Download Sudoku CE

(original post starts here)
I've been working on a Sudoku game written in C for the CE series of calculators.



This implementation of the game will be very much inspired by JWinslow23's Puzzler's Sudoku for the monochrome calcs.

Currently Implemented Features:

• Draw a puzzle from a 9x9 array
  
• Move the cursor and insert numbers in empty cells
  
• Erase number from a cell with [0]

Planned Features:

• Enlarged view of current puzzle section, as can be seen in Puzzler's Sudoku linked above
  
• "Penciling in" numbers, shown in the enlarged section
  
• Loading level packs from an Appvar
  
• Randomly generated puzzles
  

As this is my first ever project written in C, I would greatly appreciate any feedback related to code. The GitHub repository for this project can be found here.

My first (minor) question is, what is the "proper" way to prevent super fast key repeating? Right now I just have a delay(100) after every arrow key press, but is there a better/more generally accepted way to do this?

I like to have it loop until the user releases the key, which would look something like this:

Code:


So that would do something when you press enter, then loop until enter is released. This means that the game will respond as fast as you can click, as well.

Some notes:

* Global variables like this: https://github.com/Jeffitus/Sudoku-CE/blob/master/src/main.c#L26-L29
Don't use global variables, unless they are large data blocks or some other item. Even then they should be avoided.
Use local variables as much as possible. The variable names you gave also are not at all helpful in telling what they do.

* This data block: https://github.com/Jeffitus/Sudoku-CE/blob/master/src/main.c#L26-L29
Is a global, yet you are passing it around to other other functions. If you are going to make it a global, make it a global and never treat it like a local. Otherwise, put this in the main function as a "static" local.

* There's a lot of these kind of lines: https://github.com/Jeffitus/Sudoku-CE/blob/master/src/main.c#L80-L83
This is nearly impossible to read. Use a local variable inside the loop to store intermediates rather than one huge line. E.g. "int col = i * (PLAYING_GRID_SIZE - 1);", and then combine them in the statement.

* This should be a do {} while loop: https://github.com/Jeffitus/Sudoku-CE/blob/master/src/main.c#L101
This is because kb_Data isn't updated until kb_Scan is called.

* This chuck of code is unnecessary: https://github.com/Jeffitus/Sudoku-CE/blob/master/src/main.c#L137-L187
This code can be greatly optimized. Feel free to think about how, remember if you ever feel like you are copying / pasting there's usually a better way.

* This other chunk of code: https://github.com/Jeffitus/Sudoku-CE/blob/master/src/main.c#L108-L135
You can see here for detecting presses, and then extend that to repeating.

* Use gfx_BlitBuffer() here: https://github.com/Jeffitus/Sudoku-CE/blob/master/src/main.c#L207

* For some reason this function is called multiple times: https://github.com/Jeffitus/Sudoku-CE/blob/master/src/main.c#L96

* These two lines don't make sense: https://github.com/Jeffitus/Sudoku-CE/blob/master/src/main.c#L75-L76
Either use blitting, or use swapping, but usually it doesn't make sense to use both. I'll point you to this page.

* Unless I'm mistaken, you only need to check current_board here: https://github.com/Jeffitus/Sudoku-CE/blob/master/src/main.c#L199

* And lastly: why the hell is this function not used anywhere but at the start: https://github.com/Jeffitus/Sudoku-CE/blob/master/src/main.c#L54
This function should render the lines and the numbers lol.

Thanks! I'll be sure to look into all of these in-depth later, but this:

I'm checking both because I only want it to draw to numbers in cells that are allowed to be updated. If I don't check puzzle, it will draw the whole puzzle in the dark blue color, rather than the dark gray color (which reminds me, I should probably change those colors so they aren't so similar).

I've been working on this on and off for a while; most of the changes I've made are not visible, but they will benefit me when adding features in the future. Here's a list of what has been accomplished:

• The entire puzzle handling code has been redone (previously it involved two arrays, but it now only requires one).
  
• The puzzle is now displayed accurately (It is actually incorrect in the apng in the first post- somehow I didn't notice this until later).
  
• Key handling now can detect presses vs. holds.
  
• Everything Mateo mentioned in his post has been fixed (I think? I'm not exactly sure if my number pressing code is optimized fully) with the exception of point three regarding readability. To be honest, I forgot about this point until reviewing this thread today, so this can easily be resolved soon.
  

I'm currently almost finished with the win checking code; once that is done I'll begin working on randomly generated puzzles of different difficulties.

Win checking is complete!



It is pretty fast, and it only runs when every cell is filled in. However, it does noticeably slow the game down slightly if every cell is filled but the puzzle is not completed correctly.

Also, the win text is temporary; I only added it so the program doesn't quit instantly once you win. It will be more polished in the final release, as will the numbers themselves (I'll most likely use FontLibC).

As of today, all game mechanics are completed, including penciled in numbers!

As you can see in the screenshot, when the puzzle is as big as it can possibly be on the CE's screen, the smallest text size can just barely fit 3x3 in the cells.

My next step is to work on menus and the UI for the game. I'm hoping to be able to import puzzles from Appvars as well, but that might take some time (like this whole project hasn't taken some time ) given I have never tried anything with FileIOC before.

Looking cool man, glad you got the penciled stuff working!

Some smaller updates:

• A modified version of the calvetica font, for use with FontLibC.
  
• A pencil sprite in the bottom right corner, used to show when pencil mode is on or off.
  
• A timer in the top right corner.

Here's a screenshot showing off these latest changes:



At this point, I'm likely going to just add a menu and then release the first version, leaving loading from Appvars for a later release.

The first release of this game is complete! Thanks to everyone who helped me finish my first C program.
Right now you can download this release from GitHub, and from the archives.

Pretty much the only things added since the last update were the menus and some minor optimizations.

I am still planning on working on levels from AppVars, but it might be a while before that happens.

Looking great!! I'm glad that you added the tiny text markings :3