Question

All right, so I have made a basic game, in which I made a character go left and right (using a and d) and allowed it to jump. What I’m trying to do right now is get it so that the terrain generated will allow the character to stop on top of it. For example, if the character jumps, then it will stop on top of a block when it touches it. What I really need is just some basic code that will work well for the code I have already written, not an entire re-writing. And as a side note, many have said to use KeyBindings instead of KeyListener, but the KeyListener works a lot better in the way I’m handling this coding. Thanks for your help!

import javax.swing.*;
import javax.swing.event.*;
import java.awt.*;
import java.awt.event.*;
import java.awt.geom.*;
import java.io.*;
import java.net.*;
import java.lang.*;
import static java.lang.Math.*;
import static java.lang.System.out;
import java.util.Random.*;
import java.util.*;
import javax.swing.JApplet;
import java.awt.Graphics;

public class Ultima extends JFrame implements KeyListener
{
    String map [][] = 
    {{" ", " ", " ", "#", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " "},
     {" ", "#", "#", " ", " ", " ", " ", " ", " ", " ", " ", "#", "#", " ", " ", " ", " ", " ", " ", " "},
     {" ", "#", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " "},
     {" ", "#", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " "},
     {" ", " ", "#", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " "},
     {" ", " ", " ", "#", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " "},
     {" ", " ", " ", " ", "#", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", "#"},
     {" ", " ", " ", " ", " ", "#", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " "},
     {" ", " ", " ", " ", " ", " ", "#", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " "},
     {" ", " ", " ", " ", " ", " ", " ", "#", " ", " ", " ", " ", " ", " ", " ", " ", "#", " ", " ", " "},
     {" ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " "},
     {" ", " ", " ", " ", " ", " ", " ", " ", "#", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " "},
     {" ", " ", " ", " ", " ", " ", " ", "#", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", "#"},
     {" ", " ", " ", " ", " ", " ", "#", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " "},
     {" ", " ", " ", " ", " ", "#", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " "},
     {" ", " ", " ", " ", "#", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " "},
     {" ", " ", " ", "#", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " "},
     {" ", " ", "#", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " "},
     {" ", "#", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " "},
     {"#", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " "}};

    int score = 0;
    double gravity = 1;
    boolean jumping = false;
    boolean moveRight = false;
    boolean moveLeft = false;
    boolean jumpRight = false;
    boolean jumpLeft = false;
    boolean moveRightWhileJumping = false;
    boolean moveLeftWhileJumping = false;
    final int WIDTH = 900;
    final int HEIGHT = 650;
    int RESPAWNX = WIDTH/20;
    int RESPAWNY = HEIGHT/2;

    Rectangle charRect = new Rectangle( RESPAWNX, RESPAWNY, 20, 32 );
    JLabel character = new JLabel( new ImageIcon( "characterg.gif" ) );
    JLabel scoreLabel = new JLabel( "Score: " + score );
    JMenuBar mb = new JMenuBar( );
    JMenu menuFile = new JMenu("File");
    JMenuItem menuItemSave = new JMenuItem("Save");
    JMenuItem menuItemLoad = new JMenuItem("Load");

    ArrayList trailList = new ArrayList( );
    Runner runner;
    Container cont;
    JLabel spaceLabel = null;

    public static void main( String args[] )
    {
        new Ultima( );
    }

    public Ultima( )
    {
        super( "Ultima" );
        setSize( WIDTH, HEIGHT );
        setVisible( true );
        setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE );

        cont = getContentPane( );
        cont.setLayout( null );
        addKeyListener( this );
        cont.setBackground( Color.WHITE );

        cont.add( mb );
        setJMenuBar( mb );
        menuFile.add( menuItemSave );
        menuFile.add( menuItemLoad );
        mb.add( menuFile );

        cont.add( scoreLabel );
        scoreLabel.setBounds( 50, 50, 100, 30 );
        scoreLabel.setFont( new Font( "arial", Font.BOLD, 13 ) );
        scoreLabel.setForeground( Color.BLACK );

        cont.add( character );
        character.setBounds( charRect.x, charRect.y, 20, 32 );

    for( int row = 0; row < map.length; row++ )
    {
        for( int col = 0; col < map[0].length; col++ )
        {
            if( map[row][col].equals( "#" ) )
            {
                spaceLabel = new JLabel( new ImageIcon( "block.png" ) );
            }
            else if( map[row][col].equals( " " ) )
            {
                spaceLabel = new JLabel(new ImageIcon( "air.png" ) );
            }
            else
            {

            }
            trailList.add( spaceLabel );
            cont.add( spaceLabel );
            cont.setComponentZOrder( spaceLabel, 1 );
            spaceLabel.setBounds( col*30, row*30, 30, 30 );
        }
    }

    repaint( );
    cont.validate( );
    runner = new Runner( );
    runner.start( );
    setContentPane( cont );
}

public void keyPressed( KeyEvent e )
{
    if( e.getKeyChar( ) == 'd' || e.getKeyChar( ) == 'D' )
    {
        moveRight = true;
    }
    if( e.getKeyChar( ) == 'a' || e.getKeyChar( ) == 'A' )
    {
        moveLeft = true;
    }
}

public void keyReleased( KeyEvent e )
{
    if( e.getKeyChar( ) == 'd' || e.getKeyChar( ) == 'D' )
    {
        moveRight = false;
    }
    if( e.getKeyChar( ) == 'a' || e.getKeyChar( ) == 'A' )
    {
        moveLeft = false;
    }
}

public void keyTyped( KeyEvent e )
{
    if( e.getKeyChar( ) == KeyEvent.VK_SPACE )
    {
        jumping = true;
    }
}

public class Runner extends Thread
{
    public void run( )
    {
        while( true )
        {
            try
            {
                int j = 10;
                double t = 0;

                while( jumping )
                {
                    charRect.y = ( int ) ( charRect.y - j + gravity );
                    gravity *= 1.2;
                    character.setBounds( charRect.x, charRect.y, 20, 32 );
                    repaint( );
                    cont.validate( );
                    t++;
                    Thread.sleep( 30 );//basically, lower #, faster, and higher fps
                }

                if( moveLeft )
                {
                    charRect.x = charRect.x - ( int ) ( j/5 );
                    character.setBounds( charRect.x, charRect.y, 20, 32 );
                    repaint( );
                    cont.validate( );
                    t++;
                    Thread.sleep( 30 );
                }
                if( moveRight )
                {
                    charRect.x = charRect.x + ( int ) ( j/5 );
                    character.setBounds( charRect.x, charRect.y, 20, 32 );
                    t++;
                    Thread.sleep( 30 );
                    repaint( );
                    cont.validate( );
                }
                scoreLabel.setText( "Score: " + score );
            }
            catch( Exception e )
            {
                break;
            }
        }
    }
}
}

Answer 1

I think you will find this guide on implementing 2d platformers useful.