ImGuiManager: Remove multiple sources of truth for prescale/margins

src/core/gpu_thread.cpp

@@ -696,8 +696,7 @@ bool GPUThread::CreateDeviceOnThread(RenderAPI api, bool fullscreen, bool clear_
     return false;
   }
 
-  if (!ImGuiManager::Initialize(g_gpu_settings.display_osd_scale / 100.0f, g_gpu_settings.display_osd_margin,
-                                &create_error))
+  if (!ImGuiManager::Initialize(&create_error))
   {
     ERROR_LOG("Failed to initialize ImGuiManager: {}", create_error.GetDescription());
     Error::SetStringFmt(error, "Failed to initialize ImGuiManager: {}", create_error.GetDescription());
@@ -1038,9 +1037,7 @@ void GPUThread::UpdateSettingsOnThread(GPUSettings&& new_settings)
   if (g_gpu_device)
   {
     if (g_gpu_settings.display_osd_scale != old_settings.display_osd_scale)
-      ImGuiManager::SetGlobalScale(g_settings.display_osd_scale / 100.0f);
-    if (g_gpu_settings.display_osd_margin != old_settings.display_osd_margin)
-      ImGuiManager::SetScreenMargin(g_settings.display_osd_margin);
+      ImGuiManager::RequestScaleUpdate();
 
     FullscreenUI::CheckForConfigChanges(old_settings);
   }

src/core/settings.cpp

@@ -368,7 +368,7 @@ void Settings::Load(const SettingsInterface& si, const SettingsInterface& contro
   display_show_enhancements = si.GetBoolValue("Display", "ShowEnhancements", false);
   display_auto_resize_window = si.GetBoolValue("Display", "AutoResizeWindow", false);
   display_osd_scale = si.GetFloatValue("Display", "OSDScale", DEFAULT_OSD_SCALE);
-  display_osd_margin = si.GetFloatValue("Display", "OSDMargin", ImGuiManager::DEFAULT_SCREEN_MARGIN);
+  display_osd_margin = std::max(si.GetFloatValue("Display", "OSDMargin", ImGuiManager::DEFAULT_SCREEN_MARGIN), 0.0f);
 
   save_state_compression = ParseSaveStateCompressionModeName(
                              si.GetStringValue("Main", "SaveStateCompression",

src/util/imgui_manager.cpp

@@ -73,6 +73,7 @@ struct OSDMessage
 
 static_assert(std::is_same_v<WCharType, ImWchar>);
 
+static float GetGlobalPrescale();
 static void UpdateScale();
 static void SetStyle(ImGuiStyle& style, float scale);
 static bool LoadFontData(Error* error);
@@ -128,10 +129,7 @@ struct ALIGN_TO_CACHE_LINE State
   // Owned by GPU thread
   ALIGN_TO_CACHE_LINE Timer::Value last_render_time = 0;
 
-  float global_prescale = 0.0f; // before window scale
   float global_scale = 0.0f;
-  float screen_margin = 0.0f;
-
   float window_width = 0.0f;
   float window_height = 0.0f;
   GPUTexture::Format window_format = GPUTexture::Format::Unknown;
@@ -178,16 +176,7 @@ void ImGuiManager::SetTextFontOrder(const TextFontOrder& order)
   ReloadFontDataIfActive();
 }
 
-void ImGuiManager::SetGlobalScale(float global_scale)
-{
-  if (s_state.global_prescale == global_scale)
-    return;
-
-  s_state.global_prescale = global_scale;
-  s_state.scale_changed = true;
-}
-
-bool ImGuiManager::Initialize(float global_scale, float screen_margin, Error* error)
+bool ImGuiManager::Initialize(Error* error)
 {
   if (!LoadFontData(error))
   {
@@ -197,9 +186,7 @@ bool ImGuiManager::Initialize(float global_scale, float screen_margin, Error* er
 
   GPUSwapChain* const main_swap_chain = g_gpu_device->GetMainSwapChain();
 
-  s_state.global_prescale = global_scale;
-  s_state.global_scale = std::max((main_swap_chain ? main_swap_chain->GetScale() : 1.0f) * global_scale, 1.0f);
-  s_state.screen_margin = std::max(screen_margin, 0.0f);
+  s_state.global_scale = std::max((main_swap_chain ? main_swap_chain->GetScale() : 1.0f) * GetGlobalPrescale(), 1.0f);
   s_state.scale_changed = false;
 
   s_state.imgui_context = ImGui::CreateContext();
@@ -275,11 +262,6 @@ bool ImGuiManager::IsInitialized()
   return (s_state.imgui_context != nullptr);
 }
 
-void ImGuiManager::SetScreenMargin(float margin)
-{
-  s_state.screen_margin = std::max(margin, 0.0f);
-}
-
 float ImGuiManager::GetWindowWidth()
 {
   return s_state.window_width;
@@ -318,11 +300,16 @@ void ImGuiManager::RequestScaleUpdate()
   s_state.scale_changed = true;
 }
 
+float ImGuiManager::GetGlobalPrescale()
+{
+  return g_gpu_settings.display_osd_scale / 100.0f;
+}
+
 void ImGuiManager::UpdateScale()
 {
   const float window_scale =
     (g_gpu_device && g_gpu_device->HasMainSwapChain()) ? g_gpu_device->GetMainSwapChain()->GetScale() : 1.0f;
-  const float scale = std::max(window_scale * s_state.global_prescale, 1.0f);
+  const float scale = std::max(window_scale * GetGlobalPrescale(), 1.0f);
   const bool scale_changed = (scale != s_state.global_scale);
 
   if (!FullscreenUI::UpdateLayoutScale() && !scale_changed)
@@ -964,7 +951,7 @@ void ImGuiManager::DrawOSDMessages(Timer::Value current_time)
   const ImVec4 subtext_color = DarkerColor(text_color, 0.85f);
   const float scale = s_state.global_scale;
   const float spacing = std::ceil(6.0f * scale);
-  const float margin = std::ceil(s_state.screen_margin * scale);
+  const float margin = std::ceil(GetScreenMargin() * scale);
   const float padding = std::ceil(10.0f * scale);
   const float rounding = std::ceil(10.0f * scale);
   const float normal_icon_margin = std::ceil(4.0f * scale);
@@ -1181,7 +1168,7 @@ float ImGuiManager::GetGlobalScale()
 
 float ImGuiManager::GetScreenMargin()
 {
-  return s_state.screen_margin;
+  return g_gpu_settings.display_osd_margin;
 }
 
 ImFont* ImGuiManager::GetTextFont()

src/util/imgui_manager.h

@@ -80,11 +80,8 @@ inline constexpr float DEFAULT_SCREEN_MARGIN = 16.0f;
 TextFontOrder GetDefaultTextFontOrder();
 void SetTextFontOrder(const TextFontOrder& order);
 
-/// Changes the global scale.
-void SetGlobalScale(float global_scale);
-
 /// Initializes ImGui, creates fonts, etc.
-bool Initialize(float global_scale, float screen_margin, Error* error);
+bool Initialize(Error* error);
 
 /// Frees all ImGui resources.
 void Shutdown(bool clear_fsui_state);
@@ -95,9 +92,6 @@ ImGuiContext* GetMainContext();
 /// Returns true if there is currently a context created.
 bool IsInitialized();
 
-/// Sets the size of the screen margins, or "safe zone".
-void SetScreenMargin(float margin);
-
 /// Returns the size of the display window. Can be safely called from any thread.
 float GetWindowWidth();
 float GetWindowHeight();