Resize Window - ImGui::GetWindowWidth()

[PrzemyslawBiernat]

Hi,

I have problem with resizing a window. The window is resizing fina with app window but if I want to resize manualy that doesn't work:
So I add ImGui::GetWindowWidth(); and ImGui::GetWindowHeight(); and it works unpredictable. Can anybody help me.
My code:

nvidia::Int UserControls::windowWidth_ = 1280;
nvidia::Int UserControls::windowHeight_ = 720;

nvidia::Int UserControls::defaultWindowWidth_ = 1280;
nvidia::Int UserControls::defaultWindowHeight_ = 720;

float UserControls::slidersWindowWidth = 300;
float UserControls::slidersWindowHeight = 300;

bool UserControls::ShowSliders(bool* isShow, const nvidia::HairWorks::InstanceDescriptor& desc) {

ImGui::Begin("Sliders", isShow, ImGuiWindowFlags_None);

ImGui::SetWindowSize({ slidersWindowWidth * windowWidth_ / defaultWindowWidth_,
						slidersWindowHeight* windowHeight_ / defaultWindowHeight_ });	

float newWidth = ImGui::GetWindowWidth();

if(newWidth != slidersWindowWidth)
	slidersWindowWidth = newWidth;

float newHeight = ImGui::GetWindowHeight();

if(newHeight != slidersWindowHeight)
	slidersWindowHeight = newHeight;


ImGuiIO& io = ImGui::GetIO();
ImFontAtlas* atlas = io.Fonts;	

atlas->Fonts[0]->Scale = (float)windowHeight_ / (float)defaultWindowHeight_;

ImGui::PushFont(atlas->Fonts[0]);	

bool result = false;

result |= ImGui::SliderFloat("Length", &(float)desc.m_lengthScale, 0.0f, 1.0f, "%3f");
result |= ImGui::SliderFloat("Width", &(float)desc.m_width, 0.0f, 1.0f, "%3f");
result |= ImGui::SliderFloat("Density", &(float)desc.m_density, 0.0f, 1.0f, "%3f");
result |= ImGui::SliderFloat("Wave", &(float)desc.m_waveScale, 0.0f, 1.0f, "%3f");
result |= ImGui::SliderFloat3("Wind", &(float)desc.m_wind.x, -20.0f, 20.0f, "%3f");

ImGui::PopFont();

ImGui::End();	

return result;

}