Week02 

1.寫出一個按住背景會切換顏色

void setup(){

  size(500,500);

}

void draw(){

  if(mousePressed) background(255,0,0);

  else background(0,255,0);

}

2.接下來改寫成畫線

void setup(){

  size(500,500);

}

void draw(){

  if(mousePressed) line(mouseX,mouseY,0,0);

}

3.進一步更改為能畫圖的程式碼

void setup(){

  size(500,500);

}

void draw(){

  if(mousePressed) line(mouseX,mouseY,pmouseX,pmouseY);

}

4.更改畫筆顏色

void setup(){

  size(500,500);

  fill(255,0,0); rect(0,0,100,100);//紅色

  fill(0,255,0); rect(0,100,100,100);//綠色

}

void draw(){

  if(mousePressed){

    if(mouseX<100){

      if(mouseY<100) stroke(255,0,0);//紅色

      else if(mouseY<200) stroke(0,255,0);//綠色

    }else line(mouseX,mouseY,pmouseX,pmouseY);

  }

}

5.更改畫筆寬度

void setup(){

  size(500,500);

  rect(0,0,100,100); ellipse(50,50,8,8);//8的圓形

  rect(0,100,100,100); ellipse(50,150,4,4);//4的圓形

}

void draw(){

  if(mousePressed){

    if(mouseX<100){

      if(mouseY<100) strokeWeight(8);//粗

      else if(mouseY<200) strokeWeight(4);//細

    }else line(mouseX,mouseY,pmouseX,pmouseY);

  }

}