Settings: add FPS cap

[archbirdplus]

Adds fpsCap field which lets Cubyz sleep if it processes the frame fast enough. On lower end hardware, this would let Cubyz deliver a more consistent framerate, albeit lower.

• settings.json option
• in-game menu slider
• update physics to use real time, not rendering time
• update fps label in debug window to count actual frames, not inverse rendering time
• update fps label to use real time between frames, not rendering time

Resolves #487.

[archbirdplus]

Actually, I would group point 4 along with #438.

[archbirdplus]

Sliders are bugged for me in general. We might want to round the fps from the slider because people probably usually just want to reset it to 60 fps without a hassle. On the other hand, some people prefer to set their framerate just under the refresh rate for some reason, so I'm not sure which is a priority.

[IntegratedQuantum]

You could also make it a text field. Then players could be arbitrarily precise.

[IntegratedQuantum]

It crashes when I move the slider to the end:

Segmentation fault at address 0x1211879
/home/mint/Cubyz/compiler/zig/lib/compiler_rt/memset.zig:19:14: 0x17fb1d0 in memset (compiler_rt)
            d[0] = c;
             ^
/home/mint/Cubyz/compiler/zig/lib/std/mem/Allocator.zig:313:26: 0x137d134 in free__anon_31205 (Cubyzig)
    @memset(non_const_ptr[0..bytes_len], undefined);
                         ^
/home/mint/Downloads/Cubyz/src/utils.zig:749:22: 0x134c6de in free__anon_29033 (Cubyzig)
  self.allocator.free(memory);
                     ^
/home/mint/Downloads/Cubyz/src/gui/components/ContinuousSlider.zig:91:27: 0x14a39db in updateLabel (Cubyzig)
 main.globalAllocator.free(self.currentText);
                          ^
/home/mint/Downloads/Cubyz/src/gui/components/ContinuousSlider.zig:104:19: 0x14ef408 in updateValueFromButtonPos (Cubyzig)
  self.updateLabel(value, self.size[0]);
                  ^
/home/mint/Downloads/Cubyz/src/gui/components/ContinuousSlider.zig:142:32: 0x14814d4 in render (Cubyzig)
  self.updateValueFromButtonPos();
                               ^
/home/mint/Downloads/Cubyz/src/gui/gui_component.zig:102:17: 0x13f98b8 in render (Cubyzig)
     impl.render(mousePosition);
                ^
/home/mint/Downloads/Cubyz/src/gui/components/VerticalList.zig:141:15: 0x1481c9c in render (Cubyzig)
  child.render(mousePosition - shiftedPos);
              ^
/home/mint/Downloads/Cubyz/src/gui/gui_component.zig:102:17: 0x13f9930 in render (Cubyzig)
     impl.render(mousePosition);
                ^
/home/mint/Downloads/Cubyz/src/gui/GuiWindow.zig:467:19: 0x1361148 in render (Cubyzig)
  component.render((mousePosition - self.pos)/@as(Vec2f, @splat(self.scale)));
                  ^
/home/mint/Downloads/Cubyz/src/gui/gui.zig:539:16: 0x1327fd0 in updateAndRenderGui (Cubyzig)
  window.render(mousePos);
               ^
/home/mint/Downloads/Cubyz/src/main.zig:486:26: 0x131e8eb in main (Cubyzig)
   gui.updateAndRenderGui();
                         ^
/home/mint/Cubyz/compiler/zig/lib/std/start.zig:514:22: 0x131db19 in main (Cubyzig)
            root.main();
                     ^
../sysdeps/nptl/libc_start_call_main.h:58:16: 0x7f01d253ed8f in __libc_start_call_main (../sysdeps/x86/libc-start.c)
../csu/libc-start.c:392:3: 0x7f01d253ee3f in __libc_start_main_impl (../sysdeps/x86/libc-start.c)
???:?:?: 0x131d7c4 in ??? (???)
???:?:?: 0x0 in ??? (???)

I'm guess this happens because you return a global string from your format function, which gets freed later.

[archbirdplus]

Does it crash in release mode for you?

[IntegratedQuantum]

It not crash in ReleaseFast, but it does crash in ReleaseSafe.

[archbirdplus]

Zig no longer reports memory issues, but I don't think I accomplished that in the cleanest way.

[IntegratedQuantum]

Could you also fix the merge conflicts?

[archbirdplus]

Fixed.