/* PlotCanvas.java
 * Basic 2-D Plotting Canvas
 * 20-July-1997
 * Author: Bryan Lewis
 * Kent State University 
 * Department of Mathematics & Computer Science
 * mail: blewis@rocketcalc.com
 * url: http://www.mcs.kent.edu/~blewis/
 *  For use with JVM 1.1x and higher
 * Revisions:
 * October, 98: Added a fixed plot scale option, 
 *               a text component (plotText), a clear method
 * September, 1998: Added aspect ratio control variable,
 *                  plotStyle variable for lines or dots, multi-color plotting,
 *                  addapted for plotting ellipses for dots.
 * Revised: August, 2003
 * 
 * January, 2004: Added linear interpolant style, fade method, displayData
 * catesian(j,k) and screen(x,y) functions
 *
 */

import java.awt.*;
import java.lang.*;
import java.util.Vector;
import java.util.Enumeration;

class PlotCanvas extends Canvas {
    // coordinate system:
    double xmax, xmin, ymax, ymin;
    int xcenter, ycenter;

    /* The plot area dimensions */
    Dimension d;

    /* Scaling */
    // change autoScale to false to set scale manually
    boolean autoScale=true;

    // set squareAspectRatio to true for a square plot
    boolean squareAspectRatio = false;

    // set ticks to true to display tick marks on the axes
    boolean ticks = true;
    boolean gridlines=false;
    int ntick=4;
    Color axesColor = new Color(180,180,180);
    Color tickColor = new Color(180,180,180);

    Vector points;

    PlotCanvas() {
	/* The constructor method for this object: most initialization
	 * steps take place here.
	 */
	super();
	points=new Vector();
    }

    public void clear(){
	/* The clear method clears the list of points and
	 * redraws the plot (effectively clearing the plot).
	 */
	points=new Vector();
	repaint();
    }


    public void plot(MPoint p) {
	/* Add an MPoint object p to the list of points 
	 *  and redraw the plot.
	 */
	points.addElement(p);
	repaint();
    }

    public void plot(double x, double y) {
	/* Create a point object with the given x and y coordinates,
	 * add it to the list of points and redraw the plot.
	 */
	MPoint p=new MPoint(x,y);
	points.addElement(p);
	repaint();
    }

    public void plot(Vector v) {
	/* Add a whole list of points to the list of points
	 * to be plotted and redraw the plot.
	 */
	for(Enumeration e=v.elements();e.hasMoreElements();) 
	    points.addElement((MPoint)e.nextElement());
	repaint();
    }

    public void plot1D(Vector v) {
	/* Plot a vector of MPoints using the position in the list 
	 * as the x-coordinate. Don't count points that have non-null
	 * text fields.
	 */
 	double j=1;
	MPoint p;
	points=new Vector();
	for (Enumeration e=v.elements();e.hasMoreElements();) {
	    p=(MPoint)e.nextElement();
	    p.x=(double)j;
	    p.setSize(5);
	    points.addElement(p);
	    if(p.text=="") 
	       j=j+1;
	}
	repaint();
    }


    public void setSquareAspectRatio (boolean b) {
	squareAspectRatio = b;
    }

    public void setAutoScale(boolean b) {
	autoScale=b;
    }

    public void setScale(double xmn,double xmx, double ymn, double ymx) {
	autoScale=false;
	xmin=xmn;
	xmax=xmx;
	ymin=ymn;
	ymax=ymx;
    }

    public MPoint cartesian(int j, int k) {
	/* Convert the screen pixel coordinates j,k to Cartesian coordinates */
	MPoint p=new MPoint();
	p.x = (double)((j - xcenter)*(xmax - xmin)) / (double)d.width;
	p.y = (double)((ycenter - k)*(ymax - ymin)) / (double)d.height;
	return p;
    }


    public java.awt.Point screen(double x, double y) {
	/* Convert the Cartesian coordinates into screen coordinates */
	java.awt.Point p=new java.awt.Point();
	p.x = xcenter + (int)(x*d.width/(xmax-xmin));
	p.y = ycenter - (int)(y*d.height/(ymax-ymin));
	return p;
    }

    public void setTicks(boolean b) {
	ticks = b;
    }

    public void setGridlines(boolean b){
	gridlines=b;
    }

    public void lighter()  {
	/* Lighten the color of all existing points */
	Vector v=new Vector();
	Enumeration e=points.elements();
	while(e.hasMoreElements()) {
	    MPoint p=(MPoint)e.nextElement();
	    if(p.style != MPoint.STYLE_TEXT) {
	      p.brighter();
	    }
	    v.addElement(p);
	}	
	points=v;
    }

    public void fade()  {
	/* Lighten the color of all existing points */
	Vector v=new Vector();
	Color c;
	int r,g,b;
	Enumeration e=points.elements();
	while(e.hasMoreElements()) {
	    MPoint p=(MPoint)e.nextElement();
	    if(p.style != MPoint.STYLE_TEXT) {
		c=p.getColor();
		g=c.getGreen();
		r=c.getRed();
		b=c.getBlue();
		if( (r-b)*2 + (b-g)*3 + (r-g) !=0) {
		    /* Not already gray...make it so */
		    p.setColor(new Color(190,190,190));
		}
		else {
		    r=Math.min(r+5,255);
		    p.setColor(new Color(r,r,r));
		}
	    }
	    c=p.getColor();
	    g=c.getGreen();
	    r=c.getRed();
	    b=c.getBlue();
	    /* Remove faded out points from the plot */
	    if( (r<255) || (g<255) || (b<255) ) 
		v.addElement(p);
	}	
	points=v;
    }


    public void setColor(Color c)  {
	/* Set the color of all existing points */
	Vector v=new Vector();
	Enumeration e=points.elements();
	while(e.hasMoreElements()) {
	    MPoint p=(MPoint)e.nextElement();
	    p.setColor(c);
	    v.addElement(p);
	}	
	points=v;
    }


    public void paint(Graphics g) {
	/* The paint method is responsible for displaying the plot
	 * on the screen. We will add double-buffering to this later
	 * if the plot exhibits flicker or other display problems.
	 */

	/* draw border, ticks, first 
	 *  checking coordinate system bounds 
	 */
	d = getSize();

	if(autoScale){
	    xmax=0;xmin=0;ymax=0;ymin=0;
	    for(Enumeration e=points.elements();e.hasMoreElements();){
		MPoint p=(MPoint)e.nextElement();
		if(p.style != MPoint.STYLE_TEXT){ 
		    if(p.x > xmax) xmax=p.x;
		    if(p.x < xmin) xmin=p.x;
		    if(p.y > ymax) ymax=p.y;
		    if(p.y < ymin) ymin=p.y;
		}
	    }
	    /* This is a little arbitrary... */
	    xmax=xmax+1;
	    ymax=ymax+1;
	    xmin=xmin-1;
	    ymin=ymin-1;
	}

	if(xmax==0 && xmin==0) {
	    xmax=1; xmin=-1;
	}

	if(ymax==0 && ymin==0) {
	    ymax=1; ymin=-1;
	}

	if(squareAspectRatio){
	    // make square...
	    double s;
	    s=Math.max(xmax,ymax);
	    s=Math.max(s,Math.abs(xmin));
	    s=Math.max(s,Math.abs(ymin));
	    xmax=s; xmin=-s;
	    ymax=s; ymin=-s;
	}

	double x,y,xx,yy;

	x=(double)d.width; y=(double)d.height;

	xcenter=(int)Math.abs(xmin*x/(xmax-xmin));
	ycenter=(int)Math.abs(ymax*y/(ymin-ymax));

	g.setColor(Color.white);
	g.fillRect(0,0,d.width-1, d.height-1);
	g.setColor(Color.black);
	g.draw3DRect(0,0, d.width-1, d.height-1, true);
	
	plotAxes(g);
	plotData(g);

    }
    

    void plotAxes(Graphics g) {
	double x,y,xx,yy;
	d = getSize();
	/* Draw the tick marks                   XXX add labels too 
	 * XXX make more flexible
	 */
	g.setColor(tickColor);
	if(ticks){
	    double dx=Math.pow(10,(int)(Math.log(xmax)/Math.log(10)))/ntick;
	    double dy=Math.pow(10,(int)(Math.log(ymax)/Math.log(10)))/ntick;
	    xx=dx;
	    while(xx<xmax){
		x = xx*d.width/(xmax-xmin);
		if(gridlines)
		  g.drawLine((int)(xcenter+x),0,
			   (int)(xcenter+x),d.height);
		else
		  g.drawLine((int)(xcenter+x),(int)(ycenter-2),
			   (int)(xcenter+x),(int)(ycenter+2));
		xx+=dx;
	    }
	    xx=-dx;
	    while(xx>xmin){
		x = xx*d.width/(xmax-xmin);
		if(gridlines)
		   g.drawLine((int)(xcenter+x),0,
			   (int)(xcenter+x),d.height);
		else 
		   g.drawLine((int)(xcenter+x),(int)(ycenter-2),
			   (int)(xcenter+x),(int)(ycenter+2));
		xx-=dx;
	    }
	    yy=dy;
	    while(yy<ymax){
		y = yy*d.height/(ymax-ymin);
		if(gridlines)
		   g.drawLine(0,(int)(ycenter-y),
			   d.width,(int)(ycenter-y));
		else
		   g.drawLine((int)(xcenter+2),(int)(ycenter-y),
			   (int)(xcenter-2),(int)(ycenter-y));
		yy+=dy;
	    }
	    yy=dy;
	    while(yy>ymin){
		y = yy*d.height/(ymax-ymin);
		if(gridlines)
		   g.drawLine(0,(int)(ycenter-y),
			   d.width,(int)(ycenter-y));
		else
		   g.drawLine((int)(xcenter+2),(int)(ycenter-y),
			   (int)(xcenter-2),(int)(ycenter-y));
		yy-=dy;
	    }
	}
	/* Draw the axes */
	g.setColor(axesColor);
	g.drawLine(xcenter, 0,
		   xcenter, d.height );
	g.drawLine(0, ycenter,
		   d.width, ycenter );

    }


    void plotData(Graphics g) {
	/* Plot the data points */
	double x,y,x0,y0;
	MPoint p,p0=null;
	for(Enumeration e=points.elements();e.hasMoreElements();){
	    p=(MPoint)e.nextElement();
	    if(p0==null)
		p0=p;
	    g.setColor(p.color);
	    /* XXX Add additional point styles here */
	    switch(p.style){
	    case MPoint.STYLE_TEXT: 
		/* text */
		x = p.x;
		y = p.y - getFontMetrics(getFont()).getAscent() 
		        - 2*getFontMetrics(getFont()).getDescent();
		g.drawString(p.getText(),(int)x,(int)y);
		break;
	    case MPoint.STYLE_RECT:
		/* rectangle */
		x = p.x*d.width/(xmax-xmin);
		y = p.y*d.height/(ymax-ymin);
		g.drawRect((int)(xcenter+x-p.size),(int)(ycenter-y-p.size),
			   2*p.size, 2*p.size);
		break;
	    case MPoint.STYLE_CROSS:
		/* cross */
		x = p.x*d.width/(xmax-xmin);
		y = p.y*d.height/(ymax-ymin);
		g.drawLine((int)(xcenter+x),(int)(ycenter-y-p.size),
			   (int)(xcenter+x),(int)(ycenter-y+p.size));
		g.drawLine((int)(xcenter+x-p.size),(int)(ycenter-y),
			   (int)(xcenter+x+p.size),(int)(ycenter-y));
		break;
	    case MPoint.STYLE_LINTERP:
		/* linear interpolation between points -- size ignored */
		x  = p.x*d.width/(xmax-xmin);
		y  = p.y*d.height/(ymax-ymin);
		x0 = p0.x*d.width/(xmax-xmin);
		y0 = p0.y*d.height/(ymax-ymin);
		g.drawLine((int)(xcenter+x),(int)(ycenter-y),
			   (int)(xcenter+x0),(int)(ycenter-y0));
		break;
	    default: 
		/* disc */
		x = p.x*d.width/(xmax-xmin);
		y = p.y*d.height/(ymax-ymin);
		if(p.size<2) 
		    g.drawLine((int)(xcenter+x),(int)(ycenter-y),
			   (int)(xcenter+x),(int)(ycenter-y));
		else {
		    x = x - p.size/2;
		    y = y + p.size/2;
		    g.fillOval((int)(xcenter+x),(int)(ycenter-y),p.size,p.size);
		}
		break;
	    }
	    p0=p;
	}
    }

    void displayData(Graphics g, Vector v) {
	displayData(g,v,null);
    }

    void displayData(Graphics g, Vector v, Color fixedColor) {
	/* Plot non-saved data points */
	double x,y,x0,y0;
	MPoint p,p0=null;
	if(fixedColor!=null)
	    g.setColor(fixedColor);
	for(Enumeration e=v.elements();e.hasMoreElements();){
	    p=(MPoint)e.nextElement();
	    if(p0==null)
		p0=p;
	    if(fixedColor==null)
		g.setColor(p.color);
	    /* XXX Add additional point styles here */
	    switch(p.style){
	    case MPoint.STYLE_TEXT: 
		/* text */
		x = p.x;
		y = p.y - getFontMetrics(getFont()).getAscent() 
		        - 2*getFontMetrics(getFont()).getDescent();
		g.drawString(p.getText(),(int)x,(int)y);
		break;
	    case MPoint.STYLE_RECT:
		/* cross */
		x = p.x*d.width/(xmax-xmin);
		y = p.y*d.height/(ymax-ymin);
		g.drawRect((int)(xcenter+x-p.size),(int)(ycenter-y-p.size),
			   2*p.size, 2*p.size);
		break;
	    case MPoint.STYLE_CROSS:
		/* cross */
		x = p.x*d.width/(xmax-xmin);
		y = p.y*d.height/(ymax-ymin);
		g.drawLine((int)(xcenter+x),(int)(ycenter-y-p.size),
			   (int)(xcenter+x),(int)(ycenter-y+p.size));
		g.drawLine((int)(xcenter+x-p.size),(int)(ycenter-y),
			   (int)(xcenter+x+p.size),(int)(ycenter-y));
		break;
	    case MPoint.STYLE_LINTERP:
		/* linear interpolation between points -- size ignored */
		x  = p.x*d.width/(xmax-xmin);
		y  = p.y*d.height/(ymax-ymin);
		x0 = p0.x*d.width/(xmax-xmin);
		y0 = p0.y*d.height/(ymax-ymin);
		g.drawLine((int)(xcenter+x),(int)(ycenter-y),
			   (int)(xcenter+x0),(int)(ycenter-y0));
		break;
	    default: 
		/* disc */
		x = p.x*d.width/(xmax-xmin);
		y = p.y*d.height/(ymax-ymin);
		if(p.size<2) 
		    g.drawLine((int)(xcenter+x),(int)(ycenter-y),
			   (int)(xcenter+x),(int)(ycenter-y));
		else {
		    x = x - p.size/2;
		    y = y + p.size/2;
		    g.fillOval((int)(xcenter+x),(int)(ycenter-y),p.size,p.size);
		}
		break;
	    }
	    p0=p;
	}
    }


}