I want to make a game where lava chase the actor and the actor stay at the center of the background ( the background scrolling horizontally)
how to make something like that ?
Conscience wrote ...
2016/12/13
How to keep actor at the center
Conscience wrote...
I want to make a game where lava chase the actor and the actor stay at the center of the background ( the background scrolling horizontally)
how to make something like that ?danpost wrote...
Conscience wrote...
I want to make a game where lava chase the actor and the actor stay at the center of the background ( the background scrolling horizontally)
how to make something like that ?Conscience wrote...
can u explain me the code pls , im so confused right now :(import greenfoot.*;
/**
* CLASS: Scroller extend Object
* AUTHOR: danpost (greenfoot.org username)
* DATE: November 11, 2016
*
* DESCRIPTION: This is a support class for a scrolling world. It contains two constructors;
* one for unlimited scrolling and one for limited scrolling. Both constructors have an 'image'
* parameter. Because image manipulation can hog up CPU time, it is important to remember that
* it is better not to have a scrolling background image (having an Actor for the background is
* probably worse than having the background scroll). For unlimited scrolling using a background
* image, the smaller that background image to be tiled, the better. Making the viewport (the
* size of the world that is visible) smaller can help in CPU expense, also. Scrolling worlds
* should be unbounded, allowing actors to move beyond the visible area. Ensuring that actors
* are removed from the world if no longer needed when out of view will help to prevent lag,
* as well.
*
* It is the responsibility of the World object that creates a Scroller object to determine when
* to scroll and by how much.
*/
public class Scroller
{
private World world; // view window world
private GreenfootImage scrollImage; // scrolling image
private boolean limited;
private int scrolledX, scrolledY;
/**
* This constructor is for an unlimited scrolling world;
* If 'image' is null, the background will not change; else the given image is wrapped
*
* @param viewWorld the world that scrolling will be performed on
* @param image the background image that will be tiled, if needed, and wrap with scrolling
*/
public Scroller(World viewWorld, GreenfootImage image)
{
world = viewWorld;
scrollImage = image;
scroll(0, 0); // sets initial background image
}
/**
* This constructor is for a limited scrolling world;
* If 'image' is smaller than the given total scrolling area, it will be tiled
* If 'image' is null, the background will not change
*
* @param viewWorld the world that scrolling will be performed on
* @param image the background image that will be tiled, if needed, to fill the scrolling area
* @param wide the width of the visible area encompassed through scrolling;
* the given value must be at least equal to the width of 'viewWorld' and
* is given in world cells (not in pixels)
* @param high the height of the visible area encompassed through scrolling;
* the given value must be at least equal to the height of 'viewWorld' and
* is given in world cells (not in pixels)
*/
public Scroller(World viewWorld, GreenfootImage image, int wide, int high)
{
limited = true;
world = viewWorld;
if (image != null)
{
// create an image as large as scrolling area; tiled, if needeed
scrollImage = new GreenfootImage(wide*world.getCellSize(), high*world.getCellSize());
for (int x=0; x<wide*world.getCellSize(); x+= image.getWidth())
for (int y=0; y<high*world.getCellSize(); y+=image.getHeight())
scrollImage.drawImage(image, x, y);
// set initial background image
scroll(0, 0);
}
}
/**
* performs scrolling on 'world' by the given distances along the horizontal and vertical;
* if 'limited' is false, requested distances are actual scrolling distances;
* if 'limited' is true, the distances may be adjusted due to the limits of scrolling
*
* @param dsx the requested distance to shift everything horizontally
* @param dsy the requested distance to shift everything vertically
*/
public void scroll(int dsx, int dsy)
{
if (scrollImage != null)
{
if (limited)
{
// calculate limits of scrolling
int maxX = scrollImage.getWidth()/world.getCellSize()-world.getWidth();
int maxY = scrollImage.getHeight()/world.getCellSize()-world.getHeight();
// apply limits to distances to scroll
if (scrolledX+dsx < 0) dsx = -scrolledX;
if (scrolledX+dsx >= maxX) dsx = maxX-scrolledX;
if (scrolledY+dsy < 0) dsy = -scrolledY;
if (scrolledY+dsy >= maxY) dsy = maxY-scrolledY;
// update scroll positions
scrolledX += dsx;
scrolledY += dsy;
// adjust background image
world.getBackground().drawImage
(
scrollImage,
-scrolledX*world.getCellSize(),
-scrolledY*world.getCellSize()
);
}
else
{
// update scroll positions
scrolledX += dsx;
scrolledY += dsy;
// create working variables of scroll positions
int imageX = scrolledX*world.getCellSize();
int imageY = scrolledY*world.getCellSize();
// find a similar positive value for scroll positions
while (imageX < 0) imageX += 100*scrollImage.getWidth();
while (imageY < 0) imageY += 100*scrollImage.getHeight();
// get new starting positions for drawing 'scrollImage'
imageX = imageX%scrollImage.getWidth();
imageY = imageY%scrollImage.getHeight();
// create image of appropriate size and tile fill 'scrollImage' onto it
GreenfootImage hold = new GreenfootImage(scrollImage);
hold.drawImage(scrollImage, -imageX, -imageY);
if (imageX > 0) hold.drawImage(scrollImage, scrollImage.getWidth()-imageX, -imageY);
if (imageY > 0) hold.drawImage(scrollImage, -imageX, scrollImage.getHeight()-imageY);
if (imageX > 0 && imageY > 0)
hold.drawImage(scrollImage, scrollImage.getWidth()-imageX, scrollImage.getHeight()-imageY);
// set image to background of 'world'
world.setBackground(hold);
}
}
// adjust position of all actors (that can move with 'setLocation')
for (Object obj : world.getObjects(null))
{
Actor actor = (Actor) obj;
actor.setLocation(actor.getX()-dsx, actor.getY()-dsy);
}
}
/**
* getter method for the current total scrolled distance horizontally
*
* @return the current total offset of horizontal scrolling
*/
public int getScrolledX()
{
return scrolledX;
}
/**
* getter method for the current total scrolled distance vertically
*
* @return the current total offset of vertical scrolling
*/
public int getScrolledY()
{
return scrolledY;
}
}import greenfoot.*; // (World, Actor, GreenfootImage, Greenfoot and MouseInfo)
/**
* Write a description of class ScrollingWorld here.
*
* @author (your name)
* @version (a version number or a date)
*/
public class ScrollingWorld extends World
{
private Scroller scroller;
public ScrollingWorld()
{
scroller = new Scroller(this , new GreenfootImage("background.png"),1366,613);
}
public void act()
{
scroll();
}
private void scroll()
{
scroller.scroll(-5,0);
}
}
You are missing the 'super' call at the beginning of your ScrollingWorld constructor:
// starting at line 14
public ScrollingWorld()
{
super(600, 400, 1); // this line is missing (adjust view window size as needed)
scroller = ...danpost wrote...
Oh -- I also wanted to mention what to do with objects you do not want to be moved when scrolling. Add the following line to any class that creates those objects (usually counters, timers, buttons, maps, text messages or other types of gui components):
public void setLocation(int x, int y) { } public void setLocation(int x,int y)
{
//what should i put here ?
}Conscience wrote...
where i should put that method ? myworld (ScrollingWorld) creates that objects , so
public void setLocation(int x,int y)
{
//what should i put here ?
}how to keep my actor in the center of the screen while the background scroll ?
The tutorial explains how. Do not change the way the actor moves. Have the world determine when to scroll, which is triggered by the actor not being in the center of the screen. Code is even provided for that in the tutorial.this is my ScrollingWorld now
i need to make that Timer actor keep still ( fixed object) ..
what should i do to make it like that ?
my timer class
import greenfoot.*; // (World, Actor, GreenfootImage, Greenfoot and MouseInfo)
/**
* Write a description of class ScrollWorld here.
*
* @author (your name)
* @version (a version number or a date)
*/
public class ScrollWorld extends World
{
/**
* Constructor for objects of class ScrollWorld.
*
*/
Ground ground = new Ground();
Lava lava = new Lava();
Time time = new Time();
private int lavaAnimation = 0;
private Scroller scroller;
public ScrollWorld()
{
// Create a new world with 600x400 cells with a cell size of 1x1 pixels.
super(1366, 613, 1,false);
scroller = new Scroller(this, new GreenfootImage("Background.png"),5466,613);
prepare();
}
public void prepare()
{
addObject(ground,getWidth()/2,539);
addObject(lava,31,295);
addObject(time,88,23);
}
public void act()
{
lavaAnimation++;
LavaAnimation();
scroll();
}
private void LavaAnimation()
{
if ( lavaAnimation == 10 )
{
lava.setImage(new GreenfootImage("lava 1.png"));
}
else if ( lavaAnimation == 20 )
{
lava.setImage(new GreenfootImage("lava 2.png"));
}
else if ( lavaAnimation == 30 )
{
lava.setImage(new GreenfootImage("Lava 3.png"));
}
else if ( lavaAnimation == 40 )
{
lava.setImage(new GreenfootImage("lava 4.png"));
}
else if ( lavaAnimation == 50 )
{
lava.setImage(new GreenfootImage("lava 5.png"));
}
else if ( lavaAnimation == 60 )
{
lava.setImage(new GreenfootImage("lava 6.png"));
}
else if ( lavaAnimation == 70 )
{
lava.setImage(new GreenfootImage("lava 7.png"));
}
else if ( lavaAnimation == 80 )
{
lava.setImage(new GreenfootImage("lava 8.png"));
}
else if ( lavaAnimation == 90 )
{
lava.setImage(new GreenfootImage("lava 9.png"));
lavaAnimation = 0;
}
}
private void scroll()
{
scroller.scroll(5,0);
}
}
import greenfoot.*; // (World, Actor, GreenfootImage, Greenfoot and MouseInfo)
import java.awt.Color;
public class Time extends Actor
{
int time = 0;
int counter = 0;
public Time()
{
updateImage();
}
public void act()
{
counter++;
if ( counter >= 60 )
{
time += 1;
counter = 0;
}
updateImage();
Hold();
}
private void Hold()
{
setLocation(getX()+5,getY());
}
public void updateImage()
{
setImage(new GreenfootImage("Time Elapsed : "+time,24,Color.black,new Color(0,0,0,0)));
}
}
this is out of topic but i want to ask
how to make my actor animation jump up when i jump and jump down when i fall
when i make it like this
import greenfoot.*; // (World, Actor, GreenfootImage, Greenfoot and MouseInfo)
/**
* Write a description of class Rex here.
*
* @author (your name)
* @version (a version number or a date)
*/
public class Rex extends Actor
{
private boolean walking;
private boolean facingLeft;
private boolean isKeyPressed;
private int frame = 0;
private int vSpeed = 0;
private int jumpPower = 25;
private int acceleration = 2;
private int apexTimer;
private int xSpeed;
private int animationCounter = 0;
public boolean onTheGround;
public void Rex()
{
walking = false;
facingLeft = true;
}
public void act()
{
checkFall();
animationCounter++;
checkIdle();
move();
checkHit();
}
private void move ()
{
move(5);
if (Greenfoot.isKeyDown("space") && onGround())
{
jump();
}
if (Greenfoot.isKeyDown("down"))
{
setImage(new GreenfootImage("Crouch 1.png"));
}
onTheGround = false;
while(getOneObjectAtOffset(0, getImage().getHeight()/2+1, null)!=null)
{
setLocation(getX(), getY()-1);
onTheGround=true;
vSpeed=0;
}
//check above the actor
while(getOneObjectAtOffset(0, -getImage().getHeight()/2-1, null)!=null)
{
setLocation(getX(), getY()+1);
vSpeed = 0;
}
// check to right of actor
while(getOneObjectAtOffset(getImage().getWidth()/2+1, 0, null)!=null)
{
setLocation(getX()-1, getY());
xSpeed = 0;
}
// check to left of actor
while(getOneObjectAtOffset(-getImage().getWidth()/2-1, 0, null)!=null)
{
setLocation(getX()+1, getY());
xSpeed = 0;
}
}
private void walkRight()
{
int delay = 4;
walking = true;
facingLeft = false;
frame++;
if(frame== 1 * delay )
{
setImage(new GreenfootImage("Rex 1 Right.png"));
}
else if(frame== 2 * delay )
{
setImage(new GreenfootImage("Rex 2 Right.png"));
}
else if(frame==3 * delay )
{
setImage(new GreenfootImage("Rex 3 Right.png"));
}
else if(frame==4 * delay )
{
setImage(new GreenfootImage("Rex 4 Right.png"));
frame = 1;
}
}
private void walkLeft()
{
int delay = 4;
walking = true;
facingLeft = true;
frame++;
if(frame== 1 * delay)
{
setImage(new GreenfootImage("Rex 1.png"));
}
else if(frame== 2 * delay)
{
setImage(new GreenfootImage("Rex 2.png"));
}
else if(frame==3 * delay)
{
setImage(new GreenfootImage("Rex 3.png"));
}
else if(frame==4 * delay )
{
setImage(new GreenfootImage("Rex 4.png"));
frame = 1;
return;
}
}
public void checkFall()
{
if (onGround() )
{
vSpeed = 0;
}
else
{
fall();
}
}
public void jump()
{
setImage(new GreenfootImage("Jump Up.png"));
vSpeed = -jumpPower;
setLocation(getX(),getY()+vSpeed);
}
public void fall()
{
setImage(new GreenfootImage("Jump Down.png"));
setLocation(getX(),getY() + vSpeed);
vSpeed = vSpeed + acceleration;
}
public boolean onGround()
{
int rexHeight = getImage().getHeight();
int lookForGround = (int)(rexHeight/2) + 5;
Actor tanah = getOneObjectAtOffset(0,lookForGround,Ground.class);
if(tanah == null)
{
return false;
}
else
{
// moveToGround(tanah);
return true;
}
}
// public void moveToGround(Actor tanah)
// {
// int tanahHeight = tanah.getImage().getHeight();
// int newY = tanah.getY() - (tanahHeight + getImage().getHeight())/2;
// setLocation(getX(),newY);
// }
public void checkIdle()
{
if ( isKeyPressed == false && facingLeft == false && onGround())
{
setImage(new GreenfootImage("Rex Idle Right.png"));
}
if ( isKeyPressed == false && facingLeft == true && onGround())
{
setImage(new GreenfootImage("Rex Idle.png"));
}
}
public void checkHit()
{
Actor hit = getOneIntersectingObject(Lava.class);
if ( hit != null )
{
Greenfoot.playSound("GameOver.wav");
Greenfoot.stop();
}
}
}
You could check if vSpeed positive of negative. If it is negative, the actor moves up and the image can be the Jump Up image.
Super_Hippo wrote...
You could check if vSpeed positive of negative. If it is negative, the actor moves up and the image can be the Jump Up image.import greenfoot.*; // (World, Actor, GreenfootImage, Greenfoot and MouseInfo)
/**
* Write a description of class Rex here.
*
* @author (your name)
* @version (a version number or a date)
*/
public class Rex extends Actor
{
private boolean walking;
private boolean facingLeft;
private boolean isKeyPressed;
private int frame = 0;
private int vSpeed = 0;
private int jumpPower = 25;
private int acceleration = 2;
private int apexTimer;
private int xSpeed;
private int animationCounter = 0;
public boolean onTheGround;
public void Rex()
{
walking = false;
facingLeft = true;
}
public void act()
{
checkFall();
move();
checkHit();
Animation();
}
private void move ()
{
move(5);
if (Greenfoot.isKeyDown("space") && onGround())
{
jump();
}
if (Greenfoot.isKeyDown("down"))
{
setImage(new GreenfootImage("Crouch 1.png"));
}
//check above the actor
while(getOneObjectAtOffset(0, -getImage().getHeight()/2-1, null)!=null)
{
setLocation(getX(), getY()+1);
vSpeed = 0;
}
// check to right of actor
while(getOneObjectAtOffset(getImage().getWidth()/2+1, 0, null)!=null)
{
setLocation(getX()-1, getY());
xSpeed = 0;
}
// check to left of actor
// while(getOneObjectAtOffset(-getImage().getWidth()/2-1, 0, null)!=null)
// {
// setLocation(getX()+1, getY());
// xSpeed = 0;
// }
}
private void Animation()
{
int delay = 8;
walking = true;
facingLeft = false;
frame++;
if(frame== 1 * delay && vSpeed == 0)
{
setImage(new GreenfootImage("Rex 1 Right.png"));
}
else if(frame== 2 * delay && vSpeed == 0)
{
setImage(new GreenfootImage("Rex 2 Right.png"));
}
else if(frame==3 * delay && vSpeed == 0)
{
setImage(new GreenfootImage("Rex 3 Right.png"));
}
else if(frame==4 * delay && vSpeed == 0)
{
setImage(new GreenfootImage("Rex 4 Right.png"));
frame = 1;
}
if (vSpeed > 0 && !onGround() )
{
setImage(new GreenfootImage("Jump Down.png"));
}
else if (vSpeed < 0 )
{
setImage(new GreenfootImage("Jump Up.png"));
}
}
public void checkFall()
{
if (onGround() )
{
vSpeed = 0;
}
else
{
fall();
}
}
public void jump()
{
vSpeed = -jumpPower;
setLocation(getX(),getY()+vSpeed);
}
public void fall()
{
setLocation(getX(),getY() + vSpeed);
vSpeed = vSpeed + acceleration;
}
public boolean onGround()
{
int rexHeight = getImage().getHeight();
int lookForGround = (int)(rexHeight/2) + 5;
Actor tanah = getOneObjectAtOffset(0,lookForGround,Ground.class);
if(tanah == null)
{
return false;
}
else
{
// moveToGround(tanah);
return true;
}
}
// public void moveToGround(Actor tanah)
// {
// int tanahHeight = tanah.getImage().getHeight();
// int newY = tanah.getY() - (tanahHeight + getImage().getHeight())/2;
// setLocation(getX(),newY);
// }
public void checkIdle()
{
if ( isKeyPressed == false && facingLeft == false && onGround())
{
setImage(new GreenfootImage("Rex Idle Right.png"));
}
if ( isKeyPressed == false && facingLeft == true && onGround())
{
setImage(new GreenfootImage("Rex Idle.png"));
}
}
public void checkHit()
{
Actor hit = getOneIntersectingObject(Lava.class);
if ( hit != null )
{
Greenfoot.playSound("GameOver.wav");
Greenfoot.stop();
}
}
}
The problem is that your frame variable only gets reset if the vSpeed is at 0 when frame is 32. If not, the frame variable keeps increasing and will never match the conditions in the animation method anymore.
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