【processing】小代码3

鼠标响应： mouseX, mouseY 鼠标的坐标

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void setup()
{
  size(,);
  smooth();
  background();
}

void draw()
{
  fill(,,);
  rectMode(CENTER);
  rect(mouseX,mouseY,,);
}

随着鼠标的移动画方块

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dist(x1,y1,x2,y2) 计算两点之间的距离

void setup()
{
  size(,);
  smooth();
}

void draw()
{
  background();
  stroke();
  float d = dist(mouseX, mouseY,,);
  strokeWeight(d/);
  fill();
  ellipse(,,d*,d);
  strokeWeight(d/);
  fill(,,);
  ellipse(,,d,d);
  fill();
  noStroke();
  ellipse(,,d/,d/);
}

眼睛的大小会随着鼠标位置改变

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pmouseX,pmouseY: 鼠标的上一个坐标点

void setup()
{
  size(,);
  strokeWeight();
  smooth();
  stroke(,,,);
  background();
}
void draw()
{
  line(mouseX,mouseY,pmouseX,pmouseY);
}

画出鼠标的轨迹

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鼠标响应事件

void mousePressed(){} 等价于 void draw(){if(mousePressed){}}

void mouseMoved(){}

void mouseDragged(){}

void setup()
{
  size(,);
  smooth();
  background(,,,);
}
void draw()
{
  if(mousePressed)
  {
    stroke();
    fill(,,);
    ellipse(mouseX,mouseY,,);
  }
}

鼠标按下时画圆，一直按着不放就一直画圆 不要边框后更好看些

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void setup()
{
  size(,);
  smooth();
  background(,,,);
}
void draw()
{
}
void mouseMoved()
{
  stroke(,,,);
  rectMode(CENTER);
  fill(,,,);
  rect(mouseX,mouseY,,);
}
void mouseDragged()
{
  stroke(,,,);
  fill(,,,);
  ellipse(mouseX,mouseY,,);
}

鼠标移动画方，鼠标拖动画圆

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mouseButton  含 LEFT, RIGHT, CENTER

void setup()
{
  size(,);
  smooth();
  background();
  rectMode(CENTER);
}

void draw()
{
  if(mousePressed)
  {
    if(mouseButton == LEFT)
    {
      fill();
    }
    else if(mouseButton==CENTER)
    {
      fill();
    }
    else
    {
      fill();
    }
    rect(mouseX,mouseY,,);
  }
}

按下鼠标不同键颜色不同

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键盘响应：

keyPressed 按键响应 void keyPressed(){} 或 void draw(){if(keyPressed){}}

key 特定键响应 在keyPressed基础上加 if(key == 'a')

keyCode 功能键响应 包括 ALT, CONTROL, SHIFT,UP,DOWN,LEFT,RIGHT

int x = ;
int y = ;
void setup()
{
  size(,);
  smooth();
  background();
  rectMode(CENTER);
}
void draw()
{
  if(keyPressed && (key == CODED))
  {
    if(keyCode == LEFT)
    {
      x--;
    }
    else if(keyCode == RIGHT)
    {
      x++;
    }
    else if(keyCode == UP)
    {
      y--;
    }
    else if(keyCode == DOWN)
    {
      y++;
    }
  }
  ellipse(x,y,,);
}

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随机：random(10) 生成0-10的任意浮点数

int(random(6,10)), 生成6 7 8 9中任意一个数

void setup()
{
  size(,);
  smooth();
  background();
  stroke(,);
  colorMode(HSB,,,);
}
void draw()
{
  float d = random();
  fill(random(),,,);
  ellipse(random(),random(),d,d);
}

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限制 constrain(value,min,max); 限制value值在min-max范围内

int x = ;
int y = ;
void setup()
{
  size(,);
  smooth();
}
void draw()
{
  background();
  fill();
  rect(,,,);
  fill();
  rect(,,,);
  float mx = constrain(mouseX,,);
  float my = constrain(mouseY,,);
  fill();
  ellipse(mx,my,,);
}