我已经创建了一个简单的AS3青蛙游戏，并使用. hittestobject来测试青蛙是否碰到了任何障碍。这是无效的，因为青蛙击中的物体根本没有接触到它。我是AS3的新手，不知道从哪里开始编写代码。任何帮助将不胜感激!
包{import flash.display.*;
import flash.events.*;
import flash.utils.*;
import flash.ui.*;
import flash.events.Event;
import flash.utils.Timer;
import flash.events.TimerEvent;
import flash.media.Sound;
import flash.media.SoundChannel;
import flash.utils.Timer;
import flash.display.BitmapData;
import flash.display.Bitmap;
public class Main extends MovieClip
{
//set variables
public var frog_spriteInstance:frog_sprite;
public var safeZoneInstance1 : safeZone;
public var safeZoneInstance2: safeZone;
public var safeZoneInstance3 : safeZone;
public var whitecar : car1;
public var whitecar1 : car1;
public var whitecar2 : car1;
public var truck1 : truck_sprite;
public var truck2: truck_sprite;
public var redcar : car_sprite;
public var redcar2 : car_sprite;
public var redcar3 : car_sprite;
public var log1 : log_sprite;
public var log2 : log_sprite;
public var log3 : log_sprite;
public var letters : Letters;
public var letters2 : Letters_2;
public var letters3 : Letters_3;
public var letters4 : Letters_4;
public var health : HealthBar;
public var firstletter : firstLetter;
public var secondletter : secondLetter;
public var thirdletter : thirdLetter;
public var fourthletter : fourthLetter;
var mysound:Sound = new (mySound);
public function Main()
{
// constructor code
safeZoneInstance1 = new safeZone();
stage.addChild(safeZoneInstance1);
safeZoneInstance1.x = 300;
safeZoneInstance1.y=545
safeZoneInstance2 = new safeZone();
stage.addChild(safeZoneInstance2);
safeZoneInstance2.x = 300;
safeZoneInstance2.y=300
safeZoneInstance3 = new safeZone();
stage.addChild(safeZoneInstance3);
safeZoneInstance3.x = 300;
safeZoneInstance3.y=100
whitecar = new car1();
stage.addChild(whitecar);
whitecar.x = 300;
whitecar.y = 500
whitecar1 = new car1();
stage.addChild(whitecar1);
whitecar1.x = 550;
whitecar1.y = 480
whitecar2 = new car1();
stage.addChild(whitecar2);
whitecar2.x = 50;
whitecar2.y = 480
truck1 = new truck_sprite();
stage.addChild (truck1);
truck1.x = 1000;
truck1.y = 430
truck2 = new truck_sprite();
stage.addChild (truck2);
truck2.x = 300;
truck2.y = 430
redcar = new car_sprite();
stage.addChild (redcar);
redcar.x = 300;
redcar.y = 340
redcar2 = new car_sprite();
stage.addChild (redcar2);
redcar2.x = 100;
redcar2.y = 375
redcar3 = new car_sprite();
stage.addChild (redcar3);
redcar3.x = 500;
redcar3.y = 375
log1 = new log_sprite();
stage.addChild(log1);
log1.x = 300;
log1.y = 230
log2 = new log_sprite();
stage.addChild(log2);
log2.x = 100;
log2.y = 150
log3 = new log_sprite();
stage.addChild(log3);
log3.x = 500;
log3.y = 150
letters = new Letters();
letters.x = randomRange(100,500) ;
letters.y = randomRange(100,500);
stage.addChild(letters);
letters2 = new Letters_2();
letters2.x = randomRange(100,500) ;
letters2.y = randomRange(100,500);
stage.addChild(letters2);
letters3 = new Letters_3();
letters3.x = randomRange(100,500) ;
letters3.y = randomRange(100,500);
stage.addChild(letters3);
letters4 = new Letters_4();
letters4.x = randomRange(100,500) ;
letters4.y = randomRange(100,500);
stage.addChild(letters4);
frog_spriteInstance = new frog_sprite();
stage.addChild(frog_spriteInstance);
frog_spriteInstance.x=300;
frog_spriteInstance.y=550;
health = new HealthBar();
stage.addChild(health);
health.x = 130;
health.y = 20;
health.width = 100;
stage.addEventListener(KeyboardEvent.KEY_DOWN, moveFrog);
stage.addEventListener(Event.ENTER_FRAME, movecars);
stage.addEventListener(Event.ENTER_FRAME, movetrucks);
stage.addEventListener(Event.ENTER_FRAME, moveredcars);
stage.addEventListener(Event.ENTER_FRAME, movelogs);
stage.addEventListener(Event.ENTER_FRAME,checkforcollision);
mysound.play();
}
public function moveFrog(e:KeyboardEvent)
{
// get the key pressed and then move the player
{
if (e.keyCode == Keyboard.UP)
{
frog_spriteInstance.rotation = 0;
frog_spriteInstance.y -= 50;
}
if (e.keyCode == Keyboard.DOWN)
{
frog_spriteInstance.rotation = 180;
frog_spriteInstance.y += 50;
}
if (e.keyCode == Keyboard.LEFT)
{
frog_spriteInstance.rotation = -90;
frog_spriteInstance.x -= 50;
}
if (e.keyCode == Keyboard.RIGHT)
{
frog_spriteInstance.rotation = 90;
frog_spriteInstance.x += 50;
}
}
}
function movecars(event:Event)
{
//move cars across screen and when they disappear, reappear at the other side
whitecar.x -= 3;
if (whitecar.x<-100){
whitecar.x=650;
}
whitecar1.x -= 3;
if (whitecar1.x<-100){
whitecar1.x=650;
}
whitecar2.x -= 3;
if (whitecar2.x<-100){
whitecar2.x=650;
}
}
function movelogs(event:Event)
{
//move logs across screen and when they disappear, reappear at the other side
log1.x -= 5;
if (log1.x<-100){
log1.x=650;
}
log2.x -= 5;
if (log2.x<-100){
log2.x=650;
}
log3.x -= 5;
if (log3.x<-100){
log3.x=650;
}
}
function movetrucks(event:Event)
{
//move trucks across screen and when they disappear, reappear at the other side
truck1.x +=3;
if (truck1.x>650){
truck1.x=-100;
}
truck2.x +=3;
if (truck2.x>650){
truck2.x=-100;
}
}
function moveredcars(event:Event)
{
//move red cars across screen and when they disappear, reappear at the other side
redcar.x +=3;
if (redcar.x>650){
redcar.x=-100;
}
redcar2.x +=3;
if (redcar2.x>650){
redcar2.x=-100;
}
redcar3.x +=3;
if (redcar3.x>650){
redcar3.x=-100;
}
}
function checkforcollision(event:Event)
{
//check for collisions
if (frog_spriteInstance.hitTestObject(log1) || (frog_spriteInstance.hitTestObject(log2) || (frog_spriteInstance.hitTestObject(log3) || (frog_spriteInstance.hitTestObject(whitecar) || (frog_spriteInstance.hitTestObject(whitecar1) || (frog_spriteInstance.hitTestObject(whitecar2) || (frog_spriteInstance.hitTestObject(log2) || (frog_spriteInstance.hitTestObject(truck1) || (frog_spriteInstance.hitTestObject(truck2) || (frog_spriteInstance.hitTestObject(redcar) || (frog_spriteInstance.hitTestObject(redcar2) || (frog_spriteInstance.hitTestObject(redcar3))))))))))))){
//reset frog if hits an obstacle
stage.addChild(frog_spriteInstance);
frog_spriteInstance.x=300;
frog_spriteInstance.y=550;
//reduce health bar
health.width -= 10;
}
//remove event listeners when health is empty
if (health.width == 0){
stage.removeEventListener(Event.ENTER_FRAME, movecars);
stage.removeEventListener(KeyboardEvent.KEY_DOWN, moveFrog);
stage.removeEventListener(Event.ENTER_FRAME, movetrucks);
stage.removeEventListener(Event.ENTER_FRAME, moveredcars);
stage.removeEventListener(Event.ENTER_FRAME, movelogs);
}
//add letters to bottom of screen when hit correctly
if (frog_spriteInstance.hitTestObject(letters)){
stage.addChild(frog_spriteInstance);
frog_spriteInstance.x=300;
frog_spriteInstance.y=550;
stage.removeChild(letters);
firstletter = new firstLetter();
stage.addChild(firstletter);
firstletter.x=345;
firstletter.y=600;
}
if (frog_spriteInstance.hitTestObject(letters2)){
stage.addChild(frog_spriteInstance);
frog_spriteInstance.x=300;
frog_spriteInstance.y=550;
stage.removeChild(letters2);
secondletter = new secondLetter();
stage.addChild(secondletter);
secondletter.x=206;
secondletter.y=600;
}
if (frog_spriteInstance.hitTestObject(letters3)){
stage.addChild(frog_spriteInstance);
frog_spriteInstance.x=300;
frog_spriteInstance.y=550;
stage.removeChild(letters3);
thirdletter = new thirdLetter();
stage.addChild(thirdletter);
thirdletter.x=273;
thirdletter.y=600;
}
if (frog_spriteInstance.hitTestObject(letters4)){
stage.addChild(frog_spriteInstance);
frog_spriteInstance.x=300;
frog_spriteInstance.y=550;
stage.removeChild(letters4);
health.width -= 10;
fourthletter = new fourthLetter();
stage.addChild(fourthletter);
fourthletter.x=25;
fourthletter.y=620;
}
}
function randomRange(minNum:Number, maxNum:Number):Number
{
//random generator for letter positioning
return (Math.floor(Math.random() * (maxNum - minNum + 1)) + minNum);
}
}
}
我的代码也很不可靠，所以任何改进的建议都是非常欢迎的。
要从两个任意显示对象执行像素完美命中测试，您必须将它们绘制为位图并使用BitmapData/hitTest()。
下面是一个通用函数:
function hitTestShapes(object1:DisplayObject, object2:DisplayObject, threshold:uint = 1):Boolean {
var bounds1:Rectangle = object1.getBounds(object1.parent);
var matrix1:Matrix = object1.transform.matrix;
matrix1.tx = object1.x - bounds1.x;
matrix1.ty = object1.y - bounds1.y;
var bmp1:BitmapData = new BitmapData(bounds1.width, bounds1.height, true, 0);
bmp1.draw(object1, matrix1);
var bounds2:Rectangle = object2.getBounds(object2.parent);
var matrix2:Matrix = object2.transform.matrix;
matrix2.tx = object2.x - bounds2.x;
matrix2.ty = object2.y - bounds2.y;
var bmp2:BitmapData = new BitmapData(bounds2.width, bounds2.height, true, 0);
bmp2.draw(object2, matrix2);
return bmp1.hitTest(bounds1.topLeft, threshold, bmp2, bounds2.topLeft, threshold);
}
注意，不过，绘制到位图是相当慢的，所以要小心不要过度使用这种功能，否则你会有性能问题。事实上，首先使用hitTestObject()是一个好主意，它非常快并检测边界框交叉点，然后只调用hitTestShapes()来完善您的检查。换句话说:
if (frog_spriteInstance.hitTestObject(log1) && hitTestShapes(frog_spriteInstance, log1)) { }
对于代码的建议，通过数组、循环和函数有很多重复数据删除的可能性。例如，与其将所有对象定义为单独的变量，不如将它们全部存储在数组(或向量)中:
public var safeZones:Array = [];
public var obstacles:Array = [];
public var letters:Array = [];
要填充数组，您可以将值压入其中，并使用一个函数来合并所有重复的对象设置代码:
(代码约定注意:类名使用"UpperCamelCase")
public function Main(){
addSafeZone(300, 545);
addSafeZone(300, 300);
addSafeZone(300, 100);
addObstacle(WhiteCar, 300, 500);
addObstacle(WhiteCar, 550, 480);
addObstacle(WhiteCar, 50, 480);
addObstacle(Truck, 1000, 430);
addObstacle(Truck, 300, 430);
addObstacle(RedCar, 300, 340);
addObstacle(RedCar, 100, 375);
addObstacle(RedCar, 500, 375);
addObstacle(Log, 300, 230);
addObstacle(Log, 100, 150);
addObstacle(Log, 500, 150);
addRandomLetters(Letters_1);
addRandomLetters(Letters_2);
addRandomLetters(Letters_3);
addRandomLetters(Letters_4);
}
private function addSafeZone(x:Number, y:Number):void {
var safeZone:SafeZone = new SafeZone();
stage.addChild(safeZone);
safeZone.x = x;
safeZone.y = y
safeZones.push(safeZone);
}
private function addObstacle(spriteClass:Class, x:Number, y:Number):void {
var obstacle:Sprite = new spriteClass();
stage.addChild(obstacle);
obstacle.x = x;
obstacle.y = y
obstacles.push(obstacle);
}
private function addRandomLetters(lettersClass:Class):void {
var lettersSprite:Sprite = new lettersClass();
lettersSprite.x = randomRange(100, 500);
lettersSprite.y = randomRange(100, 500);
stage.addChild(lettersSprite);
letters.push(lettersSprite);
}
现在可以遍历数组来执行所有操作。例如，检查是否命中任何障碍物:
for each(var obstacle:DisplayObject in obstacles){
if(frog.hitTestObject(obstacle) && hitTestShapes(frog, obstacle)){
// The frog hit an obstacle!
}
}
你也可以把我们所有的"移动"函数组合成一个，它根据每个障碍物的类型移动它们:
private function moveObstacles(e:Event):void {
for each(var obstacle in obstacles){
if(obstacle is WhiteCar){
obstacle.x -= 3;
}
else if(obstacle is RedCar){
obstacle.x += 3;
}
else if(obstacle is Truck){
obstacle.x += 3;
}
else if(obstacle is Log){
obstacle.x -= 5;
}
if(obstacle.x < -100){
obstacle.x = 650;
}
else if(obstacle.x > 650){
obstacle.x = -100;
}
}
}
最后，您实际上只需要一个ENTER_FRAME处理程序。从这里调用你想要的任何函数。添加多个ENTER_FRAME处理程序可能会变得难以管理。例如，只需这样做:
addEventListener(Event.ENTER_FRAME, update);
private function update(e:Event):void {
moveObstacles();
doOtherStuff();
anythingYouNeedToDo();
}
这样你只需要removeEventListener(Event.ENTER_FRAME, update)来停止游戏，而不是一堆ENTER_FRAME处理程序。
我还没有测试过这些代码，但是您可以得到大致的想法。如果你有任何问题，请告诉我，我可以帮忙。