ImGuiManager: Separate debug and OSD fonts

Don't need to rasterize the former if it's not used, and saves blowing
up the debug window font size if the OSD scale is not 100%.

src/util/imgui_manager.cpp

@@ -71,7 +71,7 @@ static void SetStyle(ImGuiStyle& style, float scale);
 static void SetKeyMap();
 static bool LoadFontData(Error* error);
 static void ReloadFontDataIfActive();
-static bool AddImGuiFonts(bool fullscreen_fonts);
+static bool AddImGuiFonts(bool debug_font, bool fullscreen_fonts);
 static ImFont* AddTextFont(float size, bool full_glyph_range);
 static ImFont* AddFixedFont(float size);
 static bool AddIconFonts(float size);
@@ -100,7 +100,7 @@ static std::vector<WCharType> s_font_range;
 static std::vector<WCharType> s_emoji_range;
 
 static ImGuiContext* s_imgui_context;
-static ImFont* s_standard_font;
+static ImFont* s_debug_font;
 static ImFont* s_osd_font;
 static ImFont* s_fixed_font;
 static ImFont* s_medium_font;
@@ -270,7 +270,7 @@ bool ImGuiManager::Initialize(float global_scale, float screen_margin, Error* er
   SetKeyMap();
   SetStyle(s_imgui_context->Style, s_global_scale);
 
-  if (!AddImGuiFonts(false) || !g_gpu_device->UpdateImGuiFontTexture())
+  if (!AddImGuiFonts(false, false) || !g_gpu_device->UpdateImGuiFontTexture())
   {
     Error::SetString(error, "Failed to create ImGui font text");
     ImGui::DestroyContext();
@@ -296,7 +296,7 @@ void ImGuiManager::Shutdown()
     s_imgui_context = nullptr;
   }
 
-  s_standard_font = nullptr;
+  s_debug_font = nullptr;
   s_fixed_font = nullptr;
   s_medium_font = nullptr;
   s_large_font = nullptr;
@@ -351,7 +351,7 @@ void ImGuiManager::UpdateScale()
   s_global_scale = scale;
   SetStyle(s_imgui_context->Style, s_global_scale);
 
-  if (!AddImGuiFonts(HasFullscreenFonts()))
+  if (!AddImGuiFonts(HasDebugFont(), HasFullscreenFonts()))
     Panic("Failed to create ImGui font text");
 
   if (!g_gpu_device->UpdateImGuiFontTexture())
@@ -695,17 +695,26 @@ bool ImGuiManager::AddIconFonts(float size)
   return true;
 }
 
-bool ImGuiManager::AddImGuiFonts(bool fullscreen_fonts)
+bool ImGuiManager::AddImGuiFonts(bool debug_font, bool fullscreen_fonts)
 {
+  const float window_scale =
+    (g_gpu_device && g_gpu_device->HasMainSwapChain()) ? g_gpu_device->GetMainSwapChain()->GetScale() : 1.0f;
+  const float debug_font_size = std::ceil(15.0f * window_scale);
   const float standard_font_size = std::ceil(15.0f * s_global_scale);
   const float osd_font_size = std::ceil(17.0f * s_global_scale);
 
+  INFO_LOG("Allocating fonts winscale={} globalscale={} debug={} fullscreen={}", window_scale, s_global_scale,
+           debug_font, fullscreen_fonts);
+
   ImGuiIO& io = ImGui::GetIO();
   io.Fonts->Clear();
 
-  s_standard_font = AddTextFont(standard_font_size, false);
-  if (!s_standard_font)
-    return false;
+  if (debug_font)
+  {
+    s_debug_font = AddTextFont(debug_font_size, false);
+    if (!s_debug_font)
+      return false;
+  }
 
   s_fixed_font = AddFixedFont(standard_font_size);
   if (!s_fixed_font)
@@ -714,6 +723,8 @@ bool ImGuiManager::AddImGuiFonts(bool fullscreen_fonts)
   s_osd_font = AddTextFont(osd_font_size, true);
   if (!s_osd_font || !AddIconFonts(osd_font_size))
     return false;
+  if (!debug_font)
+    s_debug_font = s_osd_font;
 
   if (fullscreen_fonts)
   {
@@ -748,7 +759,7 @@ void ImGuiManager::ReloadFontDataIfActive()
   if (!LoadFontData(nullptr))
     Panic("Failed to load font data");
 
-  if (!AddImGuiFonts(HasFullscreenFonts()))
+  if (!AddImGuiFonts(HasDebugFont(), HasFullscreenFonts()))
     Panic("Failed to create ImGui font text");
 
   if (!g_gpu_device->UpdateImGuiFontTexture())
@@ -765,10 +776,11 @@ bool ImGuiManager::AddFullscreenFontsIfMissing()
   // can't do this in the middle of a frame
   ImGui::EndFrame();
 
-  if (!AddImGuiFonts(true))
+  const bool debug_font = HasDebugFont();
+  if (!AddImGuiFonts(debug_font, true))
   {
     ERROR_LOG("Failed to lazily allocate fullscreen fonts.");
-    AddImGuiFonts(false);
+    AddImGuiFonts(debug_font, false);
   }
 
   g_gpu_device->UpdateImGuiFontTexture();
@@ -777,6 +789,32 @@ bool ImGuiManager::AddFullscreenFontsIfMissing()
   return HasFullscreenFonts();
 }
 
+bool ImGuiManager::HasDebugFont()
+{
+  return (s_debug_font != s_osd_font);
+}
+
+bool ImGuiManager::AddDebugFontIfMissing()
+{
+  if (HasDebugFont())
+    return true;
+
+  // can't do this in the middle of a frame
+  ImGui::EndFrame();
+
+  const bool fullscreen_font = HasFullscreenFonts();
+  if (!AddImGuiFonts(true, fullscreen_font))
+  {
+    ERROR_LOG("Failed to lazily allocate fullscreen fonts.");
+    AddImGuiFonts(true, fullscreen_font);
+  }
+
+  g_gpu_device->UpdateImGuiFontTexture();
+  NewFrame();
+
+  return HasDebugFont();
+}
+
 bool ImGuiManager::HasFullscreenFonts()
 {
   return (s_medium_font && s_large_font);
@@ -1044,9 +1082,9 @@ float ImGuiManager::GetScreenMargin()
   return s_screen_margin;
 }
 
-ImFont* ImGuiManager::GetStandardFont()
+ImFont* ImGuiManager::GetDebugFont()
 {
-  return s_standard_font;
+  return s_debug_font;
 }
 
 ImFont* ImGuiManager::GetOSDFont()
@@ -1396,6 +1434,8 @@ bool ImGuiManager::CreateAuxiliaryRenderWindow(AuxiliaryRenderWindowState* state
     return false;
   }
 
+  AddDebugFontIfMissing();
+
   state->imgui_context = ImGui::CreateContext(s_imgui_context->IO.Fonts);
   state->imgui_context->IO.DisplaySize =
     ImVec2(static_cast<float>(state->swap_chain->GetWidth()), static_cast<float>(state->swap_chain->GetHeight()));
@@ -1465,6 +1505,7 @@ bool ImGuiManager::RenderAuxiliaryRenderWindow(AuxiliaryRenderWindowState* state
   ImGui::SetCurrentContext(state->imgui_context);
 
   ImGui::NewFrame();
+  ImGui::PushFont(s_debug_font);
   ImGui::SetNextWindowPos(ImVec2(0.0f, 0.0f), ImGuiCond_Always);
   ImGui::SetNextWindowSize(state->imgui_context->IO.DisplaySize, ImGuiCond_Always);
   if (ImGui::Begin("AuxRenderWindowMain", nullptr,
@@ -1475,6 +1516,7 @@ bool ImGuiManager::RenderAuxiliaryRenderWindow(AuxiliaryRenderWindowState* state
   }
 
   ImGui::End();
+  ImGui::PopFont();
 
   const GPUDevice::PresentResult pres = g_gpu_device->BeginPresent(state->swap_chain.get());
   if (pres == GPUDevice::PresentResult::OK)

src/util/imgui_manager.h

@@ -118,8 +118,14 @@ bool HasFullscreenFonts();
 /// Allocates/adds fullscreen fonts if they're not loaded.
 bool AddFullscreenFontsIfMissing();
 
+/// Returns true if there is a separate debug font.
+bool HasDebugFont();
+
+/// Changes whether a debug font is generated. Otherwise, the OSD font will be used for GetStandardFont().
+bool AddDebugFontIfMissing();
+
 /// Returns the standard font for external drawing.
-ImFont* GetStandardFont();
+ImFont* GetDebugFont();
 
 /// Returns the standard font for on-screen display drawing.
 ImFont* GetOSDFont();