week 17

虎克定律

void setup()

{

  size(300,300);

}

float x=100,y=150;

void draw()

{

  background(#002966);

  stroke(#b7efff);//畫出線

  line(x,y,200,150);

  

  fill(#b7efff);

  ellipse(x,y,13,13);//畫出左右的圓

  ellipse(200,150,13,13);

  if(! mousePressed)//如果滑鼠沒有按下

  {

    float dx=x-200;

    float dy=y-150;

    float len =sqrt(dx*dx+dy*dy);

    x-=dx*(len-100)/len*0.1;//讓線慢慢回到原本的長度

    y-=dy*(len-100)/len*0.1;

  }//用直角三角形 算出線的長度 在滑鼠放開時回到原長度

}

void mouseDragged()

{

  x=mouseX; y=mouseY;//滑鼠拉線

}

void setup()

{

  size(300,300);

}

float x=100,y=150;

float vx=0,vy=0;

void draw()

{

  background(#002966);

  stroke(#b7efff);

  line(x,y,200,150);

  

  fill(#b7efff);

  ellipse(x,y,13,13);

  ellipse(200,150,13,13);

  if(! mousePressed)

  {

    float dx=x-200;

    float dy=y-150;

    float len =sqrt(dx*dx+dy*dy);

    float f=(len-100);

    dx/=len;

    dy/=len;

    vx-=f*dx*0.01;

    vy-=f*dy*0.01;

    x+=vx;

    y+=vy;

    x-=dx*(len-100)/len*0.1;

    y-=dy*(len-100)/len*0.1;

  } //虎克定律 讓線彈跳

}

void mouseDragged()

{

  x=mouseX; y=mouseY;

}

魚吃飼料

void setup()

{

  size(400,300);

}

float x=100,y=150;

void draw()

{

  background(#002966);

  ellipse(x,y,50,50);

  

  float dx=x-mouseX;

  float dy=y-mouseY;

  float len=sqrt(dx*dx+dy*dy);

  x-=dx*(len-100)/len*0.1;

  y-=dy*(len-100)/len*0.1;//讓魚不會太靠近滑鼠 也不會太遠

}//讓魚慢慢地去吃飼料