Return Image...

[ShUr1k3n]

Hey guys,
how can i return a image from a Class?

for example:

i have this code:

Image* TANK::GetSprite(int index)
{
	return sprite[index];
}

and i use this here:

blitAlphaImageToScreen(0, 0, 25, 25, tank->GetSprite(0), 100, 100);

the prototype of that function is:

void blitAlphaImageToScreen(int sx, int sy, int width, int height, Image* source, int dx, int dy);

but when i use the "tank->GetSprite(0)", the PSP freeze. And i need to reboot.

So, whats the wrong with this:

Image* TANK::GetSprite(int index)
{
	return sprite[index];
}

thanks in advance,

ShUr1k3n

[Ravine]

Well, you are calling GetImage and have the function set as GetSprite().

[ShUr1k3n]

Originally Posted by Ravine

Well, you are calling GetImage and have the function set as GetSprite().

No, thats not the problem. Thats an error when i type this thread.

Edited now...

[Ravine]

A few things, have you created the object tank from the TANK class by calling,

TANK tank;

If you have done that then try changing

blitAlphaImageToScreen(0,   0, 25, 25, tank->GetSprite(0), 100, 100);

to

blitAlphaImageToScreen(0,   0, 25, 25, tank.GetSprite(0), 100, 100);

Also, make sure you have created the tank object before making that call.

[ShUr1k3n]

No, the problem isnt that too.

Because if u use tank->GetX() or tank->SetX(). Works fine.

I think that the problem is with this code:

Image* TANK::GetSprite(int index)
{
	return sprite[index];
}

But whats wrong???

[Ravine]

What type of variable is sprite?

[Garak]

What you have so far should be fine.

When you call tank->GetSprite(0), you are returning a pointer to an image. It would seem index 0 does not contain a pointer to a valid image. Do this:

// Ensure your tank class initilizes all pointers in the sprite array to 0.
Image *i1 = tank->GetSprite(0);

if (i1) { blitAlphaImageToScreen(.. .); }
else { printf("Null pointer returned"); }

Also, verify that you have actually stored an Image at index 0 in your sprite array.

Garak

[ShUr1k3n]

Garak i use ur method. And i got the "Null pointer return".

But in my class i have this:

TANK::TANK()
{
	strcpy(type,"Tank");
	maxEnergy = 10;
	energy = 10;
	shotSpeed = 1;
	direction = 1;
	x = 10;
	y = 10;
	sprite[0] = loadImage("Data/Tanks/Tank1.png");
	sprite[1] = loadImage("Data/Tanks/Tank2.png");
	sprite[2] = loadImage("Data/Tanks/Tank3.png");
	sprite[3] = loadImage("Data/Tanks/Tank4.png");
}

Anything wrong with this?

[Ravine]

Did you, in your class definition delcare sprite as an array of Images, like so:
Image* sprite[4]; ?

[ShUr1k3n]

Yap...

If in the "void main()" i use "AddSprite(0,path)".. . Works fine.
So why dont work good when i use in the "TANK::TANK" ???

[SG57]

Well, I dont know C++ as the next guy, but I do undrstand a class and function's 'names' if you will, should not be the same, case-sensitive.

[ShUr1k3n]

Originally Posted by SG57

Well, I dont know C++ as the next guy, but I do undrstand a class and function's 'names' if you will, should not be the same, case-sensitive.

But the other's variables are ok.

Look:

TANK::TANK()
{
	strcpy(type,"Tank");
	maxEnergy = 10;
	energy = 10;
	shotSpeed = 1;
	direction = 1;
	x = 100;
	y = 100;
	sprite[0] = loadImage("Data/Tanks/Tank1.png");
	sprite[1] = loadImage("Data/Tanks/Tank2.png");
	sprite[2] = loadImage("Data/Tanks/Tank3.png");
	sprite[3] = loadImage("Data/Tanks/Tank4.png");
}

i "print" all variables (x,y,...) and the numbers are ok. x = 100, y = 100...

The only problem is with the sprites, that return NULL...

[Ravine]

Are you trying to use the different sprites as different tanks? Like they are not all controlled by the same person or AI?