问题

当我运行这个程序时，点击后，绿色的三角形会出现在各个地方，而我希望它重新定位到一个随机的位置，并移除原始的绿色三角形。

float x;

void setup()
{
size (800, 600);
background(29, 154, 178);
x=random(width);
frameRate(30);
}

void draw()
{
noStroke();

fill(91, 180, 118 );
triangle(x, 20, 0, height, width, height);

fill(82, 45, 80);
triangle(width/2-200, 120, 0, height, width, height);

fill(82, 45, 60);
triangle(width/2+150, 220, 0, height, width, height);

fill(82, 45, 28);
triangle(width/2-100, 320, 0, height, width, height);
fill(243, 245, 158);
rect(0, 525, 800, 100);

if(mousePressed == true)
{
x=random(width);
}
}

<details>
<summary>英文:</summary>

When I run this program the green triangles appear all over the place when I click instead I want it to reposition itself to a random place and remove the original green triangle

float x;

void setup()
{
size (800, 600);
background(29, 154, 178);
x=random(width);
frameRate(30);
}

void draw()
{
noStroke();

fill(91, 180, 118 );
triangle(x, 20, 0, height, width, height);

fill(82, 45, 80);
triangle(width/2-200, 120, 0, height, width, height);

fill(82, 45, 60);
triangle(width/2+150, 220, 0, height, width, height);

fill(82, 45, 28);
triangle(width/2-100, 320, 0, height, width, height);
fill(243, 245, 158);
rect(0, 525, 800, 100);

if(mousePressed == true)
{
x=random(width);
}
}

</details>


# 答案1
**得分**: 1

然后在你的`setup`中添加`noLoop()`，这样你就不会以每秒60次的频率绘制相同的内容，而是使用[鼠标点击处理](https://processing.org/reference/mouseClicked_.html)，结合[redraw](https://processing.org/reference/redraw_.html)调用，这样只有在有新内容需要绘制时才进行绘制：

```java
float x, y, triangleSideLength;

void setup() {
  size(300, 300);
  noLoop();
  triangleSideLength = 30; // 或者根据需要设定合适的值
}

void draw() {
  x = random(0, width - triangleSideLength);
  y = random(0, height - triangleSideLength);
  drawTriangleAt(x, y);
}

void drawTriangleAt(float x, float y) { 
  //...三角形绘制代码在这里...
}

void mouseClicked() {
  redraw();
}

另外还要注意通常要约束你的x/y坐标，以便三角形始终“适合屏幕”，而不是获得一个x/y坐标，使得x=width，导致三角形基本上完全看不见。

float x, y, triangleSideLength;

void setup() {
  size(300,300);
  noLoop();
  triangleSideLength = 30; // or whatever value it needs to be of course
}

void draw() {
  x = random(0, width - triangleSideLength);
  y = random(0, height - triangleSideLength);
  drawTriangleAt(x, y);
}

void drawTriangleAt(float x, float y) { 
  //...triangle drawing code here...
}

void mouseClicked() {
  redraw();
}