C/C++ Programming Help Thread

[pspballer07]

I checked on there about 5 minutes before posting here, the only tutorial I could find was for loading it all into RAM, which isn't really suitable.

why not? you can free the memory it takes up after its done playing.

[Archaemic]

http://forums.ps2dev.org/viewtopic.php?t=8469&start=30
Mess around with that source.

[Auraomega]

why not? you can free the memory it takes up after its done playing.

*Sigh*... because loading mp3s into RAM takes up a lot of space, and I have songs that are almost 100mb big (over an hour long) which simply won't fit into the PSPs memory.

Mess around with that source.

Thanks, I'll take a look :)

-Aura

[hallo007]

what about , dam whats the name again , alright the thing that sony uses to play big mp3files , youresam made one too I guess

[MrChaos]

I wasn't sure if you wanted it so that it registers a 1 ONLY when a button is being pressed or not. If you want a 1 to register only when a button is pressed, then when nothing is pressed the negative kicks in, and allows the code under it to run. As I said, only use if you need it


-Aura

Acutally, that's exactly what I need. Thanks a bunch. :)

[pspballer07]

*Sigh*... because loading mp3s into RAM takes up a lot of space, and I have songs that are almost 100mb big (over an hour long) which simply won't fit into the PSPs memory.

dang dude, what would you need a 100 mb song for?

[Auraomega]

dang dude, what would you need a 100 mb song for?

Lol, I just like VNV Nation (a little too much), the song is 94.4mb big... and its not the only one (I have a few others tending towards that sort of size).

A lot of my music is over 16mb big anyway (16mb being the biggest you can get in a partition if I remember rightly?), so this is more just so I can play all my music how I want, not with Sony's crappy one that only works in the XMB :Argh:

-Aura

[hallo007]

you dont need to copy the complete file to memory

[pspballer07]

oh i see, but I think the mp3player.c from the psp-programming tuts streams it. Did u try it?

[hallo007]

streaming that was the word:):):)

[psp_jono]

No I'm pretty sure the mp3 player library given in the psp-programming tutes loads the entire file into memory.

After a bit of a seach I came up with this thread at ps2dev.org: http://forums.ps2dev.org/viewtopic.php?t=5089.

Specifically PeterM's code half way down the page.

It seems others have also had trouble with this, the solution is to buffer the file reading, filling the buffer from the memory stick while the at the same time playing the stream. The code seems pretty easy to follow.
He does note that it is a bit slow however.

[califrag]

printf("Hello");
printf("Hi");

would be even simplier, but I doubt anyone is going to want their program to just say
Hello
Hi
The string is going to have different values store in it no doubt, which makes both of the above useless.

-Aura

what i was trying to get across is there is no need for having a buffer at all.. you can just do

printf("%s %02f %s", "a string", 2.5f, "another string"); or whatever you want...

printf("%s %02d %s", myCharVariable1, myIntVariable, myCharVariable2); ....

printf("Some Text %s My Int %02d More Text %s", myCharVariable1, myIntVariable, myCharVariable2);

etc etc

of course nobody will have their program just say "hello hi" that's retarded of you to think that is what I was implying.

now of course if you want to make your program twice as long and have to fill a buffer everytime you want to printf something you can always do as mentioned above and do

strcpy(buffer, "Some text");
printf("%s", buffer);

everytime you want something printed...

but then how will you get other variables in there like floats or ints?
you can't with strcpy at least not without casting.. at least as far as I know everytime I try strcpy(buffer, "%s %d", myCharVariable, myIntVariable) I get massive errors ;) (of course I know that doesn't work)

so in the end you would be left with

strcpy(buffer, "some text");
printf("%s %02d", buffer, myIntVariable);

which.. well.. nevermind just do what you want... it all works.

[Auraomega]

@psp_jono:
Cheers, the more source code the merrier

what i was trying to get across is there is no need for having a buffer at all.. you can just do

printf("%s %02f %s", "a string", 2.5f, "another string"); or whatever you want...

printf("%s %02d %s", myCharVariable1, myIntVariable, myCharVariable2); ....

printf("Some Text %s My Int %02d More Text %s", myCharVariable1, myIntVariable, myCharVariable2);

etc etc

of course nobody will have their program just say "hello hi" that's retarded of you to think that is what I was implying.

I never thought you were implying that, but, if you do what you've done there, you will ALWAYS have the same text, because its not in a variable. All the other peices of code shown allow use of loops, but if you looped any code written how you've done it, there will be no variation because you just hardcode the text you want.

Your way would work fine, but its big and bulky, and taking up a lot of pointless space that could just be simplified a LOT by using sprintf.

As for the

printf("%s %02d %s", myCharVariable1, myIntVariable, myCharVariable2);

umm... how do you expected to get a variable into myCharVariable without using sprintf, or hell, without even using a buffer? Not going to happen.
-Aura

[myschoo]

char myCharVar[9] = "hello all"

printf("%s",myCharVar);

this would work right? and i didnt use sprintf

[psp_jono]

char myCharVar[9] = "hello all"

printf("%s",myCharVar);

this would work right? and i didnt use sprintf

Actually no, it would fail because the string is too long for the buffer variable. The string constant "hello all" is actually 10 characters long because of the termenating null character at the end.
All strings should have a terminating null character at the end.

Correct code:

char myCharVar[10] = "hello all";

printf("%s",myCharVar);

:)

[brethren]

char myCharVar[9] = "hello all"

printf("%s",myCharVar);

this would work right? and i didnt use sprintf

yeah jono's right. the compiler automatically adds the '\0' null terminator to a string literal therefore 9 characters isn't enough to store your string. just let the compiler work out the size of myCharVar

char myCharVar[] = "hello all";

[hallo007]

char hallo[5] = "hallo";
works 100% fine


before u say , i say BS
look at this from cprograming.com

#include <iostream>

using namespace std;

int main()
{
  int x;
  int y;
  int array[8][8]; // Declares an array like a chessboard
  
  for ( x = 0; x < 8; x++ ) {
    for ( y = 0; y < 8; y++ )
      array[x][y] = x * y; // Set each element to a value
  }
  cout<<"Array Indices:\n";
  for ( x = 0; x < 8;x++ ) {
    for ( y = 0; y < 8; y++ )
      cout<<"["<<x<<"]["<<y<<"]="<< array[x][y] <<" ";
    cout<<"\n";
  }
  cin.get();
}

[brethren]

char hallo[5] = "hallo";
works 100% fine


before u say , i say BS
look at this from cprograming.com

#include <iostream>

using namespace std;

int main()
{
  int x;
  int y;
  int array[8][8]; // Declares an array like a chessboard
  
  for ( x = 0; x < 8; x++ ) {
    for ( y = 0; y < 8; y++ )
      array[x][y] = x * y; // Set each element to a value
  }
  cout<<"Array Indices:\n";
  for ( x = 0; x < 8;x++ ) {
    for ( y = 0; y < 8; y++ )
      cout<<"["<<x<<"]["<<y<<"]="<< array[x][y] <<" ";
    cout<<"\n";
  }
  cin.get();
}

i'm not a c++ programmer so i'm not qualified to comment on that code but i fail to see what a 2 dimensional array of integers has to do with the point i was making about string literals.

maybe char hallo[5] = "hallo"; does work but that doesn't stop it being wrong

[Archaemic]

No, char hallo[5] = "hallo" will not work. "hallo" is six characters long. The double quotes alway add a null byte at the end. Therefore, even though it appears to be five characters long, it's really six.

[brethren]

i've just seen the point your making, hallo007 (the bolded bit)

when you declare int x[8]; it stores its values like this - x[0] for the first integer of the array and x[7] for the last. thats why the second expression of the for loop is x < 8

[hallo007]

I see my mistak , I mostly use array pointers , they dont have it

[Moca]

I see my mistak , I mostly use array pointers , they dont have it

eh? Assuming you are talking about a C string, a null byte is appended to the end of it...

When you use double quotes, a null byte is appended to the end of the array.

[_dysfunctional]

eh? Assuming you are talking about a C string, a null byte is appended to the end of it...

When you use double quotes, a null byte is appended to the end of the array.

:o Yay! I spotted a moca!

[MrChaos]

Is there anything you guys I could suggest for me to be able to save a homebrew game with? (Besides a .txt?)

[Anti-QuickJay]

.sav file

[pspballer07]

Is there anything you guys I could suggest for me to be able to save a homebrew game with? (Besides a .txt?)

*.anythingyouwant

then u could have ur own save file format that stores all the vars

[_dysfunctional]

Just do something similar to,

typedef struct _GAME_STATE
{
	int blah1;
	int blah2;

	char name[20];
	char lala;

	int level;
	int start;
	int health;
} SGameState;

int saveGameState(const char* path, SGameState* gs)
{
	FILE* pFile = fopen(path, "rb");
	fwrite(gs, sizeof(SGameState, 1, pFile);
	fclose(pFile);
	return 1;
}

int loadGameState(const char* path, SGameState* gs)
{
	FILE* pFile = fopen(path, "rb");
	fread(gs, sizeof(SGameState), 1, pFile);
	fclose(pFile);
	return 1;
}

Then just pick a convenient extension, like '.sav' as Anti has said.

(With error checking, of course.)

[psp_jono]

I see my mistak , I mostly use array pointers , they dont have it

I'm not sure what this post actually means but I'm sorry if I didn't explain the problem well. As you know an array is a collection of common structures stored in sequential memory.

The string "hello all" should actually be stored in sequential memory as:

    [h] [e] [l] [l] [o] [ ] [a] [l] [l] [\0]

rather than:

    [h] [e] [l] [l] [o] [ ] [a] [l] [l]

Where the square brackets are a single byte/char variable.

As you can see the correct example requires the array to be 10 elements long rather than 9.

While a string could be stored in memory without the null char, it isn't a good idea. Many function rely on the null character to signify the end of a string, without it they would continue working past the end of the string reading or writing to random data, this could cause weird, hard to track bugs or complete crashes.

Hopefully this helps :)

char hallo[5] = "hallo";
works 100% fine

I'm pretty sure that wont even compile.

Originally Posted by MrChaos
Is there anything you guys I could suggest for me to be able to save a homebrew game with? (Besides a .txt?)

I'd go with a binary format like _dysfunctional's example. While easier to understand, text format save files are often too easy for people to edit in order to cheat. With binary you can make it harder to modify the variables that are important to cheaters. Especially those with little knowledge of programming.

[califrag]

@psp_jono:
Cheers, the more source code the merrier


I never thought you were implying that, but, if you do what you've done there, you will ALWAYS have the same text, because its not in a variable. All the other peices of code shown allow use of loops, but if you looped any code written how you've done it, there will be no variation because you just hardcode the text you want.

Your way would work fine, but its big and bulky, and taking up a lot of pointless space that could just be simplified a LOT by using sprintf.

As for the

printf("%s %02d %s", myCharVariable1, myIntVariable, myCharVariable2);

umm... how do you expected to get a variable into myCharVariable without using sprintf, or hell, without even using a buffer? Not going to happen.
-Aura

I don't see how using "sprintf" and buffers can simplify this code:

printf("Sometext 2 Moretext");

or

printf("%s %02d %s", myCharVariable1, myIntVariable, myCharVariable2);

to:

char myCharVariable1[50], myCharVariable2[50]; int myIntVariable;
sprintf(myCharVariable1, "Sometext");
sprintf(myCharVariable2, "Moretext");
myIntVariable = 2;
sprintf(buffer, "%s %02d %s", myCharVariable1, myIntVariable, myCharVariable2);
printf("%s", buffer);

keep using sprintf's and buffers for everything and i will keep a minimalist approach. Thanks!
Plus it all depends on what you are doing and whether the text is static or not, and if it is not static of course you will need to use sprintfs to initialize the variables with the data you need.

[Archaemic]

So many things wrong with both of those, I don't know where to begin @@