automatic detection of scale factor on macos

daemon/app/ghc-specter-daemon/Render.hs

@@ -16,7 +16,7 @@ import Control.Monad.IO.Class (MonadIO (..))
 import Control.Monad.Trans.Reader (ReaderT (runReaderT))
 import Data.Maybe (isNothing)
 import Foreign.C.String (CString, withCString)
-import Foreign.C.Types (CInt (..))
+import Foreign.C.Types (CFloat (..))
 import Foreign.Marshal.Alloc (callocBytes, free)
 import Foreign.Marshal.Utils (toBool)
 import Foreign.Ptr (nullPtr)
@@ -46,16 +46,11 @@ import ImGui.Enum
     ImGuiMouseButton_ (..),
   )
 import ImGui.ImGuiIO.Implementation
-  ( imGuiIO_DisplayFramebufferScale_get,
-    imGuiIO_FontGlobalScale_set,
+  ( imGuiIO_FontGlobalScale_set,
     imGuiIO_Fonts_get,
     imGuiIO_MouseWheelH_get,
     imGuiIO_MouseWheel_get,
   )
-import ImGui.ImVec2.Implementation
-  ( imVec2_x_get,
-    imVec2_y_get,
-  )
 import Paths_ghc_specter_daemon (getDataDir)
 import Render.BlockerView qualified as BlockerView
 import Render.Console (consoleInputBufferSize)
@@ -78,8 +73,8 @@ import Util.GUI
   )
 import Util.Render (SharedState (..))
 
-foreign import ccall unsafe "scale"
-  c_scale :: IO CInt
+foreign import ccall unsafe "detectScaleFactor"
+  c_detectScaleFactor :: IO CFloat
 
 singleFrame ::
   ImGuiIO ->
@@ -194,23 +189,21 @@ prepareAssets io = do
       free_mono_path = dir </> "assets" </> "FreeMono.ttf"
   fonts <- imGuiIO_Fonts_get io
   -- _fontDefault <- imFontAtlas_AddFontDefault fonts
-  let scale = 2.0
+  scale <- c_detectScaleFactor
   _fontDefault <-
     withCString free_sans_path $ \cstr -> do
       imFontAtlas_AddFontFromFileTTF fonts cstr (13 * scale)
-  v <- imGuiIO_DisplayFramebufferScale_get io
-  scaleX <- imVec2_x_get v
-  scaleY <- imVec2_y_get v
-  print (scaleX, scaleY)
+  -- v <- imGuiIO_DisplayFramebufferScale_get io
+  -- scaleX <- imVec2_x_get v
+  -- scaleY <- imVec2_y_get v
+  -- print (scaleX, scaleY)
   imGuiIO_FontGlobalScale_set io (1.0 / scale)
   fontSans <-
     withCString free_sans_path $ \cstr -> do
       imFontAtlas_AddFontFromFileTTF fonts cstr (8 * scale)
   fontMono <-
     withCString free_mono_path $ \cstr ->
       imFontAtlas_AddFontFromFileTTF fonts cstr (8 * scale)
-  s <- c_scale
-  putStrLn $ "scale = " <> show s
   pure (fontSans, fontMono)
 
 main ::

daemon/app/ghc-specter-daemon/cbits/shim.mm

@@ -0,0 +1,16 @@
+#ifdef __MACOS__
+#include <Cocoa/Cocoa.h>
+#endif
+
+extern "C" {
+
+float detectScaleFactor( void ) {
+#ifdef __MACOS__
+  return NSScreen.mainScreen.backingScaleFactor;
+#else
+  return 1.0;
+#endif
+}
+
+}
+

daemon/ghc-specter-daemon.cabal

@@ -75,9 +75,10 @@ library
   hs-source-dirs:
       src
   if os(darwin)
-    cxx-options: -D__MACOSX__
+    cxx-options: -D__MACOS__
+    frameworks: Cocoa
   cxx-sources:
-      app/ghc-specter-daemon/cbits/shim.cpp
+      app/ghc-specter-daemon/cbits/shim.mm
   ghc-options: -Wall -Wunused-packages -Werror
   build-depends:
       OGDF

flake.nix

@@ -117,7 +117,8 @@
               pkgs.ormolu
               pyenv
             ]
-            ++ (pkgs.lib.optional (pkgs.stdenv.isLinux && !pkgs.lib.inPureEvalMode) nixGL.packages.${system}.default);
+            ++ (pkgs.lib.optional (pkgs.stdenv.isLinux && !pkgs.lib.inPureEvalMode) nixGL.packages.${system}.default)
+            ++ (pkgs.lib.optionals (pkgs.stdenv.isDarwin) [pkgs.darwin.apple_sdk.frameworks.Cocoa]);
           shellHook = ''
             export PS1="\n[${prompt}:\w]$ \0"
           '';