Week17

程式設計二
1.畫出簡單的點

程式:

void setup(){
    size(300,300);
}
void draw(){
  background(#002966);
  fill(#b7efff);
  noStroke();
  ellipse(100,150,13,13);
  ellipse(200,150,13,13);
}

2.可移動右邊的點改變線的位子

程式:

void setup(){
    size(300,300);
}  
float x=200,y=150;
void draw(){
  background(#002966);
  stroke(#b7efff);
  line(100,150,x,y);
  
  fill(#b7efff);
  noStroke();
  ellipse(100,150,13,13);
  ellipse(x,y,13,13);
}
void mouseDragged(){
  x=mouseX; y=mouseY;
}


3.力量的大小與向量相關




程式:
void setup(){
    size(300,300);
}  
float x=200,y=150;
void draw(){
  background(#002966);
  stroke(#b7efff);
  line(100,150,x,y);
  
  fill(#b7efff);
  noStroke();
  ellipse(100,150,13,13);
  ellipse(x,y,13,13);
  if(! mousePressed){
    float dx=x-100,dy=y-150;
    float len=sqrt(dx*dx+dy*dy);
    x-=dx*(len-100)/len;
    y-=dy*(len-100)/len;
  }
}
void mouseDragged(){
  x=mouseX; y=mouseY;
}


4.向外拉會回彈




程式:
void setup(){
    size(300,300);
}  
float x=200,y=150;
void draw(){
  background(#002966);
  stroke(#b7efff);
  line(100,150,x,y);
  
  fill(#b7efff);
  noStroke();
  ellipse(100,150,13,13);
  ellipse(x,y,13,13);
  if(! mousePressed){
    float dx=x-100,dy=y-150;
    float len=sqrt(dx*dx+dy*dy);
    x-=dx*(len-100)/len*0.1;
    y-=dy*(len-100)/len*0.1;
  }
}
void mouseDragged(){
  x=mouseX; y=mouseY;
}



5.向外拉會自動回彈與向外彈




程式:
void setup(){
    size(300,300);
}  
float x=200,y=150;
float vx=0,vy=0;
void draw(){
  background(#002966);
  stroke(#b7efff);
  line(100,150,x,y);
  
  fill(#b7efff);
  noStroke();
  ellipse(100,150,13,13);
  ellipse(x,y,13,13);
  if(! mousePressed){
    float dx=x-100,dy=y-150;
    float len=sqrt(dx*dx+dy*dy);
    vx -= dx*(len-100)/len*0.001;
                           越大彈力越強
    vy -= dy*(len-100)/len*0.001;
                           越大彈力越強
    x+=vx;
    y-=vy;
  }
}
void mouseDragged(){
  x=mouseX; y=mouseY;
}


6.物體會隨著滑鼠移動






程式:
void setup(){
    size(400,300);
}  
float x=200,y=150;
void draw(){
  background(#002966);
  fill(255);
  rect(x,y,80,20);
  //魚(貓),每次往你的mouse移動1/10
  float dx=x-mouseX,dy=y-mouseY;
  //float len=sqrt(dx*dx+dy*dy);
    x-=dx*0.1;
    y-=dy*0.1;
  }