HTML5與Javascript 實現網頁彈球遊戲
終於效果圖：
1. 使用html 5 的canvas 技術和javascript實現彈球遊戲
總體流程圖：
1.1 html5 canvas技術的使用
首先在html頁面中定義畫布。
<canvas bgcolor = "#FFF" id="gamePane" width="1000" height="500" tabindex="0"> Sorry, your browser doesn‘t support the HTML5 game. </canvas>
定義完畫布之後就能夠在javascript代碼中對畫布進行操作。
canvas = document.getElementById(‘gamePane‘);
ctx = canvas.getContext("2d");在畫布中構繪圖形。
ballImg = new Image();
ballImg.src = "/site_media/images/kkball.ico";
ctx.drawImage(ballImg, ballX- radius, ballY-radius, 2*radius, 2*radius);1.2 javascript彈球遊戲實現
使用canvas技術我們實現了彈球遊戲的GUI界面，接下來是遊戲功能邏輯。
1.2.1首先明白遊戲功能：
A. 遊戲元素： 彈球，磚塊。擋板，道具。
B. 遊戲開始， 球從擋板出發。碰撞到磚塊或者遊戲邊界時會反彈，碰撞到磚塊時磚塊消失，假設磚塊隱藏了道具，道具顯示並下落，碰到擋板時會發揮道具效果。彈球碰到擋板時也會反彈，可是假設碰到下邊界則會損失遊戲生命。
C. 當磚塊全然消失時進入下一關，隨著關卡數添加。板的長度會減小。球的速度回加快。
D. 道具： 1. 使彈球速度乘以1.3；2. 使彈球速度除以1.3；3. 使板的長度乘以2。4. 使板的長度除以2；
1.2.2 畫布的刷新
畫布的刷新使用html中的定時器實現。每0.003秒調用一次draw。更新畫面。
interval = setInterval(draw, 3);
1.2.3用戶交互
用戶通過鼠標進行交互，遊戲還未開始時， 球和板的x坐標都會隨鼠標x坐標變化。這時點擊鼠標左鍵，球和板的x坐標不再變化。這時能夠設置球執行方向。方向為鼠標所在位置。
遊戲開始後，板x坐標隨鼠標x坐標變化。
為鼠標點擊和移動設置響應函數。
canvas.addEventListener(‘mousedown‘,onMouseDown, false); canvas.addEventListener(‘mousemove‘, padMove, false); canvas.addEventListener(‘mouseup‘, start, false);
鼠標事件響應函數。
//鼠標落下點擊事件
function onMouseDown(e){
if(isStart==0){
isPressed = 1;
}
}
//鼠標移動點擊事件
function padMove(e){
var x;
x = e.layerX;
x = x<padWidth/2?padWidth/2:x;
x = x>(worldWidth-padWidth/2)?(worldWidth-padWidth/2):x;
padX = x;
if(isStart==0){ //假設遊戲還未開始，則須要又一次繪制板。假設遊戲開始了，板的繪制在draw中完畢。
if(isPressed == 0){
ballX = padX;
ctx.clearRect(0, worldHeight-padHeight-2*radius, worldWidth, 2*radius); //clear the pad
drawBall();
drawPad();
}
}
}
//鼠標擡起事件函數，設置彈球角度，設置定時器定時刷新頁面。
function start(e){
if(isStart==0){
ballAngle = Math.atan((worldHeight- e.layerY)/(e.layerX - ballX));
if(ballAngle > 0){
ballAngle = - ballAngle;
}
else{
ballAngle = Math.PI - ballAngle;
}
isStart =1;
isPressed = 0;
interval = setInterval(draw, 3);
}
}
1.2.4 彈球運動與碰撞檢測
彈球位置更新。
ballX = ballX + ballSpeed * Math.cos(ballAngle);
ballY = ballY + ballSpeed * Math.sin(ballAngle);球遊戲邊界碰撞檢測。
//球碰撞到左右兩邊邊界
if(ballX < radius || ballX > worldWidth - radius){
ballAngle = Math.PI - ballAngle;
}
//球碰到上邊界
if(ballY < radius){
ballAngle = Math.PI*2 - ballAngle;
}
//球碰到下邊界
if(ballY > worldHeight-radius){
//假設球未碰到板上。則遊戲停止，推斷生命是否用完，用完遊戲結束
if(ballX< padX-padWidth/2 || ballX > padX + padWidth/2){
ctx.clearRect(0,0,worldWidth,worldHeight-padHeight);
self.clearInterval(interval);
if(life>0){
drawInfo(1);
life = life -1;
reset();
}
else if(life ==0){
drawInfo(2);
getData();
}
return;
}
//球碰到板上
else{
ballAngle = Math.PI*2 - ballAngle;
}
}
//推斷磚塊是否打完，假設打完進入下一關
if(count>= col*row){
ctx.clearRect(0,0,worldWidth,worldHeight-padHeight);
self.clearInterval(interval);
newLevel();
return;
}
1.2.5 彈球與磚塊碰撞檢測。
每次彈球到達可能有磚塊的那一層的時候。推斷彈球位置所在磚塊是否還在。假設還在。則消去它。同一時候推斷其是否有道具。假設有。則創建道具。
function testCollision(){
//球的位置不可能有磚塊
if(ballY > brickHeight * row){
return;
}
//循環推斷彈球在那一層
for(var i = row;i>0;i--){
if((ballY-radius)<=(brickHeight*i)){
if((ballY-radius)>(brickHeight*(i-1))){
var x = Math.floor(ballX/brickWidth);
if(bricks[i-1][x].isdisplay==0){
continue;
}
else{
bricks[i-1][x].isdisplay=0;
ballAngle= Math.PI*2-ballAngle;
score= score+100;
count = count +1;
//推斷是否有道具
if(bricks[i-1][x].tool!=0){
var brickX = bricks[i-1][x].col * brickWidth;
var brickY = bricks[i-1][x].row * brickHeight;
var temp = new tool(brickX, brickY, bricks[i-1][x].tool);
toolArray.push(temp); }
return;
}
}
else{
continue;
}
}
else
break;
}
}1.2.6 道具的實現
初始化時創建一個存放道具的Array。
toolArray = new Array();
if(bricks[i-1][x].tool!=0){
var brickX = bricks[i-1][x].col * brickWidth;
var brickY = bricks[i-1][x].row * brickHeight;
var temp = new tool(brickX, brickY, bricks[i-1][x].tool);
toolArray.push(temp);
}每次碰到磚塊時，推斷磚塊是否有道具，假設有道具就創建道具。將其放入數組。
磚塊是否有道具及道具類型由隨機數產生。
每次刷新畫面時調用testTool函數。推斷道具是否落究竟部。
假設落到板上則發揮效果。
function testTool(){
//循環遍歷整張道具數組
for(var i = 0;i<toolArray.length;i++){
console.log("tesetool", toolArray[i].type);
var temp = toolArray[i];
//道具還未落究竟部
if(temp.y<worldHeight-padHeight){
continue;
}
else{
//道具落到板上，推斷道具類型。發揮效果。
if(temp.x>=padX-padWidth/2 && temp.x<=padX+padWidth/2){
switch(temp.type){
case 1:{
if(ballSpeed<2.6)
ballSpeed=ballSpeed*1.3;
console.log("tool", temp.type);
break;
}
case 2:{
if(ballSpeed>1.5)
ballSpeed=ballSpeed/1.3;
console.log("tool", temp.type);
break;
}
case 3:{
if(padWidth<200){
padWidth = padWidth *2;
}
console.log("tool", temp.type);
break;
}
case 4:{
if(padWidth>50)
padWidth=padWidth /2;
console.log("tool", temp.type);
break;
}
}
}
toolArray.splice(i, 1);
}
}
}完整代碼：
var canvas;
var ctx;
var ballX = 500;
var ballY = 470;
var ballAngle = -Math.PI/2;
var radius = 20;
var ballSpeed = 2;
var padX = 500; //擋板位置
var padWidth = 100;
var padHeight = 10;
var worldWidth;
var worldHeight;
var interval;
var score = 0;
var brickWidth = 100;
var brickHeight = 25;
var bricks;
var color;
var col = 10;
var row = 5;
var isStart = 0;
var time = 0;
var life = 3;
var isPressed = 0;
var level = 1;
var count = 0;
var ballImg;
var brickImg;
var padImg;
var tool1Img;
var tool2Img;
var tool3Img;
var tool4Img;
var toolArray;
var toolLength = 30;
var toolHeight = 30;
var isLoad = [0,0,0,0,0,0,0];
var loadInterval;
function brick(){
this.col = 0;
this.row = 0;
this.isdisplay = 1; //是否顯示
this.tool = 0; //道具類型，0 表示無道具。
this.color = "#000000"
}
//tool:
//type:
//1: make the ball speed x1.3
//2: make the ball speed /1.3
//3: make the pad length twice
//4: make the pad length 1/2
function tool(x , y ,type){
this.x = x;
this.y = y;
this.type = type;
}
function loadImage(){
tool1Img = new Image();
tool1Img.src = "/site_media/images/tool1.png";1
tool1Img.addEventListener(‘load‘, function(){isLoad[0]=1}, false);
tool2Img = new Image();
tool2Img.src = "/site_media/images/tool2.png";
tool2Img.addEventListener(‘load‘, function(){isLoad[1]=1}, false);
tool3Img = new Image();
tool3Img.src = "/site_media/images/tool3.png";
tool3Img.addEventListener(‘load‘, function(){isLoad[2]=1}, false);
tool4Img = new Image();
tool4Img.src = "/site_media/images/tool4.png";
tool4Img.addEventListener(‘load‘, function(){isLoad[3]=1}, false);
padImg = new Image();
padImg.src = "/site_media/images/pad.png";
padImg.addEventListener(‘load‘, function(){isLoad[4]=1}, false);
ballImg = new Image();
ballImg.src = "/site_media/images/kkball.ico";
ballImg.addEventListener(‘load‘, function(){isLoad[5]=1}, false);
brickImg = new Image();
brickImg.src = "/site_media/images/brick.ico";
brickImg.addEventListener(‘load‘, function(){isLoad[6]=1}, false);
//brickImg.addEventListener(‘load‘, init, false);
loadInterval = setInterval(loadTest, 3);
}
//to test if all of the image is loaded
function loadTest(){
var i;
for(i=0;i<isLoad.length;i++){
if(isLoad[i]==0){
break;
}
}
if(i>=isLoad.length){
self.clearInterval(loadInterval);
init();
}
}
function GetRandomNum(Min,Max)
{
var Rand = Math.random();
console.log("Rand", Rand);
if(Rand>0 && Rand<0.6){
return 0;
}
else if(Rand<=0.7){
return 1;
}
else if(Rand<=0.8){
return 2;
}
else if(Rand<=0.9){
return 3;
}
else if(Rand <=1){
return 4;
}
}
function init(){ //init the game pane
padWidth = 100;
ballSpeed = 2;
count = 0;
isStart = 0;
ballX = 500;
ballY = 470;
padX = 500;
canvas = document.getElementById(‘gamePane‘);
worldWidth = canvas.width;
worldHeight = canvas.height;
ctx = canvas.getContext("2d");
toolArray = new Array();
//create the array of the bricks
//canvas.addEventListener(‘keydown‘, onKeyDown, true);
drawInfo(3);
color = new Array("#FF0000", "#00FF00", "#0000FF", "#ff00ff")
bricks = new Array();
for(var i = 0; i< row; i++){
bricks[i] = new Array();
for(var j = 0;j<col;j++){
var temp = new brick();
temp.col = j;
temp.row = i;
temp.isdisplay=1;
temp.tool = GetRandomNum(1, 4);
console.log("temp.tool", temp.tool);
temp.color = color[(i*col+j)%4];
bricks[i][j]= temp;
}
}
canvas.focus();
drawBall();
drawPad();
drawText();
drawBricks();
canvas.addEventListener(‘mousedown‘,onMouseDown, false);
canvas.addEventListener(‘mousemove‘, padMove, false);
canvas.addEventListener(‘mouseup‘, start, false);
}
function reset(){
padWidth = 100;
ballSpeed =2;
toolArray = new Array();
isStart=0;
ballX = 500;
ballY = 470;
padX = 500;
drawBricks();
drawBall();
drawPad();
drawText();
}
function newLevel(){
padWidth = padWidth - 5;
ballSpeed = ballSpeed + 0.1;
if(padWidth<= 40){
drawInfo(4);
getData();
return;
}
else{
row = row +1;
level =level + 1;
init();
}
}
function onMouseDown(e){
if(isStart==0){
isPressed = 1;
}
}
function padMove(e){
var x;
x = e.layerX;
x = x<padWidth/2?padWidth/2:x;
x = x>(worldWidth-padWidth/2)?(worldWidth-padWidth/2):x;
padX = x;
if(isStart==0){
if(isPressed == 0){
ballX = padX;
ctx.clearRect(0, worldHeight-padHeight-2*radius, worldWidth, 2*radius); //clear the pad
drawBall();
drawPad();
}
}
}
function start(e){
if(isStart==0){
ballAngle = Math.atan((worldHeight- e.layerY)/(e.layerX - ballX));
if(ballAngle > 0){
ballAngle = - ballAngle;
}
else{
ballAngle = Math.PI - ballAngle;
}
isStart =1;
isPressed = 0;
interval = setInterval(draw, 3);
}
}
function testCollision(){
if(ballY > brickHeight * row){
return;
}
for(var i = row;i>0;i--){
if((ballY-radius)<=(brickHeight*i)){
if((ballY-radius)>(brickHeight*(i-1))){
var x = Math.floor(ballX/brickWidth);
if(bricks[i-1][x].isdisplay==0){
continue;
}
else{
bricks[i-1][x].isdisplay=0;
ballAngle= Math.PI*2-ballAngle;
score= score+100;
count = count +1;
if(bricks[i-1][x].tool!=0){
var brickX = bricks[i-1][x].col * brickWidth;
var brickY = bricks[i-1][x].row * brickHeight;
var temp = new tool(brickX, brickY, bricks[i-1][x].tool);
toolArray.push(temp); }
return;
}
}
else{
continue;
}
}
else
break;
}
}
function testTool(){
for(var i = 0;i<toolArray.length;i++){
console.log("tesetool", toolArray[i].type);
var temp = toolArray[i];
if(temp.y<worldHeight-padHeight){
continue;
}
else{
if(temp.x>=padX-padWidth/2 && temp.x<=padX+padWidth/2){
switch(temp.type){
case 1:{
if(ballSpeed<2.6)
ballSpeed=ballSpeed*1.3;
console.log("tool", temp.type);
break;
}
case 2:{
if(ballSpeed>1.5)
ballSpeed=ballSpeed/1.3;
console.log("tool", temp.type);
break;
}
case 3:{
if(padWidth<200){
padWidth = padWidth *2;
}
console.log("tool", temp.type);
break;
}
case 4:{
if(padWidth>50)
padWidth=padWidth /2;
console.log("tool", temp.type);
break;
}
}
}
toolArray.splice(i, 1);
}
}
}
function postData(){
var xmlhttp = new XMLHttpRequest();
xmlhttp.open("POST","../storeScore/",true);
xmlhttp.setRequestHeader("Content-type","application/x-www-form-urlencoded");
var text = "score="+score;
xmlhttp.send(text)
}
function getData(){
var url = "../storeScore/"+score+"/";
window.location = url;
}
function drawInfo(num){
ctx.font = ‘50pt Calibri‘;
ctx.fillStyle = "#E67E22";
var text="One life lost!"
if (num ==2){
text = "Game over!"
}
else if(num ==3){
text = "Level "+ level;
}
else if(num ==4){
text = "Congratulations!"
}
ctx.fillText(text, 350, 250);
}
function drawBall(){
ctx.drawImage(ballImg, ballX- radius, ballY-radius, 2*radius, 2*radius);
}
function drawBricks(){
for(var i =0;i<row;i++){
for(var j=0;j<col;j++){
if(bricks[i][j].isdisplay ==1){
ctx.fillStyle = bricks[i][j].color;
var x = bricks[i][j].col * brickWidth;
var y = bricks[i][j].row * brickHeight;
//ctx.fillRect(x, y, brickWidth, brickHeight);
ctx.drawImage(brickImg, x, y, brickWidth, brickHeight);
}
}
}
}
function drawPad(){
//ctx.fillStyle = "#0000FF";
ctx.clearRect(0, worldHeight-padHeight, worldWidth, padHeight); //clear the pad
//ctx.fillRect(padX-padWidth/2, worldHeight-padHeight, padWidth, padHeight);
ctx.drawImage(padImg, padX-padWidth/2, worldHeight-padHeight, padWidth, padHeight);
}
function drawText(){
ctx.font = ‘15pt Calibri‘;
ctx.fillStyle = "black";
var text= "level:"+level;
ctx.fillText(text, 900, 370)
text = "life: " + life;
ctx.fillText(text, 900, 430);
text = ‘point:‘+score;
ctx.fillText(text, 900, 390);
var min;
if(time > 60){
min =Math.floor(time/60);
}
else{
min =0;
}
var sec = Math.floor(time % 60);
if(min <10){
tMin = ‘0‘+ min;
}
else
tMin = ‘‘+min;
if(sec<10){
tSec = ‘0‘+sec;
}
else
tSec=‘‘+ sec;
text = ‘time: ‘+ tMin +":"+tSec;
ctx.fillText(text, 900, 410);
}
function drawTool(){
for(var i =0;i<toolArray.length;i++){
switch(toolArray[i].type){
case 1:{
ctx.drawImage(tool1Img, toolArray[i].x, toolArray[i].y, 30, 30);
break;
}
case 2:{
ctx.drawImage(tool2Img, toolArray[i].x, toolArray[i].y, 30, 30);
break;
}
case 3:{
ctx.drawImage(tool3Img, toolArray[i].x, toolArray[i].y, 30, 30);
break;
}
case 4:{
ctx.drawImage(tool4Img, toolArray[i].x, toolArray[i].y, 30, 30);
break;
}
}
toolArray[i].y = toolArray[i].y+1;
}
}
function draw(){
//first clear the canvas
ctx.clearRect(0,0,worldWidth,worldHeight-padHeight);
//ball
drawBall();
drawPad();
drawBricks();
drawTool();
drawText();
//flush the position of the ball
ballX = ballX + ballSpeed * Math.cos(ballAngle);
ballY = ballY + ballSpeed * Math.sin(ballAngle);
//test the collision of the brick and the ball
testCollision();
testTool();
if(ballX < radius || ballX > worldWidth - radius){
ballAngle = Math.PI - ballAngle;
}
if(ballY < radius){
ballAngle = Math.PI*2 - ballAngle;
}
if(ballY > worldHeight-radius){
if(ballX< padX-padWidth/2 || ballX > padX + padWidth/2){
ctx.clearRect(0,0,worldWidth,worldHeight-padHeight);
self.clearInterval(interval);
if(life>0){
drawInfo(1);
life = life -1;
reset();
}
else if(life ==0){
drawInfo(2);
getData();
}
return;
}
else{
ballAngle = Math.PI*2 - ballAngle;
}
}
if(count>= col*row){
ctx.clearRect(0,0,worldWidth,worldHeight-padHeight);
self.clearInterval(interval);
newLevel();
return;
}
time = time +0.003;
}
HTML5與Javascript 實現網頁彈球遊戲