Support Dear ImGui 1.92 (#20)

Uses the new way to get font scale in Dear ImGui 1.92

Author: Madman10K

imgui-knobs.cpp

@@ -162,7 +162,13 @@ namespace ImGuiKnobs {
 
  auto speed = _speed == 0 ? (v_max - v_min) / 250.f : _speed;
  ImGui::PushID(label);
- auto width = size == 0 ? ImGui::GetTextLineHeight() * 4.0f : size * ImGui::GetIO().FontGlobalScale;
+
+#if IMGUI_VERSION_NUM < 19197
+ auto font_scale = ImGui::GetIO().FontGlobalScale;
+#else
+ auto font_scale = ImGui::GetStyle().FontScaleMain;
+#endif
+ auto width = size == 0 ? ImGui::GetTextLineHeight() * 4.0f : size * font_scale;
  ImGui::PushItemWidth(width);
 
  ImGui::BeginGroup();