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| <!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>greedy snake</title>
</head>
<style>
* {
margin: 0;
padding: 0;
box-sizing: border-box;
--background-color: #2C3E50;
--snake-color: #4CAF50;
--food-color: #E74C3C;
}
body {
min-height: 100vh;
min-width: 100vw;
background-color: var(--background-color);
}
</style>
<body>
<canvas id="mycanvas"></canvas>
</body>
<script>
const colors = {
background: '#2c3e50',
snake: '#42b983',
food: '#e74c3c',
grid: '#34495e',
};
const canvas = document.getElementById('mycanvas');
const ctx = canvas.getContext('2d');
const body = document.body;
let width = canvas.width = window.innerWidth;
let height = canvas.height = window.innerHeight;
const currentMousePosition = { x: height / 2, y: width / 2 };
// 世界座標偏移
// 螢幕位置 = 世界位置 - camera 偏移量
// 世界位置 = 螢幕位置 + camera 偏移量
const camera = { x: 0, y: 0 };
const speed = 2;
const snakeSize = 16;
const foodSize = 6;
const snakePath = []; // 紀錄蛇頭的世界座標路徑（每幀）
let totalSegments = 1; // 身體節點數量
const segmentDistance = 8; // 身體每個節點之間的間隔距離（每隔8幀才是第二個身體節點）
const aiSnakes = [];
const numAiSnakes = 10; // AI 蛇的數量
for (let i = 0; i < numAiSnakes; i++) {
aiSnakes.push({
worldX: (Math.random() - 0.5) * 2000,
worldY: (Math.random() - 0.5) * 2000,
angle: Math.random() * Math.PI * 2,
speed: 1, // AI 稍微慢一點
snakePath: [],
totalSegments: 10,
color: `hsl(${Math.random() * 360}, 70%, 50%)` // 隨機顏色
});
}
const foots = [];
// 隨機生成新食物
for(let i = 0; i < 50; i++){
foots.push({
x: (Math.random() - 0.5) * 2000,
y: (Math.random() - 0.5) * 2000
});
}
window.addEventListener('mousemove', (e) => {
currentMousePosition.x = e.clientX;
currentMousePosition.y = e.clientY;
});
function drawGrid(){
const gridSize = 50;
console.log(-camera.x % gridSize);
ctx.strokeStyle = colors.grid;
ctx.lineWidth = 1;
for(let x = -camera.x % gridSize; x < width; x += gridSize){
ctx.beginPath();
ctx.moveTo(x, 0);
ctx.lineTo(x, height);
ctx.stroke();
ctx.closePath();
}
for(let y = -camera.y % gridSize; y < height; y += gridSize){
ctx.beginPath();
ctx.moveTo(0, y);
ctx.lineTo(width, y);
ctx.stroke();
ctx.closePath();
}
}
function redraw() {
ctx.clearRect(0, 0, canvas.width, canvas.height);
// draw background
drawGrid();
aiSnakes.forEach(ai => {
for (let i = ai.totalSegments - 1; i >= 0; i--) {
const pathIndex = i * segmentDistance;
const point = ai.snakePath[pathIndex];
if (point) {
// AI 世界座標 - 相機偏移 = 螢幕位置
const screenX = point.worldX - camera.x - snakeSize / 2;
const screenY = point.worldY - camera.y - snakeSize / 2;
ctx.fillStyle = i === 0 ? ai.color : ai.color + "88"; // 身體半透明
ctx.fillRect(screenX, screenY, snakeSize, snakeSize);
}
}
});
// 繪製蛇身
for (let i = 0; i < totalSegments; i++) {
// 取得該節點在路徑中的索引
const pathIndex = i * segmentDistance;
const point = snakePath[pathIndex];
if (point) {
// 將「世界座標」轉換回「螢幕座標」進行繪製
const screenX = point.worldX - camera.x;
const screenY = point.worldY - camera.y;
ctx.fillStyle = i === 0 ? colors.snake : '#388E3C'; // 頭用亮色，身體深色
ctx.fillRect(screenX, screenY, snakeSize, snakeSize);
}
}
// draw foots
foots.forEach(foot => {
ctx.fillStyle = colors.food;
ctx.beginPath();
ctx.arc(foot.x - camera.x, foot.y - camera.y, foodSize/2, 0, Math.PI * 2);
ctx.fill();
ctx.closePath();
});
}
function updateAi() {
aiSnakes.forEach(ai => {
// 1. 隨機改變方向 (每幀有 2% 的機率轉彎)
if (Math.random() < 0.02) {
ai.angle += (Math.random() - 0.5) * 2;
}
// 2. 根據角度更新世界座標
ai.worldX += Math.cos(ai.angle) * ai.speed;
ai.worldY += Math.sin(ai.angle) * ai.speed;
// 3. 記錄路徑 (用於畫身體)
ai.snakePath.unshift({ worldX: ai.worldX, worldY: ai.worldY });
if (ai.snakePath.length > ai.totalSegments * segmentDistance) {
ai.snakePath.pop();
}
// 4. AI 也可以吃食物
foots.forEach((foot, index) => {
const dx = ai.worldX - foot.x;
const dy = ai.worldY - foot.y;
const dist = Math.sqrt(dx * dx + dy * dy);
if (dist < snakeSize) {
foots.splice(index, 1);
ai.totalSegments += 2;
// 補償食物
foots.push({
x: (Math.random() - 0.5) * 2000,
y: (Math.random() - 0.5) * 2000
});
}
});
});
}
function moving(){
const x = currentMousePosition.x - width / 2;
const y = currentMousePosition.y - height / 2;
const angle = Math.atan2(y, x)
const dx = Math.cos(angle) * speed;
const dy = Math.sin(angle) * speed;
// console.log(`Angle: ${angle}, dx: ${dx}, dy: ${dy}`);
camera.x += dx;
camera.y += dy;
snakePath.unshift({
worldX: width / 2 + camera.x,
worldY: height / 2 + camera.y
});
if(snakePath.length > totalSegments * segmentDistance){
snakePath.pop();
}
}
function eating(){
const head = snakePath[0];
foots.forEach((foot, index) => {
if(head.worldX < foot.x + foodSize && head.worldX + snakeSize > foot.x &&
head.worldY < foot.y + foodSize && head.worldY + snakeSize > foot.y){
foots.splice(index, 1);
// 增加蛇的長度
totalSegments += 5;
for(let i = 0; i < 5; i++){
// 隨機生成新食物
foots.push({
x: (Math.random() - 0.5) * 2000,
y: (Math.random() - 0.5) * 2000
});
}
}
});
}
function checkCollisions() {
const playerWorldHead = { x: snakePath[0].worldX, y: snakePath[0].worldY };
aiSnakes.forEach((ai, aiIndex) => {
// --- 玩家撞到 AI 的身體 ---
// 跳過 AI 的頭部幾節，避免誤判
for (let i = segmentDistance * 2; i < ai.snakePath.length; i += segmentDistance) {
const segment = ai.snakePath[i];
const dx = playerWorldHead.x - segment.worldX;
const dy = playerWorldHead.y - segment.worldY;
const distance = Math.sqrt(dx * dx + dy * dy);
if (distance < snakeSize) {
// 玩家死亡
alert("遊戲結束！你被 AI 蛇吃掉了。");
setTimeout(() => {
location.reload(); // 簡單處理：重新整理網頁
}, 0);
}
}
// --- AI 撞到玩家的身體 ---
const aiWorldHead = { x: ai.worldX, y: ai.worldY };
for (let i = segmentDistance * 2; i < snakePath.length; i += segmentDistance) {
const segment = snakePath[i];
const dx = aiWorldHead.x - segment.worldX;
const dy = aiWorldHead.y - segment.worldY;
const distance = Math.sqrt(dx * dx + dy * dy);
if (distance < snakeSize) {
// AI 死亡
for(let j = 0; j < ai.snakePath.length; j++){
// 玩家吃掉 AI 後，生成一些食物作為獎勵
foots.push({
x: ai.snakePath[j].worldX,
y: ai.snakePath[j].worldY
});
}
aiSnakes.splice(aiIndex, 1);
spawnNewAi(); // 生成新 AI 補充
return;
}
}
});
}
// 生成新的 AI 蛇
function spawnNewAi() {
aiSnakes.push({
worldX: (Math.random() - 0.5) * 2000,
worldY: (Math.random() - 0.5) * 2000,
angle: Math.random() * Math.PI * 2,
speed: 1,
snakePath: [],
totalSegments: 10,
color: `hsl(${Math.random() * 360}, 70%, 50%)`
});
}
function repeating(){
redraw();
moving();
updateAi();
checkCollisions();
eating();
requestAnimationFrame(repeating);
}
const frameId = requestAnimationFrame(repeating);
// 监听窗口大小变化
window.addEventListener('resize', () => {
width = canvas.width = window.innerWidth;
height = canvas.height = window.innerHeight;
});
</script>
</html>
|