CODEWITHSUNDEEP
processing
Jsuf
Jsuf

Reputation: 185

Processing: Simultaneous drawing of random particle trajectories

class loc {
float[] x;
float[] y;
float v_o_x, v_o_y;

float[] locationx = new float[0];
float[] locationy = new float[0];

loc(float x_o, float y_o, float v_o, float theta, int t_end) {

theta = radians(theta);

v_o_x = v_o_x = v_o * cos(theta);

v_o_y = abs(v_o) * sin(theta);

for (int i=0; i<t_end; i++) {
  locationx = append(locationx, (v_o_x * i + x_o));
  locationy = append(locationy, (0.5*10*pow(i, 2) - v_o_y*i + y_o));
}

this.x = locationx;
this.y = locationy;
}
}

loc locations;

int wait = 75; // change delay between animation
int i = 0;
int j = 0;

float randV = random(-70, 70);
float randAng = random(30, 50);

int len = 17;

void setup() {

  size(1500, 800);

  background(255);
}

void draw() {


  fill(0);


  int d = 20; // diameter

  float[] xx, yy;

  if (i < len) {

    locations = new loc(width/2, height/3.5, randV, randAng, len);

    xx = locations.x;
    yy = locations.y;

    //background(255);
    rect(width/2-d, height/3.5+d, d*2, d*2);

    float s = 255/locations.x.length;
    fill((0+i*s));
    ellipse(xx[i], yy[i], d, d);

    i += 1;

    delay(wait);
  } else { 
    randV = random(-70, 70);
    randAng = random(30, 50);
    i = 0;
  }
}

I have a simple code written that animates the trajectory of a ball for a random initial angle and velocity. As it currently runs, it will send one ball out, wait for it to land, and then send another random ball out. My hopes are to get it to simultaneously send out multiple random balls, to create a sort of fountain effect. I have had a lot of trouble getting it to do that, any suggestions?

Upvotes: 1

Views: 102

Answers (2)

justincouch
justincouch

Reputation: 101

Agreed with Kevin Workman, classes are the way to go here. One of the best resources for this stuff is Daniel Shiffman, particularly his book Nature of Code. Your question is dealt with in the Particle Systems chapter (Chapter 4).

Upvotes: 2

Kevin Workman
Kevin Workman

Reputation: 42176

Right now you've got some variables that represent the position (and past positions) of a single ball. For the sake of the question, I'll ignore for a second that you don't ever seem to use some of those variables.

You could copy all of those variables and repeat them for every ball you want. You would have ballOneLocations, ballTwoLocations, etc.

But that's pretty horrible, so you should wrap all of those variables up into a Ball class. Each instance of Ball would represent a separate ball and its past locations.

Then all you'd need to do is create an array or an ArrayList of Ball instances, and loop through them to update and draw them.

Here is a tutorial on how to use OOP in Processing to create multiple balls bouncing around the screen.

Upvotes: 2

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