22C:030/115 Computer Science III

Program 3: Polylines

DUE DATES:

• Class implementation and test program (items 1-4 ) 10/22/01
  
• Demonstration program and data set (items 5-6) 10/29/01

This program requires you to design, implement and test a templated class called Polyline. The Polyline class represents a connected sequence of three-dimensional line segments. You are to write a program demonstrating your classes that generates a set of Polylines approximating several mathematically defined shapes including spiral curves, sine waves, and Kock snowflakes. The assignment will give you experience in developing a clear specification from a problem statement, experience in the use of linked lists, and additional experience in software coding and testing.

What to submit:

You should submit a directory that includes:

1. README: A file giving a overview of the contents of the directory including:
• Your name and section number.
• A short (2-3 sentence description) of the assignment.
• A one sentence description of each file in the directory.
• An explanation of how to compile your programs.
2. polyline.h: The header file for the new Polyline class.
3. polyline.template: The implementation file for the new Polyline class.
4. polylinetest.cxx: An program that tests the Polyline class.
5. polylinedemo.cxx: An demonstration program.
6. polyline.dat: The output of your demonstration program including polylines approximating spirals, sine curves, a Koch snowflake.
7. A printed copy of the files README, polyline.h, polyline.template, polylinetest.cxx, and, polylinedemo.cxx to be submitted in lecture at the beginning of class on the due date.

The Polyline Class

p = ((1.0,1.0,0.0), (-1.0,1.0,0.0), (-1.0,-1.0,0.0),

                                (1.0,-1.0,0.0), (1.0,1.0,0.0)

In addition to its shape, a Polyline should have a color attribute expressed by three values giving red, green, and blue components of the color. You should use the Point3D class from the first project to represent the points in a line segment.

A Polyline must be represented as a linked list of points.  You may choose to use either a singly or doubly linked list. You should base the Node class and linked list toolkit on the versions defined in the text. A templated version of this code is available in the class account in the directory /group/class/c030/programs/chapter6. The node structure for a singly linked list is pictured below.
 

The Polyline class should include the following functions and operations:

• A default constructor.
• A copy constructor.
• A destructor.
• A set of member functions to add and remove points from a Polyline. 
  
• An assignment operator:

p1 = p2;

• An addition operator that returns that the concatenation of two Polylines (i.e. the combined series of points.)

p3 = p1 + p2;

• Member functions to rotate a Polyline about the X, Y, and Z axes. To rotate a Polyline, each point of the Polyline must be rotated in the same way:

p.rotateX(angle);

p.rotateY(angle);

p.rotateZ(angle);

• A member function that shifts a Polyline. To shift a Polyline, each point of the Polyline must be shifted in the same way:

p.shift(shiftx, shifty, shiftz);

where shiftx, shiftx, and shiftx are doubles giving the amount to shift in the x, y, and z directions.


• Member functions to get and set the color of a Polyline.

p.colorset(red, green, blue);

rvalue = p.colorgetRed();

gvalue = p.colorgetGreen();

bvalue = p.colorgetBlue();

where red, green, and blue are the components of the color. The values of red, green, and blue must be in the range 0.0-1.0.


• An output operator << that prints a polyline. Polylines should be printed in the Virtual Reality Modeling Language (VMRL) format. VRML provides a format for specifying polylines called an IndexedLineSet. An IndexedLineSet represents a set of polylines by giving a list of points followed by lists of indices telling how points are connected terminiated with the value -1. For our purposes, we will give a single list of indices that is simply the sequence [0, 1, 2, ..., n-1, -1] (indicating that point 0 connects to point 1, point 1 connects to point 2, etc.) An example of a polyline in VRML format is shown below:

# Demonstrates a simple indexed lineset
Shape {
       geometry IndexedLineSet {
         coord Coordinate {
           point [
                  # A sequence of five 3 dimensional points
                  0.0 0.0 0.0,
                  1.0 0.0, 0.0,
                  1.0 1.0, 0.0,
                  1.0 1.0, 1.0,
                  2.0 1.0, 1.0,
                  ]
            }
         coordIndex [
                   # Indices of point to connects
                   0, 1, 2, 3, 4, -1,
                  ] 
         color Color {
           color [ 
                  # Red, Green, Blue values to color lines
                  1.0 .5  0.0
                 ]
            } # end color

         # Flag indicating to color the whole line
         colorPerVertex FALSE

       } # End geometry IndexedLineSet

      } # End Shape

The format includes definitions for the coordinates of the end points of the line segments, the indices of the points to be connected, and the color of the line. The three color values are the red, green, and blue components. You should print all of the points in the polyline here. The LineSet defintion indicates that the preceeding points should be interpreted as a line set. For an example of an output file containing two polylines see the file lines.wrl in the class programs directory (/group/class/22c030/programs). To package the shape in VRML format you must include the following line at the beginning of your file:

      #VRML V2.0 utf8

For an example of an output file containing two polylines see the file LineSet.wrl in the class programs directory (/group/class/22c030/programs).

     %vrml LineSet.wrl

A Test Program

You are to write a program that tests your implementation of the Polyline class. This program should carefully test all Polyline member functions. It is your responsibility to demonstrate that each member function satisfies your specifications. Your grade will be determined, in part, by the quality of your testing.

A Demonstration Program

You are to write a second program that demonstrates the use of polylines. This program should include at least one example of a Polyline approximating a spiral and a sine curve. It should also include a Koch snowflake.
• (Specifications for the polyline generating functions are given here.)

Bonus Credit

There will be a contest for the most artistic data set. The top five data sets, judged on their artistic merits by a panel of experts, will get 10 bonus points on the project. Artwork should be separately submitted to the art submission directory. Each student can submit one or two art files by 10/29/01.