ch14.htm

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&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;ImagineMax = 1.20;<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;ImagineMin = -1.20;<BR>
&nbsp;&nbsp;&nbsp;}<BR>
<BR>
&nbsp;&nbsp;&nbsp;// Create zoom of Mandelbrot set<BR>
&nbsp;&nbsp;&nbsp;public Mandelbrot(int width,int height,double
RealMax,double RealMin,<BR>
&nbsp;&nbsp;&nbsp;&nbsp;double ImagineMax,double ImagineMin) {
<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;this.width = width;<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;this.height = height;<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;this.RealMax = RealMax;&nbsp;&nbsp;//
Default starting sizes...<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;this.RealMin = RealMin;<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;this.ImagineMax = ImagineMax;
<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;this.ImagineMin = ImagineMin;
<BR>
&nbsp;&nbsp;&nbsp;}<BR>
<BR>
&nbsp;&nbsp;&nbsp;// Start producing the Mandelbrot set...<BR>
&nbsp;&nbsp;&nbsp;public Image getImage() {<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;img = new CalculatorImage(width,height,this);
<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;return img.getImage();<BR>
&nbsp;&nbsp;&nbsp;}<BR>
<BR>
&nbsp;&nbsp;&nbsp;// Start thread to produce data...<BR>
&nbsp;&nbsp;&nbsp;public void start(int pix[],CalculateFilterNotify
filter) {<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;this.pix = pix;<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;this.filter = filter;<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;new Thread(this).start();
<BR>
&nbsp;&nbsp;&nbsp;}<BR>
<BR>
&nbsp;&nbsp;&nbsp;// See if user wants to stop before completion...
<BR>
&nbsp;&nbsp;&nbsp;public void stop() {<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;synchronized (stopCalc) {
<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;stopCalc
= Boolean.TRUE;<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;}<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;System.out.println(&quot;GOT
STOP!&quot;);<BR>
&nbsp;&nbsp;&nbsp;}<BR>
<BR>
&nbsp;&nbsp;&nbsp;// Create data here...<BR>
&nbsp;&nbsp;&nbsp;public void run() {<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;// Establish Mandelbrot parameters...
<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;double Q[] = new double[height];
<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;// Pixdata is for image filter
updates...<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;int pixdata[] = new int[height];
<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;double P,diffP,diffQ, x, y,
x2, y2;<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;int color, row, column,index;
<BR>
<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;System.out.println(&quot;RealMax
= &quot; + RealMax + &quot; RealMin = &quot; + RealMin +<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&quot;
ImagineMax = &quot; + ImagineMax + &quot; ImagineMin = &quot;
+ ImagineMin);<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;// Setup calculation parameters...
<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;diffP = (RealMax - RealMin)/(width);
<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;diffQ = (ImagineMax - ImagineMin)/(height);
<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Q[0] = ImagineMax;<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;color = 0;<BR>
<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;// Setup delta parameters...
<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;for (row = 1; row &lt; height;
row++)<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Q[row] =
Q[row-1] - diffQ;<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;P = RealMin;<BR>
<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;// Start calculating!<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;for (column = 0; column &lt;
width; column++) {<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;for (row
= 0; row &lt; height; row++) {<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;x
= y = x2 = y2 = 0.0;<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;color
= 1;<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;while
((color &lt; maxIterations) &amp;&amp;<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;((x2
+ y2) &lt; maxSize)) {<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;x2
= x * x;<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;y2
= y * y;<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;y
= (2*x*y) + Q[row];<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;x
= x2 - y2 + P;<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;++color;
<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;}
<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;//
plot...<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;index
= (row * width) + column;<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;pix[index]
= (int)(color % numColors);<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;pixdata[row]
= pix[index];<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;} // end
row<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;// Update
column after each iteration...<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;filter.dataUpdateColumn(column,pixdata);
<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;P += diffP;
<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;// See if
we were told to stop...<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;synchronized
(stopCalc) {<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;if
(stopCalc == Boolean.TRUE) {<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;column
= width;<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;System.out.println(&quot;RUN:
Got stop calc!&quot;);<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;}
<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;}&nbsp;&nbsp;//
end sync<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;} // end col<BR>
<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;// Tell filter that we're
done producing data...<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;System.out.println(&quot;FILTER:
Data Complete!&quot;);<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;filter.setComplete();<BR>
&nbsp;&nbsp;&nbsp;}<BR>
<BR>
&nbsp;&nbsp;&nbsp;// Save the Mandelbrot set as a BMP file...
<BR>
&nbsp;&nbsp;&nbsp;public void saveBMP(String filename) {<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;img.saveBMP(filename,pix);
<BR>
&nbsp;&nbsp;&nbsp;}<BR>
}</TT>
</BLOCKQUOTE>
<HR>
<H2><A NAME="CalculateFilterNotifyInterface"><FONT SIZE=5 COLOR=#FF0000>CalculateFilterNotify
Interface</FONT></A></H2>
<P>
The CalculateFilterNotify interface defines the methods needed
to update an image filter that works with a calculation thread.
As shown in Listing 14.2, the &quot;data&quot; methods are used
for conveying a new batch of data to the filter. The <TT>setComplete()</TT>
method indicates that the calculations are complete.
<HR>
<BLOCKQUOTE>
<B>Listing 14.2. The CalculateFilterNotify interface.<BR>
</B>
</BLOCKQUOTE>
<BLOCKQUOTE>
<TT>/* Interface for defining methods for
updating a<BR>
&nbsp;&nbsp;&nbsp;Calculator Filter... */<BR>
public interface CalculateFilterNotify {<BR>
&nbsp;&nbsp;&nbsp;public void dataUpdate();&nbsp;&nbsp;&nbsp;//
Update everything...<BR>
&nbsp;&nbsp;&nbsp;public void dataUpdateRow(int row); // Update
one row...<BR>
&nbsp;&nbsp;&nbsp;public void dataUpdateColumn(int col,int pixdata[]);&nbsp;&nbsp;//
Update one column...<BR>
&nbsp;&nbsp;&nbsp;public void setComplete();<BR>
}</TT>
</BLOCKQUOTE>
<HR>
<H2><A NAME="CalculatorProducerInterface"><FONT SIZE=5 COLOR=#FF0000>CalculatorProducer
Interface</FONT></A></H2>
<P>
The CalculatorProducer interface, as shown in Listing 14.3, defines
the method called when a calculation filter is ready to kick off
a thread that produces the data used to generate an image. The
CalculateFilterNotify object passed to the <TT>start()</TT>
method is called by the producer whenever new data is yielded.
<HR>
<BLOCKQUOTE>
<B>Listing 14.3. The CalculatorProducer interface.<BR>
</B>
</BLOCKQUOTE>
<BLOCKQUOTE>
<TT>// Interface for a large calculation
to produce image...<BR>
interface CalculatorProducer {<BR>
&nbsp;&nbsp;&nbsp;public void start(int pix[],CalculateFilterNotify
cf);<BR>
}</TT>
</BLOCKQUOTE>
<HR>
<H2><A NAME="TheCalculatorFilterClass"><FONT SIZE=5 COLOR=#FF0000>The
CalculatorFilter Class</FONT></A></H2>
<P>
The CalculatorFilter class in Listing 14.4 is a subclass of ImageFilter.
Its purpose is to receive image data produced by some long calculation
(like the Mandelbrot set) and update any consumer of the the new
data's image. The CalculatorProducer, indicated by variable <TT>cp</TT>,
is what produces the data.
<P>
Since the ImageFilter class was explained in detail in Part III,
issues related to this class are not repeated here. However, a
couple of things should be pointed out. When the image is first
requested, the filter gets the dimensions the consumer wants by
a call of the <TT>setDimensions()</TT>
method. At this point, the CalculatorFilter will allocate a large
array holding the color values for each pixel.
<P>
When the original ImageProducer is finished creating the original
image, the filter's <TT>imageComplete()</TT>
method will be called, but the filter needs to override this method.
In this case, the CalculatorFilter will start the CalculatorProducer
thread, passing it the pixel array to put in its updates. Whenever
the CalculatorProducer has new data, it will call one of the four
methods specified by the CalculateFilterNotify interface: <TT>dataUpdate()</TT>,
<TT>dataUpdateRow()</TT>, <TT>dataUpdateColumn()</TT>,
or <TT>setComplete()</TT>. (The <TT>dataUpdateColumn()</TT>
method is called by the Mandelbrot calculation since it operates
on a column basis.) In each of these cases, the filter updates
the appropriate consumer pixels by using the <TT>setPixels()</TT>
method, then calls the consumer's <TT>imageComplete()</TT>
method to indicate the nature of the change. For the three &quot;data&quot;
methods, the updates are only partial, so a SINGLEFRAMEDONE flag
is sent. The <TT>setComplete()</TT>
method, on the other hand, indicates that everything is complete,
so it sets a STATICIMAGEDONE flag.
<HR>
<BLOCKQUOTE>
<B>Listing 14.4. The CalculatorFilter class.<BR>
</B>
</BLOCKQUOTE>
<BLOCKQUOTE>
<TT>import java.awt.image.*;<BR>
import java.awt.Image;<BR>
import java.awt.Toolkit;<BR>
import java.lang.*;<BR>
<BR>
public class CalculatorFilter extends ImageFilter<BR>
 implements CalculateFilterNotify {<BR>
&nbsp;&nbsp;&nbsp;private ColorModel defaultRGBModel;<BR>
&nbsp;&nbsp;&nbsp;private int width, height;<BR>
&nbsp;&nbsp;&nbsp;private int pix[];<BR>
&nbsp;&nbsp;&nbsp;private boolean complete = false;<BR>
&nbsp;&nbsp;&nbsp;private CalculatorProducer cp;<BR>
&nbsp;&nbsp;&nbsp;private boolean cpStart = false;<BR>
<BR>
&nbsp;&nbsp;&nbsp;public CalculatorFilter(ColorModel cm,CalculatorProducer
cp) {<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;defaultRGBModel = cm;<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;this.cp = cp;<BR>
&nbsp;&nbsp;&nbsp;}<BR>
<BR>
&nbsp;&nbsp;&nbsp;public void setDimensions(int width, int height)
{<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;this.width = width;<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;this.height = height;<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;pix = new int[width * height];
<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;consumer.setDimensions(width,height);
<BR>
&nbsp;&nbsp;&nbsp;}<BR>
<BR>
&nbsp;&nbsp;&nbsp;public void setColorModel(ColorModel model)
{<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;consumer.setColorModel(defaultRGBModel);
<BR>
&nbsp;&nbsp;&nbsp;}<BR>
<BR>
&nbsp;&nbsp;&nbsp;public void setHints(int hints) {<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;consumer.setHints(ImageConsumer.RANDOMPIXELORDER);
<BR>
&nbsp;&nbsp;&nbsp;}<BR>
<BR>
&nbsp;&nbsp;&nbsp;public void resendTopDownLeftRight(ImageProducer
p) {<BR>
&nbsp;&nbsp;&nbsp;&nbsp;}<BR>
<BR>
<BR>
&nbsp;&nbsp;&nbsp;public void setPixels(int x, int y, int w, int
h,<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;ColorModel model, int pixels[],int
off,int scansize) {<BR>