C/C++ Programming Help Thread

[eldiablov]

This is one big fat request, I haven't even seen an attempt at code.

[MiKeY188]

I don't want you guys to code it ;) i just want to know away to do it.

EDIT:

There is only one problem now Thanks.

[_df_]

Ive been trying all day and ain't gotten anywhere please if someone can help in anyway!

if(some_random_number() == 42)
    block_shot();
else
    dont_block_shot();

[MiKeY188]

Yeah i will try something like that out thanks :)

[Mraellis]

I know it is a bit noobish to ask but i haven't ever checked this for PSP so;

What gfx libraries does the PSP support?

SDL OpenGL OpenGL 2.0 etc.

P.s wasn't sure where to ask this but since there used in c and c++ stuff not lua i may as well ask here.

[Hardrive]

I know it is a bit noobish to ask but i haven't ever checked this for PSP so;

What gfx libraries does the PSP support?

SDL OpenGL OpenGL 2.0 etc.

P.s wasn't sure where to ask this but since there used in c and c++ stuff not lua i may as well ask here.

I know that it supports SDL, as I have made a few apps that use it.

I am not so sure about OpenGL though. I know it supports some kind of OpenGL, I just don't know if it's the official OpenGL.

[Mraellis]

I was wondering more about the OpenGl tbh because i was hoping when i have finished learning how to make things for the Pandora (Different to the battery thing) it will be easy to port the stuff to the PSP to.

I guessed from one of the recent posts it does some form but does it support the official OpenGL? (and 2.0)

[slicer4ever]

it's not opengl it's called pspgu, although their is a port of opengl it is recommended not to use the port and instead to make your program use pspgu, ask xfactor, jj_calvin, or IWN about it for more information i can only give you some even with me using it, if you want to know more hop onto irc, server: freenode room: #psp-programming=-)

[the_darkside_986]

These are fairly good tutorials for PSPGU, and they are based on OpenGL tutorials:
http://www.skistovel.com/index.php?page=tutorials-psp

Even though the method of managing the display list appears to be coded incorrectly, it is still more than enough to get started with PSPGU.

Or you might want to check on OSLib for PSP. I've never used it but I've heard it is nice and renders images fast.

Whatever you do, just don't use old, poorly written graphics.c and graphics.h from LuaPlayer. There are very many things wrong with the way things are rendered with that code.

[Raphael]

I was wondering more about the OpenGl tbh because i was hoping when i have finished learning how to make things for the Pandora (Different to the battery thing) it will be easy to port the stuff to the PSP to.

I guessed from one of the recent posts it does some form but does it support the official OpenGL? (and 2.0)

Unless you code your stuff with SDL, porting won't be as easily possible. The pandora uses OpenGL|ES 2.0, while the PSP only has an inofficial OpenGL-alike library that supports the basic features of OpenGL 1.6. Even if pspgl were a complete OpenGL 2.0 implementation, it would be impossible to just switch from OpenGL|ES to OpenGL. They're different in many things.

You might as well just write your game for both platforms native graphics libraries - OpenGL|ES 2.0 and pspgu (not pspgl), which in turn is already very OpenGL alike and if you know basic OpenGL you will also know pspgu in no time.

[lukespalding]

hi all, well considering this is a c/c++ programming help thread, ill take advantage of it!

wellim new to C codin been doing lua n i have been a c coder for about 4 hours lol and im stuck already, well str8 to the point . . .

How can u create a table in c?

coz in lua u just put

table = { name = "luke",age = 18 }
or
table = {}
table[1] = { name = "luke", age = 18}
table[2] = { name = "jfjfsf", age = 65 }

but how can u create tables like that in c?

i need a table to hold likeplayer data, AI data etc
does anybody know?

thankyou
Luke

[yaustar]

Look/Google for array of structs.

[lukespalding]

Look/Google for array of structs.

well i did what u said and i search and i have no idea what im looking for?!

all i need is for someone to tell me how to create a table in c that can hold data or point me to information on how to do it etc but no offence like but look/google for array of tables, ima newby i said tht i duno what im lookin for lol bit more info if u will.

luke

[PSProgramer]

Dude first result in google, when I searched, this isn't a tut, but it's an example of one in C.

http://mail.python.org/pipermail/tut...ay/005957.html

:) lol hope it helps

[Khatharr]

There are no 'tables' in C. You have to build your own. When I need a size-conscious array I do this:

typdef struct {
  int* values;
  int size;
} sizedIntArray;

Then to declare an array I say:

sizedIntArray my_array;
my_array.size = 0; //Set the size of the array
my_array.values = (int*)malloc(0); //Make malloc aware of the array location

Then when I add something:

my_array.size++; //increase the size by 1
my_array.values = (int*)realloc(my_array.values, my_array.size * sizeof(int)); //allocate more memory for the array

Removing a value from the end is similar and removing a value from the beginning/middle can be done by manually shifting later values down and then removing the last value. You can refer to an item at a specific index by 'my_array.values[?]' where ? is the index you want.

As for tables used as dictionaries, you'll need to create an array of structs. Make a typedef struct and then create an array of them:

typedef struct {
  char name[50];
  unsigned int age;
  int gender;
} Person;
Person my_array[10];
my_array[0].age = 30;
my_array[0].gender = 1; //male
sprintf(my_array[0].name, "Mr. Bob");

That's an array of 10 people. Each one is a 'Person'. Each person has a 'name', an 'age', and a 'gender'. The first person is set up there so you can see how to refer to it.

[lukespalding]

Dude first result in google, when I searched, this isn't a tut, but it's an example of one in C.

http://mail.python.org/pipermail/tut...ay/005957.html

:) lol hope it helps

ye i saw that to had a look at it i was just confused lol
i did try n make a table in my code but i just got loads of errors, i did . . .

struct player
{
char name;
int X;
int Y;
}


then in my main code i put
player.name = "luke";
player.X = 45;
player.Y = 65;

but i think ive got that allwrong lol but worth a try i just dont know what to do i dont want to make loads of variables holding all the data coz id have tones, but i dont have any idea how to make a struct! :Argh:
luke

[lukespalding]

As for tables used as dictionaries, you'll need to create an array of structs. Make a typedef struct and then create an array of them:

typedef struct {
  char name[50];
  unsigned int age;
  int gender;
} Person;
Person my_array[10];
my_array[0].age = 30;
my_array[0].gender = 1; //male
sprintf(my_array[0].name, "Mr. Bob");

That's an array of 10 people. Each one is a 'Person'. Each person has a 'name', an 'age', and a 'gender'. The first person is set up there so you can see how to refer to it.

it worked omg it reli worked thanks man im soo pleased omg thankyou sooo much
luke:Punk::Jump:

[yaustar]

well i did what u said and i search and i have no idea what im looking for?!

all i need is for someone to tell me how to create a table in c that can hold data or point me to information on how to do it etc but no offence like but look/google for array of tables, ima newby i said tht i duno what im lookin for lol bit more info if u will.

luke

If are at the stage where you can't tell what results to look for because you don't understand the terminology, you are jumping too far ahead and you need to 'fall back' a bit.

Look for tutorials on Arrays. Once you have understood how arrays work then look for tutorials on structs in C (C++ structs are slightly different). Once you have understood how to use structs, then you can put the two together to make an array of structs.

[slicer4ever]

well if your just looking for an array, not a structure as Khatharr said it's fairly simple:

int array[] = { 1, 2, 3}; <-- similar to how lua does it

another way:

int array[3];
array[0] = 1;
array[1] = 2;
array[2] = 3;

than theirs the pointer method

#include <malloc.h>
int *array = (int*)malloc(sizeof(int)*3); <--creates room for the array(in this case 3 spots are created)
array[0] = 1;
array[1] = 2;
array[2] = 3;
free(array) <--free the memory up

arrays are farly simple, and at this point i suggest learning more about arrays before you jump into structures as Khatharr pointed you to

also Khatharr why did you make the gender an unsigned int, seems a tad un-needed(and something that can confuse him since he's still fairly new)

[Moca]

well if your just looking for an array, not a structure as Khatharr said it's fairly simple:

int array[] = { 1, 2, 3}; <-- similar to how lua does it

another way:

int array[3];
array[0] = 1;
array[1] = 2;
array[2] = 3;

than theirs the pointer method

#include <malloc.h>
int *array = (int*)malloc(sizeof(int)*3); <--creates room for the array(in this case 3 spots are created)
array[0] = 1;
array[1] = 2;
array[2] = 3;

arrays are farly simple, and at this point i suggest learning more about arrays before you jump into structures as Khatharr pointed you to

also Khatharr why did you make the gender an unsigned int, seems a tad un-needed(and something that can confuse him since he's still fairly new)

Age is an unsigned int. He probably did that since a person cannot have a negative age. The age probably won't reach anywhere near 0x7FFF, but it still makes sense to have it unsigned.

[slicer4ever]

true, but i don't think it was necessary imo, anywho must have over looked it as gender my bad

[zeroxorxdiexskater]

i used a PNG file to make a background and i am wanting that to go away when i push a button, and then go to another background with a sprite on it. my main problem is getting rid of the first one, i tried using oslClr() since im using OSlib but that only seems to work with text. how do i get rid of it?

[Khatharr]

true, but i don't think it was necessary imo, anywho must have over looked it as gender my bad

I figured why not throw it in since he's a noob maybe he'll look it up and learn something. 'unsigned' is a fairly straightforward concept. I wouldn't have done it with something more complex. Just trying to edge him forward a little.

[slicer4ever]

true, good call i guess

zero check your thread

[yaustar]

also Khatharr why did you make the gender an unsigned int, seems a tad un-needed(and something that can confuse him since he's still fairly new)

So showing him how to allocate memory without teaching memory management (ie freeing what you allocate) isn't going to confuse someone new?

[slicer4ever]

ahh my bad, forgot to free the memory

[zeroxorxdiexskater]

i am still pretty confused on my question, i think its because of the way my code is set up. but here is most of my code

//OSlib header file
#include <oslib/oslib.h>

//Necessary to create eboot
PSP_MODULE_INFO("Sample", 0, 1, 1);
PSP_MAIN_THREAD_ATTR(THRE AD_ATTR_USER | THREAD_ATTR_VFPU);

//declaration of the pointers of our images
OSL_IMAGE *background, *videlectrix, *sprite;

//definitions
#define DOWN 0
#define UP 35
#define RIGHT 70
#define LEFT 105

//variables
int sprite_position;
int sprite_march;

//function declarations
void Buttons();
void SpriteAnimate();

int main()
{
//Initialization of the Oslib library
oslInit(0);

//Initialization of the graphics mode
oslInitGfx(OSL_PF_8888, 1);

//Sets the transparency color (pink)
oslSetTransparentColor(RG B(255,0,255));

//loads our images into memory
background = oslLoadImageFile("backgro und.png", OSL_IN_RAM, OSL_PF_5551);
sprite = oslLoadImageFile("sprite. png", OSL_IN_RAM, OSL_PF_5551);
videlectrix = oslLoadImageFile("videlec trix.png", OSL_IN_RAM, OSL_PF_5551);

//Disables the transpaent color (pink)
oslDisableTransparentColo r();

//verification that all files are present
if (!background || !sprite || !videlectrix)
oslDebug("It is impossible to load one or more of the images that are required in this program. Please make sure you have all the files required in the eboot folder");

//Sets the sprite's original position on the screen
sprite->x = 155;
sprite->y = 95;
sprite_position = DOWN;

//main while loop
while (!osl_quit)
{
//To be able to draw on the screen
oslStartDrawing();

//calls the Buttons() function
Buttons();

//Draw the images to the screen
oslDrawImage(videlectrix) ;

//Ends drawing mode
oslEndDrawing();

//Synchronizes the screen
oslSyncFrame();
}

//Terminate the program
oslEndGfx();
oslQuit();
return 0;
}


void Buttons()
{
//initiate the PSP's buttons
oslReadKeys();

if (osl_keys->held.down)
{
//Sprite movement
sprite->y += 2;

//Sets the sprite's position on the spritesheet
sprite_position = DOWN;

//Calls the SpriteAnimate() function
SpriteAnimate();
}
if (osl_keys->held.up)
{
sprite->y -= 2;
sprite_position = UP;
SpriteAnimate();
}

if (osl_keys->held.right)
{
sprite->x += 2;
sprite_position = RIGHT;
SpriteAnimate();
}
if (osl_keys->held.left)
{
sprite->x -= 2;
sprite_position = LEFT;
SpriteAnimate();
}

//If a button is not pressed
if (!osl_keys->held.value)
{
//Start the variable over for when a button is pressed again
sprite_march = 0;

//Sets the sprite's direction
oslSetImageTileSize(sprit e,0,sprite_position,22,35 );
}
}


void SpriteAnimate()
{
//Moves the sprite in the row that it is in
sprite_march++;

//Moves the sprite constantly
oslSetImageTileSize(sprit e,(sprite_march * 22),sprite_position,22,35 );

//resets the sprite movement in that row
if (sprite_march == 6) sprite_march = 0;

}

the places in bold are the areas i am dealing with. the first bold is the place that i am loading my first image which works, but i want to overlap that with a second pic and a sprite with a button command. so i go to the second bold part and try to put this in.

if (osl_keys->held.cross)
{
//Draw the images to the screen
oslDrawImage(background);
oslDrawImage(sprite);
}

but it just doesnt work. what am i doing wrong?

[lukespalding]

I figured why not throw it in since he's a noob maybe he'll look it up and learn something. 'unsigned' is a fairly straightforward concept. I wouldn't have done it with something more complex. Just trying to edge him forward a little.

well thats gd coz i read it n wa like unsigned :S
lookd it up n it means --a value that can only be positive therefore it cannot be a negative number-- :humped:

also say i created an array n then i wanted to free that array so i have more memory would i do this . . .

int array[3];
array[0] = 1;
array[1] = 2;
array[2] = 3;

free(array) or would it be free(array[3]) also to free a variable would i just set it to NULL or free(variable).
just wondering
luke

[slicer4ever]

no free only works on things that you malloc

[Raphael]

Just don't deal with dynamic memory allocation alltogether for the time being... you're still missing on basic C syntax and programming techniques which is much more important to learn. As long as you declare variables like you did, you don't have to care about freeing the memory.

And never ever call free upon an object that you didn't explicitly allocate with malloc() before.

PS: And please try to write at least halfway proper english. It's a nuisance to read your writing.