HW#2 --- last modified January 16 2019 00:35:19..

Due date: May 1st 5:30
=========

Files to be submitted: p197hw2file1.zip -- a zip file containing your
======================                     project directory and all the files
                                           in it.

HW1 Purpose: Become more familiar with sprites and data structures in
============ game programming.

Specification:
==============
For this assignment you need to modify demo 03 out of the book. The goal of
this assignment is to write part of a space invaders games.
As a first step you should modify Bckgnd.bmp to be some space-like setting.
Then modify Sprites.bmp to contain the various kinds of space invader
characters in various states of motions. You can also make some bunkers,
and the players character. (Be imaginative if you don't like the traditional
characters one's.)

You should modify LoadImages() in Main.cpp to load in these new images.

Then you should add getX, setX, getXVel, setXVel and getY, setY, getYVel
setYVel methods to CObject so you can get and fix a CObjects location.

You should write a new class CInvaderGroup. It should contain in it
an STL vector of Space Invaders (which are just CObjects). Its clear method
should clear all the invaders from the vector. Its create method
should set up the CObject space invaders in the vector. i.e., set their
initial locations and speed and images. You can make this
method as general as you want in terms of the parameters you have to supply
--for instance maybe pass a struct called CINVADERGRPDESC --
or take no parameters if you feel like this assignment is taking too long.
Although all the invaders are in one vector they should appear on
arranged in rows and columns on the screen and each row should use
a different kind of invader image.
The CInvaderGroup's remove(int i) method removes the invader at the ith
location of its vector. The size button returns the current number of
invaders left in the group.
The CInvaderGroup's draw method calls all the draw methods of invaders
stored in the group.
The CInvaderGroup getTop, getLeft, getRight,
getBottom methods should return the coordinates of the Topmost, RightMost,
Left-most, Bottom-most invader in the group.
The CInvaderGroup's move method call all the move methods of invaders
initially it should make invaders move left to right. When they reach
the right-most invaders reach the right hand side of the screen
all the invaders should move down a bit and start moving
right to left. When they reach the left hand side they should switch
direction again. When the Bottom-most invaders reach the height of the
bunker, the CInvaderGroup should be cleared and recreated.

You should then modify Main.cpp's CreateObject function to
create and instances of the class CInvaderGroup and initialize it and then also
create CBaseSprite's for each of the three bunkers and the players character
and say where each of these should be on the screen.

Next modify ComposeFrame to move the CInvaderGroup object, then
draw out the background, CInvaderGroup object, your character
and the bunkers.

The keyboard_handler should be modified so that left and right
starts your character moving left or right. The space key
should cause the size of the the CInvader group object to be checked.
Then a random space invader from the CInvaderGroup should be deleted.
The up and down keys should stop your character from moving.

Point Breakdown for HW2
=======================

Documentation..........................1pt
CObject correctly modified.............1pt
CInvaderGroup's create method works....1pt

CInvaderGroup's draw method works......1pt
CInvaderGroup's remove method works....1pt
getTop,getBottom,getRight, getLeft
               work....................1pt
CreateObject modified correctly........1pt
ComposeFrame correctly modified........1pt
keyboard_handler correctly modified....1pt

Total.................................10pts