農場的櫻桃樹快枯死了Week17

傳說中的虎克定律出現了

程式如下:

void setup()

{

  size(300,300);

}

void draw()

{

  background(#004586);

  stroke(#b7efff);

  line(100,150,200,150);

  

  fill(#b7efff);

  ellipse(100,150,13,13);

  ellipse(200,150,13,13);

}

ps.變的可以拉動點

程式如下:

void setup()
{
  size(300,300);
}
float x=100,y=150;
void draw()
{
  background(#004586);
  stroke(#b7efff);
  line(x,y,200,150);
  
  fill(#b7efff);
  ellipse(x,y,13,13);
  ellipse(200,150,13,13);
}
void mouseDragged()
{
  x=mouseX;y=mouseY;
}

ps.滑鼠放開後會回到原位

程式如下:

void setup()
{
  size(300,300);
}
float x=100,y=150;
void draw()
{
  background(#004586);
  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);
    x-=dx*(len-100)/len;                      //////如果變成  x-=dx*(len-100)/len*0.1;  他跑回去會比較慢
    y-=dy*(len-100)/len;
  }
}
void mouseDragged()
{
  x=mouseX;y=mouseY;
}

讓球追著滑鼠跑

程式如下:

void setup()

{

  size(400,300);

}

float x=100,y=150;

void draw()

{

  background(#004586);

  ellipse(x,y,50,50);

  float dx=x-mouseX;

  float dy=y-mouseY;

  float len=sqrt(dx*dx+dy*dy);

  x-=dx*0.1;

  y-=dy*0.1;

}

ps.讓他保持100的距離
使出欲擒故縱的技能

程式如下:

void setup()

{

  size(400,300);

}

float x=100,y=150;

void draw()

{

  background(#004586);

  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;

  

}

回到虎克定律

ps.讓他如同彈簧

程式如下:

void setup()

{

  size(300,300);

}

float x=100,y=150;

float vx=0,vy=0;

void draw()

{

  background(#004586);

  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*0.1;

    vy-=f*dy*0.1;

    x+=vx;

    y+=vy;

  }

}

void mouseDragged()

{

  x=mouseX;y=mouseY;

}

FILE檔案讀取

程式如下:

#include <stdio.h>

int main()

{

    FILE *fout=fopen("my_first_file.txt","w+");

    printf("Hello World\n");

    fprintf(fout,"Hello World\n");

}