PROJECT: Breakout In Assembly (BIA0)

OBJECTIVE

This week the effort will be towards implementing an assembly breakout game.

EDIT

You will want to go here to edit and fill in the various sections of the document:

https://lab46.g7n.org/notes/comporg/fall2023/projects/bia0

BIA0

Arrays of Structs in Assembly

In Breakout coded in C, we used an array of brick structs to keep track of all the bricks on the field. When porting over to assembly, the approach needs to be changed due to a multitude of factors.

Arrays don't formally exist in assembly. Since in array is simply an unchanging space of sequential memory, the stack must include the data for all the bricks in order. For breakout, each brick has five properties:

X-axis Position
Y-axis Position
Color
Health
Visibility Toggle

Accessing an individual array element uses an ID value to get that position's specific data. In Assembly, we use a register to hold the memory address of a given element's first property. Here's an example in practice:

The first Brick's X Position is in BP-24(The 24th element in the Stack). We copy this memory address and store it within a general register (preferably a later one so its not likely to get overwritten):

mov  R0,  BP
isub R0,  24
mov  R10, R0

Within our for-loop we use to access all the bricks sequentially, we reference individual elements through R10. (i.e. [R10-3] is the current Brick's color value.)

When moving from one brick to the next, we directly adjust the memory address stored in R10. It's simple in practice:

isub R10, 5

This reference point moves from the current Brick's X Position, to the next Brick's X Position. This way, our relative point R10 doesn't change when inside any brick. This allows for loops to work with arrays.

SUBMISSION

To be successful in this project, the following criteria (or their equivalent) must be met:

Project must be submit on time, by the deadline.
- Late submissions will lose 33% credit per day, with the submission window closing on the 3rd day following the deadline.
Executed programs must display in a manner similar to provided output
- output formatted, where applicable, must match that of project requirements
Processing must be correct based on input given and output requested
Output, if applicable, must be correct based on values input
Code must be nicely and consistently indented
Code must be consistently written, to strive for readability from having a consistent style throughout
Code must be commented
- Any “to be implemented” comments MUST be removed
  - these “to be implemented” comments, if still present at evaluation time, will result in points being deducted.
  - Sufficient comments explaining the point of provided logic MUST be present
No global variables (without instructor approval), no goto statements, no calling of main()!
Track/version the source code in your lab46 semester repository
Submit a copy of your source code to me using the submit tool by the deadline.

Submit Tool Usage

Let's say you have completed work on the project, and are ready to submit, you would do the following:

lab46:~/src/SEMESTER/DESIG/PROJECT$ submit DESIG PROJECT file1 file2 file3 ... fileN

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.

RUBRIC

I'll be evaluating the project based on the following criteria:

52:bia0:final tally of results (52/52)
*:bia0:start of effort toward assembly implementation [52/52]

Pertaining to the collaborative authoring of project documentation

each class member is to participate in the contribution of relevant information and formatting of the documentation
- minimal member contributions consist of:
  - near the class average edits (a value of at least four productive edits)
  - near the average class content change average (a value of at least 1024 bytes (absolute value of data content change))
  - near the class content contribution average (a value of at least 1kiB)
  - no zero-sum commits (adding in one commit then later removing in its entirety for the sake of satisfying edit requirements)
- adding and formatting data in an organized fashion, aiming to create an informative and readable document that anyone in the class can reference
- content contributions will be factored into a documentation coefficient, a value multiplied against your actual project submission to influence the end result:
  - no contributions, co-efficient is 0.50
  - less than minimum contributions is 0.75
  - met minimum contribution threshold is 1.00

Additionally

Solutions not abiding by spirit of project will be subject to a 50% 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 or otherwise maintaining consistency in code style and presentation will be subject to a 25% overall deduction
Solutions not organized and easy to read (assume a terminal at least 90 characters wide, 40 characters tall) are subject to a 25% overall deduction

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