Implement auto font scaling and update docs

.github/ISSUE_TEMPLATE/new_release.md

@@ -150,3 +150,4 @@ Once a release cycle:
 
 - Check that completions are still working with `fish` and `zsh` when tab is pressed
 - Check that F3D is added for extensions on a fresh Windows installation
+- Check that the font scale has been scaled correctly when using a HiDPI screen (only supported on Windows)

application/F3DStarter.cxx

@@ -858,7 +858,10 @@ class F3DStarter::F3DInternals
       f3d::window& window = this->Engine->getWindow();
       if (this->AppOptions.Resolution.size() == 2)
       {
-        window.setSize(this->AppOptions.Resolution[0], this->AppOptions.Resolution[1]);
+        double dpiScale = f3d::utils::getDPIScale();
+
+        window.setSize(static_cast<int>(this->AppOptions.Resolution[0] * dpiScale),
+          static_cast<int>(this->AppOptions.Resolution[1] * dpiScale));
       }
       else if (!this->AppOptions.Resolution.empty())
       {

doc/user/11-DESKTOP_INTEGRATION.md

@@ -65,6 +65,10 @@ cd C:\path\to\f3d\bin\
 regsvr32 /u F3DShellExtension.dll
 ```
 
+On Windows platforms where screen DPI detection is supported, the F3D window resolution and fonts are scaled by the display scaling factor.
+
+For example, if you specify `--resolution=800,600` in the CLI options and the system display scale is set to `150%`, the effective window resolution becomes `1200×900`.
+
 ## MacOS
 
 There is no support for thumbnails on MacOS, the .dmg binary release provides automatic file openings.

library/public/utils.h

@@ -91,6 +91,13 @@ class F3D_EXPORT utils
    */
   [[nodiscard]] static std::string globToRegex(std::string_view glob, char pathSeparator = '/');
 
+  /**
+   * Get the primary monitor system zoom scale base on DPI.
+   * Currently only supported on Windows platform.
+   * Return a hardcoded 1.f on other platform.
+   */
+  [[nodiscard]] static double getDPIScale();
+
   /**
    * Get an environment variable value, returns std::nullopt if not set
    */

library/src/utils.cxx

@@ -1,5 +1,6 @@
 #include "utils.h"
 
+#include "F3DUtils.h"
 #include "levenshtein.h"
 #include "log.h"
 
@@ -331,6 +332,12 @@ std::string utils::globToRegex(std::string_view glob, char pathSeparator)
   return result;
 }
 
+//----------------------------------------------------------------------------
+double utils::getDPIScale()
+{
+  return F3DUtils::getDPIScale();
+}
+
 //----------------------------------------------------------------------------
 std::optional<std::string> utils::getEnv(const std::string& env)
 {

python/F3DPythonBindings.cxx

@@ -230,6 +230,7 @@ PYBIND11_MODULE(pyf3d, module)
     .def_static("tokenize", &f3d::utils::tokenize, py::arg("str"), py::arg("keep_comments") = true)
     .def_static(
       "glob_to_regex", &f3d::utils::globToRegex, py::arg("glob"), py::arg("path_separator") = '/')
+    .def_static("get_dpi_scale", &f3d::utils::getDPIScale)
     .def_static("get_env", &f3d::utils::getEnv)
     .def_static("get_known_folder", &f3d::utils::getKnownFolder);
 

vtkext/private/module/vtkF3DImguiActor.cxx

@@ -328,17 +328,17 @@ void vtkF3DImguiActor::Initialize(vtkOpenGLRenderWindow* renWin)
     // ImGui API is not very helpful with this
     fontConfig.FontDataOwnedByAtlas = false;
     font = io.Fonts->AddFontFromMemoryTTF(
-      const_cast<void*>(reinterpret_cast<const void*>(F3DFontBuffer)), sizeof(F3DFontBuffer), 18,
-      &fontConfig, ranges.Data);
+      const_cast<void*>(reinterpret_cast<const void*>(F3DFontBuffer)), sizeof(F3DFontBuffer),
+      18 * this->FontScale, &fontConfig, ranges.Data);
   }
   else
   {
-    font = io.Fonts->AddFontFromFileTTF(this->FontFile.c_str(), 18, &fontConfig, ranges.Data);
+    font = io.Fonts->AddFontFromFileTTF(
+      this->FontFile.c_str(), 18 * this->FontScale, &fontConfig, ranges.Data);
   }
 
   io.Fonts->Build();
   io.FontDefault = font;
-  io.FontGlobalScale = this->FontScale;
 
   ImVec4 colTransparent = ImVec4(0.0f, 0.0f, 0.0f, 0.0f); // #000000
 
@@ -352,6 +352,7 @@ void vtkF3DImguiActor::Initialize(vtkOpenGLRenderWindow* renWin)
   style->WindowBorderSize = 0.f;
   style->WindowPadding = ImVec2(10, 10);
   style->WindowRounding = 8.f;
+  style->ScaleAllSizes(this->FontScale);
   style->Colors[ImGuiCol_Text] = F3DStyle::imgui::GetTextColor();
   style->Colors[ImGuiCol_WindowBg] = F3DStyle::imgui::GetBackgroundColor();
   style->Colors[ImGuiCol_FrameBg] = colTransparent;

vtkext/private/module/vtkF3DRenderer.cxx

@@ -3,6 +3,7 @@
 #include "F3DColoringInfoHandler.h"
 #include "F3DDefaultHDRI.h"
 #include "F3DLog.h"
+#include "F3DUtils.h"
 #include "vtkF3DCachedLUTTexture.h"
 #include "vtkF3DCachedSpecularTexture.h"
 #include "vtkF3DInteractorStyle.h"
@@ -1345,7 +1346,7 @@ void vtkF3DRenderer::ConfigureTextActors()
     }
   }
 
-  this->UIActor->SetFontScale(this->FontScale);
+  this->UIActor->SetFontScale(this->FontScale * F3DUtils::getDPIScale());
 
   this->TextActorsConfigured = true;
 }

vtkext/public/module/F3DUtils.cxx

@@ -2,6 +2,7 @@
 
 #include <vtkObject.h>
 #include <vtkSetGet.h>
+#include <vtkWindows.h>
 
 #include <charconv>
 #include <stdexcept>
@@ -53,3 +54,16 @@ int F3DUtils::ParseToInt(const std::string& str, int def, const std::string& nam
   }
   return value;
 }
+
+//----------------------------------------------------------------------------
+double F3DUtils::getDPIScale()
+{
+  double dpiScale = 1.0;
+
+#ifdef _WIN32
+  int dpi = GetDeviceCaps(wglGetCurrentDC(), LOGPIXELSY); // Default return 96
+  dpiScale = static_cast<double>(dpi) / 96;
+#endif
+
+  return dpiScale;
+}

vtkext/public/module/F3DUtils.h

@@ -30,6 +30,13 @@ VTKEXT_EXPORT double ParseToDouble(
  * Use nameError in the log for easier debugging.
  */
 VTKEXT_EXPORT int ParseToInt(const std::string& str, int def, const std::string& nameError);
+
+/*
+ * Get the primary monitor system zoom scale base on DPI.
+ * Currently only supported on Windows platform.
+ * Return a hardcoded 1.f on other platform.
+ */
+VTKEXT_EXPORT double getDPIScale();
 };
 
 #endif