Using KeyPressed to increase a counter [Fixed]

Programming Questions

kushal_ca

Using KeyPressed to increase a counter [Fixed]

in Programming Questions • 7 months ago

Hi,

I have the following code and I am trying to use KeyPressed to increase a counter. I would then like to use the counter within an array.

The code has random spheres moving around the screen and I am working on creating 'attrators' which I can place using my mouse one after the other.

The problem:

When I run the code, as I press 'CONTROL' to increase my counter, that works fine and using print I can see the counter increase. However, as soon as I right click to active mousePressed and hence use the counter, clicking 'CONTROL' does not increase my counter anymore.

Can anyone help or point me in the right direction.

This is part of an experiment using Daniel Shiffman's Nature of Code.

Code:

Mover[] m = new Mover[10];
Attractor[] a = new Attractor[2];
int x = 0; //counter
void setup() {
size(600, 600, P3D);
sphereDetail(10);
background(255);
for (int i = 0;i < m.length; i++) {
m[i] = new Mover();
}
for (int i = 0;i < a.length; i++) {
a[i] = new Attractor();
}
}
void draw() {
lights();
background(255);
if (mousePressed) {
a[x].update();
print(x);
}
for (int i =0;i < m.length; i++) {
m[i].update();
m[i].checkEdges();
m[i].display();
}
for (int i =0;i < a.length; i++) {
if(a[i].location.mag() != 0) {
a[i].display(); for (int j = 0; j < m.length; j++) {
a[i].attract(m[j]);}
}
}
}
void keyPressed() {
if( key == CODED ) {if (keyCode == CONTROL ) {x+=1;print(x);}}
if(x>10) {x=0;}
loop();}

Replies(4)

amnon.owed

Re: Using KeyPressed to increase a counter

7 months ago

That's possibly because your sketch crashes due to the fact that your counter can go up to 10, but your array only consists of 2 elements (0 and 1). Other than that it's kinda hard to tell since your code example isn't runnable because of the missing code / classes.

kushal_ca

Re: Using KeyPressed to increase a counter

7 months ago

Hi amnon,

Thanks for the feedback. I have posted the completed code below. Basically, I will run it, and then if I press CONTROL, I can see x increase by 1 everytime as I coded. However, as soon as I click my mouse and activate mousePressed, it seems that processing does not run the 'keyPressed' section anymore.

Any insights?

Thanks again for the help!!

Mover[] m = new Mover[10];
Attractor[] a = new Attractor[10];
int x = 0; //counter
void setup() {
size(600, 600, P3D);
sphereDetail(10);
background(255);
for (int i = 0;i < m.length; i++) {
m[i] = new Mover();
}
for (int i = 0;i < a.length; i++) {
a[i] = new Attractor();
}
}
void draw() {
lights();
background(255);
if (mousePressed) {
a[x].update();
print(x);
}
for (int i =0;i < m.length; i++) {
m[i].update();
m[i].checkEdges();
m[i].display();
}
for (int i =0;i < a.length; i++) {
if(a[i].location.mag() != 0) {
a[i].display(); for (int j = 0; j < m.length; j++) {
a[i].attract(m[j]);}
}
}
}
void keyPressed() {
if( key == CODED ) {if (keyCode == CONTROL ) {x+=1;print(x);}}
if(x>10) {x=0;}
loop();}
class Attractor {
PVector location;
int i;
Attractor() {
location = new PVector(0, 0);
}
void attract(Mover m) {
PVector dir = PVector.sub(location, m.location);
PVector dist = PVector.sub(location, m.location);
dir.normalize();
dir.mult(5);
m.acceleration = dir;
if (dist.mag() <= 3) {
m.acceleration = new PVector(0, 0);
m.velocity = new PVector(0, 0);
}
m.velocity.add(m.acceleration);
m.velocity.limit(5);
m.location.add(m.velocity);
}
void update() {
location = new PVector(mouseX,mouseY);
}
void display() {
ellipse(location.x, location.y,10,10);
}
}
class Mover {
PVector location, velocity, acceleration;
float sphSize;
Mover() {
location = new PVector(random(width), random(height));
velocity = new PVector(0, 0);
acceleration = new PVector(random(-1.0, 1.0), random(-1.0, 3.0));
sphSize = 10;
}
void update() {
acceleration = PVector.random2D();
velocity.add(acceleration);
velocity.limit(5);
location.add(velocity);
}
void display() {
pushMatrix();
noStroke();
translate(location.x, location.y, 0);
sphere(sphSize);
popMatrix();
}
void checkEdges() {
if (location.x > width) {
location.x = 0;
}
else if (location.x < 0) {
location.x = width;
}
if (location.y > height) {
location.y = 0;
}
else if (location.y < 0) {
location.y = height;
}
}
}

amnon.owed

Re: Using KeyPressed to increase a counter

7 months ago

I can't reproduce your issue (winxp, processing 2.0b8). When I run your code I can press CONTROL to change x and press the mouse and press CONTROL and then mouse, etc. in any order without problems. I see x changing and I can set attractors. The print on line 22 causes a lot of console numbers so perhaps you can take it out and also use a println() in line 38 so it's easier distinguishable.

I already mentioned the other problem which is still present. Your array contains 10 elements (0-9) and your x can go up to 10, so this will cause a NPE. So it should be (x>=10)

kushal_ca

Re: Using KeyPressed to increase a counter

7 months ago

Hi amnon,

I upgraded processing to 2.0b8 and its now working. Seems like it was a bug with the older version.

I also fixed x to x>=10.

Thank you again for your help!

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