Messages

1

General / Re: Simple hex arithmetic not yielding expected results.

« on: December 17, 2016, 05:37:06 pm »

Thank you and sorry.

2

General / Simple hex arithmetic not yielding expected results.

« on: December 17, 2016, 08:59:15 am »

I am trying to understand the "contiguous" nature of vectors and where they assign their values in memory.
Can someone please explain why the 2nd cout yields a 1 instead of a 4?

std::vector<int> test = { 2,13,4 };
std::cout << &test[2] << " " << &test[1] << std::endl;
std::cout << &test[2] - &test[1] << std::endl;

An int on my machine is 4 bytes large.
So that means test[2] is 4 bytes away from test[1] in memory.

if I write:

std::cout << (int)&test[2] << " " << (int)&test[1] << std::endl;
std::cout << (int)&test[2] - (int)&test[1] << std::endl;

Then I get 4...
Can someone explain why the first example yields 1?

Thank you.

3

General / *SOLVED* STL inludes error after SFGUI include?

« on: September 09, 2016, 05:16:41 pm »

I'm using VS2015 and I wanted to start playing around with SFGUI. So I added its include files to my SFML Project.
After adding the include folder and lib folder to the VC++ directories I get errors in my code.
Like "cannot open source file "vector"" and also an error with sf::RenderWindow not having matching params.

So i removed SGUI from the VC++ directories and I still can't compile.
Has anyone encountered this issue before?

EDIT: I found the problem, i had to check the "Inherent from parent or project defaults" check box.

4

General / Re: Textures going out of scope?

« on: September 05, 2016, 07:43:51 pm »

Passing the unique_ptr to a function was where I was getting errors. something about a deleted function.

I didn't know you had to use std::move.

Very good, thank you!

5

General / Re: Textures going out of scope?

« on: September 05, 2016, 05:20:18 am »

Solved the problem, thank you for your help! I would still like to know more about a memory management system, it would be a good way for me to push my knowledge.

Here's the revised version:
MapGrid.h

class MapGrid
{
public:
        MapGrid();

        void createTile();
        void adjustTilePosition();
        void populateGrid(MapTile* mapTile);
       
        int tileCount;

        float x_offset;
        float y_offset;

        std::vector<MapTile*> mapTiles;
}

MapGrid.cpp

MapGrid::MapGrid()
{
        x_offset = 0.0f;
        y_offset = 0.0f;
        tileCount = 0;
}

void MapGrid::createTile()
{
        MapTile* newMapTile = new MapTile(x_offset, y_offset);
        tileCount++;
        adjustTilePosition();
        populateGrid(newMapTile);
}

void MapGrid::adjustTilePosition()
{
        if (tileCount % 10 == 0)
        {
                x_offset = 0;
                y_offset += 50;
        }
        else
        {
                x_offset += 50;
        }
}

void MapGrid::populateGrid(MapTile* mapTile)
{
        mapTiles.push_back(mapTile);
}

I know raw pointers are frowned upon, so I'll use a unique_ptr.
Thanks again.

Edit: unique_ptr was giving me some problems, so I switched to shared_ptr.

6

General / Re: Textures going out of scope?

« on: September 05, 2016, 12:23:34 am »

So I learned something new while writing some test code and googling a few things.
From what I read, you can't have a vector of references, but you can have a vector of pointers.

So i'll just create the MapTile Object and push_back it's address onto the vector.
I'm at work now, so I can't test it, but I can only hope that it will work.

Here's the test code:

int main()
{
   std::vector<int*> vect;
   int x = 1;
   
   vect.push_back(&x);
   
   std::cout << vect[0] << std::endl;
   std::cout << &x << std::endl;
   
   return 0;
}

Also, would a map container's insert be different than a vector's push_back?
I suppose not because you can use an iterator on it...
Thanks!

7

General / Re: Textures going out of scope?

« on: September 04, 2016, 08:19:53 pm »

Here's some code.

MapGrid.h

class MapGrid
{
public:
        MapGrid();

        void createTile();
        void adjustTilePosition();
        void populateGrid(MapTile &mapTile);
       
        int tileCount;

        float x_offset;
        float y_offset;

        std::vector<MapTile> mapTiles;
};

MapGrid.cpp

MapGrid::MapGrid()
{
        x_offset = 0.0f;
        y_offset = 0.0f;
        tileCount = 0;
}

void MapGrid::createTile()
{
        MapTile newMapTile(x_offset, y_offset);
        tileCount++;
        adjustTilePosition();
        populateGrid(newMapTile);
}

void MapGrid::adjustTilePosition()
{
        if (tileCount % 10 == 0)
        {
                x_offset = 0;
                y_offset += 50;
        }
        else
        {
                x_offset += 50;
        }
}

void MapGrid::populateGrid(MapTile &mapTile)
{
        mapTiles.push_back(mapTile);
}
 

MapTile.h

class MapTile
{
public:
        MapTile() = default;
        MapTile(float x, float y);

        int id;
        float x;
        float y;

        sf::FloatRect rectangle;
        sf::Texture texture;
        sf::Sprite sprite;
 

MapTile.cpp

MapTile::MapTile(float _x, float _y)
{
        texture.loadFromFile("Zelda Sprites/Blank.png");
        sprite.setTexture(texture);
        sprite.setPosition(_x, _y);
}
 

Perhaps it's going out of scope when createTile() ends?

8

General / Textures going out of scope?

« on: September 04, 2016, 03:35:57 am »

So I have 2 classes. One is called MapGrid and the other is called MapTile. My MapGrid class' job is to create and store MapTiles in a vector that is part of the MapGrid class. MapGrid class also control the Position of the MapTile sprite. In the MapTile class I have an sf::sprite and an sf::texture. Everytime MapGrid constructs a MapTile, it assigns a .png file to a texture and then that texture is assigned to a sprite and is pushed back onto the vector in MapGrid.

I then try to render the MapGrid with code that looks something like this. (going off memory)

for(auto iter : mapGrid.mapTiles)
window.draw(iter.sprite);

Can someone tell me if this is a scope issue and the texture reference is being destroyed before it can be rendered? Is there any way to work around this other than not storing each sf::texture in the MapTile object?

Thanks!

9

General / To inherit or not?

« on: August 25, 2016, 05:20:12 am »

So I'm not sure if my MapTile and BrushTile classes should inherit from the sf::Sprite class.
From what I've read it depends on the relationship. With a HAS_A relationship you would simply add the sprite as member. But if it's a IS_A relationship, you would tell your class to inherit from the other.

I hope I'm making sense, could some one please clarify the rules.

10

Feature requests / Re: OutputFileSteam

« on: August 24, 2016, 12:21:02 am »

Propably offtop (a bit), sorry. 

Do not write monoplatform code if you don't have to do so.

"C:/binary.txt"
 

This will work only on Windows, use relative paths or typedefs to specify root directory.

std::ios::binary
 

Linux (and propably any Unix-like system) doesn't really support binary mode. Of course code will work, but files will contain normal, readable data.

Although writing code that would be compatible for other OS' is a little too advanced for me right now, I'll keep that in mind and learn it in the future.

Here's a pastebin of my saving and loading code:
http://pastebin.com/gedzPuJS

Thanks for all the help and suggestions everyone!

11

Feature requests / Re: OutputFileSteam

« on: August 22, 2016, 01:16:07 am »

Well thanks to your help, I figured it out. Thank you so much. I have something to work with now.
Here is what I came up with.

#include <fstream>
#include <iostream>


int main()
{
        int testVariable = 72;
        int testVariable2 = 0;

        std::cout << testVariable << std::endl;

        std::ofstream outputFile;
        outputFile.open("C:/binary.txt", std::ios::out | std::ios::binary);
        outputFile << testVariable;
        outputFile.close();

        std::ifstream inputFile;
        inputFile.open("C:/binary.txt", std::ios::in | std::ios::binary);
        inputFile >> testVariable2;
        inputFile.close();

        std::cout << testVariable2 << std::endl;
       
        system("pause");
    return 0;
}

12

Feature requests / Re: OutputFileSteam

« on: August 21, 2016, 04:00:21 pm »

Oh great! I can use the insertion/extractor operators. This is way more help than what I got on stackoverflow when that wasn't the reason for my post.

Thank you!
<3 this community.

13

Feature requests / OutputFileSteam

« on: August 21, 2016, 07:11:20 am »

I'm currently reading about <fstream> and how to use it. I'm finding it difficult to write an output file in binary using the fstream::write() function. This is due to the fact that it only accepts a char* type instead of void* as it's first param. I know that SFML has an InputFileStream class, but I would like to see a OutputFileStream class as well.

14

SFML projects / Re: My first SFML Program

« on: August 15, 2016, 12:44:25 am »

Thanks I'll review my book and re-read those portions.

15

SFML projects / Re: My first SFML Program

« on: August 14, 2016, 09:17:16 pm »

I read about this loop type in C++ primer 5th edition(C++11).
Is it called a for each loop?