C/C++ Programming Help Thread

[BlackShark]

You need to make you image variable global. So define the image in a ".h" file and you will be able to manipulate it from any file that you include it from.

Does that mean i would put,

extern Image* zombiepic;

in Game.h?

I also have

 
zombie[0].x;
zombie[0].y;

that is defined in enemyAI.c which i would like it to be "seen" by game.c.
would i put the two in enemyAI.h as

 
extern int zombie[0].x;
extern int zombie[0].y;

?

[pspballer07]

okay here is what you do.

game.h:

extern Image *zombiepic;
extern int zombie[0].x;
extern int zombie[0].y;

game.c:

Image *zombiepic;

enemyAI.c:

int zombie[0].x;
int zombie[0].y;

and have all the .c files #include "game.h" and have all the files in the makefile. What "extern" does is it says that Image *zombiepic was defined but in a different location which is in game.c

[Grimfate126]

Does that mean i would put,

extern Image* zombiepic;

in Game.h?

I also have

 
zombie[0].x;
zombie[0].y;

that is defined in enemyAI.c which i would like it to be "seen" by game.c.
would i put the two in enemyAI.h as

 
extern int zombie[0].x;
extern int zombie[0].y;

?

the first part is right, but the zombie part is not. instead of doing this:

 
extern int zombie[0].x;
extern int zombie[0].y;

you should make the whole zombie external:

 
extern Zombie zombie[NUM_ZOMBIES];

something like that.

and pspballer, why are are defining the image twice in two files? you post make no sense. could you re-explain please?

[hallo007]

Why do all the entries on this list print on the same line? It's almost as if it's ignoring the "\n".

void readDir(char* directory) {
        int z;
	SceUID dir = sceIoDopen(directory);
        if(dir > 0)
        {
        	SceIoDirent folder;
	        memset(&folder, 0, sizeof(SceIoDirent)); 
	        while(sceIoDread(dir, &folder) > 0){//if there is still something in folder
		      printf("%s\n",folder.d_name);
                      z+=8;//text height
                      if(z > 272) break;//screen height
	              }
	        sceIoDclose(dir);
                }
}

int main() {
	pspDebugScreenInit();
	SetupCallbacks();
	readDir("ms0:/PSP/GAME/");
	sceKernelSleepThread();
	return 0;
}

[pspballer07]

pspballer, why are are defining the image twice in two files? you post make no sense. could you re-explain please?

When you use 'extern', it only means that the var exists somewhere, so you have to declare the "real" var in a C file. There is an article about this somewhere but my internet can't stay connected

[Grimfate126]

ah yes, you're right. just checked my book

havent used extern in a while ;)

[BlackShark]

ok, the only problem i get now is,

enemyAI.h(5) syntax error before 'zombie' 
enemyAI.h(5) [Warning] type defaults to 'int' in declaration of 'zombie' 
enemyAI.h(5) [Warning] data definition has no type or storage class

here is enemyAI.h,

#ifndef __ENEMYAI__
#define __ENEMYAI__

extern void enemyAI();
extern ENEMY zombie[1];
#endif

EDIT: also, How would I Load an Eboot? IE, load the one I am using to "restart" it?

[yaustar]

ok, the only problem i get now is,

enemyAI.h(5) syntax error before 'zombie' 
enemyAI.h(5) [Warning] type defaults to 'int' in declaration of 'zombie' 
enemyAI.h(5) [Warning] data definition has no type or storage class

here is enemyAI.h,

#ifndef __ENEMYAI__
#define __ENEMYAI__

extern void enemyAI();
extern ENEMY zombie[1];
#endif

Re-read the error and look specifically at what it is referring to. Think of reasons of why it can't figure out what to do. One of the skills that any programmer must learn is to be able to compiler and execute code in their head. This includes the highlighting of errors.

Spoiler for answer:

In the file scope of enemyAI.h, you haven't defined what the ENEMY structure is. You will have to #include the file that has the class declaration of enemy in this file

[BlackShark]

But enemyAI.c is what defines it, how would i include that in the enemyAI.h file?

#include "enemyAI.c" ?

[yaustar]

No, don't EVER include source files. Just move the definition of ENEMY from the source file to the header file.

[BlackShark]

I knew that wouldn't work :P, Thanks!

alright, i know i must be driving you all crazy with this question attack of mine, so weather this is the last one I have or not, this will be the very last one i post....for tonight, (this morning, what ever :P)

ok, im still getting errors for that damn Image zombiepic :/,
the error list is this,

  [Linker error] undefined reference to `zombiepic' 
 K:\Black Pack\WorldWarZ\enemyAI.o R_MIPS_GPREL16 against `zombiepic'

now if you remember, zombiepic is an Image I load in Game.c and would also like it to be available in enemyAI.c.

I checked enemyAI.c to make sure it had Game.h included, here is the game.h

#ifndef __GAME__
#define __GAME__

extern void Game();
extern Image *zombiepic;
    
#endif

I tried "extern Image* zombiepic;" too
I also tried putting the * on zombiepic in the Game.c while loading like

Image *zombiepic = loadImage("zombie");

but that didn't work either, I made sure that enemyAI.h was included in the Game.c too. Any ideas?

[yaustar]

Post up full code of Game.c as it is at the moment with that error.
-= Double Post =-

// Header file
#ifndef (BLAH_H)
#define (BLAH_H)

extern int * gAGlobal;

#endif // (BLAH_H)

// Source file where gAGlobal is instantiated 
// No need to include header file
// IN GLOBAL SCOPE!
int * gAGlobal = NULL;

void blah( void )
{
	gAGlobal = someRandomValue;
}

[hallo007]

Spoiler for code:

/INCLUDES
#include <stdlib.h>
#include <malloc.h>
#include <pspdisplay.h>
#include <psputils.h>
#include <png.h>
#include <pspgu.h>
#include <string>
#include <pspkernel.h>
#include <pspctrl.h>

#include "desktop.h"
#include "graphics/graphics.h"
#include "graphics/images.h"
#include "io/iO.h"
#include "variabels.h"

//DEFINES
#define blitImage  blitAlphaImageToScreen        //Blit image to screen (GUI)
#define printg     printTextScreen               //GUI text printfs
#define printf     pspDebugScreenPrintf          //Debug console

//MODULE INFO
PSP_MODULE_INFO("Desktop Example" , 0x1000, 1, 1);
PSP_MAIN_THREAD_ATTR(0);

Image *desktopBack;

class fileInfo
{
      private:                         
              long int size;           //the size in bytes
              long int kbSize;         //the size in kilobytes
              long int mbSize;         //the size in megabytes
              std::string folder;      //the folder path
              std::string extension;   //the file extension   
              std::string fileName;    //name without extension                                                                                                                              
      public:
              int file;                //file or folder , file = 1 , folder = 0;                 
              void researchDir(std::string directory);
              int xFile;               //coordinates on desktop
              int yFile;               // same here  
              int xEndFile;            //the coordinates of the last pixel
              int yEndFile;            //same here
              std::string name;        //file name (with extension)
              std::string path;        //the compolete file path   
};
fileInfo fileBuffer[222];

int LoadStartModule(char *path)
{
    u32 loadResult;
    u32 startResult;
    int status;

    loadResult = sceKernelLoadModule(path, 0, NULL);
    if (loadResult & 0x80000000) return -1;
    
    startResult =   sceKernelStartModule(loadResult, 0, NULL, &status, NULL);

    if (loadResult != startResult) return -2;

    return 0; 
}
int isFile( std::string filename)
{ 
	SceIoStat stats;
	sceIoGetstat( filename.c_str(), &stats);//get the stats
	
	if ( stats.st_mode & FIO_S_IFDIR) //directory?
	{
         return 0; //if directory 
         }
	else 
	{
		return 1;  //if file
    }
}
void fileInfo::researchDir(std::string directory)
{
     int x = 10;
     int y = 10;
     getFileList(directory); 
     for(unsigned int loop = 0; loop < z; loop++ )
     {
           fileBuffer[loop].path.clear();        
           fileBuffer[loop].path.append( directory, 0 , directory.size());   
           fileBuffer[loop].path.append( fileList[loop]);    
           if(fileList[loop].size() > 10)
           {
                 fileBuffer[loop].name.clear(); 
                 fileBuffer[loop].name.append( fileList[loop], 0 , 10);
                 fileBuffer[loop].name.append( 3, '.' );
                 }
           else
           {
                 fileBuffer[loop].name.clear();
                 fileBuffer[loop].name.append( fileList[loop], 0 , fileList[loop].size());
                 }
           fileBuffer[loop].file = isFile(fileBuffer[loop].path); 

           fileBuffer[loop].xFile = x;
           fileBuffer[loop].yFile = y;  
           fileBuffer[loop].xEndFile = x + 40;
           fileBuffer[loop].yEndFile = y + 50;                              
           y += 55;    
           if(y > 249)
           {
                x += 108;
                y = 10;
                }

           }
}
int main(SceSize args, void *argp)
{
    int x = 0;                            //storage for x coordinate
    int y = 0;                             //storage for y coordinate
    int mouseX = 10;                       //storage for mouse coordinates on x-as
    int mouseY = 10;                       //storage for mouse coordinates on y as
    int imageError = 0;                    //bool for error on image loading
    
    //*std::string fileBuffer[222];                //for the filelist
    
    //Pad init
    SceCtrlData pad;
    sceCtrlSetSamplingCycle(0);
    sceCtrlSetSamplingMode(PSP_CTRL_MODE_ANALOG);   
    
    //init the garphics
    initGraphics();
    pspDebugScreenInit();
    pspDebugScreenClear();    
    
    //Image loading
    Image *iconExample = loadImageMemory(folderIcon , size_folderIcon);
    if(iconExample == NULL) imageError = 1;    
    Image *iconFolder  = loadImage("data/desktop/folder.PNG");
    if(iconFolder == NULL) imageError = 1;    
    Image *mouse       = loadImage("data/desktop/mouse.PNG");
    if(mouse == NULL) imageError = 1;  
    desktopBack = loadImage("data/desktop/wallpaper.PNG");
    if(desktopBack == NULL) imageError = 1;
    
    if(imageError)//if some images failed to load
    {
                  pspDebugScreenClear();
                  printf("error : failed to load an image:\n");
                  sceKernelSleepThread();
                  return 0;
                  } 
                  
    //printf("Images loaded\n"); 
                  
    //Load screenshot module
    LoadStartModule("data/screenshot.prx");    

    //get al files stored to a std::string of a directory
    
    fileBuffer[221].researchDir("ms0:/");
    //printf("filelist\n");
    
    while(1)
    { 
            //sceDisplayWaitVblankStart();
            blitImage(0 , 0 , desktopBack);//wallpaper   
            for(unsigned int loop = 0; loop < z; loop++ )
            { 
                 x = fileBuffer[loop].xFile;     
                 y = fileBuffer[loop].yFile;                      
                 if( fileBuffer[loop].file == 1)
                 {
                       blitImage(x , y ,iconExample);
                       }
                 else
                 {
                       blitImage(x , y ,iconFolder);
                       }    
                  y += 45;    
                  printg(x , y , fileBuffer[loop].name.c_str() , white);
                  }  
                  
                  blitImage(mouseX , mouseY , mouse);
                  flipScreen();
                  while(1)
                  {
                          sceCtrlReadBufferPositive(&pad, 1);	 
                          
                          if (pad.Lx < 80) //left
                          {
                                     mouseX -= 10;
                                     if(mouseX<0) mouseX = 460;
                                     break;
                                     }
                          if (pad.Lx > 175) //right
                          {
                                     mouseX += 10; 
                                     if(mouseX > 480) mouseX = 0;
                                     break;
                                     }
	                      if (pad.Ly > 175) //down
	                      {
                                     mouseY += 10;
                                     if(mouseY > 272) mouseY = 0;
                                     break;
                                     }
	                      if (pad.Ly < 80) //up
	                      {
                                     mouseY -= 10;
                                     if(mouseY<0) mouseY = 255;
                                     break;
                                     }									 
                          if(pad.Buttons & PSP_CTRL_HOME)
                          {
                                         sceKernelExitGame();
                                         }
                          if(pad.Buttons & PSP_CTRL_CROSS)
                          {
                                         int xLine = 0;
                                         int yLine = 0;
                                         for(unsigned int loop = 0; loop < z; loop++)
                                         {
                                               if(mouseX >= fileBuffer[loop].xFile && mouseX <= fileBuffer[loop].xEndFile)
                                               {
                                                         xLine = 1;
                                                         }
                                               else xLine = 0;
                                               if(mouseY >= fileBuffer[loop].yFile && mouseY <= fileBuffer[loop].yEndFile)
                                               {
                                                         yLine = 1;
                                                         }
                                               else yLine = 0;
                                               if(yLine == 1 && xLine == 1)
                                               {
                                                        if(fileBuffer[loop].file == 1)
                                                        {
                                                             clearScreen(0xFFFFFF);
                                                             printg(0,0,"No files supported , returning in 5 seconds", 0x0000FF);
                                                             flipScreen();
                                                             sceKernelDelayThread(5000000);
                                                             break;
                                                             }
                                                        else
                                                        {                                                                  
                                                             fileBuffer[221].researchDir(fileBuffer[loop].path);
                                                             break;
                                                             }
                                                        }
                                               }//end for
                                         }//end cross
                                                          
                    }//end while
                   
    }//end while

    
    sceKernelSleepThread();
    return 0;
}

I am not able to go to a folder , why?
The first step works great , i see the files of the root and can move the mouse , but when i select something:
file : shows the text and crashes
folder : shows the text for files and carshes:s

[sony psp player]

i´ve got a question that may be hard to answer.

how do i use a .txt file for a map?
please give some examples and please don´t flame me

thanks

[pspballer07]

i´ve got a question that may be hard to answer.

how do i use a .txt file for a map?
please give some examples and please don´t flame me

thanks

say your map file is like this:

000010000
000110000
000111000
000111001
00...ect

All the '0's are grass or whatever and '1's are something else. You would make a loader that gets a char from the file and do that how many times the file is in length. You would check each char to see is it was a number with isdigit(ch); (ch is the char that was read from the file)

Just set the tiles accordingly or draw them, whatever

[sony psp player]

can you make an example that is nearly working?

[pspballer07]

the way I do it isn't that reusable, it would be better to google it.

[sony psp player]

can you find something on google?
-= Double Post =-
i have another question

a string: abcdefghiklmnopqrstuvwxyz

how do i get the letters "cdefgh" out of this string?

[pspballer07]

you mean find them specifically or cut them out of it?

[sony psp player]

i have the beginning position and the end position and i wanna have them in another string, while the first string isn´t changed

[pspballer07]

Do get those specifically you would do this:

int main()
{
     char *str = "abcdefghiklmnopqrstuvwxyz";
     char specific_data[10];
     char *ptr;
     ptr = strstr(str,"cdefgh"); /*strstr returns the pointer to where "cdefgh" starts*/
     strncpy(specific_data,ptr,6); /*copys "cdefgh"  to string specific_data*/
      //specific_data now holds "cdefgh" and str remains the same
      return 0;
}

[SG57]

sony_psp_player - There's multiple ways, but you still haven't answered the question. Would you like to be able to call a function saying:

if "cdefgh" is found in string "abcdefghijklmnopqrstuvwx yz" then ...

Or would you just like to take out the 3rd,4th,5th,6th,7th and 8th element out of an array of characters...

[adrahil]

For maps you're better off with serialization. (Search on google)

[sony psp player]

sony_psp_player - There's multiple ways, but you still haven't answered the question. Would you like to be able to call a function saying:

if "cdefgh" is found in string "abcdefghijklmnopqrstuvwx yz" then ...

Or would you just like to take out the 3rd,4th,5th,6th,7th and 8th element out of an array of characters...

i wanna take out the 3rd,4th,5th,6th,7th and 8th, so if the string was

"abcdefghijkl"

it would take out "cdefgh"


"ajsdafhdjajdkfja"

it would take out "sdafhd"

[SG57]

Ok. I suggest you read up on arrays and write it yourself, but if you get stuck or whatever, use this as a reference.

int grabber(char *dest_string, const char *source_string) { // for lack of a better function name
    static const MINIMUM_STRING_SIZE = 8;
    static const NUM_CHARS_TO_EXTRACT = 6;
    
    if(strlen(source_string) < MINIMUM_STRING_SIZE || sizeof(dest_string) < NUM_CHARS_TO_EXTRACT+1 /* compensate for '\0' */)
        return 0; // failure :(
    
    dest_string[0] = source_string[2];
    dest_string[1] = source_string[3];
    dest_string[2] = source_string[4];
    dest_string[3] = source_string[5];
    dest_string[4] = source_string[6];
    dest_string[5] = source_string[7];
    dest_string[6] = '\0'; // not sure whether this is automatically added or not, so it's a safety percaution
    
    return 1; // success :)
}

I haven't messed with strlen or sizeof in a long time, so I'm not sure whether strlen includes the '\0' and if sizeof reserves space for the '\0', so sorry ifthe numbering is off a little (a quick fix if so).

[adrahil]

Wow, you really like to make things complicated, SG57..... Just use strncpy ;)

strncpy(dest, alphabet+2, 6);

Will yield "cdefgh" if alphabet is "abcdefghijklmnopqrstuvwx yz"

Just don't forget to memset(dest, 0, XXX);, where XXX is the size of the dest buffer (declared as char dest[XXX];), and remember to make a buffer big enough so that there is a trailing 0 left.

[SG57]

I like manual conversions, it gives me a sense of safety for some reason.

[adrahil]

I like manual conversions, it gives me a sense of safety for some reason.

Manual CONVERSIONS? :/ There are no "conversions" here... Moreover, there is no possible WAY in which you'd be able to outperform standard libc functions... I bet you'd not be able to understand completely the operation of functions such as these:

char *
strncpy(char *dst, const char *src, size_t n)
{
        if (n != 0) {
                char *d = dst;
                const char *s = src;

                do {
                        if ((*d++ = *s++) == 0) {
                                while (--n != 0)
                                        *d++ = 0;
                                break;
                        }
                } while (--n != 0);
        }
        return (dst);
}

(from OpenBSD source code repository for libc)
Well, to come back to the subject, your method is really unoptimized and is not made for a dynamic map loading, as the lengths are static. With strncpy, it is much easier to split a string into different parts...

[hallo007]

why isnt it

char *
strncpy(char *dst, const char *src, size_t n)
{
        if (n != 0) {
                char *d = dst;
                const char *s = src;

            
                 if ((*d++ = *s++) == 0) {
                            while (--n != 0)
                                   *d++ = 0;
                             }  
        }
        return (dst);
}

[adrahil]

Uhm... You're only copying one char here, no? (No while() loop to do (*d++ = *s++))... I think you meant "while((*d++ = *s++)...", but tbh, I think the code in the repository is the way they found it to be a good compromise between portability, speed and readability. :)

(There were a few comments in the original code, but i didn't bother to copy/paste them ;) )