start: add --force-nixgl and check /run/opengl-driver (#13385)

start/src/core/State.hpp

@@ -8,7 +8,8 @@
 struct SState {
     std::span<const char*>     rawArgvNoBinPath;
     std::optional<std::string> customPath;
-    bool                       noNixGl = false;
+    bool                       noNixGl    = false;
+    bool                       forceNixGl = false;
 };
 
 inline UP<SState> g_state = makeUnique<SState>();

start/src/helpers/Nix.cpp

@@ -82,6 +82,9 @@ std::expected<void, std::string> Nix::nixEnvironmentOk() {
 }
 
 bool Nix::shouldUseNixGL() {
+    if (g_state->forceNixGl)
+        return true;
+
     if (g_state->noNixGl)
         return false;
 
@@ -103,7 +106,19 @@ bool Nix::shouldUseNixGL() {
 
     if (IS_NIX) {
         const auto NAME = getFromEtcOsRelease("NAME");
-        return !NAME || *NAME != "NixOS";
+
+        // Hyprland is nix: recommend nixGL iff !NIX && !NIX-OPENGL
+
+        if (*NAME == "NixOS")
+            return false;
+
+        std::error_code ec;
+
+        if (std::filesystem::exists("/run/opengl-driver", ec) && !ec) // NOLINTNEXTLINE
+            return false;
+
+        // we are not on nix / no nix opengl driver
+        return true;
     }
 
     return false;

start/src/main.cpp

@@ -22,6 +22,7 @@ Any arguments after -- are passed to Hyprland. For Hyprland help, run start-hypr
 Additional arguments for start-hyprland:
  --path [path]       -> Override Hyprland path
  --no-nixgl          -> Force disable nixGL
+ --force-nixgl       -> Force enable nixGL
 )#";
 
 //
@@ -79,6 +80,10 @@ int main(int argc, const char** argv, const char** envp) {
             g_state->noNixGl = true;
             continue;
         }
+        if (arg == "--force-nixgl") {
+            g_state->forceNixGl = true;
+            continue;
+        }
     }
 
     if (startArgv != -1)