static
uint64_t GenRandom64()
{
    uint64_t buf;
    BCryptGenRandom(nullptr, (uint8_t*)&buf, sizeof(buf), BCRYPT_USE_SYSTEM_PREFERRED_RNG);
    return buf;
}

static uint32_t
GetNumberOfCores()
{
    return S->SysInfo.dwNumberOfProcessors;
}




auto CALLBACK MainWndProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam) -> LRESULT;

auto win32_WinGetHandle() -> HWND
{
    ASSERT(g_HWnd);
    return g_HWnd;
}

auto win32_GetHInstance() -> HINSTANCE
{
    return g_HInstance;
}

void win32_SetHInstance(HINSTANCE hInstance)
{
    g_HInstance = hInstance;
}

//

auto UpdateGamepad(uint32_t index) -> bool
{
    auto& state = Gamepads[index];
    MemZero(&state.Gamepad);

    const DWORD dwResult = XInputGetState(0, &state);
    return (dwResult == ERROR_SUCCESS);
}

namespace {

void GetGamepadStick(auto rawX, auto rawY, auto rawDeadzone, float* outX, float* outY)
{
    const float x = (float)rawX / (float)limits<int16_t>::Max();
    const float y = (float)rawY / (float)limits<int16_t>::Max();

    const float magnitude = Sqrt(x * x + y * y);
    const float deadzone = (float)rawDeadzone / (float)limits<int16_t>::Max();

    if (magnitude < deadzone) {
        *outX = 0.f;
        *outY = 0.f;
    } else { // Renormalize so movement starts smoothly from the edge of the deadzone
        const float scale = (magnitude - deadzone) / (1.0f - deadzone);

        *outX = (x / magnitude) * scale;
        *outY = (y / magnitude) * scale;
    }
}

auto GetGamepadTrigger(uint8_t rawValue, uint8_t rawDeadzone) -> float
{
    const float val = (float)rawValue / (float)limits<uint8_t>::Max();
    const float deadzone = (float)rawDeadzone / (float)limits<uint8_t>::Max();

    if (val < deadzone) {
        return 0.0f;
    }

    // Renormalize so movement starts smoothly from the edge of the deadzone
    return (val - deadzone) / (1.0f - deadzone);
}

} // namespace

auto API GetGamepadLeftStick(uint32_t index) -> float2
{
    auto& gamepad = Gamepads[index].Gamepad;
    float2 ret;
    GetGamepadStick(gamepad.sThumbLX, gamepad.sThumbLY,
                    XINPUT_GAMEPAD_LEFT_THUMB_DEADZONE,
                    &ret.x, &ret.y);
    return ret;
}

auto API GetGamepadRightStick(uint32_t index) -> float2
{
    auto& gamepad = Gamepads[index].Gamepad;
    float2 ret;
    GetGamepadStick(gamepad.sThumbRX, gamepad.sThumbRY,
                    XINPUT_GAMEPAD_RIGHT_THUMB_DEADZONE,
                    &ret.x, &ret.y);
    return ret;
}

auto API GetGamepadLeftTrigger(uint32_t index) -> float
{
    auto& gamepad = Gamepads[index].Gamepad;
    return GetGamepadTrigger(gamepad.bLeftTrigger,
                             XINPUT_GAMEPAD_TRIGGER_THRESHOLD);
}

auto API GetGamepadRightTrigger(uint32_t index) -> float
{
    auto& gamepad = Gamepads[index].Gamepad;
    return GetGamepadTrigger(gamepad.bRightTrigger,
                             XINPUT_GAMEPAD_TRIGGER_THRESHOLD);
}