Some introductory graphics programs

We are providing the following auxiliary document which you should read before doing the corresponding part of the lab:

• Using gmake

Drawing triangles (1 point)

1. Go to your mc38 directory, create a new subdirectory called graphics-fun, and then copy the following file into the graphics-fun directory:

        cp ~mc38/labs/graphics-fun/triangle.cc graphics-fun
   

   The program triangle.cc is the shell of the program you are going to expand into a solution to exercise P3.2. We are providing it since it includes the correct files and provides a starting point for you to write the Makefile you need in order to use gmake.

   Now go to the graphics-fun directory and open up triangle.cc in emacs.

2. First compile the program triangle.cc from emacs using the following command, which I will have explained in class:

        g++ -I/usr/local/lib/cccfiles -L/usr/X11R6/lib -g -Wall -o triangle triangle.cc -lX11
   

3. We now ask you to write a Makefile that will cause the exact same compilation to occur when you execute the following command:

        make -k
   

   Note that this is the default command when you do M-x compile in emacs. This implies that you will no longer have to remember what compile/link command to issue from one emacs session to the next; the Makefile remembers it for you.

   In order to correctly write Makefile, you will need to read the online notes on Using gmake, at least through (and including) the section Basic Operation and Syntax.

4. Now add the necessary code to triangle.cc so that it solves programming exercise P3.2.

5. Check-off: Show us your completed code and demonstrate that it works as stipulated. Also, show us your Makefile and demonstrate that it causes the correct compilation to occur.

Drawing a clock (1 point)

1. Create a shell of a program called, say, clock.cc in the same directory as triangle.cc and Makefile. Note that you will have to include ccc_time.cpp in addition to ccc_win.cpp. You also need to link in the math library by tacking -lm onto the end of your compile/link command.

2. Now modify Makefile so that it simultaneously maintains the two programs. You should refer again to Using gmake; the easiest way you do this is to create a new dependency called, for example all the that refers to the two executables you are maintaining. Then make sure that you have separate dependencies for each of them.

3. Now add the necessary code to clock.cc so that it solves programming exercise P3.16. Be sure that you don't use magic numbers in your code; use constants instead.

4. Check-off: Show us your completed code and demonstrate that it works as stipulated. Also, show us your Makefile and demonstrate that it causes the correct compilations to occur.

Drawing a better clock (1 point)

1. Write another program called, say, better-clock.cc the add twelve ``tick-marks'' around the clock you drew in the previous part corresponding to the twelve hours. Be sure to update Makefile so that it maintains all three programs.

2. (optional improvement) Add text to the clock giving the twelve hours. Be sure the text is placed in a visually appealing manner. As usual, update Makefile.

3. Check-off: Show us your completed code and demonstrate that it works as stipulated. Also, show us your Makefile and demonstrate that it causes the correct compilations to occur.

Adding variables to your Makefile (1 point)

1. Read the Variables section in the online notes on Using gmake, and modify your Makefile so that it defines and uses the following variables. (These variables names, though seemingly obscure, are standard.)

        CXX
        CXXLIBS
        LDFLAGS
        CXXFLAGS
   

2. Check-off: Show us your Makefile and demonstrate that it causes the correct compilations to occur.