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Comments for Jump and Run Demo w/Moving Platform

Return to Jump and Run Demo w/Moving Platform

A new version of this scenario was uploaded on Tue Apr 15 01:26:41 UTC 2014
Arthur114Arthur114

2014/4/15

thank you !
Arthur114Arthur114

2014/4/15

that will help me in the future, but for now i have solved my problem by adding huge platform on the ground.
Entity1037Entity1037

2014/4/15

I got my player stuck between the wall of the scenario and the moving platform...
A new version of this scenario was uploaded on Tue Apr 15 19:38:21 UTC 2014
danpostdanpost

2014/4/15

@Entity1037, fixed. I added collision detection to the What (platform) class.
docinkcdocinkc

2014/6/8

I tried writing this code to my game and i got an error message under the What class with the this(0); it was saying that "call to this must first statement in constructor",
danpostdanpost

2014/6/8

@docinkc, start a new discussion thread and using the 'code' tag below the input box to insert the problem code. Include a brief explanation of the problem.
AbidaKhanAbidaKhan

2014/9/15

Hi...i am a newbie....Can anyone pleas tell me how to download this demo?
fejfofejfo

2015/2/22

u can't unless he posts it with sorce
A new version of this scenario was uploaded on 2017-12-19 17:46:13 UTC
A new version of this scenario was uploaded on 2017-12-19 17:52:51 UTC
A new version of this scenario was uploaded on 2017-12-19 18:11:32 UTC
danpostdanpost

2017/12/19

Now, updated for HTML 5.
Super_HippoSuper_Hippo

2017/12/19

Is it just me or is the escape button not working with HTML 5? For example in this scenario, I can't leave the code view with escape. (x works). Not sure if this was always the case, but right now, it doesn't seem to work.
danpostdanpost

2017/12/20

@Hippo, escape works for me in HTML5.
Super_HippoSuper_Hippo

2017/12/20

Okay, maybe that's only a problem with Edge and Internet Explorer then.
Nice Game! I like how the code is as simple as possible for a very common game type. Thank you!
saw444saw444

2022/10/5

Why is he not jumping? import greenfoot.*; // (World, Actor, GreenfootImage, Greenfoot and MouseInfo) /** * Write a description of class Dante here. * * @author (your name) * @version (a version number or a date) */ public class Dante extends Actor { /** * Act - do whatever the Dante wants to do. This method is called whenever * the 'Act' or 'Run' button gets pressed in the environment. */ static final int gravity = 2; static final int jumpForce = 30; int xSpeed = 4; int ySpeed = 0; public void act() { // Add your action code here. moveHorizontal(); } public void moveHorizontal() { int worldWidth = getWorld().getWidth(); int myWidth = getImage().getWidth(); int dx = 0; if(Greenfoot.isKeyDown("a")) dx--; if(Greenfoot.isKeyDown("d")) dx++; setLocation(getX()+dx*xSpeed, getY()); } private void moveVertically() { int worldHeight = getWorld().getHeight(); int myHeight = getImage().getHeight(); boolean onGround = false; ySpeed += gravity; setLocation(getX(), getY()+ySpeed); if(getY() > worldHeight-myHeight/2) { ySpeed = 0; onGround = true; } if(onGround && Greenfoot.isKeyDown("w")) { ySpeed =-jumpForce; } } }
saw444saw444

2022/10/5

ah i know why
WkotWkot

2023/2/19

hey could you please explain to me what this: worldHeight-myHeight/2 does, thanks
danpostdanpost

2023/2/19

@Wkot, to prevent the Who actor from sinking below the bottom of the screen, its y-coordinate must be kept below a point in the world that is half the actor's image height less than the world height. That expression gives that y-coordinate of the line that the center of the actor is not allowed to go beyond in the downward direction.
WkotWkot

2023/2/19

ok, thank you very much
maxminkymaxminky

2023/5/19

I have implemented the same exact movement code in my game, however the actor floats on either end of the platform even though the plat form isn't that big. Its as if the platform is wide and the image is too small in either direction. Do you know what the fix could be.
danpostdanpost

2023/5/19

@maxminky, it is possible the your actor has excess transparency as well.