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1996-01-17
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Demonstrating GDI and USER Functions in Fractals
SUMMARY
=======
The MANDEL sample demonstrates GDI and USER functions by working with
fractals. The Mandelbrot Dream provides the following features:
- Drawing the Mandelbrot set and the corresponding Julia set.
- Zooming into any of the sets.
- MDI fractal drawing windows.
- Floating point math and fixed point math.
- Shifting color table entries.
- Changing palette entries and animating palette (color cycling).
- Loading and saving bitmaps created with special effects.
- Changing bitmap colors with flood fill.
- Boundary tracing and creating a clip region for special effects.
- Enumerating printers.
- Loading RLE (or converting .bmp files to RLE) for playing in viewer.
- Saving the RLE in memory to disk.
Note: The sample makes use of 64-bit integers for its fixed point math.
MORE INFORMATION
================
Drawing the Mandelbrot Set and the Corresponding Julia Set
- Choose the Mandelbrot Set menu item from the Create menu to create an
MDI child window to draw the set in, if one has not already been
created.
- Choose either "use Fix Point math" or "use Floating Point math" from the
Draw menu to decide if floating point or fixed point math is to be used.
Fixed point is faster, however, you lose resolution sooner as you zoom
in.
- Choose the number of iterations from the Iteration menu item and choose
Step from the Draw menu. The higher the number of iterations, the more
detail in the picture, but the more time it takes to generate the
picture. The step determines whether every scan line is drawn. The more
scan lines, the better the picture, but the longer it takes to generate
the picture.
- Choose Draw Set from the Draw menu.
- Use the right mouse button to select a point in the Mandelbrot set (the
drawing surface of the Mandlebrot window). A new Julia MDI window is
created. Choose Draw Set from the Draw menu to start drawing.
- The point selected with the right mouse button determines the complex
constant to use for the Julia Set.
Zooming Into Any of the Sets
- Click, drag and release with the left mouse button to describe the zoom
in the region. A new MDI child of the same type as the parent
(Mandelbrot window or Julia window) is created.
- Choose Draw Set from the Draw menu to start drawing.
MDI Fractal Drawing Windows
- Choose either Mandelbrot Set or Julia Set from the Create menu to create
a new MDI window for drawing.
- Or, use the left mouse button to describe a zoom-in region in either a
Mandelbrot or Julia MDI window to create a new MDI window for drawing.
- Or, click on the Mandelbrot window with the right mouse button to create
a Julia MDI window corresponding to the mouse click position in the
Mandelbrot window.
Floating Point Math and Fixed Point Math
Choose the appropriate menu item ("Floating Point math" or "Fix Point math")
from the Draw menu. The Fix Point math uses 20.11 fixed point integer
arithmetic for calculations.
Shifting Color Table Entries
Choose Shift from the Color menu or hit F10 to shift the color table entry.
The picture of the active MDI window is updated.
Changing Palette Entries and Animating Palette (Color Cycling)
Choose Cycle from the Color menu or hit F11 to start color cycling the
picture. The menu item is grayed if the display device does not support
palette management.
Loading and Saving Bitmaps Created With Special Effects
Choose Load Bitmap from the Bitmap menu to load a bitmap into the active
child window. Or, choose Save Bitmap As to save the picture in the active
MDI child window.
Changing Bitmap Colors With Flood Fill
Choose Custom from the Color menu to select a color. The cursor is changed
to a paint can over the active child window. Click with the left mouse
button on the picture; the old color under the cursor is changed to the new
color.
Boundary Tracing and Creating a Clip Region For Special Effects
From any active Mandelbrot window, choose Set Mandelbrot Clip region from
the Region menu. The boundary of the escape region is traced. The region is
then selected as a clip region. Thus, if you load a bitmap for display, the
bitmap only shows through the clip region. The new picture can then be
saved. To remove the clip region, choose Remove Clip Region from the Region
menu.
Note: The boundary tracing algorithm may trace out a small island of only
several pixels and stop. If that happens, change the size of the window or
create another zoom window and trace again.
Enumerating Printers
On start up, the Mandelbrot Dream enumerates the printers and inserts the
printers into the Print menu. Selecting the printer on the Print menu prints
the picture in the active MDI window.
Loading RLE (or convert .bmp files to RLE) for Playing in Viewer
- Choose the Viewer item from the Create menu to create a viewer window or
bring any existing viewer window to the top.
- Select Load Bitmap(s) from the File menu for loading RLE or .bmp files
into the memory from disk.
- Select Play or Play Continuously from the Options menu for viewing.
- For a demonstration, load the .\rsc\julia.rle file and select Play
Continuously. The Julia.rle is a collection of the various julia sets
along the boundary of escaping and non-escaping points of the Mandelbrot
Set.
Saving the RLE in Memory to Disk
- Choose the Viewer item from the Create menu to create a viewer window or
bring any existing viewer window to the top.
- Select Save Bitmap(s) from the File menu for saving the RLE(s) from
memory to disk.