Hey Guys,
I have been following a tutorial from the book ‘Actionscript 3.0, Game Programming University’ and one of the chapters looks at creating a racing game.
I have got the game fully working, although i want to add a couple of features, one of them being more laps to the track itself. At the moment the user can only go around the track once which gives him a lap time and the game finishes. Could someone give me some advice or solution on how to create more laps to this game?
Thanks Heaps. Code Below. Sorry .fla file was too large.
package { import flash.display.*;
import flash.events.*;
import flash.text.*;
import flash.geom.*;
import flash.utils.getTimer;
import flash.media.Sound;
import flash.media.SoundChannel;
public class Racing extends MovieClip {
// constants
static const maxSpeed:Number = 0.5;
static const accel:Number = .0002;
static const decel:Number = .0003;
static const turnSpeed:Number = .22;
// game variables
private var arrowLeft, arrowRight, arrowUp, arrowDown:Boolean;
private var lastTime:int;
private var gameStartTime:int;
private var speed:Number;
private var gameMode:String;
private var waypoints:Array;
private var currentSound:Object;
// sounds
static const theBrakestopSound:BrakestopSound = new BrakestopSound();
static const theDriveSound:DriveSound = new DriveSound();
static const theGoSound:GoSound = new GoSound();
static const theOffroadSound:OffroadSound = new OffroadSound();
static const theReadysetSound:ReadysetSound = new ReadysetSound();
static const theSideSound:SideSound = new SideSound();
private var driveSoundChannel:SoundChannel;
public function startRacing() {
// get list of waypoints
findWaypoints();
// add listeners
this.addEventListener(Event.ENTER_FRAME,gameLoop);
stage.addEventListener(KeyboardEvent.KEY_DOWN,keyDownFunction);
stage.addEventListener(KeyboardEvent.KEY_UP,keyUpFunction);
// set up game variables
speed = 0;
gameMode = "wait";
timeDisplay.text = "";
gameStartTime = getTimer()+3000;
centerMap();
}
// look at all gamesprite children and remember waypoints
public function findWaypoints() {
waypoints = new Array();
for(var i=0;i<gamesprite.numChildren;i++) {
var mc = gamesprite.getChildAt(i);
if (mc is Waypoint) {
// add to array and make invisible
waypoints.push(new Point(mc.x, mc.y));
mc.visible = false;
}
}
}
// note key presses, set properties
public function keyDownFunction(event:KeyboardEvent) {
if (event.keyCode == 37) {
arrowLeft = true;
} else if (event.keyCode == 39) {
arrowRight = true;
} else if (event.keyCode == 38) {
arrowUp = true;
} else if (event.keyCode == 40) {
arrowDown = true;
}
}
public function keyUpFunction(event:KeyboardEvent) {
if (event.keyCode == 37) {
arrowLeft = false;
} else if (event.keyCode == 39) {
arrowRight = false;
} else if (event.keyCode == 38) {
arrowUp = false;
} else if (event.keyCode == 40) {
arrowDown = false;
}
}
// main game code
public function gameLoop(event:Event) {
// calculate time passed
if (lastTime == 0) lastTime = getTimer();
var timeDiff:int = getTimer()-lastTime;
lastTime += timeDiff;
// only move car if in race mode
if (gameMode == "race") {
// rotate left or right
if (arrowLeft) {
gamesprite.car.rotation -= (speed+.1)*turnSpeed*timeDiff;
}
if (arrowRight) {
gamesprite.car.rotation += (speed+.1)*turnSpeed*timeDiff;
}
// accelerate car
if (arrowUp) {
speed += accel*timeDiff;
if (speed > maxSpeed) speed = maxSpeed;
} else if (arrowDown) {
speed -= accel*timeDiff;
if (speed < -maxSpeed) speed = -maxSpeed;
// no arrow pressed, so slow down
} else if (speed > 0) {
speed -= decel*timeDiff;
if (speed < 0) speed = 0;
} else if (speed < 0) {
speed += decel*timeDiff;
if (speed > 0) speed = 0;
}
// if moving, then move car and check status
if (speed != 0) {
moveCar(timeDiff);
centerMap();
checkWaypoints();
checkFinishLine();
}
}
// update time and check for end of game
showTime();
}
public function moveCar(timeDiff:Number) {
// get current position
var carPos:Point = new Point(gamesprite.car.x, gamesprite.car.y);
// calculate change
var carAngle:Number = gamesprite.car.rotation;
var carAngleRadians:Number = (carAngle/360)*(2.0*Math.PI);
var carMove:Number = speed*timeDiff;
var dx:Number = Math.cos(carAngleRadians)*carMove;
var dy:Number = Math.sin(carAngleRadians)*carMove;
// assume we'll use drive sound
var newSound:Object = theDriveSound;
// see if car is NOT on the road
if (!gamesprite.road.hitTestPoint(carPos.x+dx+gamesprite.x, carPos.y+dy+gamesprite.y, true)) {
// see if car is on the side
if (gamesprite.side.hitTestPoint(carPos.x+dx+gamesprite.x, carPos.y+dy+gamesprite.y, true)) {
// use special sound, reduce speed
newSound = theSideSound;
speed *= 1.0-.001*timeDiff;
} else {
// use special sound, reduce speed
newSound = theOffroadSound;
speed *= 1.0-.002*timeDiff;
}
}
// set new position of car
gamesprite.car.x = carPos.x+dx;
gamesprite.car.y = carPos.y+dy;
// if not moving, forget about drive sound
if (!arrowUp && !arrowDown) {
newSound = null;
}
// if a new sound, switch sound
if (newSound != currentSound) {
if (driveSoundChannel != null) {
driveSoundChannel.stop();
}
currentSound = newSound;
if (currentSound != null) {
driveSoundChannel = currentSound.play(0,9999);
}
}
}
// see if close enough to waypoint
public function checkWaypoints() {
for(var i:int=waypoints.length-1;i>=0;i--) {
if (Point.distance(waypoints*, new Point(gamesprite.car.x, gamesprite.car.y)) < 150) {
waypoints.splice(i,1);
}
}
}
// see if crossed finish line
public function checkFinishLine() {
// only if all waypoints have been hit
if (waypoints.length > 0) return;
if (gamesprite.car.y < gamesprite.finish.y) {
endGame();
}
}
// update the time shown
public function showTime() {
var gameTime:int = getTimer()-gameStartTime;
// if in wait mode, show countdown clock
if (gameMode == "wait") {
if (gameTime < 0) {
// show 3, 2, 1
var newNum:String = String(Math.abs(Math.floor(gameTime/1000)));
if (countdown.text != newNum) {
countdown.text = newNum;
playSound(theReadysetSound);
}
} else {
// count down over, go to race mode
gameMode = "race";
countdown.text = "";
playSound(theGoSound);
}
// show time
} else {
timeDisplay.text = clockTime(gameTime);
}
}
// convert to time format
public function clockTime(ms:int):String {
var seconds:int = Math.floor(ms/1000);
var minutes:int = Math.floor(seconds/60);
seconds -= minutes*60;
var timeString:String = minutes+":"+String(seconds+100).substr(1,2);
return timeString;
}
// make sure car stays at center of screen
public function centerMap() {
gamesprite.x = -gamesprite.car.x + 275;
gamesprite.y = -gamesprite.car.y + 200;
}
// game over, remove listeners
public function endGame() {
driveSoundChannel.stop();
playSound(theBrakestopSound);
this.removeEventListener(Event.ENTER_FRAME,gameLoop);
stage.removeEventListener(KeyboardEvent.KEY_DOWN,keyDownFunction);
stage.removeEventListener(KeyboardEvent.KEY_UP,keyUpFunction);
gotoAndStop("gameover");
}
// show time on final screen
public function showFinalMessage() {
showTime();
var finalDisplay:String = "";
finalDisplay += "Time: "+timeDisplay.text+"
";
finalMessage.text = finalDisplay;
}
public function playSound(soundObject:Object) {
var channel:SoundChannel = soundObject.play(0);
}
}
}
