C/C++ Programming Help Thread

[Raphael]

Surely

if(pad.Buttons & (PSP_CTRL_CIRCLE & PSP_CTRL_CROSS))

will only work if both buttons are pressed, which makes the code smaller again.

-Aura

No, that will never evaluate to true, because PSP_CTRL_CIRCLE and PSP_CTRL_CROSS have distinct bits set, so the logical AND of both will evaluate to 0 and any value AND 0 is 0 = FALSE.

[Auraomega]

*Looks in pspctrl.h*

PSP_CTRL_CROSS = 0100000000000000
PSP_CTRL_CIRCLE = 0010000000000000

Surely if they were AND'ed together they would become 0110000000000000? Would that still not work? Bit 14 and bit 15 are both set, so surely that would be correct, even if only in this case? (I think my electronics is conflicting here).

-Aura

[Raphael]

*Looks in pspctrl.h*

PSP_CTRL_CROSS = 0100000000000000
PSP_CTRL_CIRCLE = 0010000000000000

Surely if they were AND'ed together they would become 0110000000000000? Would that still not work? Bit 14 and bit 15 are both set, so surely that would be correct, even if only in this case? (I think my electronics is conflicting here).

-Aura

You're confusing logical AND with logical OR. That's why I used OR in my code snippet.

[brethren]

*Looks in pspctrl.h*

PSP_CTRL_CROSS = 0100000000000000
PSP_CTRL_CIRCLE = 0010000000000000

Surely if they were AND'ed together they would become 0110000000000000? Would that still not work? Bit 14 and bit 15 are both set, so surely that would be correct, even if only in this case? (I think my electronics is conflicting here).

-Aura

&
0 & 0 = 0
1 & 0 = 0
0 & 1 = 0
1 & 1 = 1

|
0 | 0 = 0
0 | 1 = 1
1 | 0 = 1
1 | 1 = 1

hope that helps:)

[Auraomega]

Hmm, is there an XOR function, or would I have to do something like:

if ( (!( a & b )) & ( a | b ) );

I think thats right... lord help me I have an exam on this sort of thing very soon and I'm getting mighty confused

-Aura

[FaT3oYCG]

hi i was just wondering i know of the

sceKernelLoadExec(); command

i just wanted to know how i would use this to load an eboot from inside another eboot

- if it is not the right command to do this could you please direct me to somewhere i could lean how to do this please or just tell me i dont mind as long as i find out

[Auraomega]

If you mean 2 seperate EBOOT files, and are running in 1.50 kernel:

     struct SceKernelLoadExecParam param;
     memset(&param, 0, sizeof(param));
     param.size = sizeof(param);
     param.key  = "game";

     sceKernelLoadExec(FILEPATH, &param);

for 3.XX:

     struct SceKernelLoadExecVSHParam param;
     memset(&param, 0, sizeof(param));
     param.size = sizeof(param);
     param.key  = "game";

     sctrlKernelLoadExecVSHMs2(FILEPATH, &param);

for loading an EBOOT that is hard coded into another EBOOT:

     struct SceKernelLoadExecParam param;
     memset(&param, 0, sizeof(param));
     param.size = sizeof(param);
     param.key  = "game";

     sceKernelLoadExecBufferPlain(sizeof(BUFFER), BUFFER, &param); //might need to be strlen(BUFFER) depending on your storage type.

//Not sure if the above will work as I've never actually loaded from a buffer before.

In any case, unless you are making a loader, you are best to load .prx files. Loading EBOOTs is best left for something like a shell, where as an app that requires plugins is best suited to .prx files.

-Aura

[FaT3oYCG]

thanks man great response

- did you get them from the samples ?????

[Auraomega]

Nope, just dragged them out of the Project4 source code (except the buffer one which I pulled from thin air and a header file )

-Aura

[brethren]

Hmm, is there an XOR function, or would I have to do something like:

if ( (!( a & b )) & ( a | b ) );

I think thats right... lord help me I have an exam on this sort of thing very soon and I'm getting mighty confused

-Aura

exclusive or ^

^
0 ^ 0 = 0
1 ^ 0 = 1
0 ^ 1 = 1
1 ^ 1 = 0

there you go:)

[Auraomega]

Well that certainly explains a lot, tried doing power with ^ the other day and my code went all weird, now I know why... incidently, is there a function for powers in c?

You know what, I think I'm gonna use Google and see what operators there are, its something I've neglected so nows a good time to check I guess.

-Aura

[Raphael]

pow/powf
There are no other operators in C for mathematical functions.
arithmetic:
+, -, *, /, %
boolean:
binary: &&, ||, !
logical: &, |, ~, ^

In C++ you can overload those operators so you can do power with ^ for example.

[FaT3oYCG]

hi relating to what i asked yesterday and what aura replied with i added it into the code and set the variable but i get this error

error: 'memset' was not declared in this scope

do i have to include a certain lib or do i have to set that as an int or something sorry im new to coding in c for the psp

[tommydanger]

you need to include the proper header files
#include <string.h>
next time ask google, as it will give you the answer within milliseconds :P

[FaT3oYCG]

thanks man - i didn't realize because in my other source that is already included so i haven't actually checked the commands

thanks again

THE RESULT OF YOUR HELP

[Archaemic]

pow/powf
There are no other operators in C for mathematical functions.
arithmetic:
+, -, *, /, %
boolean:
binary: &&, ||, !
logical: &, |, ~, ^

In C++ you can overload those operators so you can do power with ^ for example.

You forgot the ternary operator, which is perfect for obfuscating code.

boolean ? value-if-true : value-if-false

e.g.:

printf("%s",0?"true":"false"); //prints false
printf("%s",1?"true":"false"); //prints true

[Raphael]

Well, I don't consider that an operator in the same category as the above, as as you said it's a ternary operator (meaning it has three operands) :P But oh well... if you so insist, yeah, that one exists too ;)

[Archaemic]

You're right, it is different from the other operators, but I always see it listed alongside the other operators, whether they're binary or unary.

[pspfreak101]

Can someone link me too the pre-complied toolchain thanx :)

[FaT3oYCG]

on my guide

it is the pspdev folder

PSPDEV FOLDER - (precompiled by me) - THE PSPTOOLCHAIN

EDIT 1:

hi sorry for double posting but i have a problem

i have added umd functions into lua player but i am struggling adding the command to activate the umd as disc0: it all compiles fine but whenever i use the command in luaplayer it says a nil value ???? anyone know why

it is probably something with the code but i dont know what

i tried multiple different ways but none seem to work

here is the current code at the moment i just put the example code in to see if that worked but no luck

here it is

static int lua_UmdActivate(lua_State *L)
{
	if (lua_gettop(L) != 0) return luaL_error(L, "no arguments expected");
	sceUmdWaitDriveStat(UMD_WAITFORDISC);
	int i;
	i = sceUmdCheckMedium(0);
	if(i == 0)
	{
		sceUmdWaitDriveStat(UMD_WAITFORDISC);
	}
	sceUmdActivate(1, "disc0:");
	sceUmdWaitDriveStat(UMD_WAITFORINIT);
	return 0;
}

EDIT 2:

ok nevermind i figured out why it wasnt working now what i want to know is if i wanted to load the umd and play the game

how would i do that because i tried loading the boot.bin and the eboot.bin and then both and neither worked so could i have some help please

thanks

EDIT 3:

ok it has come to my attention that i will need to use

sceKernelLoadModule and sceKernelStartModule

but i cant seem to get it to work

if a specific lib is needed could you please tell me which one and give me a short example of just loading and starting a module i looked at the sample in the svn but i had no luck and just found that it confused me more

here is the code that i am using

static int lua_ExecModule(lua_State *L)
{
	if (lua_gettop(L) != 1) return luaL_error(L, "one argument expected");

	struct SceKernelLMOption option;
	memset(&option, 0, sizeof(option));
	option.size = sizeof(option);
	option.position = 0;
	option.access = 1;

	const char *FILEPATH = "";

	FILEPATH = luaL_checkstring(L, 1);

	int moduleid = sceKernelLoadModule(FILEPATH, 0, &option);
	sceKernelStartModule(moduleid, 0, NULL, 0, NULL);
	return 0;
}

thanks

[Xsjado7]

Hey, i was just wondering how i would go about storing a bmp image in an array for access later. Thanks

[Waterbottle]

pow/powf
There are no other operators in C for mathematical functions.
arithmetic:
+, -, *, /, %
boolean:
binary: &&, ||, !
logical: &, |, ~, ^

In C++ you can overload those operators so you can do power with ^ for example.

How about << and >>? Those seem pretty mathematical to me, and they also seem like operators.

@Xsjado, here's a class for bmp loading I wrote a while back. If you want to understand it I'd recommend you to use google, there's plenty of sites there regarding bmps.

loadBMP() allocates the necessary memory and makes data point to the bmp, and stores the bmp's size in the width and height variables.

class Image
{
     public:
         Image(){}
         ~Image();
         
         bool loadBMP( const char *path );
         
         unsigned char *data;
         unsigned int width;
         unsigned int height;
};

Image::~Image()
{
      free( data );         
}

unsigned int getUINT( const unsigned char *p )
{
    return p[0] + (p[1]<<8) + (p[2]<<16) + (p[3]<<24);
}

bool Image::loadBMP( const char *path )
{
     FILE *fp = fopen( path, "r" );
     if( fp == NULL ) return false;
     unsigned char header[54];
     fread( header, 54, 1, fp );
     // BM
     if( *(short*)header != 19778 )
     {
         fclose( fp );
         return false;
     }
     width = getUINT( &header[18] );
     height = getUINT( &header[22] );
     data = (unsigned char*)malloc( width*height*3 );
     
     fseek( fp, getUINT( &header[10] ), SEEK_SET );
     fread( data, width, height*3, fp );
     fclose( fp );
     // Convert from BGR to RGB
     for( UINT i = 0; i < width*height*3; i += 3 )
     {
          data[i] ^= data[i+2];
          data[i+2] ^= data[i];
          data[i] ^= data[i+2];
     }
     return true;
}

[BigSanFrey]

Gar!!! I was trying to make a basic sfx program but it keeps looping, any idea why?

Spoiler for code:

int main() {
          pspDebugScreenInit();
          SetupCallbacks();

          pspAudioInit();
          SceCtrlData pad;

	  printf("Press [O] to play/pause the music\nPress [X] to exit the program\n");
          while(1) {
                  sceCtrlReadBufferPositive(&pad, 1);
                  if(pad.Buttons & PSP_CTRL_CROSS) {
			MP3_Init(1);
			MP3_Load("./sounds/sound26.mp3");
			MP3_Play();
                    if (MP3_EndOfStream() == 1) {
                              MP3_Stop();
                              break;
                    }
                  }
          }
          MP3_Stop();
          MP3_FreeTune();

          sceKernelSleepThread();

          return 0;
}

[hallo007]

int main() {
          pspDebugScreenInit();
          SetupCallbacks();

          pspAudioInit();
          SceCtrlData pad;

	  printf("Press [O] to play/pause the music\nPress [X] to exit the program\n");
          while(1) {
                  sceCtrlReadBufferPositive(&pad, 1);
                  if(pad.Buttons & PSP_CTRL_CROSS) {
			MP3_Init(1);
			MP3_Load("./sounds/sound26.mp3");
			MP3_Play();
                        break;
                  }
          }
                    while(!MP3_EndOfStream()) {
                              //do nothing
                    }
          MP3_Stop();
          MP3_FreeTune();

          sceKernelSleepThread();

          return 0;
}

simpel it will only check once or the mp3 has stoped or not

[BigSanFrey]

that didn't work, still continues

[Xsjado7]

is your problem that it plays a few times when you press tyhe button for the sound? If so, just add a waitvblank to it. One thing you should change is where your sound is loaded and where you initialize the channel. Do:

int main() {
          pspDebugScreenInit();
          SetupCallbacks();

          pspAudioInit();
          SceCtrlData pad;

          MP3_Init(1);
	  MP3_Load("./sounds/sound26.mp3");

	  printf("Press [O] to play/pause the music\nPress [X] to exit the program\n");
          while(1) {
                  sceCtrlReadBufferPositive(&pad, 1);
                  if(pad.Buttons & PSP_CTRL_CROSS) {
			MP3_Play();
                        sceDisplayWaitVBlankStart();
                        }
                    if (MP3_EndOfStream() == 1) break;
          }
          MP3_Stop();
          MP3_FreeTune();

          sceKernelSleepThread();

          return 0;
}

Load them before the loop. The way you were doing it if the user kept pressing it would load the sound a million times and kill the psp. That code also includes the waitvblank

[FaT3oYCG]

ok i have a problem while using the

sceKernelLoadModule command in my code it throws out an error and says something to do with memory not being able to be allocated

does anyone know how to solve this problem thanks

video

[Archaemic]

class Image
{
     public:
         Image(){}
         ~Image();
         
         bool loadBMP( const char *path );
         
         unsigned char *data;
         unsigned int width;
         unsigned int height;
};

Image::~Image()
{
      free( data );         
}

unsigned int getUINT( const unsigned char *p )
{
    return p[0] + (p[1]<<8) + (p[2]<<16) + (p[3]<<24);
}

bool Image::loadBMP( const char *path )
{
     FILE *fp = fopen( path, "r" );
     if( fp == NULL ) return false;
     unsigned char header[54];
     fread( header, 54, 1, fp );
     // BM
     if( *(short*)header != 19778 )
     {
         fclose( fp );
         return false;
     }
     width = getUINT( &header[18] );
     height = getUINT( &header[22] );
     data = (unsigned char*)malloc( width*height*3 );
     
     fseek( fp, getUINT( &header[10] ), SEEK_SET );
     fread( data, width, height*3, fp );
     fclose( fp );
     // Convert from BGR to RGB
     for( UINT i = 0; i < width*height*3; i += 3 )
     {
          data[i] ^= data[i+2];
          data[i+2] ^= data[i];
          data[i] ^= data[i+2];
     }
     return true;
}

Surely I'm not the only person who sees problems with this class? Even assuming that the loader works fine (which it won't--it'll crash if it's given a BMP with a malformed header. Also, a bitmap that's too big will cause problems, too). If an Image falls out of scope or if an Image* is deleted before it's loaded, instant crash.

Here's a fixed version. Of course, it assumed UINT and NULL are defined in the scope of the class.

class Image
{
     public:
         Image(){ data = NULL; }
         ~Image();
         
         bool loadBMP( const char *path );
         
         unsigned char *data;
         unsigned int width;
         unsigned int height;
};

Image::~Image()
{
      if( data != NULL ) free( data );
}

unsigned int getUINT( const unsigned char *p )
{
    return p[0] + (p[1]<<8) + (p[2]<<16) + (p[3]<<24);
}

bool Image::loadBMP( const char *path )
{
     if( data != NULL ) free( data );
     FILE *fp = fopen( path, "r" );
     if( fp == NULL ) return false;
     unsigned char header[54];
     if( ( fread( header, 54, 1, fp ) != 54 ) ||
         ( *(short*)header != 19778 ) )
     {
         fclose( fp );
         return false;
     }
     width = getUINT( &header[18] );
     height = getUINT( &header[22] );
     data = (unsigned char*)malloc( width*height*3 );
     if( data == NULL )
     {
         fclose( fp );
         return false;
     }
     
     fseek( fp, getUINT( &header[10] ), SEEK_SET );
     fread( data, width, height*3, fp );
     fclose( fp );
     // Convert from BGR to RGB
     for( UINT i = 0; i < width*height*3; i += 3 )
     {
          data[i] ^= data[i+2];
          data[i+2] ^= data[i];
          data[i] ^= data[i+2];
     }
     return true;
}

[Raphael]

That still will have problems with <= 8bit BMP files as well as with bmp files who's width(*3) is NOT a multiple of four. Rows in a BMP are always padded to have a multiple of four number of bytes. It works for power of two sized images though, so probably that's why it never came to the OP's attention.

[Archaemic]

*doesn't know anything about the Windows bitmap format, hence I just corrected the mistakes I could identify*