Force dark title bar regardless of OS light/dark setting; v1.0.4

Without opting in via DWMWA_USE_IMMERSIVE_DARK_MODE the title bar went
white whenever the window lost focus, and a scopes app lives unfocused.
The app is dark-themed throughout, so skip the OS query and always dark.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

Author: Shadetail

CHANGELOG.md

@@ -4,6 +4,13 @@ User-facing changes per release. When a `vX.Y.Z` tag is pushed, the release
 workflow copies the matching `## vX.Y.Z` section into the GitHub Release body,
 so every release ships with a readable summary.
 
+## v1.0.4 — 2026-08-16
+
+- The title bar is now always dark to match the app's dark theme. Previously
+  it followed legacy Windows behavior and turned white whenever the window
+  lost focus — which is most of the time for a scopes app you watch while
+  working elsewhere.
+
 ## v1.0.3 — 2026-08-16
 
 - CIE: the spectral-locus horseshoe is drawn as a smooth spline through the

CMakeLists.txt

@@ -1,5 +1,5 @@
 cmake_minimum_required(VERSION 3.20)
-project(HDRScopes VERSION 1.0.3 LANGUAGES CXX)
+project(HDRScopes VERSION 1.0.4 LANGUAGES CXX)
 if(MSVC)
     enable_language(RC)
 endif()
@@ -49,7 +49,7 @@ add_executable(HDRScopes WIN32
 target_include_directories(HDRScopes PRIVATE src resources)
 target_link_libraries(HDRScopes PRIVATE
     imgui
-    d3d11 dxgi d3dcompiler dxguid msimg32 winmm
+    d3d11 dxgi d3dcompiler dxguid dwmapi msimg32 winmm
 )
 target_compile_definitions(HDRScopes PRIVATE UNICODE _UNICODE NOMINMAX WIN32_LEAN_AND_MEAN)
 

src/main.cpp

@@ -26,6 +26,7 @@
 #include "backends/imgui_impl_dx11.h"
 
 #include <d3d11.h>
+#include <dwmapi.h>
 #include <timeapi.h>
 #include <algorithm>
 
@@ -509,6 +510,12 @@ int WINAPI wWinMain(HINSTANCE hInst, HINSTANCE, LPWSTR, int) {
         wx, wy, ww, wh, nullptr, nullptr, hInst, nullptr);
     g_hwnd = hwnd;
 
+    // The app is dark-themed throughout, so force a dark title bar regardless
+    // of the OS light/dark setting (without this Windows paints it light when
+    // the window is unfocused — and a scopes app lives unfocused).
+    BOOL darkTitle = TRUE;
+    DwmSetWindowAttribute(hwnd, DWMWA_USE_IMMERSIVE_DARK_MODE, &darkTitle, sizeof(darkTitle));
+
     if (!g_d3d.Init(hwnd)) { HDRLog("D3D init failed"); return 1; }
 
     IMGUI_CHECKVERSION(); ImGui::CreateContext();