Homework...

Do step 1, and one or more of the following:


Step 1: More detailed fractal renderings...

  Modify the code you wrote during lab.

  Change all definitions of float to Flt

  Get it working.

  When it works, go to the top of the program and look for the type define

  for Flt, and change it to double.
  note: the definition may already be at double.

  Now you will be able to zoom the fractal to a greater level of detail.


Step 2: Zoom to a spot...

  Use your mouse-zoom code to find an interesting spot in the Mandelbrot set.

  Choose a key-press that will take the user to this spot, and display it.

  Update your menu, to choose this view from the menu.

  In the terminal window, display the x, y, width, height.
  You may also display the information on the image itself. Use the text that
  is used to display the menu text.


Step 3: Find this spot...

  Choose one of the images below...

A

B

C

D

E

F

  
  Each image contains the (x,y) coordinates and the dimensions of the
  location within the Mandelbrot fractal.

  (Right-click and view the image to see the coordinates and dimensions.)

  Your job is to render this image on a key-press.

  Do your best to get the palette colors correct.

  All images can be rendered using double-precision variables.

  Ask for help if needed.

Example using image A:

  X: 0.256007598142        left side
  Y: -0.000761248519       top
  Width: 0.000016640387    width
  Height: 0.000014337269   height
  iterations: 500          iterations to achieve image


Step 4: Duplicate the Wikipedia image...



here is my first attempt...







Get ready...

Do your work in your Odin directory: 3480/c/

Copy the starting files from Odin /home/fac/gordon/p/3480/code/mandel/*

Build the program: make

Run the program: ./a.out

Follow along with Gordon as we code...




Programming...

We will write code together in mandel.cpp

Look at the following link to learn more about the Mandelbrot fractal.
Wikipedia Mandelbrot

To code, we will use the pseudocode near the bottom of the page.
pseudocode

We will turn the pseudocode into C++ code.




Student additions to this lab assignment.

After we are all rendering the Mandelbrot set, you will add some features to
the program.

1. Add a color palette to the fractal display.

   Setup an array of RGB color values, such as:
      unsigned char arr[100][3];

      -or-

      struct Color {
         unsigned char r, g, b;	
	  } arr[100];


   Populate the array with random colors, or some type of sequentially
   arranged color values. You decide. You experiment.

2. Allow the user to zoom the fractal image

   How to do it...

   The user will click the mouse somewhere on the image.
   
   Record the window coordinates of the mouse position.
   
   Knowing the current coordinates of the fractal drawing, calculate the
   fractal coordinates of the mouse position.
   
   Let that point be the center of a new small rectangle. Calculate the
   coordinates of the new rectangle. Give the new rectangle the same
   aspect-ratio as the display window.

   Redraw the fractal with coordinates of the new rectangle.

   Define a key-press to return to the original coordinates.




Extra - material for a project

1. Create a zoom animation.

2. Other ideas by students.




What to turn in...
Gordon will collect your mandel.cpp and Makefile.