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Add drawStar() function to draw customizable star shapes #7816

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Add drawStar() function to draw customizable star shapes #7816

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272 changes: 272 additions & 0 deletions p5-demo.html
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Original file line number Diff line number Diff line change
@@ -0,0 +1,272 @@
<!DOCTYPE html>
<html>
<head>
<title>p5.js 功能演示</title>
<script src="lib/p5.js"></script>
<style>
body {
margin: 0;
padding: 0;
display: flex;
flex-direction: column;
align-items: center;
background-color: #f0f0f0;
font-family: Arial, sans-serif;
}
h1 {
color: #333;
margin: 20px 0;
}
.container {
display: flex;
flex-wrap: wrap;
justify-content: center;
max-width: 1200px;
}
.canvas-container {
margin: 10px;
background-color: white;
border-radius: 8px;
box-shadow: 0 4px 8px rgba(0,0,0,0.1);
overflow: hidden;
}
.description {
padding: 10px;
text-align: center;
font-size: 14px;
color: #333;
}
</style>
</head>
<body>
<h1>p5.js 功能演示</h1>
<div class="container">
<div class="canvas-container">
<div id="sketch1"></div>
<div class="description">基本形状</div>
</div>
<div class="canvas-container">
<div id="sketch2"></div>
<div class="description">五角星(新功能)</div>
</div>
<div class="canvas-container">
<div id="sketch3"></div>
<div class="description">颜色和渐变</div>
</div>
<div class="canvas-container">
<div id="sketch4"></div>
<div class="description">动画</div>
</div>
<div class="canvas-container">
<div id="sketch5"></div>
<div class="description">鼠标交互</div>
</div>
<div class="canvas-container">
<div id="sketch6"></div>
<div class="description">粒子系统</div>
</div>
</div>

<script>
// 基本形状
let s1 = function(p) {
p.setup = function() {
p.createCanvas(300, 200);
};

p.draw = function() {
p.background(240);
p.stroke(0);
p.strokeWeight(2);

// 矩形
p.fill(255, 0, 0, 150);
p.rect(50, 50, 80, 80);

// 圆形
p.fill(0, 0, 255, 150);
p.ellipse(200, 100, 100, 100);

// 三角形
p.fill(0, 255, 0, 150);
p.triangle(150, 50, 120, 150, 180, 150);

// 线条
p.stroke(100);
p.line(25, 150, 275, 150);
};
};
new p5(s1, 'sketch1');

// 五角星(新功能)
let s2 = function(p) {
let angle = 0;

p.setup = function() {
p.createCanvas(300, 200);
};

p.draw = function() {
p.background(240);
p.translate(p.width/2, p.height/2);
p.rotate(angle);

// 绘制多个不同的星形
p.fill(255, 255, 0);
p.stroke(0);
p.strokeWeight(1);
p.star(0, 0, 80, 40, 5);

p.fill(255, 100, 0, 150);
p.star(0, 0, 50, 20, 8);

angle += 0.01;
};
};
new p5(s2, 'sketch2');

// 颜色和渐变
let s3 = function(p) {
p.setup = function() {
p.createCanvas(300, 200);
};

p.draw = function() {
p.background(240);

// 创建渐变背景
for(let i = 0; i < p.width; i++) {
let r = p.map(i, 0, p.width, 255, 0);
let g = p.map(i, 0, p.width, 0, 255);
let b = p.map(i, 0, p.width, 0, 255);
p.stroke(r, g, b);
p.line(i, 0, i, p.height);
}

// 半透明形状
p.noStroke();
for(let i = 0; i < 5; i++) {
let x = p.map(i, 0, 4, 50, 250);
p.fill(255, 255, 255, 100);
p.ellipse(x, 100, 70, 70);
}
};
};
new p5(s3, 'sketch3');

// 动画
let s4 = function(p) {
let x = 0;
let speed = 3;

p.setup = function() {
p.createCanvas(300, 200);
};

p.draw = function() {
p.background(240);

// 移动的圆
p.fill(255, 0, 0);
p.noStroke();
p.ellipse(x, 100, 50, 50);

x += speed;
if (x > p.width + 25 || x < -25) {
speed *= -1;
}
};
};
new p5(s4, 'sketch4');

// 鼠标交互
let s5 = function(p) {
p.setup = function() {
p.createCanvas(300, 200);
p.noStroke();
};

p.draw = function() {
p.background(240);

// 跟随鼠标的渐变圆
for(let i = 10; i > 0; i--) {
let diameter = i * 10;
let alpha = p.map(i, 0, 10, 255, 0);
p.fill(255, 0, 255, alpha);
p.ellipse(p.mouseX, p.mouseY, diameter, diameter);
}

// 说明文字
p.fill(0);
p.text('移动鼠标在此区域内', 80, 20);
};
};
new p5(s5, 'sketch5');

// 粒子系统
let s6 = function(p) {
let particles = [];

p.setup = function() {
p.createCanvas(300, 200);
};

p.draw = function() {
p.background(0, 10);

// 添加新粒子
if(p.random(1) < 0.2) {
particles.push(new Particle(p));
}

// 更新和显示粒子
for(let i = particles.length - 1; i >= 0; i--) {
particles[i].update();
particles[i].display();

if(particles[i].isDead()) {
particles.splice(i, 1);
}
}
};

// 粒子类
class Particle {
constructor(p) {
this.p = p;
this.x = p.width / 2;
this.y = p.height / 2;
this.vx = p.random(-1, 1);
this.vy = p.random(-2, -1);
this.alpha = 255;
this.size = p.random(5, 15);
this.color = p.color(
p.random(100, 255),
p.random(100, 255),
p.random(100, 255)
);
}

update() {
this.x += this.vx;
this.y += this.vy;
this.alpha -= 2;
}

display() {
this.p.noStroke();
this.color.setAlpha(this.alpha);
this.p.fill(this.color);
this.p.ellipse(this.x, this.y, this.size, this.size);
}

isDead() {
return this.alpha <= 0;
}
}
};
new p5(s6, 'sketch6');
</script>
</body>
</html>
66 changes: 66 additions & 0 deletions src/core/shape/2d_primitives.js
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Original file line number Diff line number Diff line change
Expand Up @@ -1449,4 +1449,70 @@ p5.prototype.triangle = function(...args) {
return this;
};

/**
* Draws a five-pointed star.
*
* The star is drawn at the position specified by the `x` and `y` parameters.
* `radius1` sets the outer radius of the star, and `radius2` sets the inner radius.
* The parameter `npoints` can be used to specify the number of points in the star
* (default is 5 for a five-pointed star).
*
* @method star
* @param {Number} x x-coordinate of the star.
* @param {Number} y y-coordinate of the star.
* @param {Number} radius1 outer radius of the star.
* @param {Number} radius2 inner radius of the star.
* @param {Number} [npoints] number of points on the star (default is 5).
* @chainable
*
* @example
* <div>
* <code>
* function setup() {
* createCanvas(100, 100);
*
* background(200);
*
* // Draw a star at the center of the canvas.
* star(50, 50, 40, 20, 5);
*
* describe('A white five-pointed star on a gray background.');
* }
* </code>
* </div>
*
* @example
* <div>
* <code>
* function setup() {
* createCanvas(100, 100);
* }
*
* function draw() {
* background(200);
*
* // The star follows the mouse.
* star(mouseX, mouseY, 30, 15, 5);
*
* describe('A white five-pointed star follows the mouse.');
* }
* </code>
* </div>
*/
p5.prototype.star = function(x, y, radius1, radius2, npoints = 5) {
this.beginShape();
const angle = constants.TWO_PI / npoints;
const halfAngle = angle / 2.0;
for (let a = 0; a < constants.TWO_PI; a += angle) {
let sx = x + Math.cos(a) * radius1;
let sy = y + Math.sin(a) * radius1;
this.vertex(sx, sy);
sx = x + Math.cos(a + halfAngle) * radius2;
sy = y + Math.sin(a + halfAngle) * radius2;
this.vertex(sx, sy);
}
this.endShape(constants.CLOSE);
return this;
};

export default p5;
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