Help with tile loader code
Last night i started work on a tile loader/map creator piece of code its no where near finished at the mo, but im having a small problem with it it doesnt seem to like this piece of the code
map = createImage(sizeX*32, sizeY*32);
mapGraphics = map.getGraphics();
any ideas why? it compiles ok, but when it runs it crashes with an NullPointerException for the mapGraphics = map.getGraphics(); line
also out of curisosity is there an easier/quicker way to copy part of an image and store it into another image than the one im using?
any thoughts would be greatly appreciated
import java.awt.*;
import java.applet.*;
import java.awt.image.*;
import java.net.*;
import java.io.*;
class LevelMapextends Applet{
Graphics mapGraphics;
Image map;
Image[] tiles=new Image[50];
int sizeX;
int sizeY;
publicvoid init(){
sizeX=0;
sizeY=0;
}
publicvoid setTiles (int pos, Image tile){
tiles[pos]=tile;
}
publicvoid createImageMap (String contents){
for (int i=0 ; i<contents.length() ; i++){
if(contents.charAt(i)=='\n'){
sizeY++;
}
else{
sizeX++;
}
}
map = createImage(sizeX*32, sizeY*32);
mapGraphics = map.getGraphics();
}
publicvoid paint(Graphics g, platformMain parent){
for (int i=0 ; i><3 ; i++){
g.drawImage(tiles[i],32*i,0,parent);
}
for (int i=0 ; i<3 ; i++){
g.drawImage(tiles[i+3],32*i,32, parent);
}
}
}
publicclass platformMainextends Appletimplements Runnable{
MediaTracker tracker;
Thread painter;
Graphics bufferGraphics;
Image offscreen;
Dimension dim;
LevelMap level1=new LevelMap();
Graphics tileGraphics;
Image tile;
int delay;
Image tileSet_1;
publicvoid init(){
dim=getSize();
offscreen = createImage(dim.width,dim.height);
bufferGraphics = offscreen.getGraphics();
tile = createImage(32,32);
tileGraphics = tile.getGraphics();
int fps = 35;
delay = (fps > 0) ? (1000 / fps) : 100;
level1.init();
tracker =new MediaTracker(this);
tileSet_1=getImage(getCodeBase(),"Images/tile1.png");
tracker.addImage(tileSet_1, 0);
try{
tracker.waitForID(0);
}catch (InterruptedException e){
}
//level 1 setup
for (int i=0 ; i<(tileSet_1.getWidth(this)-1)/33 ; i++){
level1.setTiles(i, splitTileSet(tileSet_1, i, 32, 32, null,true));
}
level1.createImageMap(loadMap("test.txt"));
repaint();
}
/**********************
CUSTOM CLASSES
***********************/
public Image splitTileSet(Image map,int pos,int width,int height, Color transparent,boolean faded){
tileGraphics.drawImage(map, 0-((pos*width)+(pos+1)), -1,this);
int[] pixels=newint[width*height];
PixelGrabber pg=new PixelGrabber(tile,0,0,width,height,pixels,0,width);
try{
pg.grabPixels();
}catch(InterruptedException e){}
return createImage(new MemoryImageSource(width,height,pixels,0,width));
}
public String loadMap (String path){
String whole="";
String line;
StringBuffer buf;
URL url=null;
try{
url =new URL (getCodeBase(), path );
}catch (MalformedURLException e){}
try{
InputStream in=url.openStream();
BufferedReader dis =new BufferedReader(new InputStreamReader(in));
buf =new StringBuffer () ;
while ((line = dis.readLine()) !=null){
whole+=line+"\n";
}
in.close();
}catch (IOException e ){}
return whole;
}
/**********************
REQUIRED CLASSES
***********************/
publicvoid paint(Graphics g){
level1.paint(bufferGraphics,this);
bufferGraphics.setColor(Color.black);
bufferGraphics.drawString("testing...testing",10,10);
g.drawImage(offscreen,0,0,this);
}
publicvoid update(Graphics g){
paint(g);
}
publicvoid start(){
if(painter==null){
painter=new Thread(this);
painter.start();
}
}
publicvoid run(){
long tm = System.currentTimeMillis();
while (Thread.currentThread() == painter){
try{
tm += delay;
Thread.sleep(Math.max(0, tm - System.currentTimeMillis()));
}catch (InterruptedException e){
break;
}
repaint();
}
}
publicvoid stop(){
if(painter!=null){
painter=null;
}
}
}
