTyped(KeyEvent e)
{
}
public static void main(String[] args)
{
Game prog = new Game();
prog.init();
}
}
I'd throw that code out and start over as you've got both program logic and repaints within your painting methods, neither of which will help you, and your code appears to be one big huge "God" class, all of which will leave you with code that's a horrific nightmare to debug. Recommendations:
Create at least two separate JPanels to display your program with, a GamePanel and a MenuPanel.
Swap these JPanels using a CardLayout.
Do all graphics within a JPanel's paintComponent method and not within a JFrame's or JApplet's paint method.
Don't forget to call the super's painting method, the same method as your override within your override. This is to clean up any dirty pixels.
Separate your program logic from your GUI
This means that you should have a logical non-GUI representation of a single Brick class as well as a collection of these non-GUI bricks.
You can always give your Brick class a Color field, one that the view or gui uses to paint it with.
Create a game-loop, one that you can control, one that doesn't involve calling repaint() within a painting method, since this leads to a completely uncontrollable loop.
Favor use of Key Bindings over KeyListeners.
Try to avoid use of "magic" numbers, such as hard-coding your brick width and spacing in the class itself. Better to use constants as this too makes debugging and enhancing much easier.
For example, some code that's just to demonstrate showing random colors:
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.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.Random;
import javax.swing.*;
public class BrickBreak {
private static void createAndShowGui() {
GamePanel gamePanel = new GamePanel();
JFrame frame = new JFrame("Brick Break");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().add(gamePanel);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(() -> createAndShowGui());
}
}
// JPanel that draws the game
class GamePanel extends JPanel {
private static final long serialVersionUID = 1L;
private static final Color BACK_GRND = Color.BLACK;
private int prefW;
private int prefH;
private Bricks bricks = new Bricks();
public GamePanel() {
// wide enough to hold the complete top-row of Bricks
// using constants, so GUI automatically resizes if any sizes change
prefW = (Brick.WIDTH + Bricks.X_SPACING) * Bricks.ROW_COUNTS[0] + Bricks.X_SPACING;
prefH = prefW;
setBackground(BACK_GRND);
}
#Override
public Dimension getPreferredSize() {
if (isPreferredSizeSet()) {
return super.getPreferredSize();
}
return new Dimension(prefW, prefH);
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2 = (Graphics2D) g;
for (Brick brick : bricks) {
brick.draw(g2);
}
}
}
// non-GUI class that represents a logical Brick
class Brick {
public static final int WIDTH = 40;
public static final int HEIGHT = 20;
private int x;
private int y;
private Color color;
private Rectangle boundingRectangle;
public Brick(int x, int y, Color color) {
this.x = x;
this.y = y;
this.color = color;
boundingRectangle = new Rectangle(x, y, WIDTH, HEIGHT);
}
// yeah, I'm mixing some view with model here.
public void draw(Graphics2D g2) {
g2.setColor(color);
g2.fill3DRect(x, y, WIDTH, HEIGHT, true);
}
public int getX() {
return x;
}
public int getY() {
return y;
}
public Color getColor() {
return color;
}
// use this to test for collisions
public boolean contains(Point p) {
return boundingRectangle.contains(p);
}
#Override
public String toString() {
return "Brick [x=" + x + ", y=" + y + ", color=" + color + "]";
}
#Override
public int hashCode() {
final int prime = 31;
int result = 1;
result = prime * result + x;
result = prime * result + y;
return result;
}
#Override
public boolean equals(Object obj) {
if (this == obj)
return true;
if (obj == null)
return false;
if (getClass() != obj.getClass())
return false;
Brick other = (Brick) obj;
if (x != other.x)
return false;
if (y != other.y)
return false;
return true;
}
}
// logical class that holds all Bricks
// Have class implement Iterable<Brick> so we can easily iterate through its containing
// Brick objects in a for-each loop
class Bricks implements Iterable<Brick> {
public static final int X_SPACING = 10;
public static final int Y_SPACING = X_SPACING;
public static final int[] ROW_COUNTS = {13, 11, 9, 7, 5, 3, 1};
private static final float MIN_SAT = 0.8f;
private List<Brick> brickList;
private Random random = new Random();
public Bricks() {
init(); // safe to call since it's final
}
public final void init() {
// recreate the brickList ArrayList
brickList = new ArrayList<>();
int y = Y_SPACING;
// for each row of bricks
for (int row = 0; row < ROW_COUNTS.length; row++) {
int x = X_SPACING + ((ROW_COUNTS[0] - ROW_COUNTS[row]) / 2) * (X_SPACING + Brick.WIDTH);
// for each column
for (int j = 0; j < ROW_COUNTS[row]; j++) {
// create a random color
float hue = random.nextFloat();
float saturation = MIN_SAT + random.nextFloat() * (1f - MIN_SAT);
float brightness = MIN_SAT + random.nextFloat() * (1f - MIN_SAT);
Color color = Color.getHSBColor(hue, saturation, brightness);
Brick brick = new Brick(x, y, color); // create a new Brick with this Color
brickList.add(brick);
x += X_SPACING + Brick.WIDTH;
}
y += Y_SPACING + Brick.HEIGHT;
}
}
// returns null if no collision
public Brick collision(Point p) {
for (Brick brick : brickList) {
if (brick.contains(p)) {
return brick;
}
}
return null;
}
#Override
public Iterator<Brick> iterator() {
return brickList.iterator();
}
public boolean remove(Brick brick) {
// because Brick implements equals and hashCode, we can do this
return brickList.remove(brick);
}
}
Note that I like using Color's static getHSBColor(float h, float s, float b) method for creating random Colors as this helps me to avoid creating dull Colors, since I can guarantee that the saturation and brightness are above minimum values. All three parameters must be float values between 0f and 1.0f
float hue = random.nextFloat();
float saturation = MIN_SAT + random.nextFloat() * (1f - MIN_SAT);
float brightness = MIN_SAT + random.nextFloat() * (1f - MIN_SAT);
Color color = Color.getHSBColor(hue, saturation, brightness);
Your code has quite a lot of issues, which #HovercaftFullOfEels answer already points out.
As for why your code doesn't work:
for (int i = 0; i < Brick.length; i++)
{
if (Brick[i] != null)
{
Color mycolor=new Color(100,0,0);
art.setColor(mycolor);
art.fill3DRect(Brick[i].x, Brick[i].y, Brick[i].width,
Brick[i].height, true);
}
}
This is the part that renders the bricks. You never create a random-number, but use the same Color for each brick (new Color(100, 0, 0);). Instead introduce a new variable into Brick that specifies the color of each brick and is initialized once with a random color.
The Brick-class would afterwards look like this:
public class Brick{
public int x;
public int y;
...
public Color color;
...
}
The ... are just placeholders for other code that may be content of the class. Regarding public access of Class-variables: Encapsulation is a fundamental concept of OOP and should be used (on encapsulation). E.g. instead of giving direct access to Brick.x consider introducing a method Brick#getX().

drawString() isn't drawing the String on my game

I am using drawString() to write text on the string, but nothing shows up. I set the color to white and set the coordinates to (100,100). Is there anything else that I am doing wrong?
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import java.util.ArrayList;
import java.util.Random;
import javax.swing.JPanel;
public class Screen extends JPanel implements Runnable {
private static final long serialVersionUID = 1L;
public static final int WIDTH = 800, HEIGHT = 800;
private Thread thread;
private boolean running = false;
private BodyPart b;
private ArrayList<BodyPart> snake;
private Apple apple;
private ArrayList<Apple> apples;
private Random r;
private int xCoor = 20, yCoor = 20;
private int size = 10;
private int score = 0;
private boolean right = true, left = false, up = false, down = false;
private int ticks = 0;
private Key key;
public Screen() {
setFocusable(true);
key = new Key();
addKeyListener(key);
setPreferredSize(new Dimension(WIDTH, HEIGHT));
r = new Random();
snake = new ArrayList<BodyPart>();
apples = new ArrayList<Apple>();
start();
}
public void reset() {
snake.clear();
apples.clear();
xCoor = 20;
yCoor = 20;
size = 10;
score = 0;
running = true;
}
public void tick() {
if(snake.size() == 0) {
b = new BodyPart(xCoor, yCoor, 20);
snake.add(b);
}
if(apples.size() == 0) {
int xCoor = r.nextInt(40);
int yCoor = r.nextInt(40);
apple = new Apple(xCoor, yCoor, 20);
apples.add(apple);
}
for(int i = 0; i < apples.size(); i++) {
if(xCoor == apples.get(i).getxCoor() && yCoor == apples.get(i).getyCoor()) {
size++;
apples.remove(i);
score += 10;
i--;
}
}
for(int i = 0; i < snake.size(); i++) {
if(xCoor == snake.get(i).getxCoor() && yCoor == snake.get(i).getyCoor()) {
if(i != snake.size() - 1) {
reset();
}
}
}
if(xCoor < 0) xCoor = 40;
if(xCoor > 40) xCoor = 0;
if(yCoor < 0) yCoor = 40;
if(yCoor > 40) yCoor = 0;
ticks++;
if(ticks > 250000) {
if(right) xCoor++;
if(left) xCoor--;
if(up) yCoor--;
if(down) yCoor++;
ticks = 185000;
b = new BodyPart(xCoor, yCoor, 20);
snake.add(b);
if(snake.size() > size) {
snake.remove(0);
}
}
}
public void paint(Graphics g) {
g.clearRect(0, 0, WIDTH, HEIGHT);
g.drawString("Score: " + score, 100, 100);
g.setColor(Color.WHITE);
g.setColor(new Color(20, 50, 0));
g.fillRect(0, 0, WIDTH, HEIGHT);
g.setColor(Color.BLACK);
for(int i = 0; i < WIDTH / 20; i++) {
g.drawLine(i * 20, 0, i * 20, HEIGHT);
}
for(int i = 0; i < HEIGHT / 20; i++) {
g.drawLine(0, i * 20, WIDTH, i * 20);
}
for(int i = 0; i < snake.size(); i++) {
snake.get(i).draw(g);
}
for(int i = 0; i < apples.size(); i++) {
apples.get(i).draw(g);
}
}
public void start() {
running = true;
thread = new Thread(this, "Game Loop");
thread.start();
}
public void stop() {
running = false;
try {
thread.join();
} catch (InterruptedException e) {
e.printStackTrace();
}
}
public void run() {
while(running) {
tick();
repaint();
}
}
private class Key implements KeyListener {
public void keyPressed(KeyEvent e) {
int key = e.getKeyCode();
if(key == KeyEvent.VK_RIGHT && !left) {
up = false;
down = false;
right = true;
}
if(key == KeyEvent.VK_LEFT && !right) {
up = false;
down = false;
left = true;
}
if(key == KeyEvent.VK_UP && !down) {
left = false;
right = false;
up = true;
}
if(key == KeyEvent.VK_DOWN && !up) {
left = false;
right = false;
down = true;
}
}
}
The order in which you do things is very important, remember, painting in Swing is like painting on paper, if you paint the text first, then paint over it, it will no longer be visible...
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
g.setColor(new Color(20, 50, 0));
g.fillRect(0, 0, WIDTH, HEIGHT);
g.setColor(Color.BLACK);
for (int i = 0; i < WIDTH / 20; i++) {
g.drawLine(i * 20, 0, i * 20, HEIGHT);
}
for (int i = 0; i < HEIGHT / 20; i++) {
g.drawLine(0, i * 20, WIDTH, i * 20);
}
for (int i = 0; i < snake.size(); i++) {
snake.get(i).draw(g);
}
for (int i = 0; i < apples.size(); i++) {
apples.get(i).draw(g);
}
g.setColor(Color.WHITE);
g.drawString("Score: " + score, 100, 100);
}
Don't override paint, override paintComponent, you've circumvented the painting process, meaning you could end up with all sorts of nasty glitches
Call super.paintComponent
Take a look at Painting in AWT and Swing and Performing Custom Painting for more details about how painting is done.
Swing is also not thread safe and you need to be careful any time you are changing anything that the paint process uses to update the UI, as painting may occur at any time and for any reason.
Consider using a Swing Timer instead of Thread. The timer executes it's tick events within the context of the Event Dispatching Thread, making it safer to update the UI from within. See Creating a GUI With JFC/Swing
You have a few things in the wrong order. When painting, you need to paint in the correct order, otherwise you will paint over the top of other objects.
So, in your code, the first 5 lines of the paint() method should look like this... (note the same code, but a different order)
g.clearRect(0, 0, WIDTH, HEIGHT);
g.setColor(new Color(20, 50, 0));
g.fillRect(0, 0, WIDTH, HEIGHT);
g.setColor(Color.WHITE);
g.drawString("Score: " + score, 100, 100);
You need to paint the background color first. Then you can paint the String on top of it.

Java game slows down when player moves

I'm trying to write my first game in Java. I followed some tutorials and learned how to load and update a background using a Canvas and how to load and move a player sprite. I did these two separately and they worked fine, but when I put the two together and try to move the player, the game slows down to the point that it is unplayable. This only happens when I hold down an arrow key to move the player; the game actually runs "smoothly" if I rapidly tap the arrow key. After quite a bit of testing, I'm convinced that the problem occurs when the background is redrawn each frame. Any other improvements would also be appreciated.
Code (All of it):
Game.Java:
package Game;
import Level.Level;
import Player.Player;
import Sprites.SpriteSheetLoader;
import java.awt.Canvas;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.image.BufferStrategy;
import java.awt.image.BufferedImage;
import java.awt.image.DataBufferInt;
import javax.swing.JFrame;
public class Game extends Canvas implements Runnable {
// Set dimensions of the game.
public static final int HEIGHT = 320;
public static final int WIDTH = 480;
public static final int SCALE = 2;
public static Dimension GAME_DIM = new Dimension(WIDTH * SCALE, HEIGHT * SCALE);
private BufferedImage image = new BufferedImage(WIDTH, HEIGHT, BufferedImage.TYPE_INT_ARGB);
private int[] pixels = ((DataBufferInt) image.getRaster().getDataBuffer()).getData();
public SpriteSheetLoader loader;
public Screen screen;
public Level level;
public InputHandler input = new InputHandler(this);
public Player player = new Player();
private boolean running = false;
private boolean moving = true;
private int FPS = 60;
private long targetTime = 1000 / FPS;
// Set character's starting position at the center. I have no idea why I had to add the "- 50" to each value.
public int x = GAME_DIM.width / 2 - 50;
public int y = GAME_DIM.height / 2 - 50;
public int xScroll = 0;
public int yScroll = 0;
public int col = 0;
public int row = 0;
public int ticks = 0;
public int frame = 0;
public static void main(String[] args) {
Game game = new Game();
game.setPreferredSize(new Dimension(GAME_DIM));
game.setMaximumSize(new Dimension(GAME_DIM));
game.setMinimumSize(new Dimension(GAME_DIM));
JFrame frame = new JFrame("Valkyrie Game");
frame.add(game);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.pack();
frame.setResizable(true);
frame.setLocationRelativeTo(null);
frame.setVisible(true);
game.start();
}
public void start() {
running = true;
new Thread(this).start();
}
public Game() {
}
public void init() {
loader = new SpriteSheetLoader();
screen = new Screen(WIDTH, HEIGHT);
level = new Level(16, 16);
}
public void run() {
init();
long start, elapsed, wait;
while (running) {
start = System.nanoTime();
render();
tick();
elapsed = System.nanoTime() - start;
//System.out.println("Elapsed: " + elapsed);
wait = targetTime - elapsed / 1000000;
if(wait < 0) {
wait = 5;
}
try {
Thread.sleep(wait);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
public void stop() {
running = false;
}
public void tick() {
// Movement
if (input.right) {
xScroll++;
player.setAnimation(player.walkRight);
//x++;
row = 2;
ticks++;
if(ticks < 10) {
frame = 1;
} else if(ticks == 10) {
frame = 2;
} else if(ticks == 20) {
frame = 3;
} else if(ticks == 30) {
frame = 2;
} else if(ticks == 40) {
frame = 1;
} else if(ticks == 50) {
ticks = 0;
frame = 0;
}
moving = true;
} else if (input.left) {
xScroll--;
player.setAnimation(player.walkLeft);
//x--;
row = 1;
ticks++;
if(ticks < 10) {
frame = 1;
} else if(ticks == 10) {
frame = 2;
} else if(ticks == 20) {
frame = 3;
} else if(ticks == 30) {
frame = 2;
} else if(ticks == 40) {
frame = 1;
} else if(ticks == 50) {
ticks = 0;
frame = 0;
}
moving = true;
} else if (input.up) {
yScroll--;
player.setAnimation(player.walkUp);
//y--;
row = 3;
ticks++;
if(ticks < 10) {
frame = 1;
} else if(ticks == 10) {
frame = 2;
} else if(ticks == 20) {
frame = 3;
} else if(ticks == 30) {
frame = 2;
} else if(ticks == 40) {
frame = 1;
} else if(ticks == 50) {
ticks = 0;
frame = 0;
}
moving = true;
} else if (input.down) {
yScroll++;
player.setAnimation(player.walkDown);
//y++;
row = 0;
ticks++;
if(ticks < 10) {
frame = 1;
} else if(ticks == 10) {
frame = 2;
} else if(ticks == 20) {
frame = 3;
} else if(ticks == 30) {
frame = 2;
} else if(ticks == 40) {
frame = 1;
} else if(ticks == 50) {
ticks = 0;
frame = 0;
}
moving = true;
}
if (!input.down && !input.left && !input.right && !input.up) {
player.setAnimation(player.stand);
frame = 0;
ticks = 1;
moving = false;
}
//System.out.println("Tick: " + ticks);
}
public void render() {
BufferStrategy bs = getBufferStrategy();
if (bs == null) {
createBufferStrategy(3);
requestFocus();
return;
}
do {
Graphics g = bs.getDrawGraphics();
try {
for (int i = 0; i < ticks; i++) {
g.drawImage(image, 0, 0, getWidth(), getHeight(), null);
g.drawImage(player.Player(frame, row), x, y, null);
level.renderBackground(xScroll, yScroll, screen);
for (int y = 0; y < this.screen.h; y++) {
for (int x = 0; x < screen.w; x++) {
pixels[x + (y * WIDTH)] = screen.pixels[x + (y * screen.w)];
}
}
}
} finally {
g.dispose();
}
bs.show();
this.update(bs.getDrawGraphics());
} while (bs.contentsLost());
// Graphics g = bs.getDrawGraphics();
//
// g.dispose();
// bs.show();
}
}
InputHandler.Java:
package Game;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
public class InputHandler implements KeyListener {
public boolean up = false;
public boolean down = false;
public boolean left = false;
public boolean right = false;
public InputHandler(Game game) {
game.addKeyListener(this);
}
public void toggle(KeyEvent ke, boolean pressed) {
int keyCode = ke.getKeyCode();
if(keyCode == KeyEvent.VK_UP) up = pressed;
if(keyCode == KeyEvent.VK_DOWN) down = pressed;
if(keyCode == KeyEvent.VK_LEFT) left = pressed;
if(keyCode == KeyEvent.VK_RIGHT) right = pressed;
}
public void keyTyped(KeyEvent e) {
}
public void keyPressed(KeyEvent e) {
toggle(e, true);
}
public void keyReleased(KeyEvent e) {
toggle(e, false);
}
}
Screen.Java:
package Game;
import Sprites.Sprite;
public class Screen {
public int w, h;
int xOffset = 0;
int yOffset = 0;
public int[] pixels;
public Screen(int w, int h) {
this.w = w; // 480
this.h = h; // 320
pixels = new int[w * h]; // 153600
}
public void renderSprite(int xPos, int yPos, Sprite sprite) {
int height = sprite.h;
int width = sprite.w;
xPos -= xOffset;
yPos -= yOffset;
for(int y = 0; y < height; y++) {
if(yPos + y < 0 || yPos + y >= h) continue;
for(int x = 0; x < width; x++) {
if(xPos + x < 0 || xPos + x >= w) continue;
int col = sprite.pixels[x + (y * height)];
if(col != -65281 && col < 0) pixels[(x + xPos) + (y + yPos) *w]= col;
}
}
}
public void setOffs(int xOffs, int yOffs) {
xOffset = xOffs;
yOffset = yOffs;
}
}
Level.Java:
package Level;
import Game.Screen;
import Sprites.Sprite;
import Sprites.Sprites;
import Tiles.Tile;
public class Level {
int w, h;
public int[] tiles;
public Level(int w, int h) {
this.w = w;
this.h = h;
tiles = new int[w * h];
loadMap(0, 0, 0, 0);
}
public void renderBackground(int xScroll, int yScroll, Screen screen) {
int xo = xScroll >> 4;
int yo = yScroll >> 4;
int w = (screen.w + 15) >> 4;
int h = (screen.h + 15) >> 4;
screen.setOffs(xScroll, yScroll);
for(int y = yo; y <= h + yo; y++) {
for(int x = xo; x <= w + xo; x++) {
getTile(x, y).render(x, y, screen);
}
}
screen.setOffs(0, 0);
}
public Tile getTile(int x, int y) {
if(x < 0 || y < 0 || x >= w || y >= h) return Tile.rockTile;
return Tile.tiles[tiles[x + y * w]];
}
public void loadMap(int x0, int y0, int x1, int y1) {
Sprite sprite = Sprites.level[x0][y0];
for(int y = 0; y < sprite.h; y++) {
for(int x = 0; x < sprite.w; x++) {
if(sprite.pixels[x + y * sprite.h] == -9276814) {
tiles[x + x1 + (y + y1) * h] = Tile.rockTile.id;
} else {
tiles[x + x1 + (y + y1) * h] = Tile.grassTile.id;
}
}
}
}
}
Player.Java:
package Player;
import Animation.Animation;
import Sprites.Sprite;
import java.awt.image.BufferedImage;
public class Player {
// Images for each animation
private BufferedImage[] walkingLeft = {Sprite.getSprite(0, 1), Sprite.getSprite(1, 1), Sprite.getSprite(2, 1)}; // Gets the upper left images of my sprite sheet
private BufferedImage[] walkingRight = {Sprite.getSprite(0, 2), Sprite.getSprite(1, 2), Sprite.getSprite(2, 2)};
private BufferedImage[] walkingUp = {Sprite.getSprite(0, 3), Sprite.getSprite(1, 3), Sprite.getSprite(2, 3)};
private BufferedImage[] walkingDown = {Sprite.getSprite(0, 0), Sprite.getSprite(1, 0), Sprite.getSprite(2, 0)};
private BufferedImage[] standing = {Sprite.getSprite(1, 0)};
// These are animation states.
public Animation walkLeft = new Animation(walkingLeft, 10);
public Animation walkRight = new Animation(walkingRight, 10);
public Animation walkUp = new Animation(walkingUp, 10);
public Animation walkDown = new Animation(walkingDown, 10);
public Animation stand = new Animation(standing, 10);
// This is the actual animation
public Animation animation = stand;
public BufferedImage Player(int x, int y) {
BufferedImage player = Sprite.getSprite(x, y);
return player;
}
public void update() {
animation.update();
}
public void render() {
}
public void setAnimation(Animation animation) {
this.animation = animation;
}
}
Sprite.Java:
package Sprites;
import Game.Game;
import java.awt.image.BufferedImage;
import java.io.IOException;
import javax.imageio.ImageIO;
public class Sprite {
public int w, h;
public int[] pixels;
public static BufferedImage sprite = null;
public Sprite(int w, int h) {
this.w = w;
this.h = h;
pixels = new int[w * h];
}
public void clear(int color) {
for(int i = 0; i < pixels.length; i++) {
pixels[i] = color;
}
}
private static BufferedImage spriteSheet;
private static final int TILE_SIZE = 80;
public static BufferedImage loadSprite() {
try {
sprite = ImageIO.read(Game.class.getResource("/valkyrie.png"));
} catch (IOException e) {
e.printStackTrace();
}
return sprite;
}
public static BufferedImage getSprite(int xGrid, int yGrid) {
if(spriteSheet == null) {
spriteSheet = loadSprite();
}
// xGrid and yGrid refer to each individual sprite
return spriteSheet.getSubimage(xGrid * TILE_SIZE, yGrid * TILE_SIZE, TILE_SIZE, TILE_SIZE);
}
}
This is going to require double buffering. Any game with a lot going on needs double buffering.
How do you double buffer in java for a game?
Although I couldn't go through the code completely, it seems you do not do double buffering which affect performance drastically.
Try this in the relevant part of your program:
JFrame frame = new JFrame("Valkyrie Game");
frame.add(game);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.pack();
frame.setResizable(true);
frame.setLocationRelativeTo(null);
frame.setVisible(true);
frame.setDoubleBuffered(true); //added line, rest is the same
game.start();
You really should use Timer. It will solve all your problems.
Every tick, you redraw all what you need.
And every tick, you should just check, which keys are pressed and which are not, instead of adding listeners. To keep tracking this, you always have to remember the keys pressed "before".
You can even create two Timers, one for graphic redraw and one for game logic.
Even timers can be delayed or something, the usual approach is to find out, how much time elapsed (System.nanoTime for example) and count how much of game logic you should forward to keep game always unlaggy and fluent.

java.lang.NullPointerException Can't Find Source

I'm in the process of programming a java rpg game, and have reached an impass. My code currently has sprite animation, a random map generation with perlin noise and collision detection. The map is tiled base, so i'm currently trying to convert the perlin noise to tiles. The perlin functions generate a array, and im each number of that array to a tile png. This is where the problem comes: RUNTIME ERROR: Java.Lang.NullPointerException.
The probleme is my compiler (netbeans) does not show me where the error occurs, but instead only gives me this error code. With a process of exclusion I managed to locate the error, which occurs at line 364. If this site doesnt support lines, it is at the loadTile() method, at "if(perlinIsland[x][y] <= 0.05)blockImg[x][y] = TILE[0];". I believe all the variables are correctly initialized, but I can't manage to find a solution. Please excuse the long code, but I included everything for the sake of information. Thanks you in advance for you help!
package java4k;
import java.awt.*;
import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;
import java.awt.geom.Ellipse2D;
import java.awt.geom.Rectangle2D;
import java.awt.image.*;
import java.io.File;
import java.io.IOException;
import java.net.URL;
import java.util.Random;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.imageio.ImageIO;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import java.math.*;
import java.util.*;
/**
*
* #author Christophe
*/
public class Main extends JFrame implements Runnable{
public Image dbImage;
public Graphics dbGraphics;
//Image + Array size
final static int listWidth = 500, listHeight = 500;
//Move Variables
int playerX = 320, playerY = 240, xDirection, yDirection;
//Sprites
BufferedImage spriteSheet;
//Lists for sprite sheet: 1 = STILL; 2 = MOVING_1; 3 = MOVING_2
BufferedImage[] ARCHER_NORTH = new BufferedImage[4];
BufferedImage[] ARCHER_SOUTH = new BufferedImage[4];
BufferedImage[] ARCHER_EAST = new BufferedImage[4];
BufferedImage[] ARCHER_WEST = new BufferedImage[4];
Image[] TILE = new Image[8];
//Animation Variables
int currentFrame = 0, framePeriod = 150;
long frameTicker = 0l;
Boolean still = true;
Boolean MOVING_NORTH = false, MOVING_SOUTH = false, MOVING_EAST = false, MOVING_WEST = false;
BufferedImage player = ARCHER_SOUTH[0];
//World Tile Variables
//20 X 15 = 300 tiles
Rectangle[][] blocks = new Rectangle[listWidth][listHeight];
Image[][] blockImg = new Image[listWidth][listHeight];
Image[][] blockImgTrans = new Image[listWidth][listHeight];
Boolean[][] isSolid = new Boolean[listWidth][listHeight];
int tileX = 0, tileY = 0;
Random r = new Random();
Rectangle playerRect = new Rectangle(playerX + 4,playerY+20,32,20);
//Map Navigation
static final byte PAN_UP = 0, PAN_DOWN = 1, PAN_LEFT = 2, PAN_RIGHT = 3;
//Perlin noise variables:
Color test = new Color(0, 0, 0);
static float[][] perlinNoise = new float[listWidth][listHeight];
static float[][] gradiantNoise = new float[listWidth][listHeight];
static float[][] perlinIsland = new float[listWidth][listHeight];
static float[][] biome = new float[listWidth][listHeight];
//Saved as png
static BufferedImage perlinImage;
public Main(){
this.setTitle("JAVA4K");
this.setSize(640,505);
this.setResizable(false);
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
this.setVisible(true);
addKeyListener(new AL());
TILE[0] = new ImageIcon("C:/Users/Christophe/Documents/NetBeansProjects/Java4k/src/java4k/TILE_GRASS_1.png").getImage();
TILE[1] = new ImageIcon("C:/Users/Christophe/Documents/NetBeansProjects/Java4k/src/java4k/TILE_GRASS_2.png").getImage();
TILE[2] = new ImageIcon("C:/Users/Christophe/Documents/NetBeansProjects/Java4k/src/java4k/TILE_GRASS_3.png").getImage();
TILE[3] = new ImageIcon("C:/Users/Christophe/Documents/NetBeansProjects/Java4k/src/java4k/TILE_WATER_1.png").getImage();
TILE[4] = new ImageIcon("C:/Users/Christophe/Documents/NetBeansProjects/Java4k/src/java4k/TILE_TREE_1_BOT.png").getImage();
TILE[5] = new ImageIcon("C:/Users/Christophe/Documents/NetBeansProjects/Java4k/src/java4k/TILE_TREE_1_TOP.png").getImage();
TILE[6] = new ImageIcon("C:/Users/Christophe/Documents/NetBeansProjects/Java4k/src/java4k/TILE_TREE_2_BOT.png").getImage();
TILE[7] = new ImageIcon("C:/Users/Christophe/Documents/NetBeansProjects/Java4k/src/java4k/TILE_TREE_2_TOP.png").getImage();
loadTiles();
init();
}
//Step 1: Generates array of random number 0 < n < 1
public static float[][] GenerateWhiteNoise(int width, int height){
Random r = new Random();
Random random = new Random(r.nextInt(1000000000)); //Seed to 0 for testing
float[][] noise = new float[width][height];
for (int i = 0; i < width; i++)
{
for (int j = 0; j < height; j++)
{
noise[i][j] = (float)random.nextDouble() % 1;
}
}
return noise;
}
//Step 2: Smooths out random numbers
public static float[][] GenerateSmoothNoise(float[][] baseNoise, int octave){
int width = baseNoise.length;
int height = baseNoise.length;
float[][] smoothNoise = new float[width][height];
int samplePeriod = 1 << octave; // calculates 2 ^ k
float sampleFrequency = 1.0f / samplePeriod;
for (int i = 0; i < width; i++)
{
//calculate the horizontal sampling indices
int sample_i0 = (i / samplePeriod) * samplePeriod;
int sample_i1 = (sample_i0 + samplePeriod) % width; //wrap around
float horizontal_blend = (i - sample_i0) * sampleFrequency;
for (int j = 0; j < height; j++)
{
//calculate the vertical sampling indices
int sample_j0 = (j / samplePeriod) * samplePeriod;
int sample_j1 = (sample_j0 + samplePeriod) % height; //wrap around
float vertical_blend = (j - sample_j0) * sampleFrequency;
//blend the top two corners
float top = Interpolate(baseNoise[sample_i0][sample_j0],
baseNoise[sample_i1][sample_j0], horizontal_blend);
//blend the bottom two corners
float bottom = Interpolate(baseNoise[sample_i0][sample_j1],
baseNoise[sample_i1][sample_j1], horizontal_blend);
//final blend
smoothNoise[i][j] = Interpolate(top, bottom, vertical_blend);
}
}
return smoothNoise;
}
//Used in GeneratePerlinNoise() to derivate functions
public static float Interpolate(float x0, float x1, float alpha)
{
float ft = alpha * 3.1415927f;
float f = (float) (1 - Math.cos(ft)) * .5f;
return x0*(1-f) + x1*f;
}
//Step 3: Combines arrays together to generate final perlin noise
public static float[][] GeneratePerlinNoise(float[][] baseNoise, int octaveCount)
{
int width = baseNoise.length;
int height = baseNoise[0].length;
float[][][] smoothNoise = new float[octaveCount][][]; //an array of 2D arrays containing
float persistance = 0.5f;
//generate smooth noise
for (int i = 0; i < octaveCount; i++)
{
smoothNoise[i] = GenerateSmoothNoise(baseNoise, i);
}
float[][] perlinNoise = new float[width][height];
float amplitude = 1.0f;
float totalAmplitude = 0.0f;
//blend noise together
for (int octave = octaveCount - 1; octave >= 0; octave--)
{
amplitude *= persistance;
totalAmplitude += amplitude;
for (int i = 0; i < width; i++)
{
for (int j = 0; j < height; j++)
{
perlinNoise[i][j] += smoothNoise[octave][i][j] * amplitude;
}
}
}
//normalisation
for (int i = 0; i < width; i++)
{
for (int j = 0; j < height; j++)
{
perlinNoise[i][j] /= totalAmplitude;
}
}
return perlinNoise;
}
//Step 4: Generate circular gradiant: center = 0, outside = 1
public static float[][] GenerateCircularGradiant(float[][] base, int size, int centerX, int centerY){
base = new float[size][size];
for (int x = 0; x < base.length; x++) {
for (int y = 0; y < base.length; y++) {
//Simple squaring, you can use whatever math libraries are available to you to make this more readable
//The cool thing about squaring is that it will always give you a positive distance! (-10 * -10 = 100)
float distanceX = (centerX - x) * (centerX - x);
float distanceY = (centerY - y) * (centerY - y);
float distanceToCenter = (float) Math.sqrt(distanceX + distanceY);
//Make sure this value ends up as a float and not an integer
//If you're not outputting this to an image, get the correct 1.0 white on the furthest edges by dividing by half the map size, in this case 64. You will get higher than 1.0 values, so clamp them!
float mapSize = base.length/2;
//mapSize = 500;
distanceToCenter = distanceToCenter / mapSize;
base[x][y] = distanceToCenter - 0.2f;
}
}
return base;
}
//step 5: Combine perlin noise with circular gradiant to create island
public static float[][] GenerateIsland(float[][] baseCircle, float[][] baseNoise){
float[][] baseIsland = new float[baseNoise.length][baseNoise.length];
for(int x = 0; x < baseNoise.length; x++){
for(int y = 0; y < baseNoise.length; y++){
baseIsland[x][y] = baseNoise[x][y] - baseCircle[x][y];
}
}
return baseIsland;
}
//Method for optional paramater = float[][] biome
public static void GreyWriteImage(float[][] data, String filename){
float[][] temp = null;
GreyWriteImage(data, temp, filename);
}
//Converts array data to png image
public static void GreyWriteImage(float[][] data, float[][] biome, String fileName){
//this takes and array of doubles between 0 and 1 and generates a grey scale image from them
BufferedImage image = new BufferedImage(data.length,data[0].length, BufferedImage.TYPE_INT_RGB);
for (int y = 0; y < data[0].length; y++)
{
for (int x = 0; x < data.length; x++)
{
if (data[x][y]>1){
data[x][y]=1;
}
if (data[x][y]<0){
data[x][y]=0;
}
Color col;
//Deep Water 0 - 0.05
if(data[x][y] <= 0.05) col = new Color(0, 0, 255);
//Shallow Water 0.05 - 0.08
else if(data[x][y] <= 0.08) col = new Color(100, 100, 255);
//Beach 0.08 - 0.2
else if(data[x][y]<=0.15) col = new Color(255, 255, 0);
//Forest 0.2 - 0.6 + 0 0 0.7
else if(data[x][y]<=0.6 && biome != null && (biome[x][y] < 0.6 || biome[x][y] > 0.9)){
//Forest
if(biome[x][y] < 0.6) col = new Color(0, 150, 0);
//Desert
else col = new Color(200, 200, 0);
}
//Plains 0.2 - 0.6
else if(data[x][y] <= 0.6) col = new Color(0, 255, 0);
//Rocky Mountains 0.6 - 0.8
else if(data[x][y] <= 0.65) col = new Color(100, 100, 100);
//Snowy Mountains 0.6 - 1
else col = new Color(255, 255, 255);
image.setRGB(x, y, col.getRGB());
}
}
try {
// retrieve image
File outputfile = new File(fileName);
outputfile.createNewFile();
ImageIO.write(image, "png", outputfile);
} catch (IOException e) {
System.out.println("GREY WRITE IMAGE ERROR 303: " + e);
}
}
//First called to store image tiles in blockImg[][] and tile rectangles in blocks[][]
private void loadTiles(){
//Primary Perlin Noise Generation
perlinNoise = GenerateWhiteNoise(listWidth, listHeight);
GreyWriteImage(perlinNoise, "perlinNoise.png");
perlinNoise = GenerateSmoothNoise(perlinNoise, 7);
GreyWriteImage(perlinNoise, "smoothNoise.png");
perlinNoise = GeneratePerlinNoise(perlinNoise, 5);
GreyWriteImage(perlinNoise, "finalPerlin.png");
gradiantNoise = GenerateCircularGradiant(gradiantNoise, listWidth, listWidth/2 - 1, listHeight/2 - 1);
GreyWriteImage(gradiantNoise, "gradiantNoise.png");
perlinIsland = GenerateIsland(gradiantNoise, perlinNoise);
GreyWriteImage(perlinIsland, "perlinIsland.png");
//Biome Perlin Noise Generation
biome = GenerateWhiteNoise(listWidth, listHeight);
biome = GenerateSmoothNoise(biome, 6);
biome = GeneratePerlinNoise(biome, 5);
GreyWriteImage(perlinIsland, biome, "biome.png");
for(int y = 0; y < listHeight; y++){
for(int x = 0; x < listWidth; x++){
//Sets boundaries: 0 < perlinIsland[x][y] < 1
if (perlinIsland[x][y]>1) perlinIsland[x][y]=1;
if (perlinIsland[x][y]<0) perlinIsland[x][y]=0;
//Deep Water 0 - 0.05
if(perlinIsland[x][y] <= 0.05)blockImg[x][y] = TILE[0];
//Shallow Water 0.05 - 0.08
else if(perlinIsland[x][y] <= 0.08) blockImg[x][y] = TILE[3];
//Beach 0.08 - 0.2
else if(perlinIsland[x][y]<=0.15) blockImg[x][y] = TILE[4];
//Forest 0.2 - 0.6 + 0 0 0.7
else if(perlinIsland[x][y]<=0.6 && biome != null && (biome[x][y] < 0.6 || biome[x][y] > 0.9)){
//Forest
if(biome[x][y] < 0.6) blockImg[x][y] = TILE[5];
//Desert
else blockImg[x][y] = TILE[3];
}
//Plains 0.2 - 0.6
else if(perlinIsland[x][y] <= 0.6) blockImg[x][y] = TILE[2];
//Rocky Mountains 0.6 - 0.8
else if(perlinIsland[x][y] <= 0.65) blockImg[x][y] = TILE[3];
//Snowy Mountains 0.6 - 1
else blockImg[x][y] = TILE[1];
blocks[x][y] = new Rectangle(x*32, y*32, 32, 32);
}
}
}
//collision detection
public boolean collide(Rectangle in)
{
if(blocks[0][0] != null){
for (int y = (int)((playerRect.y - blocks[0][0].y) / 32)-1; y <= (int)((playerRect.y+playerRect.height - blocks[0][0].y) / 32)+1; y++){
for (int x = (int)((playerRect.x - blocks[0][0].x) / 32)-1; x <= (int)((playerRect.x+playerRect.width - blocks[0][0].x) / 32) + 1; x++){
if (x >= 0 && y >= 0 && x < 32 && y < 32){
if (blockImg[x][y] != null)
{
if (in.intersects(blocks[x][y]) && isSolid[x][y] == true){
{
return true;
}
}
}
}
}
}
}
return false;
}
//Key Listener
public class AL extends KeyAdapter{
public void keyPressed(KeyEvent e){
int keyInput = e.getKeyCode();
still = false;
if(keyInput == e.VK_LEFT){
navigateMap(PAN_RIGHT);
MOVING_WEST = true;
}if(keyInput == e.VK_RIGHT){
navigateMap(PAN_LEFT);
MOVING_EAST = true;
}if(keyInput == e.VK_UP){
navigateMap(PAN_DOWN);
MOVING_NORTH = true;
}if(keyInput == e.VK_DOWN){
navigateMap(PAN_UP);
MOVING_SOUTH = true;
}
}
public void keyReleased(KeyEvent e){
int keyInput = e.getKeyCode();
setYDirection(0);
setXDirection(0);
if(keyInput == e.VK_LEFT){
MOVING_WEST = false;
player = ARCHER_WEST[0];
}if(keyInput == e.VK_RIGHT){
MOVING_EAST = false;
player = ARCHER_EAST[0];
}if(keyInput == e.VK_UP){
MOVING_NORTH = false;
player = ARCHER_NORTH[0];
}if(keyInput == e.VK_DOWN){
MOVING_SOUTH = false;
player = ARCHER_SOUTH[0];
}
if( MOVING_SOUTH == MOVING_NORTH == MOVING_EAST == MOVING_WEST == false){
still = true;
}
}
}
public void moveMap(){
for(int a = 0; a < 30; a++){
for(int b = 0; b < 30; b++){
if(blocks[a][b] != null){
blocks[a][b].x += xDirection;
blocks[a][b].y += yDirection;
}
}
}
if(collide(playerRect) && blocks[0][0]!= null){
for(int a = 0; a < 30; a++){
for(int b = 0; b < 30; b++){
blocks[a][b].x -= xDirection;
blocks[a][b].y -= yDirection;
}
}
}
}
public void navigateMap(byte pan){
switch(pan){
default:
System.out.println("Unrecognized pan!");
break;
case PAN_UP:
setYDirection(-1);
break;
case PAN_DOWN:
setYDirection(+1);
break;
case PAN_LEFT:
setXDirection(-1);
break;
case PAN_RIGHT:
setXDirection(+1);
break;
}
}
//Animation Update
public void update(long gameTime) {
if (gameTime > frameTicker + framePeriod) {
frameTicker = gameTime;
currentFrame++;
if (currentFrame >= 4) {
currentFrame = 0;
}
}
if(MOVING_NORTH) player = ARCHER_NORTH[currentFrame];
if(MOVING_SOUTH) player = ARCHER_SOUTH[currentFrame];
if(MOVING_EAST) player = ARCHER_EAST[currentFrame];
if(MOVING_WEST) player = ARCHER_WEST[currentFrame];
}
public void setXDirection(int xdir){
xDirection = xdir;
}
public void setYDirection(int ydir){
yDirection = ydir;
}
//Method to get sprites
public BufferedImage grabSprite(int x, int y, int width, int height){
BufferedImage sprite = spriteSheet.getSubimage(x, y, width, height);
return sprite;
}
private void init(){
spriteSheet = null;
try {
spriteSheet = loadImage("ARCHER_SPRITESHEET.png");
} catch (IOException ex) {
Logger.getLogger(Main.class.getName()).log(Level.SEVERE, null, ex);
}
for(int i = 0; i <= 3; i++){
ARCHER_NORTH[i] = grabSprite(i*16, 16, 16,16);
ARCHER_SOUTH[i] = grabSprite(i*16, 0, 16, 16);
ARCHER_EAST[i] = grabSprite(i*16, 32, 16, 16);
ARCHER_WEST[i] = grabSprite(i*16, 48, 16, 16);
}
}
public BufferedImage loadImage(String pathRelativeToThis) throws IOException{
URL url = this.getClass().getResource(pathRelativeToThis);
BufferedImage img = ImageIO.read(url);
return img;
}
public void paint(Graphics g){
dbImage = createImage(getWidth(), getHeight());
dbGraphics = dbImage.getGraphics();
paintComponent(dbGraphics);
g.drawImage(dbImage, 0, 25, this);
}
public void paintComponent(Graphics g){
requestFocus();
/**
//Draws tiles and rectangular boundaries for debugging
for(int a = 200; a < 230; a++){
for(int b = 200; b < 230; b++){
if(blockImg[a][b] != null && blocks[a][b] != null){
g.drawImage(blockImg[a][b], Math.round(blocks[a][b].x), Math.round(blocks[a][b].y), 32, 32, null);
}
}
}
//Draw player and rectangular boundary for collision detection
g.drawImage(player, playerX, playerY, 40, 40, null);
repaint();
//Draws transparent tiles
for(int a = 0; a < 20; a++){
for(int b = 0; b < 15; b++){
if(blockImgTrans[a][b] != null && blocks[a][b] != null){
g.drawImage(blockImgTrans[a][b], blocks[a][b].x, blocks[a][b].y, 32, 32, null);
}
}
}
**/
}
public void run(){
try{
while(true){
moveMap();
if(!still) update(System.currentTimeMillis());
Thread.sleep(13);
}
}catch(Exception e){
System.out.println("RUNTIME ERROR: " + e);
}
}
public static void main(String[] args) {
Main main = new Main();
//Threads
Thread thread1 = new Thread(main);
thread1.start();
}
}
Your limited catch block code hampers your ability to find your nulls.
For instance, these lines of code:
try {
while (true) {
moveMap();
if (!still)
update(System.currentTimeMillis());
Thread.sleep(13);
}
} catch (Exception e) {
System.out.println("RUNTIME ERROR: " + e);
}
Will only print
RUNTIME ERROR: java.lang.NullPointerException
without line numbers or stack trace when this code runs into an NPE.
First off, you should not be trapping for plain Exception but rather for explicit Exceptions. Next you should use a more informative catch block, for instance one that at least prints out the stack trace via e.printStackTrace().
The block above should really be written:
public void run() {
while (true) {
moveMap();
if (!still)
update(System.currentTimeMillis());
try {
Thread.sleep(13);
// only catch the explicit exception and in localized code if possible.
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
Do this, and you'll see that the NPE occurs here:
if (in.intersects(blocks[x][y]) && isSolid[x][y] == true) {
Then you can stuff code in front of that line to see which variable is causing the problem:
e.g.,
if (blockImg[x][y] != null) {
System.out.println("in is null: " + (in == null));
System.out.println("blocks[x][y] is null: "
+ (blocks[x][y] == null));
System.out.println("isSolid is null: "
+ (isSolid == null));
System.out.println("isSolid[x][y] is null: "
+ (isSolid[x][y] == null));
if (in.intersects(blocks[x][y]) && isSolid[x][y] == true) {
{
return true;
}
}
}
And you'll see the problem is that isSolid[x][y] is null:
in is null: false
blocks[x][y] is null: false
isSolid is null: false
isSolid[x][y] is null: true
in is null: false
blocks[x][y] is null: false
isSolid is null: false
isSolid[x][y] is null: true
in is null: false
blocks[x][y] is null: false
isSolid is null: false
isSolid[x][y] is null: true
Exception in thread "Thread-3" java.lang.NullPointerException
at pkg.Main.collide(Main.java:465)
at pkg.Main.moveMap(Main.java:557)
at pkg.Main.run(Main.java:693)
at java.lang.Thread.run(Unknown Source)
in is null: false
blocks[x][y] is null: false
isSolid is null: false
isSolid[x][y] is null: true
in is null: false
blocks[x][y] is null: false
isSolid is null: false
isSolid[x][y] is null: true
in is null: false
blocks[x][y] is null: false
isSolid is null: false
isSolid[x][y] is null: true
And why is that? It's an array of Booleans, not booleans, so it is not initialized to Boolean.FALSE but rather it defaults to null. Solution: either use boolean[][] array or initialize your array explicitly.
Most important: use informative catch blocks and don't catch for general Exceptions.
Edit note that as an aside, in order for me to get your code to run, I had to disable your use of images and sprite sheets, since these are resources that are unavailable to me. This effort should be yours though since you are the one seeking in the future. I ask that in the future, you limit your code to the smallest code that we can test and run, that demonstrates your problem, but that has no code unrelated to your problem, and that does not rely on outside resources such as images, databases, etc..., an sscce.

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