C/C++ Programming Help Thread

[yaustar]

Have you done work with pointers and know how they work?

[MrChaos]

Have you done work with pointers and know how they work?

This is my first time working with them.
And I understand how they work, just not compleatly enough to notice bugs...yet.

[JustChris]

How do you initialize an array SEPARATELY from its declaration? I want all elements to be intialized in one statement, not going through the indices one by one. Is there another way besides using a typedef struct?

[yaustar]

'Found' the bug. That code is outside function scope. Eg

Image * img;
img->width = 100;
//etc
int main()
{

}

This is illegal syntax. You can create and declare, define and initialise variables outside function scope but you can't do anything more with them outside function scope.
-= Double Post =-

This is my first time working with them.
And I understand how they work, just not compleatly enough to notice bugs...yet.

No you don't otherwise you would have noticed why it would crash immediately.

[PSPJunkie_]

That wouldn't fix it. That's definitely a pointer to an object, and not an object in and of itself. Hence you'd use ->

I understand that. I was just throwing it out there.

[yaustar]

How do you initialize an array SEPARATELY from its declaration? I want all elements to be intialized in one statement, not going through the indices one by one. Is there another way besides using a typedef struct?

int anArray1[4] = { 0 }; // All values in the array are 0
int anArray2[4] = { 1, 2, 4, 6 }; // The array has been given the values 1, 2, 4 and 6
int anArray3[4] = { 1, 2 }; // Illegal. You cannot partially initialise an array.

[MrChaos]

'Found' the bug. That code is outside function scope. Eg

Image * img;
img->width = 100;
//etc
int main()
{

}

This is illegal syntax. You can create and declare, define and initialise variables outside function scope but you can't do anything more with them outside function scope.
-= Double Post =-

No you don't otherwise you would have noticed why it would crash immediately.

I said I didn't understand them "compleatly" :P.

Ok, I fixed the 'bug'. But I need to fix something else. When I fixed it, then compiled, the compiler spit out 637 errors, saying that the image data is incorrect. I'm back to my first problem now. My logo data is this:

 
logo->data = 0x7fff,0x7fff,0x7fff,0x7fff, // and so on...;

Yeah, that's where it is. What SHOULD be in the logo data, instead of what I have?

[JustChris]

Yaustar, that works in normal cases, but I guess I need to mention now that the array I'm trying to use is declared as a private member of a class. I can't initialize it in the class declaration. Ideally it needs to be initialized in one method, and other methods called after it would be able to use the array.

[Maxi_Jac']

How do you initialize an array SEPARATELY from its declaration? I want all elements to be intialized in one statement, not going through the indices one by one. Is there another way besides using a typedef struct?

See what yaustar said, but his only works at the declaration moment, later in your code, you can't us eit anymore, you'll have to go to each indices.

++ B.

[PSPJunkie_]

*Goes into a coma from banging had against wall"

bin2c spits a .c file out with the data definition already.

Do,

img->data = variable_from_bin2c;

[MrChaos]

*Goes into a coma from banging had against wall"

bin2c spits a .c file out with the data definition already.

Do,

img->data = variable_from_bin2c;

LOL! By this point you guys hate me now. Sorry guys, I studied C++, but apperently, haven't learned enough. But, I like to learn from expericence.

But...Now my compiler "can't convert short unsigned int [127840]' to Color* in assignment".

I think the compiler hates me too.

[yaustar]

Yaustar, that works in normal cases, but I guess I need to mention now that the array I'm trying to use is declared as a private member of a class. I can't initialize it in the class declaration. Ideally it needs to be initialized in one method, and other methods called after it would be able to use the array.

In that case, you can't. You can't initialise arrays in the initialisation list of a construct.

If you are using C++ then you really should be using vectors instead of arrays otherwise your only other option is to use a for loop.

[PSPJunkie_]

Maybe try masking it? I honestly don't know if that will do anything, though.

[yaustar]

LOL! By this point you guys hate me now. Sorry guys, I studied C++, but apperently, haven't learned enough. But, I like to learn from expericence.

But...Now my compiler "can't convert short unsigned int [127840]' to Color* in assignment".

I think the compiler hates me too.

An error is only useful if we see the code that refers to the error.

[MrChaos]

An error is only useful if we see the code that refers to the error.

It's:

logo->data = imageData;

But it referrs to the .c img file that bin2c made...

[Archaemic]

The first one is the only one with an assignment.

[yaustar]

It's:

logo->data = imageData;

But it referrs to the .c img file that bin2c made...

What is the datatype of logo->data and imageData?
What is the datatype of logo?
What is the declaration of the datatype of logo?
What is the declaration of the datatype of imageData?

[MrChaos]

What is the datatype of logo->data and imageData?
What is the datatype of logo?
What is the declaration of the datatype of logo?
What is the declaration of the datatype of imageData?

Datatype of logo = Not sure what you mean by that...
Declaration of the datatype of logo = Image* logo
Declaration of the datatype of imageData = unsigned short imageData

[PSPJunkie_]

'data' is a u32, and imageData is an unsigned char.

[Archaemic]

Geez, look at the previous page. Logo is an Image*
E] Make that two pages ago

[MrChaos]

'data' is a u32, and imageData is an unsigned char.

Ok. I learn stuff every day. Thanks.

[yaustar]

This is going to be problematic. Image->data is a Color * which is a typedef'ed u32 which is an unsigned int (32 bit). imageData however is an array of unsigned shorts which are 16 bit.

If you change the following code, it will compile but won't give you the correct results (ignoring the fact that the program will still crash).

unsigned short imageData
// Change to
unsigned int imageData

Basically, the data NEEDs to be in 32 bit format for this to work with graphics.h.

To make this painless, just load the image from a seperate image file rather then try to compile the data with the code. It isn't worth the hassle.

[PSPJunkie_]

Um, try looking at graphics.h or the file that bin2c created.

typedef u32 Color;

and

static unsigned char hw[] __attribute__((aligned(16)));

[MrChaos]

This is going to be problematic. Image->data is a Color * which is a typedef'ed u32 which is an unsigned int (32 bit). imageData however is an array of unsigned shorts which are 16 bit.

If you change the following code, it will compile but won't give you the correct results (ignoring the fact that the program will still crash).

unsigned short imageData
// Change to
unsigned int imageData

Basically, the data NEEDs to be in 32 bit format for this to work with graphics.h.

To make this painless, just load the image from a seperate image file rather then try to compile the data with the code. It isn't worth the hassle.

Ok. If I include it in the makefile, will it still show in the folder?

[yaustar]

Um, try looking at graphics.h or the file that bin2c created.

typedef u32 Color;

and

static unsigned char hw[] __attribute__((aligned(16)));

I don't have either at hand hance I asked for them.

Datatype of logo = Not sure what you mean by that...
Declaration of the datatype of logo = Image* logo
Declaration of the datatype of imageData = unsigned short imageData

A short is 2 bytes.

[MrChaos]

Um, try looking at graphics.h or the file that bin2c created.

typedef u32 Color;

and

static unsigned char hw[] __attribute__((aligned(16)));

I don't use bin2c (even though I said I did; I use graphicsto16bitc)

[yaustar]

Geez, look at the previous page. Logo is an Image*
E] Make that two pages ago

Saying it is an Image tells me nothing of the datatypes of the members hence I asked for a declaration since it is a non-standard datatype.

[PSPJunkie_]

Chaos, save the image as a .raw, then bin2c it.

[Archaemic]

I never said anything about its members.

[MrChaos]

Chaos, save the image as a .raw, then bin2c it.

Can you do me a favor, and send me a link to bin2c? All I find is the one I have right now, and that aint it.