Help: Record & playback positions of all particles in a system

Programming Questions

mganucheau

Help: Record & playback positions of all particles in a system

in Programming Questions • 1 year ago

I am currently trying to record and playback the positions of all particles in a particle system. I understand the concept though I am having difficulty with the implementation. I can record into a single array though I have difficulty when approaching multiple arrays.

To help illustrate my desired goal, I have created a working version with only one array:

// Record_Mouse Example
ArrayList<PVector> list = new ArrayList<PVector>(); // for storing the vector of our mouse location
int frames; // count frames for our interpolation
boolean begin = false; // our introduction screen
boolean recording;
void setup() {
size(900, 600);
smooth();
}
void draw() {
background(100);
frames++;
// Introduction ----------------------
if (!begin){
noStroke();
fill(255);
text("click the mouse to create a loop", 20, 20, 200, 200);
fill(200);
ellipse(mouseX,mouseY,60,60);
}
// Recording ----------------------
if (recording && begin) {
fill(255, 0, 0);
ellipse(mouseX,mouseY,60,60);
list.add(new PVector(mouseX, mouseY)); // add the mouse vector to the array
}
// Playback ----------------------
else if (begin) {
PVector rec = list.get(frames%list.size());
fill(0, 255, 0);
ellipse(rec.x,rec.y,60,60);
}
}
void mousePressed() {
list.clear(); // clear the array
recording = true; // turn on recording
begin = true; // move past the introduction screen
}
void mouseReleased() {
recording = false; // turn off recording
}

The example I am working with is located here:

Particle[] p = new Particle[4];
boolean recording;
boolean begin = false;
void setup() {
size(900, 600);
smooth();
noStroke();
for (int i=0; i< p.length; i++) {
p[i] = new Particle();
p[i].myIndex = i;
}
}
void draw() {
background(100);
fill(255);
text("click the mouse to create a loop", 20, 20, 200, 200);
if (begin) {
if (recording) {
for (Particle pa : p) {
pa.bounceIfColliding();
pa.display();
pa.move();
// -------------------------------------- Recording Help Needed Here
// pa.record();
}
fill(255, 0, 0);
text("RECORDING", width-100, 25, 150, 100);
}
else if (!recording && begin) {
for (Particle pa : p) {
pa.display();
// -------------------------------------- Playback Help Needed Here
// step through array list
// pa.playback(x,y);
}
fill(0, 255, 0);
text("PLAYING", width-100, 25, 150, 100);
}
}
if (!begin) {
for (Particle pa : p) {
pa.bounceIfColliding();
pa.display();
pa.move();
}
}
}
void mousePressed() {
begin = true;
recording = true;
for (Particle pa : p) {
float distance = dist(mouseX, mouseY, pa.x, pa.y);
if (distance < pa.r) {
pa.grabbed = true;
}
}
}
void mouseReleased() {
recording = false;
for (Particle pa : p) {
pa.grabbed = false;
}
}

Particle Class:

class Particle {
float x, y; // position
float vx, vy; // speed
float r; // size
color myColor;
int myIndex;
boolean grabbed;
Particle() {
r = random(50, 70);
setRandomLocation();
while ( colliding () ) setRandomLocation();
while (abs (vx) < 0.1) vx = random(-2, 2);
while (abs (vy) < 0.1) vy = random(-2, 2);
myColor = color(200);
myIndex = -1;
}
void setRandomLocation() {
x = random(r, width-r); // create a margin of r for x and y
y = random(r, height-r); // to be sure we're fully on screen
}
boolean colliding() {
for (int i=0; i< p.length; i++) { // check all circles
if (i != myIndex) { // but don't count yourself
if (p[i] == null) continue;
float distance = dist(x, y, p[i].x, p[i].y);
float radiiSum = r + p[i].r;
if (distance < radiiSum) {
return true;
}
}
}
return false;
}
void bounceIfColliding() {
if (grabbed) return;
for (int i=0; i< p.length; i++) { // check all circles
if (i != myIndex) { // but don't count yourself
if (p[i].grabbed) continue;
float distance = dist(x, y, p[i].x, p[i].y);
float radiiSum = r + p[i].r;
if (distance < radiiSum) {
float otherVx = p[i].vx;
float otherVy = p[i].vy;
p[i].vx = vx;
p[i].vy = vy;
vx = otherVx;
vy = otherVy;
}
}
}
}
void display() {
fill(myColor);
ellipse(x, y, r*2, r*2); // radius times 2 is diameter
}
void move() {
if (grabbed) {
x = mouseX;
y = mouseY;
vx = mouseX - pmouseX;
vy = mouseY - pmouseY;
}
else {
x += vx;
y += vy;
if (x > width-r || x < r) vx *= -1;
if (y > height-r || y < r) vy *= -1;
}
}
void record() {
// -------------------------------------- Recording Help Needed Here
// save to an arrayList (myIndex,x,y);
}
void playback(int x_, int y_) {
x = x_;
y = y_;
// -------------------------------------- Playback Help Needed Here
// read from an arrayList
}
}

Thank you in advance for your help.

- matt

Replies(1)

PhiLho

Re: Help: Record & playback positions of all particles in a system

1 year ago

Why do you need multiple arrays?
What is your problem in adapting the idea of the first sketch to the second one?