Add sfBuffer wrapper and implement sf::Image::saveToMemory

[kimci86]

Alternative to #195 using a C wrapper over an std::vector.

[ChrisThrasher]

I appreciate you putting this together with all the right docs and everything.

[kimci86]

I used the following code to test the API.
It made me notice the #include <SFML/Graphics/Buffer.h> was missing from SFML/Graphics.h file and fixed it.

#include <SFML/Graphics.h>
#include <stdio.h>

int main(void)
{
    const int WIDTH = 256;
    sfImage* image = sfImage_createFromColor(WIDTH, 1, sfMagenta);
    for (int x = 0; x < WIDTH; ++x)
        sfImage_setPixel(image, x, 0, sfColor_fromRGB(x, 255, x));

    sfBuffer* buffer = sfBuffer_create();
    sfBool success = sfImage_saveToMemory(image, buffer, "png");
    printf("Succes: %d\n", success);

    sfImage_destroy(image);

    FILE* f = fopen("out.png", "wb");
    fwrite(sfBuffer_getData(buffer), 1, sfBuffer_getSize(buffer), f);
    fclose(f);

    sfBuffer_destroy(buffer);

    return 0;
}

[eXpl0it3r]

@oprypin any comment from your side? 🙂

[oprypin]

It's good.
One thing is: putting sfBuffer into graphics module is strange because then we can't add a sfBuffer into system or window if we need it later. But it may be also strange to put it into system right away.

[eXpl0it3r]

Hmmm I put it off as "we can always move it later", but then we'd be breaking code. While I don't really hold myself to the same non-breaking standard for CSFML as for SFML, I think it might after all be beneficial to reduce it where possible.

So I think, it does after all matter and we should move sfBuffer to the system module. So it could be reused e.g. in the audio module in the future, without "breaking" the API.

[ChrisThrasher]

There are no other saveToMemory functions in SFML and if we added more they'd be added in SFML 3 and thus CSFML 3 so we can get away with leaving it where it is if we want. I'm fine moving it to System though. Either is fine with me.

[oprypin]

Hm but wait, if sfBuffer is first in graphics but then is moved to system, can't it just be re-exposed in graphics and then not break anything?

[oprypin]

But anyway probably system is better. Sorry to cause you work 😅

[eXpl0it3r]

Hm but wait, if sfBuffer is first in graphics but then is moved to system, can't it just be re-exposed in graphics and then not break anything?

It could, but I wouldn't want such a workaround, just to avoid some potential breaking code. No need to add technical debt.

[kimci86]

I moved sfBuffer into csfml-system.

[eXpl0it3r]

Thank you ❤️