Creating the Full No Tanks! Game - The Essential Guide to Flash Games - page 317

These are the collisions we look for in this function:

When any missile in the playerMissiles array hits an enemy tank : Enemy tanks
have healthPoints just like the player. When all healthPoints are gone, the enemy tank
is destroyed.

Missiles in the enemyMissiles array hitting the player : Each time the player is hit by
an enemy missile, one of its healthPoints is removed. When all five are gone, the
player tank explodes. If the player is out of lives, gameOver is set to true .

The player hitting the goalSprite : As soon as the player hits the goalSprite , the level
is over.

The player hitting any BlitSprite in the ammoPickupList array : The ammo variable is
increased by the ammoPickupAmount value when this is true.

The player hitting any BlitSprite in the lifePickups array : The lives variable is
increased by 1 when this is true.

Here's the new function's code:
private function checkCollisions():void {

//loop through playerMissiles and check against enemy
var playerMissileLength:int = playerMissileList.length - 1;
playerHitPoint.x = player.nextX;
playerHitPoint.y = player.nextY;

var enemyLength:int = enemyList.length - 1;

missiles: for (var ctr:int = playerMissileLength; ctr >= 0; ctr--) {
tempMissile = playerMissileList[ctr]

for (var ctr2:int = enemyLength; ctr2 >= 0; ctr2--) {
tempEnemy = enemyList[ctr2];
missileHitPoint.x = tempMissile.nextX;
missileHitPoint.y = tempMissile.nextY;
enemyHitPoint.x = tempEnemy.nextX;
enemyHitPoint.y = tempEnemy.nextY;

if (tempMissile.bitmapData.hitTest(missileHitPoint,

255, tempEnemy.bitmapData, enemyHitPoint)) {

//trace("hit enemy");
tempEnemy.healthPoints--;
if (tempEnemy.healthPoints < 1) {
createExplode(EXPLODE_LARGE, tempEnemy.x, tempEnemy.y);

dispatchEvent(new CustomEventSound(CustomEventSound.PLAY_SOUND,

Main.SOUND_EXPLODE, false, 1, 0));

enemyList.splice(ctr2, 1);
dispose(tempEnemy);
score += scoreEnemy;
}else {

createExplode(EXPLODE_SMALL, tempMissile.x, tempMissile.y);