From 1fa8213038ff1c729429e9f781aa3bd7670e4d22 Mon Sep 17 00:00:00 2001
From: Marius DAVID <git@mariusdavid.fr>
Date: Sun, 1 Feb 2026 21:25:30 +0100
Subject: [PATCH] nix: add a vulkan option and enable xcb QT platform by
 default

---
 flake.nix      |  4 +++-
 nix/overte.nix | 17 +++++++++++++++--
 2 files changed, 18 insertions(+), 3 deletions(-)

diff --git a/flake.nix b/flake.nix
index 4e95ccfcffd..b0a31cd5e4c 100644
--- a/flake.nix
+++ b/flake.nix
@@ -23,7 +23,7 @@
             ...
           }:
           {
-            packages = {
+            packages = rec {
               glad = pkgs.callPackage ./nix/glad.nix { };
               etc2comp = pkgs.callPackage ./nix/etc2comp.nix { };
 
@@ -52,6 +52,8 @@
                 libv8 = pkgs.nodejs_22.libv8;
               };
 
+              overte-full-vulkan = overte-full.override { renderingBackend = "Vulkan"; };
+
               # TODO: update/remove when overte updates to more modern version
               draco = pkgs.callPackage ./nix/draco.nix { };
 
diff --git a/nix/overte.nix b/nix/overte.nix
index 7f8d4eff1af..60dc4199371 100644
--- a/nix/overte.nix
+++ b/nix/overte.nix
@@ -31,6 +31,9 @@
   libopus,
   libsForQt5,
   libv8,
+  vulkan-loader,
+  vulkan-headers,
+  vulkan-memory-allocator,
 
   # tools for shader compilation
   scribe,
@@ -43,9 +46,13 @@
   buildClient ? true,
   buildServer ? true,
   buildTools ? false,
+  renderingBackend ? "OpenGL",
 }:
+
+assert renderingBackend == "OpenGL" || renderingBackend == "Vulkan";
+
 stdenv.mkDerivation {
-  pname = "overte";
+  pname = "overte-${lib.toLower renderingBackend}";
   version = "unstable";
   src =
     let
@@ -122,11 +129,16 @@ stdenv.mkDerivation {
       SDL2
       libopus
       libv8
-    ];
+    ] ++ (lib.optionals (renderingBackend == "Vulkan") [
+        vulkan-loader
+        vulkan-headers
+        vulkan-memory-allocator
+    ]);
 
   cmakeFlags = [
     "-DOVERTE_USE_SYSTEM_LIBS=ON"
     "-DOVERTE_BUILD_TYPE=NIGHLTY"
+    "-DOVERTE_RENDERING_BACKEND=${renderingBackend}"
   ]
   ++ lib.optional (!buildClient) "-DOVERTE_BUILD_CLIENT=OFF"
   ++ lib.optional (!buildServer) "-DOVERTE_BUILD_SERVER=OFF"
@@ -163,6 +175,7 @@ stdenv.mkDerivation {
       ln -s "$I"/interface $out/bin/overte-client
       makeWrapper "$I"/interface $out/bin/overte-client \
         --unset QT_PLUGIN_PATH \
+        --set-default QT_QPA_PLATFORM xcb \
         "''${qtWrapperArgs[@]}"
     ''
   )