Working with Audio - HTML5 Canvas - page 374

shootSound2 = document.createElement("audio");
document.body.appendChild(shootSound2);
shootSound2.setAttribute("src", "shoot1." + audioType);
shootSound2.addEventListener("canplaythrough",itemLoaded,false);
shootSound3 = document.createElement("audio");
document.body.appendChild(shootSound3);
shootSound3.setAttribute("src", "shoot1." + audioType);
shootSound3.addEventListener("canplaythrough",itemLoaded,false);
alienImage = new Image();
alienImage.onload = itemLoaded;
alienImage.src = "alien.png";
playerImage = new Image();
playerImage.onload = itemLoaded;
playerImage.src = "player.png";
missileImage = new Image();
missileImage.onload = itemLoaded;
missileImage.src = "missile.png";
appState = STATE_LOADING;
}
function startLevel() {
for (var r = 0; r < ALIEN_ROWS; r++) {
for( var c= 0; c < ALIEN_COLS; c++) {
aliens.push({speed:2,x:ALIEN_START_X+c*ALIEN_SPACING, y:ALIEN_START_Y+r*
ALIEN_SPACING,width:alienImage.width, height:alienImage.height});
}
}
}
function resetApp() {
playSound(SOUND_EXPLODE,0);
playSound(SOUND_SHOOT,0);
startLevel();
appState = STATE_PLAYING;
}
function drawScreen () {
//Move missiles
for (var i=missiles.length−1; i>= 0;i−−) {
missiles[i].y −= missiles[i].speed;
if (missiles[i].y < (0-missiles[i].height)) {
missiles.splice(i,1);
}
}
//Move Aliens
for (var i=aliens.length−1; i>= 0;i−−) {
aliens[i].x += aliens[i].speed;