NullPointerException in Minim and loading images

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NullPointerException in Minim and loading images

in Core Library Questions • 6 months ago

Making a tilemap for a programming class and it needs to be accompanied by background music. Unfortunately this error pops up and i have yet to find the cause of why....

The file "cave.png" is missing or inaccessible, make sure the URL is valid or that the file has been added to your sketch and is readable.

The file "cave1.png" is missing or inaccessible, make sure the URL is valid or that the file has been added to your sketch and is readable.

The file "cave2.png" is missing or inaccessible, make sure the URL is valid or that the file has been added to your sketch and is readable.

The file "cave3.png" is missing or inaccessible, make sure the URL is valid or that the file has been added to your sketch and is readable.

The file "cave4.png" is missing or inaccessible, make sure the URL is valid or that the file has been added to your sketch and is readable.

The file "cavet1.png" is missing or inaccessible, make sure the URL is valid or that the file has been added to your sketch and is readable.

The file "cavet2.png" is missing or inaccessible, make sure the URL is valid or that the file has been added to your sketch and is readable.

The file "dirtcave2.png" is missing or inaccessible, make sure the URL is valid or that the file has been added to your sketch and is readable.

==== JavaSound Minim Error ====

==== Failed to get method sketchPath from file loading object provided!

==== null

==== File recording will be disabled.

==== JavaSound Minim Error ====

==== Failed to get method createInput from the file loading object provided!

==== null

==== File loading will be disabled.

Exception in thread "Animation Thread" java.lang.NullPointerException

at ddf.minim.Minim.<init>(Unknown Source)

at Brogan_Assign_8_2.setup(Brogan_Assign_8_2.java:50)

at processing.core.PApplet.handleDraw(PApplet.java:2117)

at processing.core.PGraphicsJava2D.requestDraw(PGraphicsJava2D.java:193)

at processing.core.PApplet.run(PApplet.java:2020)

at java.lang.Thread.run(Thread.java:662)

Here is the original code

import ddf.minim.spi.*;

import ddf.minim.signals.*;

import ddf.minim.*;

import ddf.minim.analysis.*;

import ddf.minim.ugens.*;

import ddf.minim.effects.*;

{PImage img0, img1, img2, img3, img4, img5, img6, img7;

img0= loadImage("cave.png");

img1 = loadImage("cave1.png");

img2 = loadImage("cave2.png");

img3 = loadImage("cave3.png");

img4 = loadImage("cave4.png");

img5 = loadImage("cavet1.png");

img6 = loadImage("cavet2.png");

img7 = loadImage("dirtcave2.png");}

Minim minim;

AudioPlayer player;

String[] tileMap;

int TILE_SIZE = 16;

PImage[] tiles = new PImage[8];

void setup(){

minim = new Minim(player);

player= minim.loadFile(dataPath("cavesound1.wav"));

player.play();

tileMap = loadStrings("tilemap1.txt");

size(TILE_SIZE*tileMap[0].length(), TILE_SIZE*tileMap.length);

tiles[0]=loadImage("dirt.png");

tiles[1]=loadImage("cave.png");

tiles[2]=loadImage("cave1.png");

tiles[3]=loadImage("cave2.png");

tiles[4]=loadImage("cave3.png");

tiles[5]=loadImage("cave4.png");

tiles[6]=loadImage("cavet1.png");

tiles[7]=loadImage("cavet2.png");

println(tileMap);

}

void draw(){

for(int i=0; i<tileMap.length;i++){

for(int j=0; j<tileMap[i].length();j++){

int tileValue=Character.getNumericValue(tileMap[i].charAt(j));

image(tiles[tileValue], j*TILE_SIZE,i*TILE_SIZE,TILE_SIZE,TILE_SIZE);

}}}

void stop(){

minim.stop();

player.close();

super.stop();

}

I have highlighted the area where the error occurs. any advice or help would be greatly appreciated.

Replies(3)

GoToLoop

Re: NullPointerException in Minim and loading images

6 months ago

The variable player you're trying to use, which is of object type AudioPlayer, has not been initialized yet!
You see, declaring an object variable is not enough.

All object variables start w/ value null,
which means it doesn't point to any allocated memory block reference yet!

The most common way to initialize such variables is using keyword new,
which allocates a new memory block for the instantiated object.

But there are some methods which also do that internally, like loadFile(), loadStrings(), loadImage(), etc.
All such methods creates a new instance of a class, making a copy object outta it!

However, from examples I've seen using library Minim,
the sketch's reference itself has to be passed as parameter!
You have to use keyword this to get the sketch's reference pointer!

Thus, the correct way to initialize a variable of type Minim is something like this:
minim_variable = new Minim(this);

So, remember to initialize object variables w/ a valid reference pointer of an instantiated object from a class!

PhiLho

Re: NullPointerException in Minim and loading images

6 months ago

Beside, size() must be the first instruction in setup(). You can call it with a default value, and use size() with the right dimension later. I have seen issues with core libraries initialized before size() (code can be run twice in this zone!).

GoToLoop

Re: NullPointerException in Minim and loading images

6 months ago

I had no problems in declaring & initializing a Minim variable in the same statement!
final Minim minim = new Minim(this);

I don't think the sketch's reference pointer changes after a size() or resize(), does it?

And I had some programs that needed some calculations to do before deciding which resolution to use.
So I had to postpone size() farther within setup() and had no apparent bugs doing so!

Only thing I know to be aware of, is that the sketch isn't aware of the subfolder /data,
neither about variables width & height, before setup() is called.

So, anything which depends on such, I postpone them to be initialized inside setup()!

At least, that's my adventures I got so far!

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