Project 1

Introduction

Specification

Bonus

Project Files

How to get these files

How to submit your programs

Grading Scheme

• using STL for a user-defined data type.
• linking into Xlib functions.
• event-driven processing.

void window (int w=DEF_WIDTH, int h=DEF_HEIGHT);

The constructor creates a window of size w*h. The default sizes for width and height are defined in defs.h

Button readMouse (UNIT& x, UINT& y);

This function is used to get the coordinates of the first point. Whenever the user clicks one of the mouse buttons, it will return the respective button code and the coordinates x and y (by reference) of the mouse. Coordinates are measured relative to the upper left corner of the window (as indicated in the figure above). The enumeration type Button is defined in defs.h.

Button readMouse (UINT x1, UINT y1, UINT& x2, UINT& y2);

The second (overloaded) version has to be called for intermediate points and the final point of the polygon. x1 and y1 are the coordinates of the previous point, which have to be supplied. Again, the function will return the button code (return value), and the mouse coordinates x2 and y2 (passed by reference).

Void drawLine (UINT x1, UINT y1, UINT x2, UINT y2);

While the second form of readMouse automatically draws a provisional line, you are responsible for drawing the actual line upon receiving the appropriate mouse code. This is important because you have to keep track of the points belonging to the polygon, and you have to be able to un-draw an unfinished polygon in case the "undo" button is clicked. The lines are drawn in "xor" mode, i.e., if you call drawLine a second time for the same end points (x1,y1) and (x2,y2) the line will be erased.

Finally, you have to use adequate data structures to store the polygon. For the sake of simplicity we are using a struct (members are public by default) for the points. Two data members of type UINT (= unsigned int) are needed for the coordinates. Besides the constructor (which should initialize the x and the y coordinate), only the overloaded output operator << is required. The header file point.h will contain the definition of struct point. In main.C you have to keep points in some sort of list. Basically, any STL container class would suffice, but for our application the doubly-linked list, list is themost suitable one. New points are appended at the end (in STL: push_back). In case of an "undo" operation the queue can be emptied point by point starting at the beginning; at the same time you have to erase the line segments in the window. After the polygon is completed you can use the copy function for an output iterator (connected to cout).

defs.h

general definitions for all modules

window.h

definitions for the window class

window.C

implementations of member functions for window

icon.xbm

X11 bitmap file for the window icon

Makefile

The project make file. Thus just type "make poly" will compile your programs

point.h

this file will contain your definition of the point structure

main.C

the actual code for the polygon draw program

poly.demo

demo program

1. Be sure that you create a sub-directory with whatever name you like, copy the point.h and main.C into it, and enter this directory to make it current working directory.
2. Enter the command "add csc_info"
3. Enter the command "submit CSC311", then some question will be promted on your screen. It is not difficult to answer them correctly. Rememver our section number is 003.

Attention !

        Weight     Files    
          20%      point.h
          75%      main.C
          5%       Comments, Styles

   main.C will be graded by the following:
        Weight     Description
	  20%      Using STL list class for user-defined data type point
          15%      The left click works right
          20%      The right click works right
          10%      The middle click works right
          10%      final output to screen is right