我正在开发一款非常简单的java脚本游戏。有一个掉落的随机物体(垃圾桶(和另一个用来接住掉落物体的物体(垃圾箱(。看起来一切都很好，但我想让垃圾桶的移动更顺畅。你有什么办法解决这个问题吗？提前感谢
这是我的代码
window.onload = function(){
var canvas = document.getElementById("canvas");
var context = canvas.getContext("2d");
var canvasBack = document.getElementById("backgroundCanvas");
var contextBack = canvasBack.getContext("2d");
var timer;
//mengatur hiscore
var hiscore = 0;
//Background image, musik and arrays musik.
var background = new Image();
background.src = 'assets/bgw2.jpg';
var catchSounds = [];
var catchSoundCounter = 0;
for(var i = 0; i < 5; i++)
{
var catchSound = new Audio();
catchSound.src = 'Audio/bleep.wav';
catchSounds.push(catchSound);
}
var music = new Audio();
music.src = 'Audio/MarimbaBoy.wav';
music.loop = true;
var smashSounds = [];
var smashCounter = 0;
for(var i = 0; i < 5; i++)
{
var smash = new Audio();
smash.src = 'Audio/smash.mp3';
smashSounds.push(smash);
}
var player;
var fruits = [];
var numberOfFruits = 15;
//Player constructor
function Player()
{
this.gameOver = false;
this.score = 0;
this.fruitsCollected = 0;
this.fruitsMissed = 0;
this.playerWidth = 150;
this.playerHeight = 90;
this.playerSpeed = 10;
this.x = canvas.width / 2;
this.y = canvas.height - this.playerHeight;
this.playerImage = new Image();
this.playerImage.src = 'assets/binn.png';
//Draws the player
this.render = function()
{
context.drawImage(this.playerImage, this.x, this.y);
}
//Moves the player left
this.moveLeft = function()
{
if(this.x > 0)
{
this.x -= this.playerSpeed;
}
}
//Moves the player right
this.moveRight = function()
{
if(this.x < canvas.width - this.playerWidth)
{
this.x += this.playerSpeed;
}
}
}
//Fruit constructor
function Fruit()
{
this.fruitNumber = Math.floor(Math.random() * 5);
this.fruitType = "";
this.fruitScore = 0;
this.fruitWidth = 50;
this.fruitHeight = 50;
this.fruitImage = new Image();
this.fruitSpeed = Math.floor(Math.random() * 2 + 1);
this.x = Math.random() * (canvas.width - this.fruitWidth);
this.y = Math.random() * -canvas.height - this.fruitHeight;
//Creates a different kind of fruit depending on the fruit number
//which is generated randomly
this.chooseFruit = function()
{
if(this.fruitNumber == 0)
{
this.fruitType = "pisang";
this.fruitScore = 5 * this.fruitSpeed;
this.fruitImage.src = 'assets/pisang.png';
}
else if(this.fruitNumber == 1)
{
this.fruitType = "rubbish";
this.fruitScore = 10 * this.fruitSpeed;
this.fruitImage.src = 'assets/rubbish.png';
}
else if(this.fruitNumber == 2)
{
this.fruitType = "botol";
this.fruitScore = 15 * this.fruitSpeed;
this.fruitImage.src = 'assets/botol.png';
}
else if(this.fruitNumber == 3)
{
this.fruitType = "coke";
this.fruitScore = 20 * this.fruitSpeed;
this.fruitImage.src = 'assets/coke.png';
}
else if(this.fruitNumber == 4)
{
this.fruitType = "apple";
this.fruitScore = 25 * this.fruitSpeed;
this.fruitImage.src = 'assets/apple.png';
}
else if(this.fruitNumber == 5)
{
this.fruitType = "papikra";
this.fruitScore = 30 * this.fruitSpeed;
this.fruitImage.src = 'assets/papikra.png';
}
}
//Makes the fruit descend.
//While falling checks if the fruit has been caught by the player
//Or if it hit the floor.
this.fall = function()
{
if(this.y < canvas.height - this.fruitHeight)
{
this.y += this.fruitSpeed;
}
else
{
smashSounds[smashCounter].play();
if(smashCounter == 4)
{
smashCounter = 0;
}
else
{
smashCounter++;
}
player.fruitsMissed += 1;
this.changeState();
this.chooseFruit();
}
this.checkIfCaught();
}
//Checks if the fruit has been caught by the player
//If it is caught, the player score and fruit counter is increased, and
//the current fruit changes its state and becomes a different fruit.
this.checkIfCaught = function()
{
if(this.y >= player.y)
{
if((this.x > player.x && this.x < (player.x + player.playerWidth)) ||
(this.x + this.fruitWidth > player.x && this.x + this.fruitWidth < (player.x + player.playerWidth)))
{
catchSounds[catchSoundCounter].play();
if(catchSoundCounter == 4)
{
catchSoundCounter = 0;
}
else
{
catchSoundCounter++;
}
player.score += this.fruitScore;
player.fruitsCollected += 1;
this.changeState();
this.chooseFruit();
}
}
}
//Randomly updates the fruit speed, fruit number, which defines the type of fruit
//And also changes its x and y position on the canvas.
this.changeState = function()
{
this.fruitNumber = Math.floor(Math.random() * 5);
this.fruitSpeed = Math.floor(Math.random() * 2 + 1);
this.x = Math.random() * (canvas.width - this.fruitWidth);
this.y = Math.random() * -canvas.height - this.fruitHeight;
}
//Draws the fruit.
this.render = function()
{
context.drawImage(this.fruitImage, this.x, this.y);
}
}
//Adds controls. Left arrow to move left, right arrow to move right.
//ENTER to restart only works at the game over screen.
window.addEventListener("keydown", function(e){
e.preventDefault();
if(e.keyCode == 37)
{
player.moveLeft();
}
else if(e.keyCode == 39)
{
player.moveRight();
}
else if(e.keyCode == 13 && player.gameOver == true)
{
main();
window.clearTimeout(timer);
}
});
main();
//Fills an array of fruits, creates a player and starts the game
function main()
{
contextBack.font = "bold 20px Dominique";
contextBack.fillStyle = "WHITE";
player = new Player();
fruits = [];
for(var i = 0; i < numberOfFruits; i++)
{
var fruit = new Fruit();
fruit.chooseFruit();
fruits.push(fruit);
}
startGame();
}
function startGame()
{
updateGame();
window.requestAnimationFrame(drawGame);
}
//Checks for gameOver and makes each fruit in the array fall down.
function updateGame()
{
music.play();
if(player.fruitsMissed >= 10)
{
player.gameOver = true;
}
for(var j = 0; j < fruits.length; j++)
{
fruits[j].fall();
}
timer = window.setTimeout(updateGame, 30);
}
//Draws the player and fruits on the screen as well as info in the HUD.
function drawGame()
{
if(player.gameOver == false)
{
context.clearRect(0, 0, canvas.width, canvas.height);
contextBack.clearRect(0, 0, canvasBack.width, canvasBack.height);
contextBack.drawImage(background, 0, 0);
player.render();
for(var j = 0; j < fruits.length; j++)
{
fruits[j].render();
}
contextBack.fillText("SCORE: " + player.score, 30, 50);
contextBack.fillText("HIGHEST SCORE: " + hiscore, 140, 50);
contextBack.fillText("FRUIT CAUGHT: " + player.fruitsCollected, 320, 50);
contextBack.fillText("FRUIT MISSED: " + player.fruitsMissed, 490, 50);
}
else
{
//Different screen for game over.
for(var i = 0; i < numberOfFruits; i++)
{
console.log("Speed was" + fruits[fruits.length - 1].fruitSpeed);
fruits.pop();
}
if(hiscore < player.score)
{
hiscore = player.score;
contextBack.fillText("NEW HI SCORE: " + hiscore, (canvas.width / 2) - 80, canvas.height / 2);
}
contextBack.fillText("PRESS ENTER TO RESTART", (canvas.width / 2) - 100, canvas.height / 2 + 50);
context.clearRect(0, 0, canvas.width, canvas.height);
}
window.requestAnimationFrame(drawGame);
}
}
首先，只使用一个requestAnimationFrame代码，不使用其他setTimeout代码。这些游戏可能会开始彼此不同步，当玩家想暂停游戏时，很难将它们全部暂停。
相反，使用计数器而不是超时。
let fruitCounter = 0
function drawGame() {
// all your draw code here
...
// every 60 frames drop a new fruit
fruitCounter++
if(fruitCounter > 60){
fruitCounter = 0
dropNewFruit()
}
// request the new frame unless its game over
if(!gameOver) {
requestAnimationFrame(drawGame)
}
}
此外，如果你使用这样的键盘事件，它将总是断断续续的，因为在键盘上打字时会有延迟(只需在文本字段中长时间按下一个字母，你会看到它需要一段时间，直到出现更多的字母(
您可以通过在按键后设置变量来解决此问题。
window.addEventListener("keydown", function(e){
if(e.keyCode == 37){
moveLeft = 1
}
}
window.addEventListener("keyup", function(e){
if(e.keyCode == 37){
moveLeft = 0
}
}
然后，您可以在动画代码中使用该变量
function drawGame() {
// all your draw code here
player.x += moveLeft
// request the new frame unless its game over
if(!gameOver) {
requestAnimationFrame(drawGame)
}
}
这些只是一些小技巧！当我构建javascript游戏时，这一直对我有效。