AOL File Library: 12,000 to 12,999/12000.zip/AOLDLs/Online-Tools/Java-Applets/JAVAAPPS.lzh/JAVAAPPS/STARFIEL/STARFIEL.EXE/StarField.java

Java Source | 1996-03-11 | 4.5 KB | 230 lines

import java.awt.*;



class Star {

    int    H, V;

    int    x, y, z;

    int    type;



    Star( int width, int height, int depth, int type )

        {

        this.type = type;

        H = width/2;

        V = height/2;

        x = (int)(Math.random()*width) - H;

        y = (int)(Math.random()*height) - V;

        if( (x == 0) && (y == 0 ) ) x = 10;

        z = (int)(Math.random()*depth);

        }



    public void Draw( Graphics g, double rot )

        {

        double    X, Y;

        int    h, v, hh, vv;

        int    d;

        z-=2;

        if( z < -63 ) z = 100;

        hh = (x*64)/(64+z);

        vv = (y*64)/(64+z);

        X = (hh*Math.cos(rot))-(vv*Math.sin(rot));

        Y = (hh*Math.sin(rot))+(vv*Math.cos(rot));

        h = (int)X+H;

        v = (int)Y+V;

        if( (h < 0) || (h > (2*H))) z = 100;

        if( (v < 0) || (v > (2*H))) z = 100;

        GrayMe(g);

        if( type == 0 )

            {

            d=(100-z)/50;

            if( d == 0 ) d = 1;

            g.fillRect( h, v, d, d );

            }

        else

            {

            d=(100-z)/20;

            g.drawLine( h-d, v, h+d, v );

            g.drawLine( h, v-d, h, v+d );

            if( z < 50 ) {

                d/=2;

                g.drawLine( h-d, v-d, h+d, v+d );

                g.drawLine( h+d, v-d, h-d, v+d );

                }

            }

        }



    public void GrayMe(Graphics g)

        {

/*        if( z > 75 )

            {

            g.setColor( Color.darkGray );

            }

        else*/ if ( z > 50 )

            {

            g.setColor( Color.gray );

            }

        else if ( z > 25 )

            {

            g.setColor( Color.lightGray );

            }

        else

            {

            g.setColor( Color.white );

            }

        }

    }



public class StarField extends java.applet.Applet implements Runnable

    {

    int        Width, Height;

    Thread        me = null;

    boolean        suspend = false;

    Image        im;

    Graphics    offscreen;

    double        rot, dx, ddx;



    int        speed, stars, type;

    double        defddx, max;

    Star        pol[];        /* Points of light */



    public void init()

        {

        rot = 0;

        dx=0;

        ddx=0;

        Width = size().width;

        Height = size().height;



        String    theSpeed = getParameter( "speed" );

        Show( "speed", theSpeed );

        speed = (theSpeed == null ) ? 50 : Integer.valueOf( theSpeed ).intValue();



        String    theStars = getParameter( "stars" );

        Show( "stars", theStars );

        stars = (theStars == null ) ? 30 : Integer.valueOf( theStars ).intValue();



        String theType = getParameter( "type" );

        Show( "type", theType );

        type = (theType == null ) ? 0 : Integer.valueOf( theType ).intValue();



        String theRot = getParameter( "spin" );

        Show( "spin", theRot );

        rot = (theRot == null) ? 0 : Double.valueOf( theRot ).doubleValue();



        String theMax = getParameter( "maxspin" );

        Show( "maxspin", theRot );

        max = (theMax == null) ? .1 : Double.valueOf( theMax ).doubleValue();



        String theddx = getParameter( "ddx" );

        Show( "ddx", theddx );

        defddx = (theddx == null) ? .005 : Double.valueOf( theddx ).doubleValue();



        try

            {

            im = createImage( Width, Height );

            offscreen = im.getGraphics();

            }

        catch( Exception e)

            {

            offscreen = null;

            }

        pol = new Star[stars];

        for( int i = 0; i < stars; i++ )

            pol[i] = new Star( Width, Height, 100, type );

        }



    public void paint( Graphics g )

        {

        if( offscreen != null )

            {

            paintMe( offscreen );

            g.drawImage( im, 0, 0, this );

            }

        else

            {

            paintMe( g );

            }

        }





    public void paintMe( Graphics g )

        {

        g.setColor( Color.black );

        g.fillRect( 0, 0, Width, Height );

        //g.setColor( Color.gray );

        for( int i = 0; i < stars; i++ )

            pol[i].Draw( g, rot );

        }



    public void start()

        {

        if( me == null )

            {

            me = new Thread( this );

            me.start();

            }

        }



    public void stop()

        {

        if( me != null )

            {

            me.stop();

            me = null;

            }

        }



    public void run()

        {

        while( me != null )

            {

            rot += dx;

            dx += ddx;

            if( dx > max ) ddx=-defddx;

            if( dx < -max) ddx=defddx;

            try { Thread.sleep( speed ); }

            catch (InterruptedException e){}

            repaint();

            }

        }



    public void update( Graphics g )

        {

        paint( g );

        }



    public boolean mouseDown( java.awt.Event evt, int x, int y )

        {

        ddx = (ddx == 0) ? defddx : 0;

        return true;

        }



    public void Toggle( )

        {

        if( me != null )

            {

            if( suspend )

                {

                me.resume();

                }

            else

                {

                me.suspend();

                }

            suspend = !suspend;

            }

        }



    public void Show( String theString, String theValue )

        {

        if( theValue == null )

            {

            System.out.println( theString + " : null");

            }

        else

            {

            System.out.println( theString + " : " + theValue );

            }

        }

    }