/* built with Studio Sketchpad: 
 *   https://sketchpad.cc
 * 
 * observe the evolution of this sketch: 
 *   https://studio.sketchpad.cc/sp/pad/view/ro.FWd4dJ3j$C3/rev.188
 * 
 * authors: 
 *   David Merino

 * license (unless otherwise specified): 
 *   creative commons attribution-share alike 3.0 license.
 *   https://creativecommons.org/licenses/by-sa/3.0/ 
 */ 



float y, y0;
float v;
float a;
int i;
float t, t0;
float A = 200;
float T = 4;
float phi = PI;

boolean update;



void setup()
{
  size(600, 600);
  frameRate(70);
  background(0);

  y=height/2;

  i = 0;
  
  t0=millis()/1000.;
  
  update = true;
}

void draw()
{
 
  if(update){
    t = (millis()/1000.)-t0;
    y = height/2+A*sin(2*PI*t/T + phi);
    v = A*cos(2*PI*t/T+phi);
    a = -A*sin(2*PI*t/T+phi);

    background(0);
    fill(255); 
    stroke(0);
    ellipse(width/2, y, 10, 10);
  
    stroke(0,150,50);
    line(width/2, y, width/2, y+v);
    line(width/2 + 10, height/2, width/2 + 10, height/2 + v);
    stroke(0,0,255);
    line(width/2, y, width/2, y+a);
    line(width/2 + 20, height/2, width/2 + 20, height/2 + a);
    fill(0,150,50);
    stroke(0,150,50);
    if(v>=0)
    {
      triangle(width/2, y+v, width/2-5, y+v-10, width/2+5, y+v-10);
      triangle(width/2+10, height/2+v, width/2-5+10, height/2+v-10, width/2+5+10, height/2+v-10);
    }
    else
    {
      triangle(width/2, y+v, width/2-5, y+v+10, width/2+5, y+v+10);
      triangle(width/2+10, height/2+v, width/2-5+10, height/2+v+10, width/2+5+10, height/2+v+10);
    }
  
    stroke(0,0,255);
    fill(0,0,255);
    if(a>=0)
    {
      triangle(width/2, y+a, width/2-5, y+a-10, width/2+5, y+a-10);
      triangle(width/2+20, height/2+a, width/2-5+20, height/2+a-10, width/2+5+20, height/2+a-10);
    }
    else
    {
      triangle(width/2, y+a, width/2-5, y+a+10, width/2+5, y+a+10);
      triangle(width/2+20, height/2+a, width/2-5+20, height/2+a+10, width/2+5+20, height/2+a+10);
    }
    i++;
  }
}

void mouseClicked() {
  update = !update;
  if(update)
  {
      t0=millis()/1000. -t;
  }
}