C Q&A Thread

[fb39ca4]

Ok, but shouldn't it be & 8? 4 in binary is 100, 8 is 1000.

[calc84maniac]

Actually, it should be & 16

[fb39ca4]

Good point, I forgot to start counting from zero.
EDIT: Works great, this needs to be added to the ndless SVN.

[ExtendeD]

calc84maniac: oops, right

t0xic_kitt3n: sure! Commited as on_key_pressed().

[sammyMaX]

I tried compiling my C code and I get an error when using for loops. It says they're only allowed in C99 mode. What do I do in my makefile to change to C99?
Edit: Never mind, a quick Google found it for me. Still weird, though.

[ExtendeD]

I suppose you were trying to declare a variable within the "for" statement.

[sammyMaX]

Yes, that was the issue, but a simple change in the makefile fixed it.

I'm now looking for a good alphabet for displaying text. I stole a file from this program, http://www.ticalc.org/archives/files/fileinfo/430/43054.html, which has text similar to (or maybe the exact same as) the text seen in the GBC emulator when selecting a ROM. I truly appreciate the maker's hard work, but I am looking for a font that looks more like the default kind found on the Nspire OS.

In addition, my program has the potential to use a LOT of RAM, so is there any way to track how much RAM is left, or how much is being used? It would be convenient for users to know.

[fb39ca4]

You could edit the array with the font (though that will take quite a bit of work), but I think someone just discovered an OS routine to display text at an arbitrary location on the screen, which is worth looking at, but I don't remember the thread

I don't think it is possible to show the amount of free RAM right now, but unless you are using amounts into multiple megabytes, there shouldn't be a problem. How much RAM does your program use? The largest executable I made was 100kb in size, and that runs fine. Just keep away from large arrays of static variables and you'll be fine.

[sammyMaX]

Please point me to the thread if you find it! Anyways, my program is a bignum library, so it will use as much RAM as is available, so it would be useful if that were possible, but in the meantime I might just implement something that measures how much RAM my own program uses, or just skip RAM measurement entirely.

[fb39ca4]

Well, you should be fine then with at least hundred-thousand digit numbers.

[ExtendeD]

Just try to malloc() or realloc() and check a NULL return.

We could also try to export in Ndless the Nucleus memory pool object used by the OS and make possible direct reads of the free space value from the structure.

[sammyMaX]

Trying malloc() is a good way of ensuring enough RAM is available, which I guess is the only thing that matters. Would the second thing you mentioned require a modification to Ndless itself?

[willrandship]

no, just another library, I believe. Ndless already has access to tons of OS calls.

I defer to any higher (any) authority on this matter though

[ExtendeD]

Actually yes, the OS variable is currently not exported.

[willrandship]

There's a higher authority for ya guess I was wrong again.