Hi,

I'm trying to create more than one projectile in an array because using when using one projectile, when you fire a second time, the first projectile disappears for the projectile to fire again.

I thought using for-loops would the best way to go about it but not sure what I am doing wrong.

//Here is instantiating the class
for (int i = 0; i < PROJECTILES; i++)
{
_projectile[i] = new Projectile();
}

//Projectile Inits
for (int i = 0; i < PROJECTILES; i++)
{
_projectile[i]->_speed = 0.8f;
_projectile[i]->_frameTime = 250;
_projectile[i]->_launched = false;
}

//Loading Projectile Content
for (int i = 0; i < PROJECTILES; i++)
	{
		_projectile[i]->_texture = new Texture2D();
		_projectile[i]->_boundry = new Rect();
		_projectile[i]->_texture = projTexture;
		_projectile[i]->_boundry = projRect;
	}

//Spacebar to fire
for (int i = 0; i < PROJECTILES; i++)
	{
		if (state->IsKeyDown(Input::Keys::SPACE))
		{
			_projectile[i]->_boundry->X = _player->_position->X + 35;
			_projectile[i]->_boundry->Y = _player->_position->Y + 59;
			_projectile[i]->_launched = true;
		}
		if (i == 5)
		{
			i = 0;
		}
	}

/?Draw Projectile
for (int i = 0; i < PROJECTILES; i++)
	{
		if (_projectile[i]->_launched)
		{
			SpriteBatch::Draw(_projectile[i]->_texture, _projectile[i]->_boundry, 0.5f, 0.0f);
			_projectile[i]->_boundry->Y -= _projectile[i]->_speed * elapsedTime;
		}
	}

When that sort of problem happens you usually update the old projectiles with new information, overwriting whatever they had before. Make sure you only fire a projectile once.

In your code you iterate over the array and when you press space you select one of the five projectiles and change it. You should instead have an array that you add projectiles too and later update only the ones in there, and remove them if they hit or go too far away or whatever.

1. Fire -> add to array.

2. Update -> update the ones in the array (remove from array if they are 'dead')

3. Draw -> draw the ones in the array.

//Loading Projectile Content
for (int i = 0; i < PROJECTILES; i++)
	{
		_projectile[i]->_texture = new Texture2D();
		_projectile[i]->_boundry = new Rect();
		_projectile[i]->_texture = projTexture;
		_projectile[i]->_boundry = projRect;
	}

    //Spacebar to fire
    for (int i = 0; i < PROJECTILES; i++) {
        if (state->IsKeyDown(Input::Keys::SPACE)) {
            _projectile[i]->_boundry->X = _player->_position->X + 35;
            _projectile[i]->_boundry->Y = _player->_position->Y + 59;
            _projectile[i]->_launched = true;
        }
        if (i == 5) {
            i = 0;
        }
    }

When that sort of problem happens you usually update the old projectiles with new information, overwriting whatever they had before. Make sure you only fire a projectile once.

In your code you iterate over the array and when you press space you select one of the five projectiles and change it. You should instead have an array that you add projectiles too and later update only the ones in there, and remove them if they hit or go too far away or whatever.

1. Fire -> add to array.

2. Update -> update the ones in the array (remove from array if they are 'dead')

3. Draw -> draw the ones in the array.

How do you 'remove' from an array. I know you can remove from an List but not from an Array.

//Loading Projectile Content
for (int i = 0; i < PROJECTILES; i++)
	{
		_projectile[i]->_texture = new Texture2D();
		_projectile[i]->_boundry = new Rect();
		_projectile[i]->_texture = projTexture;
		_projectile[i]->_boundry = projRect;
	}

I highly doubt anything will work at all with this kind of code.
This makes absolutely no sense.
You create new pointers, and then you change them to something else immediately (which is also a memory leak and a crash if you ever actually attempted to free this memory).

All 5 bullets are pointing to the same texture and boundary. Very clearly they will all be drawn in the same spot. If they aren’t, you have another bug (hint: don’t mix updating and rendering as you are doing now).

    //Spacebar to fire
    for (int i = 0; i < PROJECTILES; i++) {
        if (state->IsKeyDown(Input::Keys::SPACE)) {
            _projectile[i]->_boundry->X = _player->_position->X + 35;
            _projectile[i]->_boundry->Y = _player->_position->Y + 59;
            _projectile[i]->_launched = true;
        }
        if (i == 5) {
            i = 0;
        }
    }

Why are you setting i to 0?


L. Spiro

It made no sense because I missed a bit of code out where I was assigning a Texture2D-Load("", false) to a variable and then assign that to the bit inside the loop. According to my lecturer it was more efficient.

I was setting i=0 so that it would re-iterate through the loop after the loop had reached PROJECTILES.

I was setting i=0 so that it would re-iterate through the loop after the loop had reached PROJECTILES.

All 5 bullets are pointing to the same texture and boundary. Very clearly they will all be drawn in the same spot. If they aren’t, you have another bug (hint: don’t mix updating and rendering as you are doing now).

The image used is supposed to be the same and they are supposed to be drawn from the same position. It's just when I press the spacebar, they all draw at the same time :-( I need them to draw one at a time.

I was setting i=0 so that it would re-iterate through the loop after the loop had reached PROJECTILES.

I see no reason why you should need to 're-iterate' through that loop. In fact, the way that loop is currently presented is an infinite loop. The snippets of code as you've presented them aren't going to draw anything cause it never gets out of that 'Spacebar to fire' loop, so what are we missing?

Your "spacebar to fire" code loops will set all projectiles to fire, using the same position. The keydown check will be the same for the entire loop, so if it's true for the first iteration of the loop, it will be true for all of them.

What you could do instead is something like:

- Check if spacebar is pressed.

- If it is, iterate over the array, checking if the projectile is not launched.

- If a projectile is not launched, launch it, and stop looping through the array.

You will need to clear the "launched" flag when the projectile has done whatever it should be doing.

And, as already mentioned, you shouldn't update logic in your draw code.

Another way of doing this would be to e.g. have a std::vector of projectiles, and add a new projectile to the vector when you press the spacebar.