Drawing a vector of rectangle shapes

[DylanMorgan]

Hey all, I just got back into coding. Trying to make a simple breakout game, I did start of just making a simple 'pong' game but found it quite easy so I am trying to expand it to a breakout game (image attached for those who do not know what it is).

To handle the blocks at the top of the screen I have used a vector of blocks, from which right now I am trying to draw them onto the screen. I am unable to do this as I am getting an error:

(click to show/hide)

error C2664: 'void sf::RenderTarget::draw(const sf::Vertex *,size_t,sf::PrimitiveType,const sf::RenderStates &)' : cannot convert argument 1 from 'Block' to 'const sf::Drawable &'

which is inside the block.cpp file

Here is the relevant code, there are more functions but they do not apply to this. Sorry for any bad code in there 

block.cpp

Block::Block(float startX, float startY)
{
        position.x = startX;
        position.y = startY;

        colour = sf::Color::White;

        block.setSize(sf::Vector2f(width, height));
        block.setFillColor(colour);
        block.setPosition(position);
}

void Block::draw(Block block, sf::RenderWindow& window)
{
        window.draw(block);
}

blockContainer.cpp

ContainerOfBlocks::ContainerOfBlocks(int useless)
{
        blockContainer.push_back(Block(100, 1));
        blockContainer.push_back(Block(202, 1));
}

void ContainerOfBlocks::drawContainer(sf::RenderWindow& window)
{
        for (unsigned int i = 1; i > 10; i++)
        {
                blockContainer[i].draw(blockContainer[i], window);
        }
}

blockContainer.h

#pragma once

class ContainerOfBlocks
{
public:
        ContainerOfBlocks(int useless);
        ~ContainerOfBlocks();

        std::vector<Block> getContainer();
       
        void drawContainer(sf::RenderWindow& window);

private:
        std::vector<Block> blockContainer;
};

Thank you for any help

[jamesL]

couldn't this
  blockContainer.draw(blockContainer, window);

be like this
  blockContainer.draw(window);

[DylanMorgan]

couldn't this
  blockContainer.draw(blockContainer, window);

be like this
  blockContainer.draw(window);

Yes, I just noticed that before I checked this forum.

Although i don't get an error, the shapes do not appear on screen at all now. I was thinking maybe it is to do with the way I have coded it. Does the constructor for blockContainer actually push back these objects or are they destroyed as the constructor finishes.
I think I will need to make them on the heap and then point to them? I'm not sure though I could be completely wrong, just a thought.

[Hapax]

The container does push back two blocks, yes.

However, your loop that draws the container has an error in its logic. The condition will never be true.

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i starts at 1 and is not greater than 10.

i > 10

should be

i < 10

Note, though, that there are only two blocks so this will cause a problem. Note also that the vector index should start at zero, not one.
Try:

for (auto& block : blockContainer)
    block.draw(window);

Or, if you still want to use your original counter form:

for (unsigned int i = 0; i < 10; ++i)
    blockContainer[i].draw(window);

This assumes that you are using:

void Block::draw(sf::RenderWindow& window)
{
    window.draw(block);
}

(as mentioned above)

Although there is no use in the code you used of getContainer, note that it will return a copy of the vector, not the actual vector itself so, not only can it slow down your program if this vector has a lot of elements but, if you modify anything in the vector returned by getContainer, it won't modify the actual vector.
If you want to access the vector, return a reference or a pointer:

std::vector<Block>& getContainer();

Hope this helps 

[DylanMorgan]

However, your loop that draws the container has an error in its logic. The condition will never be true.

Thank you for pointing that out. I did not notice i did that. No matter how hard I try I can't seem to get it to return a pointer to the vector.

This is the code I am using.

Block* ContainerOfBlocks::getContainer()
{
        return *blockContainer;
}

and this is my error:

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IntelliSense: no operator "*" matches these operands
            operand types are: * std::vector<Block, std::allocator<Block>>   

I know this may sound stupid, but I thought an array would be better as I could access each individual block and delete them as they get hit. Which would be easier than the vector. Yet I can't get this working with an array, it breaks when I run the program.

[Hapax]

It's still a vector of blocks so return a reference to the vector of blocks or a pointer to the vector of blocks.
i.e.

std::vector<Block>& getContainer();

or

std::vector<Block>* getContainer();

If you really want to, you can return a pointer to the actual block data but it's not as nice to use:

return blockContainer.data();

[DylanMorgan]

std::vector<Block>* getContainer()
{
        return *blockContainer;
}

This still doesn't work. It is saying it's unidentified now?

[Hapax]

blockContainer is not a pointer; it is a vector.
To return a pointer to it, return its address:

std::vector<Block>* getContainer()
{
    return &blockContainer;
}

I still think reference might be easier :p

std::vector<Block>& getContainer()
{
    return blockContainer;
}

[DylanMorgan]

std::vector<Block>& getContainer()
{
        return blockContainer;
}

that still says:

Error: identifier "blockContainer" is unidentified

[DylanMorgan]

Nevermind, error on my part. Did not put ContainerOfBlocks:: before the function name. Silly mistake thank you for all the help!

I have another problem now, funnily enough.

The constructor inside my containerOfBlocks.cpp file has an error on the '{' saying

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"ContainerOfBlocks::ContainerOfBlocks()"provides no initializer for the reference member "ContainerOfBlocks::blockContainer"

ContainerOfBlocks::ContainerOfBlocks()
{
        blockContainer.push_back(Block(0, 1));
        blockContainer.push_back(Block(102, 1));
        blockContainer.push_back(Block(204, 1));
        blockContainer.push_back(Block(306, 1));
        blockContainer.push_back(Block(408, 1));
        blockContainer.push_back(Block(510, 1));
        blockContainer.push_back(Block(612, 1));
        blockContainer.push_back(Block(714, 1));
        blockContainer.push_back(Block(816, 1));
        blockContainer.push_back(Block(918, 1));
}

Not sure what this means to be completely honest

[Hapax]

You're welcome. Glad you got it working!

[Hapax]

You didn't change:

std::vector<Block> blockContainer;

to a reference, did you?

[DylanMorgan]

Wow, good spot. I did, don't remember why I did that mind. All fixed now, cheers for your help