C/C++ Programming Help Thread

[SuperBatXS]

Ok, i am still looking for 2 things:

1) How to flip an image using oslib (my signature sprite from right to left)
2) A good scrolling tile engine (i tried to make one...not so well). If i can just get a good example...i have been asking for this quite some months now...
Sorry for being an idiot.

[Xsjado7]

How about searching information on C structs before asking retarded questions.

I didnt know how to go about it. Why research C structs if im not sure i need them. I was just asking for a push in the right direction, i could do the rest myself. And i apologised about the bad explaination. Im sorry for not knowing everything about C, which you obviously do.

@TMNT, thanks, iv never used switch statements before, they seem perfect for what i want to do after reading a little about them

[Grimfate126]

Speaking of searching...er, i still couldn't find a way i can flip an image (my signature into moving left not right). I did find one thing: the oslib samples of Mickey. I found out that you can flip Mickey by deforming him...kind of wierd but once you go past a point it works. However, i was wondering if there is an easier way.

Thanks.

Wow. i just looked and found it within 5 seconds:

oslMirrorImageH(img)
oslMirrorImageV(img)

Mirrors an image horizontally (H) or vertically (V). You can then draw it using oslDrawImage.
Note: For experimented users, the image is not really mirrored, but just its internal coordinates that are modified, so it's very fast.

from the docs.

[SuperBatXS]

Wow. i just looked and found it within 5 seconds:

oslMirrorImageH(img)
oslMirrorImageV(img)

Mirrors an image horizontally (H) or vertically (V). You can then draw it using oslDrawImage.
Note: For experimented users, the image is not really mirrored, but just its internal coordinates that are modified, so it's very fast.

from the docs.

I knew what a mirror was, lol. But i was too busy looking for "flip" so i overlooked it. Thank you and i found it too in the docs.


Thanks Grim!

[_dysfunctional]

My point is that if you obviously know so little about C, you should not be using it. Go read a book.

[Grimfate126]

if you dont use it, you will stop learning the language. just because you suck at something doesnt mean you have to stop using it. i agree with the book part though. books help.

[SG57]

Wouldn't scaling the image, horizontally and/or vertically, by a factor of negative 1 produce the same effect? I always was going to rely on that should i ever need to flip an image, didn't know there was function for it

[pHysiX]

wasn't this thread about helping each other? i've read C and C++ books, but still can't understand everything. especially how unsigned integers work.

I most definitely agree with grimfate. i learnt most of my coding skills from actually working with the code. I used a lot of src code to get to where I am today, not to mention the value of all those maths classes...

just my little thought =]

[BlackShark]

Ok, i am still looking for 2 things:

1) How to flip an image using oslib (my signature sprite from right to left)
2) A good scrolling tile engine (i tried to make one...not so well). If i can just get a good example...i have been asking for this quite some months now...
Sorry for being an idiot.

The one from the Aap lander beta Source code should help you quite a bit, it has the functions to Read, and Draw maps that you specify, its all so pretty Fast, as it doesn't draw the tiles out side the screen AND it uses osl's clipping function. If you need help weeding the things out that are game specific, then go ahead and post parts of the source thats a problem. I don't mind, since Aap lander will be open source from the get go any way. As for the map format, its very simple, it first reads the width and height of a map in the first line, and then loads them into a ray, each number seperated by spaces. and in the DRAW function, it goes through 2 for loops one for x and one for y to draw what ever number is there. It also scrolls if the maps are bigger than the screen, and stops when approaching edges.

[Grimfate126]

Wouldn't scaling the image, horizontally and/or vertically, by a factor of negative 1 produce the same effect? I always was going to rely on that should i ever need to flip an image, didn't know there was function for it

actually, i think its a macro O.o

i dunno about scaling, but it might work.

[SuperBatXS]

Wouldn't scaling the image, horizontally and/or vertically, by a factor of negative 1 produce the same effect? I always was going to rely on that should i ever need to flip an image, didn't know there was function for it

OMG!!! You are back! I missed you so much. Yes, that is a good idea.

[_dysfunctional]

wasn't this thread about helping each other? i've read C and C++ books, but still can't understand everything. especially how unsigned integers work.

I most definitely agree with grimfate. i learnt most of my coding skills from actually working with the code. I used a lot of src code to get to where I am today, not to mention the value of all those maths classes...

just my little thought =]

Unsigned just means the value cannot be less then zero...

[Archaemic]

It also means you get basically twice as many positive values. So an int usually goes from -2^31 to 2^31-1. However, an unsigned int goes from 0 to 2^32-1.

[Judas]

I didnt know how to go about it. Why research C structs if im not sure i need them. I was just asking for a push in the right direction, i could do the rest myself. And i apologised about the bad explaination. Im sorry for not knowing everything about C, which you obviously do.

@TMNT, thanks, iv never used switch statements before, they seem perfect for what i want to do after reading a little about them

My site has a small snippet on structures. Maybe I should make one on switch statements too.

[Grimfate126]

switches are extremely easy to understand. search on google, and youll have them in no time. structures too, but theyre a bit more complicated, when you get into pointers.

[Judas]

switches are extremely easy to understand. search on google, and youll have them in no time. structures too, but theyre a bit more complicated, when you get into pointers.

Yeah, switches are so usefull, and that's why I was pissed when I found out they weren't in Lua. :Argh: And pointers are stupid altogether. :mad:

[Insert_Witty_Name]

Oh yeah pointers are totally stupid...

You could just pass all the data around through functions, but then you'd be back asking questions about pointers when your program won't get above 1 FPS.

Pointers are your friend.

[Bronx]

Pointer are magic ;)

You can't live with 'em, you can't live without 'em.

[Grimfate126]

pointers are gods in disguise. if you cant use em, them yes, they "suck", but thats not their fault ;)

[Judas]

When I said pointers are stupid, I meant I hate using them. Sometimes they can be so difficult. That doesn't mean I don't think they're useful. Hopefully after I've been programming a few years, I'll be better with them. (I'm only going on one year of programming in C.)

[_dysfunctional]

When I said pointers are stupid, I meant I hate using them. Sometimes they can be so difficult. That doesn't mean I don't think they're useful. Hopefully after I've been programming a few years, I'll be better with them. (I'm only going on one year of programming in C.)

So am I...

[MaTiAz]

So am I...

Yeah but we all know that you're just inhuman.

[Moca]

Yeah but we all know that you're just inhuman.

For a second, I thought you were about to post something relevant to C <_<.
Anyway, I started C in December 2006 and had pointers down way less than one year after I started. Pointers are extremely useful. I don't see how you can actually hate them Judas. At first I didn't see the actual point of accessing a variable using pointers, but that changed after I read a paper about them.
This post isn't really related to helping people in C, but I felt that I wanted to share that little bit <_< .

[Grimfate126]

exactly. i remember i made a post in this thread a couple years ago saying "pointers seem pointless". boy was i wrong...

[Judas]

exactly. i remember i made a post in this thread a couple years ago saying "pointers seem pointless". boy was i wrong...

That's exactly why I never like them. They added more difficulty to something that I was already struggling with. And on top of that, I couldn't see a real use to using one. Now that I'm a little more advanced in C, I see the purpose of one, but still don't use them that much. Maybe when I start using them a lot, they'll become a bit more friendly.

[yaustar]

Gah, pointers. Hate the buggers. Dangling pointers, uninitialised pointers, pointers to pointers, deep and shallow copying, etc.

I generally avoid raw pointers as much as possible and use C++ references or write wrapper classes (RAII) to minimise memory leaks. I can't wait till smart pointers are part of the standard.

[Blackbelttcon]

hey if i wanted to make a formula with an exponent, i have

result = pi*r^2;

this is wrong though i get errors.

how would i make an exponent, ive also tryed re2, r^=2, but nothing has worked.

[_dysfunctional]

hey if i wanted to make a formula with an exponent, i have

result = pi*r^2;

this is wrong though i get errors.

how would i make an exponent, ive also tryed re2, r^=2, but nothing has worked.

^ is a bitwise XOR in C, use the pow() function from math.h.

[Blackbelttcon]

um so i should put
result= pi*r pow(2)


srry im just a little confused

[yaustar]

Google: http://www.cprogramming.com/fod/pow.html