C/C++ Programming Help Thread

[myschoo]

if i want to load two images, do i have to do this: ?

char buffer1[200];
Image* ourImage;
        
sprintf(buffer, "ourImage.png");
ourImage = loadImage(buffer);

char buffer2[200];
Image* ourImage2;
        
sprintf(buffer2, "ourImage2.png");
ourImage2 = loadImage(buffer2);

or is there a better way?

[PSPJunkie_]

That buffer is pointless.

Image* ourImage1 = loadImage("Image1.png");
Image* ourImage2 = loadImage("Image2.png");

[myschoo]

thx this is shorter :)
-= Double Post =-
ok new one

how do you print variable with printTextScreen ?

i tried %d - doesnt work
i tried printing variable name - doesnt work

[MrChaos]

I started looking at LTE 2.2. Any tutorals out there?

[Beat_Bob]

Nevermind I got it.

[coolguy5678]

@Beat_Bob: Put a semicolon after the struct definition to get it to compile. Although that code won't work because it'll just get stuck at the while(1) loop.

@myschoo: sprintf the variable into a different buffer and printTextScreen that buffer (unless there's an easier way).

[yaustar]

I started looking at LTE 2.2. Any tutorals out there?

Any decent SDK should have some samples included.

[sony psp player]

Hi

Can someone tell me how i can get the ".png" out of "image.png" ?

In lua it would be this:

if string.sub("image.png", -4) == ".png" then
	fimage = Image.load("image.png")
end

Thanks in advance

[Archaemic]

strrchr("image.png",'.')
Will give you the a char* starting from last instance of a period in a character string. The strings are linked, that is, so if you free "image.png" (assuming you're doing it allocated from the stack), it'll free the ".png", and if you modify the ".png", it'll modify the "image.png". Also, you can't directly free the ".png".

[sony psp player]

Thanks, i will try this

But are you sure that there is no code in C for string.sub() in LUA?

[Archaemic]

strncpy(to, from + strlen(from) - 5, 4);

[luizlizard]

How can i convert an integer to ascii (string), i heard of itoa() but i can get the compiler to include the string library.

Im using #include <string.h>

[Archaemic]

Umm, there is no string.h. If it's C++, it's just string.

[PSPJunkie_]

There IS a string.h. You use it for strcmp, strcpy, etc...

The header he needs it stdlib.h.

[Archaemic]

Ah, oh, you're right. I was in a C++ mindset after that topic about C++ strings.

Anyway, you don't want atoi anyway. That converts C strings to integers, not the other way around.

[SG57]

Archaemic = He said itoa (Integer TO Ascii), not atoi (Ascii TO Integer)

[Archaemic]

Last time I checked, there is no itoa.

[yaustar]

Last time I checked, there is no itoa.

http://www.cplusplus.com/reference/c...dlib/itoa.html
It isn't standard though across all compilers.

[MiG]

Right then, i have no idea why i'm getting this error, but it's giving it me anyways.

I Get the following errors on compile:

main.o: In function `main':
main.cpp:(.text+0xdc): undefined reference to `initGraphics()'
main.cpp:(.text+0x12c): undefined reference to `flipScreen()'

Here are my includes:

#include <malloc.h>						
#include <pspkernel.h>
#include <pspdisplay.h>
#include <pspdebug.h>
#include <stdio.h>
#include <pspcallbacks.h>
#include <pspgu.h>
#include <pspgum.h>
#include <psprtc.h>						
#include "Files/graphics.h"

And my Makefile:

#------------------- Makefile for 'Breakout' -------------------#

TARGET			= Breakout
OBJS			= main.o Files/font.o Files/graphics.o Files/framebuffer.o

INCDIR			=
LIBDIR			=
LDFLAGS			=
LIBS			= -lpspgum -lpspgu -lpsprtc -lm -lpng -lz -lm		
CFLAGS			= -O2 -G0 -Wall
CXXFLAGS		= $(CFLAGS) -fno-exceptions -fno-rtti
ASFLAGS			= $(CFLAGS)

EXTRA_TARGETS	= EBOOT.PBP
PSP_EBOOT_TITLE	= Breakout 

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

Any ideas ?

[altunozara]

whats the easiest way to make a sidescroller with text liike
V
.
.
.
.
A

[yaustar]

OBJS			= main.o Files/font.o Files/graphics.o Files/framebuffer.o

Shouldn't it be:

OBJS			= main.o font.o graphics.o framebuffer.o

IIRC, the .o files are created in the same directory as the Makefile regardless of where the source file is.

[Archaemic]

The objs line from PSPComic is such:

OBJS = zip/ioapi.o zip/unzip.o pspcomic.o xmlfuncs.o rar.o

It works just fine, even though it compiles objects from subdirectories (and the o files do go in the zip folder after they're compiled).

[Insert_Witty_Name]

Archaemic is correct.

MiG: Wrap your #include of graphics.h in an extern C statement.

extern "C" {
#include "Files/graphics.h"
}

[Beat_Bob]

Anyone know why this isnt working?

     while(1)
    {
    sceCtrlPeekBufferPositive(&pad, 1); // Find out what the state of the control pad is
    // Change the position of the box
    if(pad.Buttons & PSP_CTRL_LEFT)
    {
    if(box.x>0)
    {box.x=box.x-3;}
}
    else if(pad.Buttons & PSP_CTRL_RIGHT)
    {
    if(box.x<480-32)
    {box.x=box.x+3;}
}

  if((pad.Buttons & PSP_CTRL_CROSS) && (box.state==0))
 {box.state=1; box.jumpspeed=0;}
 
 if(box.state==1 && box.jumpspeed==0)
 { box.y=box.y-0.8; 
 box.jumpspeed+=0.3;}
 
 if (box.state==1 && box.jumpspeed>3.5)
 {box.y=box.y-0.3;}
 
 if (box.state==1 && box.jumpspeed>=5);
 { 
  box.state=2;  
 }
 
 if (box.state==2)
 {
  box.jumpspeed=5;
   box.y+=0.8;}
 
 if (box.state==2 & box.y==230)
 {box.y=230; box.state=0; 
 box.jumpspeed=0;}

No errors or anything, its just that when I try to jump (when I press X) he doesnt do anything. I want him to go in the air and have gravity come down on him (when jumpspeed=5) thats when I want him to start coming down.
Then when hes back on the ground (when hes at y: 230) it resets.
box.state (0 = ground, 1 = jumping, 2 = falling) just so you know.
Anyone?

[SG57]

whats the easiest way to make a sidescroller with text liike
V
.
.
.
.
A

If you told us what graphics library your using, itd be much easier to make a specific example for it (graphics lib, oslib, sdl, gu, pspgl, lte, etc.)

[FreePlay]

Anyone know why this isnt working?

Indeed I do.

 if((pad.Buttons & PSP_CTRL_CROSS) && (box.state==0))
 {box.state=1; box.jumpspeed=0;}
 
 if(box.state==1 && box.jumpspeed==0)
 { box.y=box.y-0.8; 
 box.jumpspeed+=0.3;}

Notice the part I bolded.

In your code, if the box isn't moving and you press Cross, you set box.state to 1 and box.jumpspeed to 0. Then, immediately after, if box.state is 1 (it is) and box.jumpspeed is 0 (it is), you change box.jumpspeed to 0.3 . And, since none of your if statements catch anything but *exact* numbers, and more explicitly, since none of them handle the case where box.jumpspeed is 0.3, once you hit this point, your box state and box speed aren't going to change any more.

Instead of

if(box.state==1 && box.jumpspeed==0)

try

if(box.state==1 && box.jumpspeed<3.5)

and instead of

if (box.state==1 && box.jumpspeed>3.5)

try

 if (box.state==1 && box.jumpspeed>=3.5 && box.jumpspeed < 5)

Gotta be sure that every possible code route is covered, so don't just check for explicit numbers for the box speed. Check for ranges instead, so that all possible box speeds will fall into one of your if statements.

[Beat_Bob]

Didnt work. But I tried another way by converting a lua tutorial (just jumping, same method)
to this way:

Spoiler for while(1) loop:

sceCtrlPeekBufferPositive (&pad, 1); // Find out what the state of the control pad is
// Change the position of the box
if(pad.Buttons & PSP_CTRL_LEFT)
{
if(box.x>0)
{box.x=box.x-3;}
}
else if(pad.Buttons & PSP_CTRL_RIGHT)
{
if(box.x<480-32)
{box.x=box.x+3;}
}

if((pad.Buttons & PSP_CTRL_CROSS) && (box.state==0))
{box.state=1;}
if(box.state==1)
{box.jumpspeed = box.jumpspeed-0.5;
box.gravity=box.gravity-box.jumpspeed;}

if (box.gravity<0)
{box.state=2;}
if ((box.gravity < 230) && (box.state==2))
{box.gravity=box.gravity + (box.jumpspeed+3);}

if (box.gravity==230)
{box.jumpspeed=10;
box.state=0;}
if(box.gravity>230)
{box.gravity=230;}

box.y=box.gravity;

Its weird. When I press X he jumps (incredibly fast....) and hes just stuck in the air then.
He wont fall back down. Why not? Ive made it so I can move left and right, and when im stuck in the air im able to move
left and right by the way, just so you know.

[luizlizard]

So itoa() is in stdlib or is there a different function?

[SG57]

Nope.

But if you don't feel like using a non-standard function for some reason, you could always make your own or use a pre-existing example (look at the external links)



altunozara - The basic concept for vertical scrolling sentences, regardless of graphics library, is

const int SCR_HEIGHT = 272; // avoid magic numbers (yaustar's teachings through me i know... :-\)
const int SCR_WIDTH = 480;
const int CHAR_HEIGHT = 10; // in pixels
const int CHAR_WIDTH = 8;

int main() {
  int mainy = SCR_HEIGHT; // starting point
  char string[/* im too lazy to count the number of chars in the string */] = "SG57 was here..."; // string to scroll

  for(;;) {
    for(int i = 0; i < strlen(string); i++)
      screen_print(SCR_WIDTH/2-CHAR_WIDTH/2, mainy+i*CHAR_HEIGHT, string, #FFFFFF)

    mainy--;
    if(mainy < -(strlen(string)*CHAR_HEIGHT))
      mainy = SCR_HEIGHT; // reset text to bottom of screen and continue scrolling, this could easily be a call to go back to main menu should you be making a credits screen or something

    vertical_sync();
    flip_buffer();
  }

  return 0;
}

You could easily make a structure for each character, to change each specific characters color, rotation, size, etc. on the fly for a neat effect.

The above snippet needs optimization, but its a rough example and should push you into the right direction.

[MiG]

Archaemic is correct.

MiG: Wrap your #include of graphics.h in an extern C statement.

extern "C" {
#include "Files/graphics.h"
}

That just broke "graphics.h", came up with all sorts of errors... i'll have a play.. see what's going off :)

EDIT - Seems like having the files in a seperate directory was causing the errors. :S
But now I have a new set of errors that don't even make sense