I wrote this Mandelbrot generator as a demo tool for my former employer's Java accelerator technology. Feel free to do with it what you like; I make no claims of ownership and will admit under duress to stealing the calculation algorithms from someone else's program. I'm making the source code available in hopes that someone may learn something from it. There are even a few comments to make life easier for the next person than it was for me.

Running the program should be obvious. But in case it isn't, here are a few hints:

• To get the first image, click on the Home button or anywhere on the canvas.
• To zoom in on a portion of the image, hold down the mouse button over the canvas. Move the rectangle to the region to be calculated and release the button.
• To zoom back out again, click on the Back button.
• There are calculation routines using int, long, float and double arithmetic. They should produce the same image, subject to precision limitations. To see the differences, calculate an image. Then select a different data type and click the Recalc button.
• The coordinates of a particular picture are represented as the X and Y position of the upper left pixel (reported as the northwest corner) and the distance between pixels in both X and Y dimensions (the delta value).
• Many of the program's features can be modified using <param> tags in the HTML file. Check the comments in the source file for details.
• The source contains code that adds a Save button and permits saving generated images as JPEG files. You'll need to find the save() method of the JTCanvas class and uncomment all of its code. You'll also need to grab a copy of a Java JPEG encoder. Compile the program and then add a <param name="save" value="whatever"> line to the HTML file. (Replace "whatever" with the name of the generated file, which will be followed by an automatically generated sequence number.) You will also need a special policy file to permit writing files. Mine is called Policy. (Clever, n'est-ce pas?) Invoke the appletviewer with the extra argument "-J-Djava.security.policy=Policy" to enable writing of files.
• If you're looking for an explanation of the Mandelbrot set that even normal people can understand, here's one from the fine folks at Cygnus Software.

Take me home:

Comments to: Hank Shiffman, Mountain View, California.