如何为Atari Breakout游戏的砖块设置随机独特色彩

需求 #

实现Atari Breakout游戏中砖块的多彩效果：每个砖块拥有随机生成的独特色彩，且不改变球、挡板等其他元素的默认颜色。

修改方案 #

1. 为砖块添加随机颜色属性 #

在初始化砖块数组的循环中，新增getRandomColor辅助函数生成随机RGB颜色，为每个砖块对象添加color属性存储独特色值。

2. 绘制砖块时应用对应颜色 #

在drawBricks函数中，绘制单个砖块前，将画布的fillStyle设置为该砖块的color属性值，再执行填充操作。

3. 锁定其他元素颜色 #

在drawBall和drawPaddle函数中显式设置fillStyle为黑色，确保砖块颜色不会影响球、挡板的默认显示效果。

修改后的完整代码 #

JavaScript代码 #

'use strict';

var canvas = document.getElementById("myCanvas");
var ctx = canvas.getContext("2d");
var ballRadius = 20;
var x = canvas.width/2;
var y = canvas.height-30;
var dx = 3;
var dy = -3;
var paddleHeight = 10;
var paddleWidth = 175;
var paddleX = (canvas.width-paddleWidth)/2;
var rightPressed = false;
var leftPressed = false;
var brickRowCount = 11;
var brickColumnCount = 5;
var brickWidth = 73;
var brickHeight = 20;
var brickPadding = 10;
var brickOffsetTop = 30;
var brickOffsetLeft = 30;
var score = 0;
var lives = 3;

// 生成随机RGB颜色的辅助函数
function getRandomColor() {
  var r = Math.floor(Math.random() * 256);
  var g = Math.floor(Math.random() * 256);
  var b = Math.floor(Math.random() * 256);
  return `rgb(${r}, ${g}, ${b})`;
}

var bricks = [];
for(var c=0; c<brickColumnCount; c++) {
  bricks[c] = [];
  for(var r=0; r<brickRowCount; r++) {
    // 为每个砖块添加随机颜色属性
    bricks[c][r] = { x: 0, y: 0, status: 1, color: getRandomColor() };
  }
}

document.addEventListener("keydown", keyDownHandler, false);
document.addEventListener("keyup", keyUpHandler, false);
document.addEventListener("mousemove", mouseMoveHandler, false);

function keyDownHandler(e) {
    if(e.key == "Right" || e.key == "ArrowRight") {
        rightPressed = true;
    }
    else if(e.key == "Left" || e.key == "ArrowLeft") {
        leftPressed = true;
    }
}

function keyUpHandler(e) {
    if(e.key == "Right" || e.key == "ArrowRight") {
        rightPressed = false;
    }
    else if(e.key == "Left" || e.key == "ArrowLeft") {
        leftPressed = false;
    }
}

function mouseMoveHandler(e) {
  var relativeX = e.clientX - canvas.offsetLeft;
  if(relativeX > 0 && relativeX < canvas.width) {
    paddleX = relativeX - paddleWidth/2;
  }
}
function collisionDetection() {
  for(var c=0; c<brickColumnCount; c++) {
    for(var r=0; r<brickRowCount; r++) {
      var b = bricks[c][r];
      if(b.status == 1) {
        if(x > b.x && x < b.x+brickWidth && y > b.y && y < b.y+brickHeight) {
          dy = -dy;
          b.status = 0;
          score++;
          if(score == brickRowCount*brickColumnCount) {
            alert("YOU WIN, CONGRATS!");
            document.location.reload();
          }
        }
      }
    }
  }
}

function drawBall() {
  // 显式设置球的颜色为黑色
  ctx.fillStyle = "#000000";
  ctx.beginPath();
  ctx.arc(x, y, ballRadius, 0, Math.PI*2);
  ctx.fill();
  ctx.closePath();  
}
function drawPaddle() {
  // 显式设置挡板颜色为黑色
  ctx.fillStyle = "#000000";
  ctx.beginPath();
  ctx.rect(paddleX, canvas.height-paddleHeight, paddleWidth, paddleHeight);
  ctx.fill();
  ctx.closePath();
}
function drawBricks() {
  for(var c=0; c<brickColumnCount; c++) {
    for(var r=0; r<brickRowCount; r++) {
      if(bricks[c][r].status == 1) {
        var brickX = (r*(brickWidth+brickPadding))+brickOffsetLeft;
        var brickY = (c * (brickHeight + brickPadding)) + brickOffsetTop;    
        bricks[c][r].x = brickX;
        bricks[c][r].y = brickY;
        ctx.beginPath();
        ctx.rect(brickX, brickY, brickWidth, brickHeight);
        // 使用砖块的随机颜色填充
        ctx.fillStyle = bricks[c][r].color;  
        ctx.fill();
        ctx.closePath();
      }
    }
  }
}
function drawScore() {
  ctx.font = "16px Arial";
  ctx.fillText("Score: "+score, 8, 20);
}
function drawLives() {
  ctx.font = "16px Arial";
  ctx.fillText("Lives: "+lives, canvas.width-65, 20);
}

function draw() {
  ctx.clearRect(0, 0, canvas.width, canvas.height);
  drawBricks();
  drawBall();
  drawPaddle();
  drawScore();
  drawLives();
  collisionDetection();

  if(x + dx > canvas.width-ballRadius || x + dx < ballRadius) {
    dx = -dx;
  }
  if(y + dy < ballRadius) {
    dy = -dy;
  }
  else if(y + dy > canvas.height-ballRadius) {
    if(x > paddleX && x < paddleX + paddleWidth) {
      dy = -dy;
    }
    else {
      lives--;
      if(!lives) {
        alert("GAME OVER");
        document.location.reload();
      }
      else {
        x = canvas.width/2;
        y = canvas.height-30;
        dx = 3;
        dy = -3;
        paddleX = (canvas.width-paddleWidth)/2;
      }
    }
  }

  if(rightPressed && paddleX < canvas.width-paddleWidth) {
    paddleX += 7;
  }
  else if(leftPressed && paddleX > 0) {
    paddleX -= 7;
  }

  x += dx;
  y += dy;
  requestAnimationFrame(draw);
}

function hardFunction(){
    ballRadius = 8;
    paddleWidth = 80;
    lives = 1;
    dx = 5;
    dy = -5;
};
   
function mediumFunction(){
    ballRadius = 15;
    paddleWidth = 120;
    lives = 2;
    dx = 4;
    dy = -4;
};
   
function easyFunction(){
    ballRadius = 20;
    paddleWidth = 175;
    lives = 3;
    dx = 3;
    dy = -3;
};
  
draw();

console.log(ctx.fillStyle);

CSS代码 #

* {
    padding: 0;
    margin: 0;
  }
  canvas {
    background: #eee;
    display: block;
    margin: 0 auto;
  }
  button {
    border: none;
    color: gray;
    padding: 16px 32px;
    text-align: center;
    text-decoration: none;
    display: inline-block;
    font-size: 16px;
    margin: 4px 2px 0px 16.67%;
    transition-duration: 0.4s;
    cursor: pointer
  }

.buttonHard:hover {
  background-color: red;
  color: black;
}

.buttonMedium:hover {
  background-color: yellow;
  color: black;
}

.buttonEasy:hover {
  background-color: green;
  color: black;
}

HTML代码 #

<canvas id="myCanvas" width="960" height="640"></canvas>

<button id="button" class="buttonHard" onclick="hardFunction();">Hard Mode</button>
<button id="button" class="buttonMedium" onclick="mediumFunction();">Medium Mode</button>
<button id="button" class="buttonEasy" onclick="easyFunction();">Easy Mode</button>

<script src="script.js"></script>

内容的提问来源于stack exchange，提问作者Riad Afandili