C/C++ Programming Help Thread

[yaustar]

Gah.. I hate structs (I am a C++ man)
Either use

typedef {
	char * name;
	int num_albums;
	char ** albums;
} artist_entry;

int get_artists_from_server(int socket, struct artist_entry * artist_list)
{
	[...]
	artist_list = (artist_entry *)realloc(artist_list, atoi(num_artists)*sizeof(artist_entry));

	[...]

	int i,j;
	for(i=0; i<atoi(num_artists); i++)
	{
		[...]
		artist_list[i].name = (char*)malloc(artist_name_lenght+1);	//l.104
		[...]
	}
}

or

typedef struct artist_entry_struct{
	char * name;
	int num_albums;
	char ** albums;
} artist_entry;

int get_artists_from_server(int socket, artist_entry * artist_list)
{
	[...]
	artist_list = (artist_entry *)realloc(artist_list, atoi(num_artists)*sizeof(artist_entry));

	[...]

	int i,j;
	for(i=0; i<atoi(num_artists); i++)
	{
		[...]
		artist_list[i].name = (char*)malloc(artist_name_lenght+1);	//l.104
		[...]
	}
}

[Raphael]

You are typedef'ing your struct therefore you don't need the "struct" specifier on the parameters. Read up on typedefs again. You have two possibilities:
Change all "struct artist_entry" parameters to "artist_entry" only, or change your declaration into "struct artist_entry { ..... };"

EDIT: Heh, basically the same is written on the site from headus' link earlier I just noticed. Read that page, seriously.

[Lukeson]

Works now, thank you!

Gah.. I hate structs (I am a C++ man)

Same here, but my fist tries using C++ on the PSP failed miserably!
-= Double Post =-
PS: Does anyone have an explanation for my first problem?

http://forums.qj.net/f-psp-developme...e138.html#1376

[Nicky]

Ive got a problem with the TIFF USB, when I run the application it wont activate the USB Port for it. Any help?

[Lukeson]

http://forums.qj.net/f-psp-developme...e138.html#1376

This is so wierd, when I use for(i=1; i<515; i++) he prints all 514 artists and their albums, but after the function has finished (I print 'Closing connection') right after it, he prints another 3 albums! That's impossible!
And if I say for(i=1; i<=514; i++) he only does 26 albums! This is crazy...

[yaustar]

Is your program multithreaded?

[Lukeson]

I use threads, but I only start 1 thread...

[yaustar]

If you mean, you have the main thread and start a new thread, your program is multithreaded and explains why you see the status of the socket closing before the function finishes.

One thread is dealing with printing the artists/albums (and is given it faster then it can print it), the other thread closes the socket.

[Moonchild]

If you mean, you have the main thread and start a new thread, your program is multithreaded and explains why you see the status of the socket closing before the function finishes.

One thread is dealing with printing the artists/albums (and is given it faster then it can print it), the other thread closes the socket.

His problem was that it printed stuff that really shouldn't be there (the three albums), I believe atleast.

[yaustar]

Hmm.. hell, if all else fails, debug the damn thing. Step through the code and check the data as it is recieved.

[Gonrai]

I have three backgrounds in an Images/Backgrounds/ directory:
Back1.png
Back2.png
Back3.png
I tried using an array but that didn't work, and heres how I load it:

Image* Background = loadImage("./Images/Backgrounds/Back1.png");

My currentBack variable:

    int currentBack = 1;

And heres where supposadly when I pres the Right Trigger its suppose to switch:

if((pad.Buttons & PSP_CTRL_RTRIGGER) && (currentBack == 1))
{
Background = loadImage("./Images/Backgrounds/Back2.png");
currentBack = currentBack+1;
}

if((pad.Buttons & PSP_CTRL_RTRIGGER) && (currentBack == 2))
{
Background = loadImage("./Images/Backgrounds/Back3.png");
currentBack = currentBack+1;
}

if((pad.Buttons & PSP_CTRL_RTRIGGER) && (currentBack == 3))
{
Background = loadImage("./Images/Backgrounds/Back1.png");
currentBack = 1;
}

It just stays the same, and it wont ever switch!! Ive tried almost everything here! And heres where I try to blit my Background variable to the screen:

 blitAlphaImageToScreen(0, 0, 480, 272, Background, 0, 0);

Help!

[Moonchild]

You sure you called flipScreen(); right after the blitAlphaImageToScreen(.. .)?

EDIT: Oh, I thought it always stayed black...

[Insert_Witty_Name]

Create an array of 3 Images and load them all up beforehand.

In your button press check just change the currentBack variable.

In your blitting function just use the position in the array ie.

blitAlphaImageToScreen(0, 0, 480, 272, Background[currentBack], 0, 0);

You also should initialise the currentBack variable to 0, as arrays are indexed from 0 to limit-1.

[SG57]

Seems more logical to load all 3 images, and switch the background according to the variable... If var = 1, have background 1blit, if var=2, have background 2 blit, etc...

[Lukeson]

What's faster? For an iPod-style menu I need to draw those little arrows

Is it faster to blit each arrow to the screen (the single small image), or blit one big image with all arrows to the screen, not showing the arrows where there's no menuitem? (Was that understandable?)
-= Double Post =-
I assume the latter is faster. Also I need to leave a bit of the screen black.

What's the fastest way to do that? Drawing a white rectangle and leaving it black? I heard that is pretty slow. Is there a better way?

[Raphael]

You should try out more than asking questions for everything you want to do. It's not hard implementing both methods for both cases and checking wich is faster.
Drawing rectangles is faster than drawing textures (images), as long as you do it with GU.

[Lukeson]

You should try out more than asking questions for everything you want to do.

These are my first steps in C, I'm still very 'careful', wanting to have confirmed every step I take. But I must confess I could have answered these questions myself, I didn't really think before writing them (a behavoir which I always which I always gripe PHP-noobs about...). :/ Sorry

[Moonchild]

EDIT: Never mind... I was just being stupid... >_<

[Raphael]

Well, I have no problem with that, because I don't have to answer your questions :P It's only that you will learn much more, when you try around and find a solution/answer yourself (because you also learn things that don't have to do with the actual solution - as in this case you would know how to do the imperfect solution too, plus how to bench the code)

[Lukeson]

true true...

[Bronx]

What's faster? For an iPod-style menu I need to draw those little arrows

Is it faster to blit each arrow to the screen (the single small image), or blit one big image with all arrows to the screen, not showing the arrows where there's no menuitem? (Was that understandable?)
-= Double Post =-
I assume the latter is faster. Also I need to leave a bit of the screen black.

What's the fastest way to do that? Drawing a white rectangle and leaving it black? I heard that is pretty slow. Is there a better way?

Ok, youresame told me to tell you this

>

Not sure what it means, do you?....

[Moonchild]

It's faster to blit the arrows separately.

[Grimfate126]

ok.i have a bullet class, and i want to use an array with bullets is it, but its giving me errors. my code:

Image * player;
Image * bullet;
Image * cursor;

int crossPressed = 1;
int currentBullet = 1;

class bullet
{
public:
	int x;
	int y;
	int fire;
	float angle;
	int speed;
}; 


bullet hBullet[];

int main(void) {          

	pspDebugScreenInit();
	SetupCallbacks();
	initGraphics();
              SceCtrlData pad;

	player = loadImage("player.png");
	bullet = loadImage("bullet.png");
	cursor = loadImage("cursor.png");

	while (1) {
	
		sceCtrlReadBufferPositive(&pad, 1);        
		
		sceDisplayWaitVblankStart();
		flipScreen();
	}
	
              return 0;
}

but it gives me this error:

main.cpp:66: error: 'bullet' does not name a type
make: *** [main.o] Error 1

and here is line 66:

bullet hBullet[];

what wrong?

[SG57]

Im sure you can convert that to a structure...

typedef struct bullet
{
	int x;
	int y;
	int fire;
	float angle;
	int speed;
} bullet;

That will make it work. But, thats not really what you asked, rather an alternative if your in a hurry. Hope someone answers your question! (oh and maybe a google search on classes will help?)

[yaustar]

You have to declare how many bullets you want in the array. You can't just use xxxxxxx[]. It has to be xxxxxxxxxx[4].

When you create an array, you have to declare the size of it on construction.

[Grimfate126]

You have to declare how many bullets you want in the array. You can't just use xxxxxxx[]. It has to be xxxxxxxxxx[4].

When you create an array, you have to declare the size of it on construction.

nope, still the same error. i definied it like this now:

bullet hBullet[9];

[yaustar]

Is the file a .cpp? Do you have any other errors? Is this all in one file?

The code itself is fine. I have just checked.

[Grimfate126]

Is the file a .cpp? Do you have any other errors? Is this all in one file?

The code itself is fine. I have just checked.

lol, i figured it out. i was declaring bullet as an image as well. i changed that, and it fixed it, BUT, now im getting linkning errors:

main.o: In function `main':
main.cpp:(.text+0xe8): undefined reference to `initGraphics()'
main.cpp:(.text+0xf4): undefined reference to `loadImage(char const*)'
main.cpp:(.text+0x108): undefined reference to `loadImage(char const*)'
main.cpp:(.text+0x11c): undefined reference to `loadImage(char const*)'
main.cpp:(.text+0x140): undefined reference to `flipScreen()'
collect2: ld returned 1 exit status
make: *** [hello.elf] Error 1

i haven included graphics.h in my main file as well as my makefile. here is my make file:

TARGET = BulletTest
OBJS = main.o graphics.o framebuffer.o 

CFLAGS = -O2 -G0 -Wall
CXXFLAGS = $(CFLAGS) -fno-exceptions -fno-rtti
ASFLAGS = $(CFLAGS)

LIBDIR =
LIBS = -lpspgu -lpng -lpsppower -lz -lm 
LDFLAGS =

EXTRA_TARGETS = EBOOT.PBP
PSP_EBOOT_TITLE = TestOne

PSPSDK=$(shell psp-config --pspsdk-path)
include $(PSPSDK)/lib/build.mak

whats wrong now??? (btw, is it just me, or does cygwin seem to hate me?)

[yaustar]

It is saying that the functions have been declared and used but not defined. Are they in graphics and/or framebuffer source files?

[Grimfate126]

It is saying that the functions have been declared and used but not defined. Are they in graphics and/or framebuffer source files?

yep. all in there