//RGBCircles.java
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class RGBCircles extends JApplet {
    
    private Color color1;    //Green circle
    private Color color2;    //Blue circle
    private Color color3;    //Red circle
    private int appletSize;
    private int length;   //2*b   length of 
    private double b;     //radius of circles
    private int x1, y1, x2, y2, x3, y3;  //centers of Green, Blue, Red circles


    public void init() {
	//	color1 = Color.GREEN;
	//	color2 = Color.BLUE;
	//	color3 = Color.RED;
	color1 = new Color(0,127,0);
	color2 = new Color(0,0,127);
	color3 = new Color(127,0,0);       

	addMouseListener(
            //anonymous inner class overrides mouseClicked
            new MouseAdapter() {
                public void mouseClicked( MouseEvent event) {
		    int colorStep = 10;
		    calcSizes();
		    int x = event.getX();
		    int y = event.getY();
		    if (x<x1 && y>y1) {  //in green 
			if (event.isMetaDown())     //right mouse button
			    if (color1.getGreen() >= colorStep)
				color1 = new Color( 0, color1.getGreen()-colorStep, 0);
			    else 
				color1 = new Color( 0, 0, 0);
			else   //left button
			    if (color1.getGreen() < 255-colorStep)
				color1 = new Color( 0, color1.getGreen()+colorStep, 0);
			    else 
				color1 = new Color( 0, 255, 0);

		    }
		    else if (x>x2 && y>y2) {  //in blue
			if (event.isMetaDown())     //right mouse button
			    if (color2.getBlue() >= colorStep)
				color2 = new Color( 0, 0, color2.getBlue()-colorStep);
			    else
				color2 = new Color( 0, 0, 0);
			else
			    if (color2.getBlue() < 255-colorStep)
				color2 = new Color( 0, 0, color2.getBlue()+colorStep);
			    else
				color2 = new Color( 0, 0, 255);

		    }
		    else if ( y<y3) {  //in red
			if (event.isMetaDown())     //right mouse button
			    if (color3.getRed() >= colorStep)
				color3 = new Color( color3.getRed()-colorStep, 0, 0);
			    else
				color3 = new Color( 0, 0, 0);
			else
			    if (color3.getRed() < 255-colorStep)
				color3 = new Color( color3.getRed()+colorStep, 0, 0);
			    else
				color3 = new Color( 255, 0, 0);
		    }
		    repaint();
		}
	    }
	);


    }


    private void calcSizes() {
	appletSize = Math.min(getWidth(), getHeight());
	//distance between centers is appletSize/3
	b = appletSize / 3;     //b is radius
	
	length = (int)(2 * b);  //radii extend to center of other circles

	x1 = appletSize / 3;
	y1 = appletSize / 3 * 2;
	x2 = appletSize / 3 * 2;
	y2 = appletSize / 3 * 2;
	
	double angle = Math.toRadians(60);
	//top (red) circle's center
	x3 = (int)(Math.cos(-angle) * appletSize/3 + x1);
	y3 = (int)(Math.sin(-angle) * appletSize/3 + y1);
    }



    public void paint( Graphics g1 )
    {
       super.paint( g1 );
       //try 2d graphics.  will be used for rotation...
       Graphics2D g = (Graphics2D) g1 ;

       double angle;

       showStatus( "click left mouse for +, right mouse for - of color" );

       calcSizes();

       //so height of equliateral triangle is 
       double height = Math.sqrt(b*b-b*b/4);
 	 
       //this interferes with drawings:  
       //getContentPane().setBackground( new Color( color3.getRed(), color1.getGreen(),color2.getBlue() ) );

       g.setColor( new Color( color3.getRed(), color1.getGreen(), color2.getBlue() )); 
       g.fillRect( 0, 0, getWidth(), getHeight() );

       g.setColor( color1 );
       //lower left Green
       g.fillOval(x1-length/2,y1-length/2,length,length);
       //g.drawOval(x1-length/2,y1-length/2,length,length);
       g.setColor( color2 ); 
       //lower right Blue
       g.fillOval(x2-length/2,y2-length/2,length,length);
       //g.drawOval(x2-length/2,y2-length/2,length,length);
       g.setColor( color3 ); 
       //top  Red
       g.fillOval(x3-length/2,y3-length/2,length,length);
       //g.drawOval(x3-length/2,y3-length/2,length,length);


       //from center, bisect triangle to outer intersection
       angle = Math.toRadians(30);
       int red_blue_x = (int)(Math.cos(-angle) * 2*height + x1);
       int red_blue_y = (int)(Math.sin(-angle) * 2*height + y1);

       angle = Math.toRadians(150);
       int red_green_x = (int)(Math.cos(-angle) * 2*height + x2);
       int red_green_y = (int)(Math.sin(-angle) * 2*height + y2);

       angle = Math.toRadians(270);
       int green_blue_x = (int)(Math.cos(-angle) * 2*height + x3);
       int green_blue_y = (int)(Math.sin(-angle) * 2*height + y3);


       //upper half of red blue 
       g.setColor( new Color( color3.getRed(), 0, color2.getBlue() ) ); 
       g.translate( x1, y1 );     //move origin
       g.rotate( -Math.PI / 6 );  //-30 degrees rotation
       //g.fillArc( x1, (int)(y1-.5*b), (int)(2*height), (int)b, 0, 180 );
       g.fillArc( 0, (int)(-.5*b), (int)(2*height), (int)b, 0, 90 );
       g.rotate( Math.PI / 6 );  //back to original
       g.translate( -x1, -y1 );    //back to original

       //lower half of red blue 
       g.translate( red_blue_x, red_blue_y );     //move origin
       g.rotate( 5 * Math.PI / 6 );  //150 degrees rotation
       g.fillArc( 0, (int)(-.5*b), (int)(2*height), (int)b, 90, 180 );
       g.rotate( -5 * Math.PI / 6 );  //back to original
       g.translate( -red_blue_x, -red_blue_y );     //move origin

       //upper half of red green 
       g.setColor( new Color( color3.getRed(), color1.getGreen(), 0 ) ); 
       g.translate( red_green_x, red_green_y );     //move origin
       g.rotate( Math.PI / 6 );  //30 degrees rotation
       g.fillArc( 0, (int)(-.5*b), (int)(2*height), (int)b, 90, 180 );
       g.rotate( -Math.PI / 6 );  //back to original
       g.translate( -red_green_x, -red_green_y );     //move origin

       //lower half of red green 
       g.translate( x2, y2 );     //move origin
       g.rotate( 7 * Math.PI / 6 );  //210 degrees rotation
       g.fillArc( 0, (int)(-.5*b), (int)(2*height), (int)b, 0, 90 );
       g.rotate( -7 * Math.PI / 6 );  //back to original
       g.translate( -x2, -y2 );     //move origin

       //left half of blue green 
       g.setColor( new Color( 0, color1.getGreen(), color2.getBlue() ) ); 
       g.translate( green_blue_x, green_blue_y );     //move origin
       g.rotate( 9 * Math.PI / 6 );  //270 degrees rotation
       g.fillArc( 0, (int)(-.5*b), (int)(2*height), (int)b, 90, 180 );
       g.rotate( -9 * Math.PI / 6 );  //back to original
       g.translate( -green_blue_x, -green_blue_y );     //move origin

       //right half of blue green 
       g.translate( x3, y3 );     //move origin to center of Red
       g.rotate( 3 * Math.PI / 6 );  //90 degrees rotation
       g.fillArc( 0, (int)(-.5*b), (int)(2*height), (int)b, 0, 90 );
       g.rotate( -3 * Math.PI / 6 );  //back to original
       g.translate( -x3, -y3 );     //move origin


       /*
       //draw the circles again for visualization debug
       g.setColor( color2 );
       g.drawOval(x1-length/2,y1-length/2,length,length);
       g.setColor( color3 ); 
       g.drawOval(x2-length/2,y2-length/2,length,length);
       g.setColor( color1); 
       g.drawOval(x3-length/2,y3-length/2,length,length);
       */

       //inner triangle
       g.setColor( new Color( color3.getRed(), color1.getGreen(), color2.getBlue() )); 
       g.fillPolygon( new int[]{x1-1,x2,x3-1}, new int[]{y1,y2,y3-1}, 3);
       //-1 tweaks to reduce background line peeking thru

       /*
       //draw triangle for visualization debug
       g.setColor( Color.BLACK );
       g.drawLine(x1,y1,x2,y2);  //lower
       g.setColor( Color.WHITE );
       g.drawLine((x1+x2)/2,(y1+y2)/2,(x1+x2)/2,(y1+y2)/2);

       g.setColor( Color.BLACK );
       g.drawLine(x1,y1,x3,y3);
       g.setColor( Color.WHITE );
       g.drawLine((x1+x3)/2,(y1+y3)/2,(x1+x3)/2,(y1+y3)/2);

       g.setColor( Color.BLACK );
       g.drawLine(x2,y2,x3,y3);
       g.setColor( Color.WHITE );
       g.drawLine((x3+x2)/2,(y3+y2)/2,(x3+x2)/2,(y3+y2)/2);
       */

       /*
       //from center, bisect triangle to outer intersection
       g.setColor( Color.WHITE );
       g.drawLine(x1,y1, red_blue_x, red_blue_y);

       g.drawLine(x2,y2, red_green_x, red_green_y);
       
       g.drawLine(x3,y3, green_blue_x, green_blue_y);
       */

       g.setFont( new Font( "SansSerif", Font.BOLD, 20 ) );
       g.drawString( ""+color1.getGreen(), (int)(x1-.5*b), (int)(y1+.5*b)  );
       g.drawString( ""+color2.getBlue(), (int)(x2+.5*b), (int)(y2+.5*b)  );
       g.drawString( ""+color3.getRed(), (int)(x3), (int)(y3-.5*b)  );


   }
}