Set additional Proton env vars

Set various environment variables automatically to ensure DXVK,
vkd3d-proton, nvapi and GStreamer are properly configured. This should
improve compatibility in scenarios in which an application launched
through Steam worked properly, but didn't work when launched through
Protontricks.

The environment variables are set fairly conservatively: env var is only
set if the Proton installation appears to support it and if the user
hasn't already set it themselves.

The environment variables are usually set by the `proton` launcher
script provided by Proton installations and used by Steam. However, it
can't be used for a variety of reasons:

* The command-line interface is not stable and can change from version
  to version
* While written in Python, it isn't suitable for programmatic usage due
  to relying on global variables

Author: Matoking

CHANGELOG.md

@@ -5,6 +5,9 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 
 ## [1.12.1] - 2025-03-08
+### Added
+ - Improve compatibility by setting additional Proton related environment variables when applicable
+
 ### Fixed
  - Fix missing app icons for games installed using newer Steam client
  - Fix spurious "unknown file arch" Winetricks warnings (newer Winetricks required)

src/protontricks/util.py

@@ -1,3 +1,4 @@
+import itertools
 import locale
 import logging
 import os
@@ -308,6 +309,109 @@ def _get_fixed_locale_env():
     return fixed_env
 
 
+_DLL_OVERRIDES = {
+    "beclient": "b,n",
+    "beclient_x64": "b,n",
+
+    # DXVK
+    "dxgi": "n",
+    "d3d9": "n",
+    "d3d10core": "n",
+    "d3d11": "n",
+
+    # vkd3d-proton
+    "d3d12": "n",
+    "d3d12core": "n",
+
+    # nvapi
+    "nvapi": "n",
+    "nvapi64": "n",
+    "nvofapi64": "n",
+    "nvcuda": "b"
+}
+
+_WINE_DEFAULT_ENV_VARS = {
+    "WINE_LARGE_ADDRESS_AWARE": "1",
+    "DXVK_ENABLE_NVAPI": "1",
+}
+
+def _get_proton_env(proton_app, steam_app, orig_env):
+    """
+    Return a dict of various Proton related environment variables.
+    These are mainly required to configure DXVK, vkd3d-proton and GStreamer
+    properly.
+
+    When using Proton proper, these are usually set by the `proton` launcher
+    script. The script is not designed for programmatic usage, so we'll have to
+    set them manually instead.
+
+    Some environment variables are not supported depending on the Python
+    version. We will err on the side of caution and check if preconditions are
+    met before attempting to set any environment variables; for example, Proton
+    installation must contain GStreamer directory in order to set GStreamer env
+    vars.
+    """
+    new_env = {}
+
+    dist_path = proton_app.proton_dist_path
+
+    # 1.Configure WINEDLLOVERRIDES
+    available_dlls = set([
+        file_.stem for file_
+        in itertools.chain(
+            (dist_path / "lib64").glob("**/*.dll"),
+            (dist_path / "lib").glob("**/*.dll")
+        )
+    ])
+
+    dll_overrides = {
+        value.split("=")[0]: value.split("=")[1]
+        for value in orig_env.get("WINEDLLOVERRIDES", "").split(";")
+        if "=" in value
+    }
+
+    logger.debug(
+        "Following Wine DLL overrides already set: %s",
+        dll_overrides
+    )
+
+    # Set DLL overrides if the corresponding DLL file exists *and* if the user
+    # hasn't declared something else
+    for name, setting in _DLL_OVERRIDES.items():
+        is_available = name in available_dlls
+        is_set = name in dll_overrides
+
+        if is_available and not is_set:
+            logger.debug("Setting Wine DLL override: %s=%s", name, setting)
+            dll_overrides[name] = setting
+
+    new_env["WINEDLLOVERRIDES"] = ";".join(
+        f"{name}={setting}" for name, setting in dll_overrides.items()
+    )
+
+    # 2. Configure GStreamer
+    is_gstreamer_available = (dist_path / "lib/gstreamer-1.0").is_dir()
+
+    if is_gstreamer_available:
+        logger.debug("Setting GStreamer environment variables")
+
+        new_env["GST_PLUGIN_SYSTEM_PATH_1_0"] = (
+            f"{dist_path / 'lib64/gstreamer-1.0'}"
+            f":{dist_path / 'lib/gstreamer-1.0'}"
+        )
+        new_env["WINE_GST_REGISTRY_DIR"] = str(
+            steam_app.prefix_path.parent / "gstreamer-1.0"
+        )
+
+    # 3. Enable various env vars unless already set by user
+    for name, value in _WINE_DEFAULT_ENV_VARS.items():
+        if name not in orig_env:
+            logger.debug("Setting default env var: %s=%s", name, value)
+            new_env[name] = value
+
+    return new_env
+
+
 def _start_process(args, wait=False, **kwargs):
     """Start a new process and return a Popen instance
     """
@@ -396,6 +500,14 @@ def run_command(
     # Fix the locale for Steam Deck, if necessary
     wine_environ.update(_get_fixed_locale_env())
 
+    # Set various Proton related environment variables
+    wine_environ.update(
+        _get_proton_env(
+            proton_app=proton_app, steam_app=steam_app,
+            orig_env=wine_environ
+        )
+    )
+
     wine_bin_dir = None
     wine_environ["PROTONTRICKS_STEAM_RUNTIME"] = "off"
     if use_steam_runtime:

tests/test_util.py

@@ -210,6 +210,98 @@ def test_locale_fixed_on_steam_deck(
         assert command.env["LC_TIME"] == "en_US.UTF-8"
         assert command.env["LC_NUMERIC"] == "en_US.UTF-8"
 
+    def test_winedlloverrides_defaults_are_set(
+            self, steam_app_factory, default_proton, command_mock, caplog):
+        """
+        Test that Protontricks will automatically set WINEDLLOVERRIDES
+        while skipping any DLLs that user has already configured
+        """
+        dxvk_lib_path = \
+            default_proton.proton_dist_path / "lib" / "wine" / "dxvk"
+        dxvk_lib_path.mkdir(parents=True)
+
+        (dxvk_lib_path / "dxgi.dll").touch()
+        (dxvk_lib_path / "d3d9.dll").touch()
+        (dxvk_lib_path / "d3d11.dll").touch()
+
+        steam_app = steam_app_factory(name="Fake game", appid=10)
+        run_command(
+            winetricks_path=Path("/usr/bin/winetricks"),
+            proton_app=default_proton,
+            steam_app=steam_app,
+            command=["/bin/env"],
+            env={
+                "WINEDLLOVERRIDES": "fakelibrary=b;dxgi=b"
+            }
+        )
+
+        command = command_mock.commands[-1]
+
+        # User-provided environment variables are not overridden
+        assert "dxgi=b" in command.env["WINEDLLOVERRIDES"]
+        assert "fakelibrary=b" in command.env["WINEDLLOVERRIDES"]
+
+        # DXVK overrides are set if the corresponding DLL files exist in the
+        # Proton installation
+        assert "d3d9=n" in command.env["WINEDLLOVERRIDES"]
+        assert "d3d11=n" in command.env["WINEDLLOVERRIDES"]
+
+        assert "d3d10core" not in command.env["WINEDLLOVERRIDES"]
+
+    def test_gstreamer_env_is_set(
+            self, steam_app_factory, default_proton, command_mock):
+        """
+        Test that Protontricks will automatically set GStreamer related
+        environment variables if GStreamer appears to be installed for Proton
+        """
+        (default_proton.proton_dist_path / "lib/gstreamer-1.0").mkdir(
+            parents=True
+        )
+
+        steam_app = steam_app_factory(name="Fake game", appid=10)
+
+        run_command(
+            winetricks_path=Path("/usr/bin/winetricks"),
+            proton_app=default_proton,
+            steam_app=steam_app,
+            command=["/bin/env"],
+        )
+
+        command = command_mock.commands[-1]
+
+        assert str(default_proton.proton_dist_path / "lib/gstreamer-1.0") \
+            in command.env["GST_PLUGIN_SYSTEM_PATH_1_0"]
+        assert str(steam_app.prefix_path.parent / "gstreamer-1.0") \
+            in command.env["WINE_GST_REGISTRY_DIR"]
+
+    def test_default_proton_env_vars_set(
+            self, steam_app_factory, default_proton, command_mock):
+        """
+        Test that Protontricks will automatically set various Proton related
+        environment variables, unless they're already set by the user
+        """
+        steam_app = steam_app_factory(name="Fake game", appid=10)
+
+        run_command(
+            winetricks_path=Path("/usr/bin/winetricks"),
+            proton_app=default_proton,
+            steam_app=steam_app,
+            command=["/bin/env"],
+            env={
+                "WINE_LARGE_ADDRESS_AWARE": "2"
+            }
+        )
+
+        command = command_mock.commands[-1]
+
+        # Default env var is set
+        assert command.env["DXVK_ENABLE_NVAPI"] == "1"
+
+        # User-set env var is not overridden
+        assert command.env["WINE_LARGE_ADDRESS_AWARE"] == "2"
+
+
+
     def test_bwrap_launcher_crash_detected(
             self, default_new_proton, steam_app_factory, command_mock):
         """