C/C++ Programming Help Thread

[yaustar]

In the end, doesn't this mean I could end up with, say, 40 source files each relatively small in size?

Yes, is that a problem? (Or you can stack multiple classes in one file if you *really* want to).

I would love to see some C++ source code of this pattern, I think I've been following something of the sort all along (as in, couldn't one say using a 3D vector class to handle storing positions/velocities/orientations a composite pattern?)

I would use a std::map myself which makes it easier to get components from the entity container. There is an issue that you can't have more then one instance of the same component in a map structure but that is easily solvable either by design or a code solution.

A PPT of the same pattern: http://www.gdcvault.com/play/1911/Th...t_Architecture

[wethegreenpeople]

Hey guys, I was wondering, how do I underline text using C++? I am also using OSLib, so if their is a way to do it please help me xP

[mootjeuh]

Emm, you could simply use the OSlib to draw a line under your text.

[Beat_Bob]

Error I got upon compiling:
make: *** No rule to make target `graphics.o', needed by `image.elf'. Stop.

Makefile:

TARGET = image
OBJS = main.o graphics.o framebuffer.o
 
CFLAGS = -O2 -G0 -Wall
CXXFLAGS = $(CFLAGS) -fno-exceptions -fno-rtti
ASFLAGS = $(CFLAGS)

LIBS = -lpspgu -lpng -lz -lm

EXTRA_TARGETS = EBOOT.PBP
PSP_EBOOT_TITLE = Image
 
PSPSDK=$(shell psp-config --pspsdk-path)
include $(PSPSDK)/lib/build.mak

main.c:

#include <pspkernel.h>
#include <pspdebug.h>
#include <pspcallbacks.h>
#include <pspctrl.h>
#include "graphics.h"

 
#define drawImage blitAlphaImageToScreen
 
PSP_MODULE_INFO("Name Of Program",0,1,1);
 
int main() {
	pspDebugScreenInit();
	//pspDebugScreenClear();
	SetupCallbacks();
	initGraphics();	
	SceCtrlData pad;
	Image* background = loadImage("back.png");

	drawImage(0,0,480,272,background,0,0);

	flipScreen();
	sceKernelSleepThread();
	return 0;
}

[mootjeuh]

It means your graphics.c (or .cpp) doesn't exist in the current directory, you should really learn the actual (Linux) C before skipping to the PSP.

[Beat_Bob]

Whats the best way to make objects in C?

Like lets say I want to make two objects:
a player and a block

The player has these attributes:
- Can walk
- Jump (gravity)
- collides with blocks
- contains animations / a sprite

The block has these attributes:
- stays stationary
- is either jump through / not jump through
- contains a sprite

How would you do this? Since you can't use classes in C, and if Im not mistaken, the PSP SDK wont let you use C++

[mootjeuh]

, and if Im not mistaken, the PSP SDK wont let you use C++

Who's the idiot that told you that? Of course you can use C++ with the pspsdk, it's just a matter of file extension.

[slicer4ever]

indeed, c++ is fully supported, in ur makefile, simply include -lstdc++ on your library line and your fine

also, you can use struct's in c, so that's how i'd go about it personally if i couldn't use c++(also generally you'll probably almost never find a situation where C is allowed, but c++ isn't, and vice versa

[Beat_Bob]

Well I changed it to .cpp instead of .c, I also added that line on my makefile.
I get these errors after running 'make' :

psp-g++ -I. -ID:/pspsdk/psp/sdk/include -O2 -G0 -Wall -I. -ID:/pspsdk/psp/sdk/i
clude -O2 -G0 -Wall -fno-exceptions -fno-rtti -D_PSP_FW_VERSION=150   -c -o mai
.o main.cpp
main.cpp: In function 'int main()':
main.cpp:18: warning: unused variable 'pad'
psp-gcc -I. -ID:/pspsdk/psp/sdk/include -O2 -G0 -Wall -D_PSP_FW_VERSION=150  -L
 -LD:/pspsdk/psp/sdk/lib   main.o graphics.o framebuffer.o -lpspgu -lpng -lz -l
 -lpspdebug -lpspdisplay -lpspge -lpspctrl -lpspsdk -lc -lpspnet -lpspnet_inet
lpspnet_apctl -lpspnet_resolver -lpsputility -lpspuser -lpspkernel -o image.elf
main.o: In function `main':
main.cpp:(.text+0x74): undefined reference to `initGraphics()'
main.cpp:(.text+0x80): undefined reference to `loadImage(char const*)'
main.cpp:(.text+0xa0): undefined reference to `blitAlphaImageToScreen(int, int,
int, int, Image*, int, int)'
main.cpp:(.text+0xa8): undefined reference to `flipScreen()'
collect2: ld returned 1 exit status
make: *** [image.elf] Error 1

main.cpp:

#include <pspkernel.h>
#include <pspdebug.h>
#include <pspcallbacks.h>
#include <pspctrl.h>
#include "graphics.h"

//
 
#define drawImage blitAlphaImageToScreen
 
PSP_MODULE_INFO("Name Of Program",0,1,1);
 
int main() {
	pspDebugScreenInit();
	//pspDebugScreenClear();
	SetupCallbacks();
	initGraphics();	
	SceCtrlData pad;
	Image* background = loadImage("back.png");

	drawImage(0,0,480,272,background,0,0);

	flipScreen();
	sceKernelSleepThread();
	return 0;
}

Makefile:

TARGET = image
OBJS = main.o graphics.o framebuffer.o
 
CFLAGS = -O2 -G0 -Wall
CXXFLAGS = $(CFLAGS) -fno-exceptions -fno-rtti
ASFLAGS = $(CFLAGS)

LIBS = -lpspgu -lpng -lz -lm -lstdc++

EXTRA_TARGETS = EBOOT.PBP
PSP_EBOOT_TITLE = Image
 
PSPSDK=$(shell psp-config --pspsdk-path)
include $(PSPSDK)/lib/build.mak

[lilmnm]

you dont need -lstdc++ so you can compile an app using graphics.h

you should make sure you have libpng and libpspgu fallow this tut and you will have a working base code for it

Lesson 04 - Simple Image Processing.

[Beat_Bob]

I have graphics.h and graphics.c and framebuffer.c and framebuffer.h, I also have libpng installed.
And I removed that line from my Makefile (since you said it's not needed)

What's wrong with my code?

[lilmnm]

main.o: In function `main':
main.cpp:(.text+0x74): undefined reference to `initGraphics()'
main.cpp:(.text+0x80): undefined reference to `loadImage(char const*)'
main.cpp:(.text+0xa0): undefined reference to `blitAlphaImageToScreen(i nt, int,
int, int, Image*, int, int)'
main.cpp:(.text+0xa8): undefined reference to `flipScreen()'
collect2: ld returned 1 exit status
make: *** [image.elf] Error 1

thats your problem the functions in your graphics.h and .c files are not being recognized

also change your main.cpp to just main.c and make sure are in the same folder as the makefile

[Beat_Bob]

But they're in the same directory as my main.cpp file..........

[Beat_Bob]

Wonder why it isnt working

[slicer4ever]

thats your problem the functions in your graphics.h and .c files are not being recognized

also change your main.cpp to just main.c and make sure are in the same folder as the makefile

the extension has nothing to do with it

beat_bob, the error is because the program doesn't see those functions, your makefile looks good, so i'm not certain why it's complaining

hmm, i wonder, unlikly, but try:

TARGET = image
OBJS = framebuffer.o graphics.o main.o
 
CFLAGS = -O2 -G0 -Wall
CXXFLAGS = $(CFLAGS) -fno-exceptions -fno-rtti
ASFLAGS = $(CFLAGS)

LIBS = -lpspgu -lpng -lz -lm -lstdc++

EXTRA_TARGETS = EBOOT.PBP
PSP_EBOOT_TITLE = Image
 
	PSPSDK=$(shell psp-config --pspsdk-path)
	include $(PSPSDK)/lib/build.mak

i doubt it'll 100% work, but give that a shot

[SG57]

GNU GCC recognizes .C, .cc, .cpp, .CPP, .c++, .cp, .cxx as C++ files and will use C++ compilation regardless of whether you invoke it through gcc (C) or g++ (C++).

Note the .C - that is a capital C, the case matters in GCC. .c is a C file whereas .C is a C++ file (if you let the compiler decide what it is compiling based of file extension that is).

Beat_Bob, you are compiling your main source file as C++ which is fine but you're including a C source file (graphics.h).

You need to either rename main.cpp to main.c to force the compiler to compile it as C (not C++ so it can include the graphics C source file)

OR

Tell the compiler in your C++ source code that you are including a C source file

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

I recommend just renaming main.cpp to main.c and removing -lstdc++ from your libs line. You are not programming in C++ (yet) and you're using a C graphics library.

[mootjeuh]

Does anyone know how to remove an image from the screen (not de-allocating it) without using flags?

[slicer4ever]

Does anyone know how to remove an image from the screen (not de-allocating it) without using flags?

don't draw it in the next frame?

[lilmnm]

the extension has nothing to do with it

beat_bob, the error is because the program doesn't see those functions, your makefile looks good, so i'm not certain why it's complaining

hmm, i wonder, unlikly, but try:

TARGET = image
OBJS = framebuffer.o graphics.o main.o
 
CFLAGS = -O2 -G0 -Wall
CXXFLAGS = $(CFLAGS) -fno-exceptions -fno-rtti
ASFLAGS = $(CFLAGS)

LIBS = -lpspgu -lpng -lz -lm -lstdc++

EXTRA_TARGETS = EBOOT.PBP
PSP_EBOOT_TITLE = Image
 
	PSPSDK=$(shell psp-config --pspsdk-path)
	include $(PSPSDK)/lib/build.mak

i doubt it'll 100% work, but give that a shot

he already had his makefile like that the order of the objects dont matter but after making changes just to be sure you should clean the source by typing "make clean" because its showing an error in the main.o file with the error code such as this from his earlier post

main.o: In function `main':
main.cpp.text+0x74): undefined reference to `initGraphics()'
main.cpp.text+0x80): undefined reference to `loadImage(char const*)'
main.cpp.text+0xa0): undefined reference to `blitAlphaImageToScreen(i nt, int,
int, int, Image*, int, int)'
main.cpp.text+0xa8): undefined reference to `flipScreen()'
collect2: ld returned 1 exit status
make: *** [image.elf] Error 1

this could help get rid of those errors cause it tries to compile the main.o files already made to save time on compiling

[slicer4ever]

i was fairly certain changing the order wouldn't matter, i do agree a make clean may solve it, otherwise i don't see an issue with the makefile, i checked the graphics.h that he was linked to in another thread, it has the appropiate functions listed, and defined, so i'm not sure of the issue

[lilmnm]

i was fairly certain changing the order wouldn't matter, i do agree a make clean may solve it, otherwise i don't see an issue with the makefile, i checked the graphics.h that he was linked to in another thread, it has the appropiate functions listed, and defined, so i'm not sure of the issue

same it could be that he may have changed names of the funtions in the graphics. h and stuff or something like that

[Beat_Bob]

I used SG57's method using extern C, and it worked!

Thanks!

[lilmnm]

I recommend just renaming main.cpp to main.c and removing -lstdc++ from your libs line. You are not programming in C++ (yet) and you're using a C graphics library.

as i said before and it was the cure :P

[slicer4ever]

i swear i've used c and cpp files without externing them, w/e

[LegendMythe]

I was wondering how should i use a doucle (%d) with printtextscreen (graphics.h) like

printf("%d", scePowerGetCpuClockFrequency());

[lilmnm]

I was wondering how should i use a doucle (%d) with printtextscreen (graphics.h) like

printf("%d", scePowerGetCpuClockFrequency());

because the way scePowerGetCpuClockFreque ncy(); was set up was to return the cpu to a buffer or t fill in the variable and %d is the variable that is being represented in the printf because we dont know what the CPU speed is so we find out what it is then return it to the variable


the way you should use it is by

int CPUClock[17]; //buffer to save the info
sprintf(CPUclock, "CPU: %d", scePowerGetCpuClockFrequency()); //Only prints out the CPU speed i.e. 333 or 222

A better way is to show both the CPU speed and the BUS speed and heres how

int CPUClock[17]; //buffer to save the info
//this following line will print out the CPU and the BUS speed i.e. 333/166 or 222/111
sprintf(CPUclock, "CPU/BUS: %d/%d", scePowerGetCpuClockFrequency(), scePowerGetBusClockFrequency());

Dont forget to add #include <psppower.h> to the main.c and or main.h if you have one for the cpu stuff and add
-lpsppower to the LIBS = line in your make file

hope i explained it clearly enough if it doesn't make any sense then ask another question and ill clarify it

[SG57]

lilmnm - Your CPUClock array of integers ought to be an array of characters.

char CPUClock[17]; //buffer to save the info
sprintf(CPUclock, "CPU: %d", scePowerGetCpuClockFrequency());

and snprintf for buffer overflow protection :)

char CPUClock[17]; //buffer to save the info
//this following line will print out the CPU and the BUS speed i.e. 333/166 or 222/111
snprintf(CPUclock, 17, "CPU/BUS: %d/%d", scePowerGetCpuClockFrequency(), scePowerGetBusClockFrequency());

[lilmnm]

lilmnm - Your CPUClock array of integers ought to be an array of characters.

char CPUClock[17]; //buffer to save the info
sprintf(CPUclock, "CPU: %d", scePowerGetCpuClockFrequency());

and snprintf for buffer overflow protection :)

char CPUClock[17]; //buffer to save the info
//this following line will print out the CPU and the BUS speed i.e. 333/166 or 222/111
snprintf(CPUclock, 17, "CPU/BUS: %d/%d", scePowerGetCpuClockFrequency(), scePowerGetBusClockFrequency());

lol the buffer is big enough so there wouldnt be an over flow its basically the same way i have it set up in my DayPR and im not having any troubles with it but good add though its better to be safe then sorry i guess lol also i havent seen the snprintif function anywhere what file is it in in the SDK?

[Beat_Bob]

Nevermind, works.

[SG57]

lilmnm - It isn't part of the SDK, it is part of stdlib. Its not that it 'will' overflow, its just a good habit and to be consciously aware of what might happen.

Practical use: I used a 256 long buffer for a texture filepath that ended up being like 300 characters long after all was done with it from the relative sub-directories. I couldn't figure out 'why' it was failing to load until I realized it was cutting off the final few chars of the filename. If I hadn't of used snprintf, it would've been a buffer overflow with undefined behavior. Instead I simply printed the buffer out to the debug stream and sure enough I saw it was missing the last half of the filename. Then I simply upped the buffer to 400 in size.