How do i make letters randomly spawn from the top of the screen and drop down to the bottom? They should be random letters and when typed should be removed....Help?
alagon wrote ...
2013/6/7
Letters
Well i have tried creating the letters with a random spawner, they just bug out. The movement is fine...it's just the spawning of the letters and that they should be a specific letter and stay that specific letter. I have done nothing so far to try and remove the letters.
danpost wrote...
What code have you tried?public void act()
{
long currentTime = System.currentTimeMillis();
elapsedTime += currentTime - lastTime;
lastTime = currentTime;
if (elapsedTime / 100 > 25)
{
GreenfootImage img = new GreenfootImage(100, 50);
img.setColor(Color.BLACK); //Change this to the colour of text that you want
float fontSize = 30.0f; //Change this to the font size that you want
Font font = img.getFont().deriveFont(fontSize); //This adjusts the default font to the correct size.
img.setFont(font);
final int letter = Greenfoot.getRandomNumber(26);
String[] alpha = {"A","B","C","D","E","F","G","H","I","J","K","L","M","N","O",
"P","Q","R","S","T","U","V","W","X","Y","Z"};
str = alpha[Greenfoot.getRandomNumber(alpha.length-1)];
}
setLocation(getX(), getY()+1);The only thing the 'act' method should have in it is the movement code and the removal code if it reaches the bottom of the window. The constructor should determine the letter and you should have an instance String or char field to hold its letter (so you have something to compare the input to). Not knowing exactly what you wanted, it appears you want the object to wait two and a half seconds while moving down the screen before displaying its letter (I fear that is not what you wanted). If you require more assistance, please explain what is supposed to happen with the creation, the behavior after creation, etc.; and explain what the purpose of tracking the elapsed time is supposed to be doing.
So what' supposed to happend, is that the letter is suposed to spawn with the bomb, and when the letter is typed, then the bomb is supposed to explode. The bomb and letter drop down to the bottom of the screen.
Is the letter on the bomb or is the letter a separate object that has to drop with the bomb? It would be easier if the letter was placed (drawn) directly on the image of the bomb. That way you do not have to work with two different objects; placing them into the world and removing them, as well as having to 'tie' each bomb to a specific letter and moving them together.
I would start with a minimum of the following two fields for the bomb class:
The only thing the 'act' method should do is:
(1) make the bomb fall;
(2) check for letter pressing; and,
(3) check for bottom edge of world.
Basically:
I will explain the destruction (or explosion) in my next post.
private static final String letters = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"; private String letter; // then in the constructor, select a letter with letter = ""+letters.charAt(Greenfoot.getRandomNumber(26)); // followed by drawing the letter on the bomb int fontsize = 36; // fontsize of letter (adjust at will) Color white = Color.white, trans = new Color(0, 0, 0, 0); GreenfootImage image = new GreenfootImage(letter, fontsize, white, trans); // creates letter image int xOff = 25; // horizontal letter placement on bomb (adjust at will) int yOff = 15; // vertical letter placement on bomb (adjust at will) getImage().drawImage(image, xOff, 15); // puts letter on bomb
public void act()
{
setLocation(getX(), getY()+1); // fall
if (!Greenfoot.isKeyDown(letter)) // check correct letter pressed
{
// create explosion
// possibly increment a counter of exploded bombs
getWorld().removeObject(this);
}
if (getWorld() != null && getY() == getWorld().getHeight()-1) // check world edge
{
// possibly increment a counter of non-exploded bombs
getWorld().removeObject(this);
}
}I believe that this asteroid scenario has an Explosion class that you can use. You not only need the class code, but also the image and the sound for the explosion from that scenario. Then, line 6 above only need add a new Explosion object into the world:
Line 11 in my fist code post above should have had '15' replaced with 'yOff'.
getWorld().addObject(new Explosion(), getX(), getY());
So the first part of the post i should put in the world class?
The second bit and third bit worked for me thanks :D
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