Processingで雪を降らせる

概要

Processingで雪を降らせる方法をメモ.
奥行きを出すため、サイズと速さが連動しています(スピードが遅い雪は小さい).

コード

class Snowflake { //Snowflake Class
  float x; //x axis
  float y; //y axis
  float s; //size
  color c; //color
  float dy; //speed
        Snowflake() { //Function to create snowflakes
        x = random(width); //initial x point is random
        y = random(height);
        dy = random(0, 3); // Falling speed is random between 3 and 10
        s =  5 * dy / 4.0; //Size is small if initial speed is slow
        c = #ffffff; //white snow
        }
       void drop() { //create snow and move
        y += dy;
        if (y > height) y = 0; //if snow gets the bottom of the screen, return to top
        noStroke(); //no outline
        fill(c);
        ellipse(x, y, s, s);
    }
}
Snowflake[] sf = new Snowflake[5000]; //prepare the area for 1000 snow object




void setup(){
  size (600,600);
  noCursor();
  for (int i = 0; i < 2000; i++) { //雪⽚オブジェクトを1000 個作る
  sf[i] = new Snowflake();
  }
}


void draw() {
   background(12,15,32);
    for(int i = 0; i < 2000; i++) {
    sf[i].drop();
}
}

結果