C/C++ Programming Help Thread

[FaT3oYCG]

Setting up cygwin is easy. I cannot understand how so many people have issues with it.

I will do up a guide when I get time to explain it step by step. It really isn't hard.

the thing is there isnt much point in spending the time setting up cygwin when you can just use MinPSPW, which also works on ubuntu and open solaris.

[robofreak111]

Hello!
I recently took up programming for the PSP and started to follow the wonderful tutorials of psp-programmng.com. However, once I try to run toolchain.sh after installing CYGWIN I get this error after around 5 seconds after me typing in "./toolchain.sh" (without the quotes)

This is the error i get:

ERROR: Add C:/pspdev/bin to your path before continuing.
../depends/check-pspdev.sh:Failed.

Thank you very much for all your help in advance.

[robofreak111]

nevermind i got it running fine, sorry

[Kode]

FaT3oYCG : minpsp has been compiled for Linux 32 bits. I guess 64 bits users'd rather compile thier own version...
(and the distribution doesn't matter here)

[atomic_boneman]

I'm new to programming for the psp and i will like someone who is a capable of teaching me to do so because i want to code some pretty amazing stuff for the psp.

[mootjeuh]

does anybody how to make a fade-in and fade-out effect using graphics.c ? (in other words, just the libpng and the pspgu)

[mootjeuh]

okay, new problem, i'm trying to create a table from the lua functions lua_Stae and lua_newtable, how do I do that?
i was thinking about something like this:

lua_newtable(lua_State *table);
table = { int variable1 };
[...]
table.variable1 = 10;

[slicer4ever]

okay, new problem, i'm trying to create a table from the lua functions lua_Stae and lua_newtable, how do I do that?
i was thinking about something like this:

lua_newtable(lua_State *table);
table = { int variable1 };
[...]
table.variable1 = 10;

what?, are u using c/++, or lua?

if it's the first, than you've got to stop thinking of tables like lua, and start thinking classes/structs and/or arrays

i.e:

//this code is for c, if i did it in c++, i'd make a class with some constructors rather than filling it manually in the main loop
typedef struct{
   int x;
   int y;
}PStruct; //position struct

int main(int argc, char **argv){
   PStruct Position; 
   Position.x = 0; Position.y = 0;
   printf("%d %d\n", Position.x, Position.y);
   return 0;
}

honestly i have no idea what your trying to do, or why your referencing too lua while working in c/++(unless your attempting to add scripts to your game?)

perhaps further explanation would help

also, for the other question, it's called the alpha channel, i'm not certain if their's a simple command for changing an image's alpha(or if it's possible with graphics.c IIRC it writes directly to the framebuffer)

[yaustar]

@slicer4ever - He is trying to use the Lua library's function to create a table and insert values into it. In short, he is using C or C++. He is probably trying to extend or write a Lua interpretor.

[mootjeuh]

nevermind, i've already solved the problem, it was a typo error in my typedef struct :P

and i'm not trying to make a lua interpretor, but a desktop environment, there'll be a release soon

[mootjeuh]

does any1 know how to return the numeric code of a passed string ?

[slicer4ever]

atoi(char *string);

[mootjeuh]

thank you :)

[mootjeuh]

okay, new question. does any1 know how to return the ASCII value of a char ?

[yaustar]

char blah = 'j';
int foo = static_cast<int>(blah);
// Or
int foo2 = static_cast<int>('j');

A char is usually an 8 bit integer.

[mootjeuh]

oh great thanks. maybe this will work:

int returnASCII(const char *text, int index)
{
    return (int)text[index];
}

?

[slicer4ever]

umm.... or you could just do:

printf("%d %c\n", 'c', 'c');

each ascii is already a 0-255 value(unsigned char an 8 bit type)

so what your doing is no diffrent then:

 char *string[] = {'h', 'e', 'l', 'l', 'o', '\0'}
 printf("%d %c\n", string[0], string[0]);

their really is no need for a function to do that you just need to understand how ascii is represented

[JaSo PsP]

I have a problem with extracting how many seconds have passed according to the tick count of the program. This is an extract from my main function:

Res = sceRtcGetTickResolution();
	Time = GetCurrentTick();

	while(!osl_quit)
	{
		if(HitStep)
		{
			MS++;
			HitStep = false;
		}

		oslStartDrawing();
		
		sprintf(Display, "Seconds: %i", (int)MS);
		oslDrawString(0, 0, Display);

		oslEndDrawing();

		if((GetCurrentTick() - Time) >= Res)
		{
			HitStep = true;
			Time = GetCurrentTick();
		}

		oslSyncFrame();
		oslAudioVSync();
	}

The seconds go slower than they are supposed to, even though it is compared with the tick resolution. HELP!

[mootjeuh]

I have a problem with extracting how many seconds have passed according to the tick count of the program. This is an extract from my main function:

Res = sceRtcGetTickResolution();
	Time = GetCurrentTick();

	while(!osl_quit)
	{
		if(HitStep)
		{
			MS++;
			HitStep = false;
		}

		oslStartDrawing();
		
		sprintf(Display, "Seconds: %i", (int)MS);
		oslDrawString(0, 0, Display);

		oslEndDrawing();

		if((GetCurrentTick() - Time) >= Res)
		{
			HitStep = true;
			Time = GetCurrentTick();
		}

		oslSyncFrame();
		oslAudioVSync();
	}

The seconds go slower than they are supposed to, even though it is compared with the tick resolution. HELP!

I don't get what you're trying to do:ROFL:

[JaSo PsP]

well, i am just in the testing phase at the moment, im trying to get a second counter based on the ticks. but it doesnt calculate a seconds from the ticks correctly. Dry-run the code and you may understand.

[mootjeuh]

well, i am just in the testing phase at the moment, im trying to get a second counter based on the ticks. but it doesnt calculate a seconds from the ticks correctly. Dry-run the code and you may understand.

oh now I get what you're trying to do.
why won't you try something like this:

int main()
{
	pspDebugScreenInit();
	int time = 0;
	
	while(1) {
		time++;
		pspDebugScreenSetXY(0,0);
		pspDebugScreenPrintf("Seconds running: %i", time/6);
	}
	
	return 0;
}

[JaSo PsP]

Because thats dependant on the speed of the processor? That piece of code doesnt relate to ANY time functions whatsoever!? How can dividing that number by 6 get the amount of seconds!?

[FaT3oYCG]

lol, I understand what you are trying to do but why?

[mootjeuh]

How can dividing that number by 6 get the amount of seconds!?

well, in 6 seconds, it counts till 6. so if you divide by 6, it'll give the number of seconds.

lol, I understand what you are trying to do but why?

for fun?

[FaT3oYCG]

well, in 6 seconds, it counts till 6. so if you divide by 6, it'll give the number of seconds.

Lol. Really? Just lol.

[slicer4ever]

well, in 6 seconds, it counts till 6. so if you divide by 6, it'll give the number of seconds.

you should really know what your talking about when you respond, what your doing, as Jaso pointed out, is dependent on the processor speed, and is not guranteed to be correct depending on rather the processor isn't bogged down, also, dividing by 6 would not give you the number of seconds

@jaso, have you considered using the time function from stdlib

int main(int argc, char **argv){
   int CurrTime = time(NULL);
   int OldTime = CurrTime;
   while(1){
       CurrTime = time(NULL);
       if(CurrTime-OldTime!=0){
           OldTime = CurrTime;
           //Code for animation
       }
   }
   return 0;
}

if all your trying to do is detect change in seconds the time function should be sufficient for your needs

[yaustar]

Where did GetCurrentTick come from? If you are using sceRtcGetTickResolution then shouldn't you be using sceRtcGetCurrentTick? When you say the seconds are going slower, how much slower? A lot or very small amounts?

I would try:

	Res = sceRtcGetTickResolution();
	Time = GetCurrentTick();

	while(!osl_quit)
	{
		oslStartDrawing();
		oslDrawString(0, 0, Display);
		oslEndDrawing();

		if((GetCurrentTick() - Time) >= Res)
		{
			MS += 1;
			// To deal with 'overflow' as GetCurrentTick() - Time is never
			// going to be exactly equal to Res
			Time = Time + Res;
		}
		
		sprintf(Display, "Seconds: %i", (int)MS);

		oslSyncFrame();
		oslAudioVSync();
	}

Although not really a concern now, also be aware of integers wrapping back to 0 when they get too large.

[JaSo PsP]

Ok a few things to make it easier to understand (sorry for the confusion).

GetCurrentTick is a function made by myself so i didnt have to create a variable to use as the parameter for sceRtcGetCurrentTick(), instead it jus returns a u64 value. It DOES use sceRtcGetCurrentTick() however.

The thing is, this program will end up needing a 'Beats Per Minute'. In order to calculate that, i need to be able to convert ticks into milliseconds, as opposed to using a pspTime struct and using functions to get the time.

At the moment, a full cycle of a 'Drum Beat' in my program has 16 steps. 'HitStep' is set to true when the next step is hit, according to the Beats Per Minute. So, as it runs through the loop, the time differences between the current tick and the last hit increase until it needs to hit another step. (This is getting confusing, even to type).

If you can extract any sort of sense from that, please help me all you can. I havent had time to try out the suggestions from slicer and yaustar (im going to ignore mootjeuh's wonderland suggestion) yet.

Thanks

[slicer4ever]

Ok a few things to make it easier to understand (sorry for the confusion).

GetCurrentTick is a function made by myself so i didnt have to create a variable to use as the parameter for sceRtcGetCurrentTick(), instead it jus returns a u64 value. It DOES use sceRtcGetCurrentTick() however.

The thing is, this program will end up needing a 'Beats Per Minute'. In order to calculate that, i need to be able to convert ticks into milliseconds, as opposed to using a pspTime struct and using functions to get the time.

At the moment, a full cycle of a 'Drum Beat' in my program has 16 steps. 'HitStep' is set to true when the next step is hit, according to the Beats Per Minute. So, as it runs through the loop, the time differences between the current tick and the last hit increase until it needs to hit another step. (This is getting confusing, even to type).

If you can extract any sort of sense from that, please help me all you can. I havent had time to try out the suggestions from slicer and yaustar (im going to ignore mootjeuh's wonderland suggestion) yet.

Thanks

ok, i see, so the end result is your going to need to detect sooner than every second, making my idea pointless, is it a consistent rate that it's slowing, or is it randomly jumping around when it changes to a new hit every second?

[JaSo PsP]

it stays at a constant rate, slower than a usual second, and i cant seem to calibrate it to exactly one second :/