Hi , I’ve been having some trouble with a 2d platform game that I’ve been working on for the past week. I used some code from a few tutorials and have basic left and right movement and some collisions. My main problem is that when i jump on a block and walk off it the player doesn’t fall. Here is my code. I’m using actionscript 3.0 in flash cs3.
Here’s the code from my as file, sorry if its a little long.
package
{
import flash.display.MovieClip;
import flash.display.*;
import flash.events.*;
import flash.events.MouseEvent;
import flash.media.Sound;
//needed to add this in to make the dynamic textfield on stage work
import flash.text.TextField;
public class MainStart extends MovieClip
{
var leftKeyDown:Boolean;
var upKeyDown:Boolean;
var rightKeyDown:Boolean;
var downKeyDown:Boolean;
var mainOnGround:Boolean = false;
//============================
//the main character's speed
//============================
var mainSpeed:Number;
//=======================================
//whether or not the main guy is jumping
//=======================================
var mainJumping:Boolean;
//=======================================
//how quickly should the jump start off
//=======================================
var jumpSpeedLimit:int;
//================================
//the current speed of the jump;
//================================
var jumpSpeed:Number;
//=================================
// declares player movieclip var
//=================================
var mcMain:MovieClip;
var background1:MovieClip;
var background2:MovieClip;
var background3:MovieClip;
//=================================
// declares level movieclip var
//=================================
var gamelevel:MovieClip;
var blockcount:Number = 0;
var platformcount:Number = 0;
var thenum:Number = 0;
private var fixedObjects:Array;
private var rotating_platforms:Array;
public function MainStart()
{
init();
}
function randNum(minNum:Number, maxNum:Number):Number
{
return Math.round(Math.random() * maxNum - minNum) + minNum;
}
function init():void
{
leftKeyDown = false;
upKeyDown = false;
rightKeyDown = false;
downKeyDown = false;
mainSpeed = 7;
mainJumping = false;
jumpSpeedLimit = 15;
jumpSpeed = 0;
background3 = new lvl1bkgd3();
background3.x = 0;
background3.y = 0;
addChild(background3);
background2 = new lvl1bkgd2();
background2.x = -600;
background2.y = 0;
addChild(background2);
background1 = new lvl1bkgd1();
background1.x = -800;
background1.y = -150;//471;
addChild(background1);
gamelevel = new myFirstLevel();
gamelevel.x = 0;
gamelevel.y = 0;
addChild(gamelevel);
mcMain = new mcPlayer();
mcMain.x = 446;
mcMain.y = 360;
addChild(mcMain);
examineLevel();
trace(fixedObjects[0].topside);
trace(gamelevel.x);
mcMain.addEventListener(Event.ENTER_FRAME, moveChar);
stage.addEventListener(KeyboardEvent.KEY_DOWN, checkKeysDown);
stage.addEventListener(KeyboardEvent.KEY_UP, checkKeysUp);
}
//------------------------------------------------------------
// Function: examineLevel
// this function loads all level objects into arrays
//------------------------------------------------------------
public function examineLevel()
{
fixedObjects = new Array();
rotating_platforms = new Array();
for (var i:int=0; i<this.gamelevel.numChildren; i++)
{
var mc = this.gamelevel.getChildAt(i);
// add bricks and platforms to fixedObjects
if ((mc is bricks) || (mc is platform))
{
var floorObject:Object = new Object();
blockcount = blockcount + 1;
floorObject.mc = mc;
floorObject.leftside = mc.x;
floorObject.rightside = mc.x+mc.width;
floorObject.topside = mc.y;
floorObject.bottomside = mc.y+mc.height;
trace("block#",blockcount, "x:",mc.x, " y:", mc.y);
fixedObjects.push(floorObject);
}
}
for (var i:int=0; i<this.gamelevel.numChildren; i++)
{
var mc = this.gamelevel.getChildAt(i);
// add rotating_platform to fixedObjects
if (mc is a_rotating_platform)
{
var rotatingObject:Object = new Object();
platformcount = platformcount + 1;
rotatingObject.mc = mc;
trace("platform#",platformcount, "x:",rotatingObject.mc.x, " y:", rotatingObject.mc.y);
rotating_platforms.push(rotatingObject);
}
}
}
//----------------------------------------------------------------------------------------------------
// Function: moveChar
//----------------------------------------------------------------------------------------------------
function moveChar(event:Event):void
{
if (leftKeyDown)
{
//trace(mainSpeed);
mcMain.x -= mainSpeed;
mcMain.scaleX = 1;
}
if (rightKeyDown)
{
mcMain.x += mainSpeed;
mcMain.scaleX = -1;
}
if (upKeyDown || mainJumping)
{
mainJump();
}
thenum = thenum + 1;
//--------------------------------------------------
// this code rotates the platforms
//--------------------------------------------------
for (var i:int = 0; i<rotating_platforms.length; i++)
{
rotating_platforms*.mc.rotate0.topside = rotating_platforms*.mc.rotate0.y + rotating_platforms*.mc.y ;
rotating_platforms*.mc.rotate0.bottomside = rotating_platforms*.mc.rotate0.y + rotating_platforms*.mc.rotate0.height + rotating_platforms*.mc.y;
rotating_platforms*.mc.theBlock.topside = rotating_platforms*.mc.theBlock.y;
rotating_platforms*.mc.theBlock.bottomside = rotating_platforms*.mc.theBlock.y + rotating_platforms*.mc.theBlock.height;
rotating_platforms*.mc.theBlock.leftside = rotating_platforms*.mc.theBlock.x - rotating_platforms*.mc.theBlock.width / 2;
rotating_platforms*.mc.theBlock.rightside = rotating_platforms*.mc.theBlock.x + rotating_platforms*.mc.theBlock.width / 2;
rotating_platforms*.mc.rotate0.y = 208 * Math.sin(.05 * thenum) ;
rotating_platforms*.mc.rotate0.x = 208 * Math.cos(.05 * thenum) ;
rotating_platforms*.mc.rotate1.y = 192 * Math.sin(.05 * thenum) ;
rotating_platforms*.mc.rotate1.x = 192 * Math.cos(.05 * thenum) ;
rotating_platforms*.mc.rotate2.y = 160 * Math.sin(.05 * thenum) ;
rotating_platforms*.mc.rotate2.x = 160 * Math.cos(.05 * thenum) ;
rotating_platforms*.mc.rotate3.y = 128 * Math.sin(.05 * thenum) ;
rotating_platforms*.mc.rotate3.x = 128 * Math.cos(.05 * thenum) ;
rotating_platforms*.mc.rotate4.y = 96 * Math.sin(.05 * thenum) ;
rotating_platforms*.mc.rotate4.x = 96 * Math.cos(.05 * thenum) ;
rotating_platforms*.mc.rotate5.y = 64 * Math.sin(.05 * thenum) ;
rotating_platforms*.mc.rotate5.x = 64 * Math.cos(.05 * thenum) ;
rotating_platforms*.mc.rotate6.y = 32 * Math.sin(.05 * thenum) ;
rotating_platforms*.mc.rotate6.x = 32 * Math.cos(.05 * thenum) ;
}
for (var i:int = 0; i<fixedObjects.length; i++)
{
var hitBlock = fixedObjects*;
if (mcMain.hitTestObject(hitBlock.mc) && mcMain.x -gamelevel.x < hitBlock.leftside)
{
trace("leftside collision");
mcMain.x = (hitBlock.leftside - (mcMain.width / 2))+gamelevel.x - 1;
}
if (mcMain.hitTestObject(hitBlock.mc) && mcMain.x -gamelevel.x > hitBlock.rightside)
{
trace("rightside collision");
mcMain.x = (hitBlock.rightside + (mcMain.width / 2))+gamelevel.x + 1;
}
}
//============================================================
// check collisions for rotating_platforms
//============================================================
for (var i:int = 0; i<rotating_platforms.length; i++)
{
var hitBlock = rotating_platforms*.mc.rotate0;
//trace(hitBlock.mc.x + " " + hitBlock.mc.y)
if (mcMain.hitTestObject(hitBlock) && mcMain.y < hitBlock.topside)
{
trace("TOP1");
mainOnGround = false;
mainJumping = false;
mcMain.y = hitBlock.topside - mcMain.height/2;// - 1;
//break;
}
if (mcMain.hitTestObject(hitBlock) && mcMain.y > hitBlock.bottomside)
{
trace("BOTTOM1");
mainOnGround = false;
mainJumping = false;
mcMain.y = hitBlock.bottomside + mcMain.height/2;// + 1;
}
}
for (var i:int = 0; i<fixedObjects.length; i++)
{
var hitBlock = fixedObjects*;
if (mcMain.hitTestObject(hitBlock.mc) && mcMain.y < hitBlock.mc.y)
{
mainOnGround = true;
break;
}
mainOnGround = false;
}
if (!mainOnGround)
{
//mainJumping = true;
}
scroll();
}
//----------------------------------------------------------------------------------------------------
// Function: scroll
//----------------------------------------------------------------------------------------------------
public function scroll():void
{
var rightEdge:Number = 500;
var leftEdge:Number = 100;
if ((mcMain.x > rightEdge) && (gamelevel.x > (-gamelevel.width + stage.stageWidth)))
{
mcMain.x = rightEdge;
gamelevel.x += -mainSpeed;
background1.x += .66 * -mainSpeed;
if (background1.x < -1600)
{
background1.x = -800;
trace("just reset background1 position");
}
background2.x += .33 * -mainSpeed;
if (background2.x < -1200)
{
background2.x = -600;
}
background3.x += 0 * -mainSpeed;
if (background3.x < -1200)
{
background3.x = -600;
}
if (gamelevel.x < (-1*(gamelevel.width - stage.stageWidth)))
{
gamelevel.x = (-1*(gamelevel.width - stage.stageWidth));
//trace("gamelevel.x " + gamelevel.x);
}
}
if ((mcMain.x < leftEdge) && (gamelevel.x < 0))
{
mcMain.x = leftEdge;
gamelevel.x += mainSpeed;
background1.x += .66 * mainSpeed;
if (background1.x > 0)
{
background1.x = -800;
trace("just reset background1 position");
}
background2.x += .33 * mainSpeed;
if (background2.x > 0)
{
background2.x = -600;
}
background3.x += 0 * mainSpeed;
if (background3.x > 0)
{
background3.x = -600;
}
if (gamelevel.x > 0)
{
gamelevel.x = 0;
}
}
}
//----------------------------------------------------------------------------------------------------
// Function: checkKeysDown
//----------------------------------------------------------------------------------------------------
function checkKeysDown(event:KeyboardEvent):void
{
if (event.keyCode == 37 || event.keyCode == 65)
{
leftKeyDown = true;
}
if (event.keyCode == 38 || event.keyCode == 87)
{
upKeyDown = true;
}
if (event.keyCode == 39 || event.keyCode == 68)
{
rightKeyDown = true;
}
if (event.keyCode == 40 || event.keyCode == 83)
{
downKeyDown = true;
}
}
//----------------------------------------------------------------------------------------------------
// Function: checkKeysUp
//----------------------------------------------------------------------------------------------------
function checkKeysUp(event:KeyboardEvent):void
{
if (event.keyCode == 37 || event.keyCode == 65)
{
leftKeyDown = false;
}
if (event.keyCode == 38 || event.keyCode == 87)
{
upKeyDown = false;
}
if (event.keyCode == 39 || event.keyCode == 68)
{
rightKeyDown = false;
}
if (event.keyCode == 40 || event.keyCode == 83)
{
downKeyDown = false;
}
}
//----------------------------------------------------------------------------------------------------
// Function: mainJump
//----------------------------------------------------------------------------------------------------
function mainJump():void
{
//trace("hello3");
//===============================
//if main isn't already jumping
//===============================
//trace("in mainJump()");
if (!mainJumping)
{
//trace("hello4");
mainJumping = true;
jumpSpeed = jumpSpeedLimit*-1;
mcMain.y += jumpSpeed;
}
else
{
//============================================
//continue jumping if already in the air
//============================================
if (jumpSpeed < 0)
{
//trace("hello2");
//jumpSpeed *= 1 - jumpSpeedLimit/125;
jumpSpeed *= 1 - jumpSpeedLimit/200;
if (jumpSpeed > -jumpSpeedLimit/5)
{
jumpSpeed *= -1;
}
}
trace("jumpSpeed: " + jumpSpeed);
trace("jumpSpeedLimit: " + jumpSpeedLimit);
if (jumpSpeed > 0 && jumpSpeed <= jumpSpeedLimit)
{
//trace("hello");
jumpSpeed *= 1 + jumpSpeedLimit/50;
//trace("the jumpSpeed is: " + jumpSpeed);
}
//trace("hello5");
mcMain.y += jumpSpeed;
//============================================================
// check collisions for fixed objects
//============================================================
for (var i:int = 0; i<fixedObjects.length; i++)
{
var hitBlock = fixedObjects*;
if (mcMain.hitTestObject(hitBlock.mc) && mcMain.y < hitBlock.topside)
{
trace("hitBlock.topside collision");
mainOnGround = false;
mainJumping = false;
mcMain.y = hitBlock.topside - mcMain.height/2;
//break;
}
if (mcMain.hitTestObject(hitBlock.mc) && mcMain.y > hitBlock.bottomside)
{
trace("hitBlock.bottomside collision");
mainOnGround = false;
mainJumping = false;
mcMain.y = hitBlock.bottomside + mcMain.height/2;
}
}
//============================================================
// check collisions for rotating_platforms
//============================================================
for (var i:int = 0; i<rotating_platforms.length; i++)
{
var hitBlock = rotating_platforms*.mc.rotate0;
//trace(hitBlock.mc.x + " " + hitBlock.mc.y)
if (mcMain.hitTestObject(hitBlock) && mcMain.y < hitBlock.topside)
{
trace("TOP");
mainOnGround = false;
mainJumping = false;
mcMain.y = hitBlock.topside - mcMain.height/2;
}
if (mcMain.hitTestObject(hitBlock) && mcMain.y > hitBlock.bottomside)
{
trace("BOTTOM");
mainOnGround = false;
mainJumping = false;
mcMain.y = hitBlock.bottomside + mcMain.height/2;// + 1;
}
}
}
}
}
}
