Fix quarter rendering window issue in MacOS

[LeeTeng2001]

The actual resolution of window is different if you have retina display (like MacOS), thus we need to query from SDL once more after we have created the window to get the actual drawable size. Thus will fix the black range in the rendering window

    auto window_flags = (SDL_WindowFlags) (SDL_WINDOW_OPENGL | SDL_WINDOW_RESIZABLE |
                                                      SDL_WINDOW_ALLOW_HIGHDPI);
    loopdata.mWindow = SDL_CreateWindow("GLSL Raytracing", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED,
                                        renderOptions.windowResolution.x, renderOptions.windowResolution.y,
                                        window_flags);

    // Query actual drawable window size
    int w, h;
    SDL_GL_GetDrawableSize(loopdata.mWindow, &w, &h);
    renderOptions.windowResolution.x = w;
    renderOptions.windowResolution.y = h;

Before:

After:

[LeeTeng2001]

Should be an easy fix

[knightcrawler25]

Thanks. I've added the code you've suggested.

Also, out of curiosity, did you have to make other changes to get the code to run on a Mac?

[LeeTeng2001]

Yes I did, do you want me to make a pr branch for adding support for MacOS build?

[knightcrawler25]

That'll be helpful as I don't have a way to test the repo on macOS :)

[LeeTeng2001]

ok! I'll work on it after my exam (which will be around early jan)

[LeeTeng2001]

I'll open another issue