With circle being a reference to the CircleMeter object, you would use:

public void act() { if(shoot=true) { if(isTouching(Bird.class) || this.isAtEdge()) { removeTouching(ViralLoad.class); int x = circle.getArcX(); int y = circle.getArcY(); ViralLoad viralload = new ViralLoad(x,y); addObject(viralload,x, y); } } if(shoot=false) { int x = circle.getArcX(); int y = circle.getArcY(); ViralLoad viralload = new ViralLoad(x,y); addObject(viralload,x,y); } i did this and i get an error for the add objects and an error for the circles

Declare the variable ( circle ) to reference a CircleMeter object and assign it the one in the world.

CircleMeter circle = (CircleMeter) getWorld(); CircleMeter circle = CircleMeter.getCircle(); like this???

First line is good up to the semi-colon. Continue with a dot ( '.' ) and get the actor.

CircleMeter circle = (CircleMeter) getWorld().getActor(); i get a error with this

getActor is not a method provided by the World class (a World object is what getWorld returns, so you must use something from there).

The getObjects method is the one you will need.

CircleMeter circle = (CircleMeter)getWorld().getObjects(); I get a error with that says it cannot be applied to given types

Look at the World class API documentation to see how the method is used.

so i got it to show up im having trouble actually shooting it at an angle viralload class public class ViralLoad extends Actor { private boolean shoot; public double xspeed; public double yspeed; public double xspeed2; public double yspeed2; public int yspot; public int xspot; /** * Act - do whatever the Person wants to do. This method is called whenever * the 'Act' or 'Run' button gets pressed in the environment. */ public ViralLoad() { shoot=true; } public void act() { MyWorld myWorld = (MyWorld) getWorld(); if(shoot) { xspot= myWorld.circle.getArcX(); yspot= myWorld.circle.getArcY(); setLocation(xspot,yspot); setLocation(getX()+(int)xspeed, getY()+(int)yspeed); if(Greenfoot.isKeyDown("space")) { shoot=true; yspeed = yspeed = .01; xspeed2 =15 * myWorld.rectangle.getFilledRatio(); yspeed2 =-15 * myWorld.rectangle.getFilledRatio(); xspeed = xspeed2 * Math.cos(myWorld.circle.getAngle()); yspeed = yspeed2 * Math.sin(myWorld.circle.getAngle()); } else if(!isAtEdge()) { setLocation(getX()+(int)xspeed, getY()+(int)yspeed); yspeed = yspeed = .01; } if(isTouching(Bird.class) || this.isAtEdge()) { removeTouching(ViralLoad.class); myWorld.addObject(new ViralLoad(), xspot, yspot); } } } } rectangle class public class RectangleMeter extends Actor { private int currVal; // the currently filled amount of the rectangle private int height; // the maximum filled amount of the rectangle /** * Build a rectangle of specifed height (and 20 width). Initially, the rectangle is empty. * * @param height - the requested height */ public RectangleMeter(int height) { currVal=0; // initial filled amount is 0 this.height=height; // use specifed height redraw(); // build and use the rectangel image } // // redraw is a private method that will rebuild the image for a RectangleMeter private void redraw() { // build an appropriate (blank) image GreenfootImage img = new GreenfootImage(20,height); // draw the unfilled rectangle img.setColor(Color.GRAY); img.fill(); // draw a red outline around the rectangle img.setColor(Color.RED); img.drawRect(0,0,19,height-1); // fill in the currently filled portion of the rectangle img.setColor(Color.GREEN); img.fillRect(1,height-currVal+1,18,currVal-2); // use the newly generated image setImage(img); } /** * getFilledRatio returns a double representing the amount the meter is full as a ratio * (i.e. a value between 0 and 1 inclusively) * * @return the ratio */ public double getFilledRatio() {return currVal/(double)height;} /** * getHeight returns the height of this RectangleMeter in pixels * * @return number of pixels high the meter image is */ public int getHeight() {return height;} /** * getWidth returns the width of this RectangleMeter in pixels * * @return number of pixels wide the meter image is */ public int getWidth() {return getImage().getWidth();} /** * act - check user keypress status and modify meter accordingly */ public void act() { // modify the filled amount based on user keypresses if (Greenfoot.isKeyDown("Up") && currVal<height) { currVal++; redraw(); } else if (Greenfoot.isKeyDown("Down") && currVal>0) { currVal--; redraw(); } } } circle meter class public class CircleMeter extends Actor { private int degFull; // how full is the meter? from 0 to maxDegree private int radius; // how big is the "sweeping" radius of this meter? private int maxDegree; // what is the maximum number of degrees in this meter? /** * constructs a 180 degree (half circle) meter with specified radius * * @param radius the size of the semicircle's radius */ public CircleMeter(int radius) { degFull=0; // starts out empty this.radius=radius; // use specified radius maxDegree=180; // by default, a half circle redraw(); // redraws the circle image, based on above. } /** * constructs a semicircle meter with specified radius and maximum degree. WARNING: this is really * intended to work with only multiples of 90 degrees. * * @param radius the size of the semicircle's radius * @param the sweeping range of the meter. Intended to work in multiples of 90 degrees. */ public CircleMeter(int radius, int maxDegree) { degFull=0; // starts out empty this.radius=radius; // use specifed radius // use specifed sweeping range (carefully) this.maxDegree=Math.min(180, Math.max(maxDegree, 10)); redraw(); // redraws the meter, based on above } // // redraw is a private method that will rebuild the image for a CircleMeter private void redraw() { // get a new (empty) image of the needed size. int imgWidth = radius + (maxDegree>90?radius:0); imgWidth = Math.max(imgWidth, radius); GreenfootImage img = new GreenfootImage( imgWidth , radius); // get underlying java awt image (need direct java awt rendering) java.awt.image.BufferedImage awtVersion = img.getAwtImage(); java.awt.Graphics2D g = (java.awt.Graphics2D) awtVersion.getGraphics(); // draw the blue filled backgound, indicating "unfilled" portion Shape arc = new Arc2D.Float(-(180-maxDegree)/90*radius, 0, 2*radius-1, 2*radius-1, 0, maxDegree, Arc2D.PIE); g.setPaint(java.awt.Color.BLUE); g.fill(arc); // draw the orange filled foregound, indicating "filled" portion arc = new Arc2D.Float(-(180-maxDegree)/90*radius, 0, 2*radius-1, 2*radius-1, 0, degFull, Arc2D.PIE); g.setPaint(java.awt.Color.ORANGE); g.fill(arc); // now that we have built the image, use it as this Actor's image. setImage(img); } /** * getAngle specifies (in radians) the current fill value of the meter * * @return the angle value in radians of the meter. */ public double getAngle() {return Math.toRadians(degFull);} /** * getDegrees specifies the current fill value of the meter in degrees * @return the angle value in degrees */ public int getDegrees() {return degFull;} /** * getArcX gives the x value of the perimeter of the circle where the meter is currently filled to * * @return the x location of the filled portion of the meter */ public int getArcX() { // find the "origin" x value of the meter int originX = getX() - (maxDegree<=90?radius/2:0); //we'll be an appropriate offset from that origin. return (int) (originX+Math.cos(Math.toRadians(degFull))*radius); } /** * getArcY gives the y value of the perimeter of the circle where the meter is currently filled to * * @return the y location of the filled portion of the meter */ public int getArcY() { // find the "origin" y value of the meter int originY = getY()+getImage().getHeight()/2; //we'll be an appropriate offset from that origin. return (int) (originY-Math.sin(Math.toRadians(degFull))*radius); } /** * Act - do whatever the CircleMeter wants to do. This method is called whenever * the 'Act' or 'Run' button gets pressed in the environment. */ public void act() { // if the left arrow key is being pressed and we can still grow, if (Greenfoot.isKeyDown("Left") && degFull<maxDegree) { degFull++; // a bit more is full redraw(); // rebuild image to note the updates fill amount } // if the right arrow key is being pressed and we could still shrink our fill ... if (Greenfoot.isKeyDown("Right") && degFull>0) { degFull--; // a bit less is fulll redraw(); // rebuild image to reflect the new fill amount } } } world public class MyWorld extends World { CircleMeter circle; RectangleMeter rectangle; ViralLoad viralload; /** * Constructor for objects of class MyWorld. * */ public MyWorld() { // Create a new world with 600x400 cells with a cell size of 1x1 pixels. super(800, 600, 1); circle = new CircleMeter(50,90); addObject(circle,20,580); rectangle = new RectangleMeter(100); addObject(rectangle,10,500); ViralLoad viralload = new ViralLoad(); addObject(viralload, 50,600); } /** * act - do whatever a MyWorld is supposed to do. (needs a better comment) */ public void act() { if (Greenfoot.isKeyDown("l")) { FileDialog fd = null; fd = new FileDialog (fd , "Open bird file" , FileDialog.LOAD); fd.setVisible(true); String fname = fd.getDirectory() + fd.getFile(); File birdFile = new File (fname); Scanner birdReader = null; try { birdReader = new Scanner(birdFile); } catch (IOException ioe) { System.out.println("no file found:" + fname); return; } while(birdReader.hasNext()) { String type = birdReader.next(); if (type.equalsIgnoreCase("bird")) { int speed = birdReader.nextInt(); int intX = birdReader.nextInt(); int intY = birdReader.nextInt(); Bird bigBird = new Bird(speed); addObject(bigBird, intX, intY); } } } } }