I try to load tiles form png file but it takes time so long.

[aratnon]

int i = 0;
        for(int y = 0; y < 17; ++y)
        {
                for(int x = 0; x < 20; ++x)
                {
                         if(!platformTexture[i].loadFromFile("Resources/Tileset/Tilesets.png", sf::IntRect(x * TILE_WIDTH, y * TILE_HEIGHT, TILE_WIDTH, TILE_HEIGHT)))
                                std::cout << "error..." << std::endl;
                       
                         ++i;
                }
        }
       

The png file size is 640*640 and tile size is 32*32
Loding tiles from this file takes time about 6 secs.
What is wrong with my code?

[Laurent]

What's wrong in your code is that:
- you load a PNG file 340 times
- you create 340 textures

The right solution would be:
- load the PNG file once, in a single texture
- use Sprite::setTextureRect to assign a different texture area to each tile

[aratnon]

It is good to have 340 textures because my render method is this

for(auto i = 0; i < TOTAL_PLATFORM; ++i)
        {
                window.draw(platformArray_test[i], &platformManager.getPlatform(i));

        }

platformArray_test = array of vertex array
and platformManager.getPlatform(i) returns a texture

[Sqasher]

Why would you store 340 textures in memory if they are exactly the same? 339 of them are basicly useless.

You could use a map and load the texture only once. If it doesn't exist you load it. If it does, you just return a pointer to the texture.

[G.]

It is good to have 340 textures

So good that you're complaining about its slowness...

Use one texture and set texCoords of your vertices in your vertex array.
You could even reduce your vertex array draw calls to one instead of TOTAL_PLATFORM times.

[Laurent]

It is good to have 340 textures because [...]

If you know better than us how to use SFML, then why are you here asking for help?

[FRex]

If you know better than us how to use SFML, then why are you here asking for help?

He is pointing out what bad job you did, 6 seconds to open a file stream, decode png and send it to gl? Just 340 times?

[aratnon]

Oh, Sorry I mistype it. Actually I wanted to ask you about this

Is it good to have 340 textures because my render method is this?

I'm really sorry 

[Ixrec]

It's never good to have 340 copies of the same texture when you can have all 340 sprites use 1 texture.

Besides, all you have to do is change your render method to:

for(auto i = 0; i < TOTAL_PLATFORM; ++i)
    {
        window.draw(platformArray_test[i], &platformManager.getPlatform());

    }
 

without the i in getPlatform. Just have getPlatform() return the one texture that you're using for every platform.

Also, consider renaming the method to "getPlatformTexture()" for clarity.

[Ivan]

I recommend you take a look at great tutorials of Coding Made Easy

Tutorial Loading Tile maps [easy]
SFML 2.0 Tutorials