Translate normalize touch event fingers coordinates to windows coordinate

hello everyone, I would like to know how can translate normalize touch event fingers coordinates to windows coordinate? 0…1 to w*h, I’m very new to it, maybe simple math but I don’t get it right now. thank you in advance.

I use something like this:

int x, y, winx, winy;
SDL_GL_GetDrawableSize(window, &winx, &winy);
x = ev.tfinger.x * winx;
y = ev.tfinger.y * winy;