Hi,
I am seriously confused, I am trying to get my head around collision detection, I had used a technique discussed at seb.ly for frame independent collision detection. I decided to test it out with a simple collision based game. Breakout! where there is a bat a ball and 3 walls I got all of that working really well, until I tried to do it for the blocks I want it to find the collisions on all 4 sides and react accordingly. I would either like a tutorial where someone explains the logic etc or if some could look at my code and point out where I am going wrong.
This is my code: all the objects are on the stage, i.e. bat, ball, leftWall, rightWall, block1, block2, block3, etc
This is my code:
package {
import flash.display.MovieClip;
import flash.events.KeyboardEvent;
import flash.display.Stage;
import flash.events.Event;
import flash.events.*;
import flash.display.*;
public class Main extends MovieClip {
public var gravity:Number = 1;
public var restitution:Number = 0.6;
public var friction:Number = 0.9;
public var velX = -5;
public var velY = 5;
public var numberOfBlocks = 10;
function Main() {
init();
}
function init() {
stage.addEventListener( KeyboardEvent.KEY_DOWN, keyDownHandler);
stage.addEventListener(Event.ENTER_FRAME,gameLoop);
}
function keyDownHandler(kb:KeyboardEvent) {
if ((bat.x>0)&&(bat.x<300)) {
if (kb.keyCode==37) {
bat.x-=10;
kb.updateAfterEvent();
}
if (kb.keyCode==39) {
bat.x+=10;
kb.updateAfterEvent();
}
}
}
function testBlocksCollisions() {
for (var i:int = 0; i<10; i++) {
if (getChildByName('block'+i)!=null) {
var myClip:MovieClip = getChildByName('block'+i) as MovieClip;
var myBottom = myClip.y//-(myClip.height);
var myTop = myClip.y;
var myRight= myClip.x+myClip.width;
var myLeft = myClip.x;
var myClipX = myClip.x;
var myClipY = myClip.y;
var ballY = ball.y;
var ballX = ball.x;
var radius = ball.width/2;
var distanceY = myClipY-(ballY+radius);
var timeHitY = distanceY / velY;
var distanceX = myClipX-(ballX+radius);
var timeHitX = distanceX / velX;
if (timeHitX>=0&&timeHitX<1) {
trace('((ballY>myTop)&&(ballY<myBottom)): ' +((ballY>myTop)&&(ballY<myBottom-20)))
if ((ballY>myTop)&&(ballY<myBottom)) {
trace('ballX: ' + ballX);
trace('myLeft: ' + myLeft);
if ((ballX<myLeft)) {
trace('.............................Left.........................');
ballX += (velX*timeHitX);
removeChild(myClip);
velX*= -1;
return;
}
if ((ballX+(myRight.height)>=myRight)) {
trace('.............................Right.............................');
ballX += (velX*timeHitX);
velX*= -1;
removeChild(myClip);
return;
}
}
}
if ((timeHitY>=0)&&(timeHitY<=1)) {
trace('HITY-----------------------')
if (ballX>myLeft&&ballX<myRight) {
if ((ballY+(ball.height/2)>=myBottom)) {
trace('**********************************Bottom**********************************');
ballY += (velY*timeHitX);
velY*= -1;
removeChild(myClip);
return;
}
if ((ballY<=myTop)) {
trace('ballY: ' + ballY);
trace('myBottom: ' + myBottom);
trace('**********************************Top**********************************');
ballY += (velY*timeHitX);
velY*= -1;
removeChild(myClip);
return;
}
}
}
}
}
}
function gameLoop(e:Event) {
//findNumberOfBlocks();
moveBall();
checkCollisionBallLeftWall();
checkCollisionBallRightWall();
collisionWithBat();
checkCollisionWithTop();
testBlocksCollisions();
}
function moveBall() {
ball.x+=velX;
ball.y+=velY;
}
function checkCollisionWithTop() {
if (ball.y<4) {
velY*=-1;
}
}
function collisionWithBat() {
var batY = bat.y;
var ballY = ball.y;
var radius = ball.width/2;
var distance = batY-(ballY+radius);
var timeHit = distance / velX;
if ((timeHit>=0)&&(timeHit<1)) {
ballY += (velY*timeHit);
if ((ball.x>=bat.x)&&(ball.x<=bat.x+bat.width)) {
velY*= -1;
}
}
}
function checkCollisionBallRightWall() {
var wallX = rightWall.x;
var ballX = ball.x;
var radius = ball.width/2;
var distance = wallX-(ballX+radius);
var timeHit = distance / velX;
if ((timeHit>=0)&&(timeHit<1)) {
ballX += (velX*timeHit);
velX*= -1;
}
}
function checkCollisionBallLeftWall() {
var wallX = leftWall.x;
var ballX = ball.x;
var radius = ball.width/2;
var distance = wallX-(ballX+radius);
var timeHit = distance / velX;
if ((timeHit>=0)&&(timeHit<1)) {
ballX += (velX*timeHit);
velX*= -1;
}
}
}
}
thank you in advance
