GSP 125 Week 5 iLab Shapes

Order ready-to-submit essays. No Plagiarism Guarantee!

Note:  All our papers are written from scratch by human writers to ensure authenticity and originality.

GSP 125 GSP/125 GSP 125 Week 5 iLab

// INSTRUCTIONS

// ————

// Compile this code. After pressing any key to clear the instructions, You

// should see three rectangles labeled ‘#’, ‘b’, and ‘c’. You should also see

// two triangles, labeled ‘d’ and ‘e’. Pressing ‘>’ and ‘<‘ will change which

// shape is labeled ‘#’. Pressing ‘w’, ‘a’, ‘s’, and ‘d’ will move the shape

// labeled ‘#’. Pressing ‘space’ will randomize the selected shape.

//

// Read through this code! Try to understand it before starting the assignment.

// Comment confusing lines with what you think code is doing, and experiment

// with existing code to test your understanding.

// Once you feel comfortable with this code, accomplish each of the following,

// and make sure your code compiles and runs after each step is completed.

//

// 1. Getting comfortable with the code

// a) Create a “makeRandom” method in both the Rect and Tri classes, based

// on the “makeRandomRect” and “makeRandomTri” functions in

// “application.cpp”. The makeRandom function should take no parameters,

// and instead make itself random. Removing the old “makeRandomRect”

// and “makeRandomTri” functions as well. Be sure to consider what to do

// about “screenMin” and “screenMax”.

// b) Create a print method for the Tri class, similar to the print method

// for the Rect class. This method may come in very handy when debugging.

// 2. Create Shape base class

// a) Create a header file (without a .cpp file) for a Shape class.

// b) Create the Shape class, which should have no member variables.

// c) Make the Shape class an interface for the Rect and Tri classes. Shape

// should have pure-virtual methods for each method that Rect and Tri have

// in common.

// d) Make sure Shape has a virtual destructor with an empty body.

// 3. Make Rect and Triangle extend Shape

// 4. Change selected

// a) Change the type of “Application::selected” from “void *” to “Shape *”.

// b) Every piece of code that typecasts “selected” (and the logic around it)

// can be removed now. Simply call functions using the “Shape” interface.

// c) Remove the “selectedType” variable from Application. Logic that needs

// some form of RunTime Type Information should use dynamic_cast instead.

// 5. Merge all Shape objects into a single array

// a) Create an array of Shape pointers in the Application called “shapes”.

// b) Making a complementary NUM_SHAPES variable would make sense.

// b) Remove “rectangles” and “triangles” arrays.

// c) Put each Tri and Rect object managed by the Application class into

// the “shapes” array. This will require re-factoring in multiple files.

// While removing references to “rectangles” and “triangles” arrays, it

// may make sense to replace pairs of for-loops using each of the old

// arrays with a single for-loop using just “shapes”.

// 6. Make “shapes” dynamic

// a) Give Application::init() 2 parameters: int numRect, int numTri

// b) Make “shapes” a pointer of type “Shape **”, and allocate it to be

// “numShapes” big, where “numShapes” is an int member of Application

// equal to (numRect + numTri), defined in Application::init().

// c) When calling “app.init()” in main, pass valid arguments for numRect

// and numTri.

// d) De-allocate the “shapes” array in Application::Release().

// 7. Clean up old variables

// a) Remove the TYPE_RECT and TYPE_TRI variables from Application.

// b) Remove NUM_TRI and NUM_RECT, and any NUM_SHAPES variable as well. Use

// numShapes where needed.

// 8. Add Circle class

// a) Create a header file AND a source file for a Circle class.

// b) Use Rect and Tri as examples to create the Circle class with.

// c) A Circle class should have at least a 2 dimensional position, and a

// radius.

// d) A simple algorithm for drawing a Circle will be similar to drawing a

// Rect or Tri, thought it might include the following code:

// float dx = center.x – col, dy = center.y – row;

// if( dxdx + dydy <= radius * radius ) {

// moveCursor(col, row);

// putchar(letter);

// }

// e) Add an additional parameter to Application::init(), “int numCircles”.

// Implement init to generate Circle objects along with Rect and Tri

// objects.

// 9. Implement add/remove for the shapes array

// a) Add code that increases the size of the shapes array, adding a random

// shape, whenever the ‘=’ or ‘+’ key is pressed. Take a look at the week

// 5 lecture showing explicit constructors for help with this algorithm.

// a) Add code that decreases the size of the shapes array, removing the last

// shape, whenever the ‘-‘ or ‘_’ key is pressed. End the program when the

// last shape is removed. Removing a shape, like adding a shape, can be

// done by allocating an array of a different size (smaller this time).