Mand
/*
********************************************************************************
** file: Mand.java
** does: Does an exercise of float math and graphics
** author: Bob Jamison, rjamison@gothamcity.jsc.nasa.gov
**
********************************************************************************
*/
import java.awt.*;
import java.applet.Applet;
/*
********************************************************************************
** MAIN CLASS
********************************************************************************
*/
public class Mand extends Applet
{
MandWin mand;
public Mand()
{
mand = new MandWin();
setLayout(new AbsoluteLayout());
add("North",mand);
show();
}
public static void main(String args[])
{
Frame f = new Frame("Mandelbrot Test");
Mand MandApp = new Mand();
MandApp.resize(410,450);
f.resize(420,420);
f.add("North",MandApp);
f.show();
}
}
/*
********************************************************************************
** MANDELBROT PANEL
********************************************************************************
*/
class MandWin extends Panel
{
Label xposlbl,yposlbl;
double range;
double xc,yc;
int xres,yres;
/*
*****
This does the actual Mandelbrot Set calculation at the given x,y coordinate
and return the number of iterations processed. Done as a separate function
in order to allow it to be used in other ways!
*****
*/
int PointMand(double x,double y,int maxiter)
{
int i;
double a,b;
double a2, b2,twoab,val;
a = b = 0.0;
for (i=0;i<maxiter;i++)
{
a2 = a*a;
b2 = b*b;
val = a2 + b2;
if (val>=4.0)
break;
twoab = 2.0*a*b;
a = a2 - b2 + x;
b = twoab + y;
}
return i;
}
/*
****
This draws the screen
*****
*/
public void update(Graphics g)
{
double x0,y0,x,y;
double delta;
float xpos,ypos,rng;
int i,row,col,tcol,xoff,yoff,iter,lastiter;
Color clr[];
String pos_lbl;
xpos = (float)xc;
ypos = (float)yc;
rng = (float)range;
pos_lbl = "X:"+xpos+" Y:"+ypos+" Range:"+rng;
resize(420,420);
g.clearRect(0,0,420,420);
pos_lbl = "X:"+xpos+" Y:"+ypos;
g.drawString(pos_lbl,155,350);
pos_lbl = "Range:"+rng;
g.drawString(pos_lbl,155,365);
if (xres<=64)
xoff = 118;
else
xoff = 1;
if (yres<=64)
yoff = 158;
else
yoff = 0;
x0 = xc - range/2.0;
y0 = yc + range/2.0;
delta = range / (double)yres;
y=y0;
iter = 0;
lastiter = -1;
clr = new Color[8];
clr[0] = Color.black; /*Use "standard" colors*/
clr[1] = Color.red;
clr[2] = Color.blue;
clr[3] = Color.green;
clr[4] = Color.yellow;
clr[5] = Color.magenta;
clr[6] = Color.cyan;
clr[7] = Color.orange;
g.setColor(Color.red);
g.drawRect(xoff-1,yoff-1,xres+2,yres+2);
g.setColor(clr[0]);
g.fillRect(xoff,yoff,xres,yres);
for (row=0;row<yres;row++)
{
x=x0; tcol=0;
for (col=0;col<xres;col++)
{
iter = PointMand(x,y,63);
if (iter != lastiter) /*Color cache*/
{
lastiter=iter;
g.drawLine(tcol+xoff,row+yoff,col+xoff,row+yoff);
g.setColor(clr[iter&7]);
tcol=col; /*Color transition cache*/
}
x += delta;
}
g.setColor(clr[iter&7]);
g.drawLine(tcol+xoff,row+yoff,col+xoff,row+yoff); /*Finish the line!*/
y -= delta;
}
}
/*
****
Do button callbacks
*****
*/
public boolean action(Event evt,Object obj)
{
double range2;
range2 = range / 2.0;
if (evt.target instanceof Button)
{
String label = (String)obj;
if (label.equals("NW"))
{
xc -= range2;
yc += range2;
repaint();
}
else if (label.equals("N"))
{
yc += range2;
repaint();
}
else if (label.equals("NE"))
{
xc += range2;
yc += range2;
repaint();
}
else if (label.equals("W"))
{
xc -= range2;
repaint();
}
else if (label.equals("E"))
{
xc += range2;
repaint();
}
else if (label.equals("SW"))
{
xc -= range2;
yc -= range2;
repaint();
}
else if (label.equals("S"))
{
yc -= range2;
repaint();
}
else if (label.equals("SE"))
{
xc += range2;
yc -= range2;
repaint();
}
else if (label.equals("In"))
{
range = range2;
repaint();
}
else if (label.equals("Out"))
{
range = range * 2.0;
repaint();
}
else if (label.equals("Big"))
{
xres=400; yres=300;
repaint();
}
else if (label.equals("Small"))
{
xres=64; yres=64;
repaint();
}
}
else if (evt.id == Event.WINDOW_DESTROY)
{
hide();
}
return true;
}
/*
****
Creates the interface
*****
*/
MandWin()
{
Button tmp;
Panel buttons = new Panel();
buttons.setLayout(new GridLayout(4,3));
buttons.add(tmp = new Button("NW"));
buttons.add(tmp = new Button("N"));
buttons.add(tmp = new Button("NE"));
buttons.add(tmp = new Button("W"));
buttons.add(tmp = new Button("In"));
buttons.add(tmp = new Button("E"));
buttons.add(tmp = new Button("SW"));
buttons.add(tmp = new Button("S"));
buttons.add(tmp = new Button("SE"));
buttons.add(tmp = new Button("Small"));
buttons.add(tmp = new Button("Out"));
buttons.add(tmp = new Button("Big"));
resize(420,420);
/*
setLayout(new AbsoluteLayout());
*/
setLayout(null);
add(buttons);
buttons.resize(150,110);
buttons.move(0,310);
range=0.25;
xc=0.0;
yc=0.85;
xres=64; yres=64;
}
}
/*
********************************************************************************
** LAYOUT MANAGER
** Note: This class is not mine. I lost the e-mail where he sent this to me, so I
** can't attribute this,
** but one of the fine engineers at Sun Inc loaned me this nice layout class.
** I'm forever grateful!
********************************************************************************
*/
class AbsoluteLayout implements LayoutManager {
public AbsoluteLayout()
{
}
public void addLayoutComponent(String name, Component comp)
{
}
public void removeLayoutComponent(Component comp)
{
}
public Dimension preferredLayoutSize(Container parent)
{
Insets insets = parent.insets();
int ncomponents = parent.countComponents();
int w = 0;
int h = 0;
for (int i = 0; i < ncomponents; i++)
{
Component comp = parent.getComponent(i);
Dimension d = comp.preferredSize();
Point p = comp.location();
if ((p.x + d.width) > w)
w = p.x + d.width;
if ((p.y + d.height) > h)
h = p.y + d.height;
}
return new Dimension(insets.left + insets.right + w,
insets.top + insets.bottom + h);
}
public Dimension minimumLayoutSize(Container parent)
{
Insets insets = parent.insets();
int ncomponents = parent.countComponents();
int w = 0;
int h = 0;
for (int i = 0; i < ncomponents; i++)
{
Component comp = parent.getComponent(i);
Dimension d = comp.preferredSize();
Point p = comp.location();
if ((p.x + d.width) > w)
w = p.x + d.width;
if ((p.y + d.height) > h)
h = p.y + d.height;
}
return new Dimension(insets.left + insets.right + w,
insets.top + insets.bottom + h);
}
public void layoutContainer(Container parent)
{
int nmembers = parent.countComponents();
for (int i = 0; i < nmembers; i++)
{
Component m = parent.getComponent(i);
Dimension d = m.preferredSize();
m.resize(d.width, d.height);
}
}
}
/* END OF FILE ********************************************************************/
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