processing中三个运用sin函数的动画案例

以下是三个运用sin函数的动画案例，基于Processing编写：

1. 弹跳球

float x, y;
float speed = 0.05;
float amplitude = 100;

void setup() {
  size(400, 400);
  x = width/2;
  y = height/2;
}

void draw() {
  background(255);
  x += 2;
  y = height/2 + sin(frameCount * speed) * amplitude;
  ellipse(x, y, 50, 50);
  if (x > width) {
    x = 0;
  }
}

2. 径向波浪

float angle = 0;
float amplitude = 100;
float frequency = 10;

void setup() {
  size(400, 400);
  stroke(0, 50);
  fill(255, 50);
}

void draw() {
  background(255);
  translate(width/2, height/2);
  beginShape();
  for (int i = 0; i <= 360; i += 10) {
    float x = sin(radians(i + angle)) * amplitude * sin(radians(i * frequency));
    float y = cos(radians(i + angle)) * amplitude * sin(radians(i * frequency));
    vertex(x, y);
  }
  endShape(CLOSE);
  angle += 2;
}

3. 摆动线条

float angle = 0;
float amplitude = 50;
float frequency = 5;

void setup() {
  size(400, 400);
  stroke(0);
}

void draw() {
  background(255);
  translate(width/2, height/2);
  rotate(radians(angle));
  line(-amplitude, 0, amplitude, 0);
  angle += sin(radians(frameCount * frequency)) * 10;
}