PROJECT: Letters of Blocks

To create a program that generates an image containing a set of letters, made from coordinated blocks.

As an exercise in toning your abstraction abilities (literally seeing one thing, but understanding and using it as something else), there will be a number of 'generic' terms used throughout this (and other) documents throughout the course, requiring you to substitute in the pertinent information (else face confusion or error).

Some examples:

• yourusername - where you see this (likely in a config file or command-line argument), you are NOT to literally type in y-o-u-r-u-s-e-r-n-a-m-e, but instead, substitute in YOUR lab46 username.
• desig - different classes have different class designations. To make one universal document pertinent to ALL classes, specific examples will instead use 'desig', where you must substitute in the class desig of the class YOU are taking and acting upon in that moment. Example class desigs:
  • c4eng - ENGR1050 “C for Engineers”
  • cprog - CSCS1320 “C/C++ Programming”
  • unix - CSCS1730 “UNIX/Linux Fundamentals”
  • data - CSCS2320 “Data Structures”
  • discrete - CSCS2330 “Discrete Structures”

This sort of abstraction is very similar to that we will find in our utilization of variables in programming, where we can have a “name”, but the data associated with it can change based on various conditions.

Do not be a literalist computer! Start to exercise your abstraction abilities.

This document is written with TWO locations in mind:

• lab46 (the system you may retrieve resources and SUBMIT projects)
• your pi (the system you will transfer resources to/from, and WORK ON/COMPLETE projects)

There are commands you can ONLY run on one system or the other. Pay attention to any prompt cues in the given examples (or section headings, context of language leading up to any examples).

For example:

• YOU cannot install software on lab46. You don't have access.
• projects CANNOT be SUBMITTED on your pi.

Please be sure to familiarize yourself with the following content in “the C book”:

• Preface
• Chapter 1
• Chapter 2

For this project, you will be using a graphics design library to render the indicated image.

It is your task to write a program that generates an image containing the representation of a set of letters, in the current directory as your source code and binary, named and accessible as lob0.png

The program will be an exercise in exploration: you will be given some example code that does something. You should poke at it to gain deeper understanding. Then you will, taking out the demo graphics, lay out a set of letters:

43×33

• 4 letters/symbols
  • each symbol is a unique render (if you had 2 letter M's, both M's should look different)
  • the 4 symbols are arranged to comfortably fit within a canvas of 1280×1024 pixels
  • the image will utilize no fewer than 8 different colours
  • letters are to be entirely constructed out of blocks (filled but square rectangles), no smaller than 30×30 pixels a piece and no larger than 50×50 pixels (all blocks must be the same size)

Symbols could be your initials, plus extra to fill up to 4 total symbols.

Restrictions:

• I don't want to see all simple letters (4 L's, 4 I's, etc.)

Develop and test this program on your pi. Only when done, verify that it compiles on lab46.

To utilize the needed functionality for this project, you will need to ensure you have the following packages installed:

• build-essential (hopefully you took care of this in ntr0)
• libgd-dev
• libgd-tools
• libgd3

Your program should:

• have valid, descriptive variable names of length no shorter than 4 symbols
• have consistent, well-defined indentation (no less than 4 spaces per level of indentation)
  • all code within the same scope aligned to its indentation level
• have proximal comments explaining your rationale and what is going on, throughout your code
• perform the intended operation, outputting the correct/accurate information in indicated format
• at the end of your main() function, use a single return statement to conclude your code, return a 0 indicating successful operation

I have prepared a grabit for resources related to this project. To obtain:

lab46:~/src/c4eng$ grabit c4eng lob0
make: Entering directory '/var/public/SEMESTER/c4eng/lob0'
'/var/public/SEMESTER/c4eng/lob0/Makefile' -> '/home/user/src/c4eng/lob0/Makefile'
'/var/public/SEMESTER/c4eng/lob0/lob0.c' -> '/home/user/src/c4eng/lob0/lob0.c'
make: Leaving directory '/var/public/SEMESTER/c4eng/lob0'
lab46:~/src/c4eng$ 

At which point you can change into the newly created and populated lob0 directory.

Since the grabit brought in a Makefile, you can compile your code simply by typing: make

Any compiler errors will go into a text file called errors

To do a full cleaning, run: make clean then make (or make debug)

If you'd like to see compiler messages as you compile, run: make debug

When done and ready to submit, on lab46: make submit

To ensure a level playing field (should some happen to have some programming experience), I would like to restrict you from using:

• selection statements of any kind (you're just manually placing a bunch of differently colored blocks)
• loops of any kind (place everything manually, the benefit is exposing yourself to the problem)

As with any process you are looking to describe or automate (in this case, both), if YOU do not personally understand or appreciate the steps involved, you are going to have a hard time communicating a proficient list of instructions to the computer to carry out.

So, the FIRST order of business would be to, BY HAND, ON A SHEET OF GRAPH PAPER:

• START EARLY: perhaps even while you are working on week 2's “pct2” project. Don't WASTE the abundance of time made available to you. Waiting until the last minute will only preserve frustration and confusion.
• decide what letters/symbols you would like to “render”
• practice plotting them out, figuring out which “squares” on the graph paper grid you would like to fill in
• determine what a good ratio of blocks to screen size would be (holding a 11“x8.5” sheet of graph paper in landscape orientation would be a good fit for the 1280×1024 image you are placing everything within).
  • Figure out what blocks you need to fill in order to “best fit” your symbols within the allocated space (ie the sheet of graph paper representing your image size)
• mark up your appropriately sized and filled out symbols with the different colors the project calls for
• ONCE you have worked out your scheme by hand, you can THEN proceed to start playing with the provided code
  • determine what shapes are being rendered (view it in a web browser or image viewer)
  • make changes to the shapes. Experiment and develop an understanding of the coordinate system and how you can predictably impact the shape as it is rendered in the image
  • once you understand how to manipulate the shapes, remove the demo shapes and start laying down your own shapes
• the provided code infrastructure may not be adequate for the demands of the project, and will need to be expanded in some areas
  • see if you understand the patterns of the existing infrastructure, and explore attempts to expand it to support your project aims
  • ASK QUESTIONS so as to maintain an understanding of what is going on

Depending on your computing setup, choose the most practical means of viewing your program's image output:

You've got a monitor and keyboard hooked up to your pi that you are using (preferred method for class).

Open a file browser, web browser, or image viewer and navigate to/open up your lob0.png image in your ~/src/c4eng/lob0/ directory.

Rinse and repeat as you go through revisions.

You don't have a monitor, so you are logging into your pi remotely (doable, and good intra-system practice)

Once your Makefile and lob0.c file are added to your repository, commit and push.

On lab46, pull and update.

Compile:

lab46:~/src/c4eng/lob0$ make

and run your program:

lab46:~/src/c4eng/lob0$ ./lob0

… which will produce an image (lob0.png); You want to put this in your web space (with the proper permissions set), so you can view it in a web browser:

lab46:~/src/c4eng/lob0$ mv lob0.png ~/public_html/
lab46:~/src/c4eng/lob0$ chmod 0644 ~/public_html/lob0.png

Then, point a web browser at the following URL:

• https://lab46.g7n.org/~yourusername/lob0.png

NOTE: sometimes the web browser caches previous results, you may have to refresh a few times on revisions to get changes to manifest.

To successfully complete this project, the following criteria must be met:

• Code must compile cleanly (no notes, warnings, nor errors)
• Output must be correct, and match the form given in the sample output above.
• Code must be nicely and consistently indented
• Code must be well commented
• Do NOT double space your code. Group like statements together.
• Output Formatting (including spacing) of program must conform to the provided output (see above).
• Track/version the source code in a repository
• Submit a copy of your source code to me using the submit tool.

To submit this program to me using the submit tool, run the following command at your lab46 prompt:

lab46:~/src/c4eng/lob0$ submit c4eng lob0 lob0.c
Submitting c4eng project "lob0":
    -> lob0.c(OK)

SUCCESSFULLY SUBMITTED

You should get some sort of confirmation indicating successful submission if all went according to plan. If not, check for typos and or locational mismatches.

What I'll be looking for:

26:lob0:final tally of results (26/26)
*:lob0:post picture of prototype to #c4eng discord channel [6/6] 
*:lob0:post picture to #c4eng by Sunday before deadline [1/1]
*:lob0:grabit the code on lab46 by Sunday before deadline [1/1]
*:lob0:code is pushed to lab46 repository [6/6]
*:lob0:no negative compiler messages for program [6/6]
*:lob0:proper output formatting per specifications [6/6]

Additionally:

• Solutions not abiding by spirit of project will be subject to a 25% overall deduction
• Solutions not utilizing descriptive why and how comments will be subject to a 25% overall deduction
• Solutions not utilizing indentation to promote scope and clarity will be subject to a 25% overall deduction
• Solutions not organized and easy to read are subject to a 25% overall deduction