add gamescope support

gamescope is using specific versions of wlroots,libliftoff,vkroots.
They are statically linked in the gamescope binary

when enabled, gamescope is prefixing the emulator commandline.

ex: gamescope -W 3840 -H 2160 -f -- /usr/bin/retroarch ....

default gamescope output resolution is set to current monitor resolution

Author: aderumier

package/batocera/core/batocera-configgen/configgen/configgen/emulatorlauncher.py

@@ -33,6 +33,7 @@
 from .generators import get_generator
 from .gun import Gun
 from .utils import bezels as bezelsUtil, videoMode, wheelsUtils
+from .utils.gamescope import add_gamescope_arguments
 from .utils.hotkeygen import set_hotkeygen_context
 from .utils.logger import setup_logging
 from .utils.squashfs import squashfs_rom
@@ -182,6 +183,8 @@ def start_rom(args: argparse.Namespace, maxnbplayers: int, rom: Path, original_r
                         if not generator.hasInternalMangoHUDCall():
                             cmd.array.insert(0, "mangohud")
 
+                add_gamescope_arguments(cmd, system, gameResolution)
+
                 with profiler.pause():
                     monitor_thread.start()
                     exitCode = runCommand(cmd)

package/batocera/core/batocera-configgen/configgen/configgen/utils/gamescope.py

@@ -0,0 +1,121 @@
+from __future__ import annotations
+
+import logging
+import subprocess
+from pathlib import Path
+from ..exceptions import BatoceraException
+from typing import TYPE_CHECKING
+
+if TYPE_CHECKING:
+    from ..generators.Generator import Generator
+
+_logger = logging.getLogger(__name__)
+
+def is_GBM_Supported() -> boolean:
+    try:
+        eglinfo_bin = Path("/usr/bin/eglinfo")
+        if not eglinfo_bin.exists():
+            return False
+
+        eglCmd = '/usr/bin/eglinfo | grep EGL_KHR_platform_gbm'
+        eglCmdResult = subprocess.run(eglCmd, shell=True, capture_output=True, text=True)
+        grep_return_code = eglCmdResult.returncode
+
+        if grep_return_code == 0:
+           return True
+        return False
+
+    except Exception:
+        return False
+
+def add_gamescope_arguments(command: Command, system: Emulator, CurrentResolution: Resolution, /) -> None:
+
+    if not system.config.get_bool("gamescope"):
+        return
+
+    if not is_GBM_Supported():
+        raise BatoceraException(f"GPU driver don't support gamescope")
+
+    gamescope_arguments = ["/usr/bin/gamescope"]
+
+    # Retrieve output resolution from system options.
+    # if not defined, inherit from the current screen resolution
+    output_resolution = system.config.get_str("gamescope_output_resolution")
+    if output_resolution:
+        output_width, _, output_height = output_resolution.partition("x")
+    else:
+        output_width = f'{CurrentResolution["width"]}'
+        output_height = f'{CurrentResolution["height"]}'
+
+    gamescope_arguments_cmd.extend([
+        "-W", output_width.strip(),
+        "-H", output_height.strip()
+    ])
+
+    # Retrieve nested resolution from system options.
+    # default undefined inherit from gamescopt_output_resoluton
+    # the nested_resolution is upscaled|downscaled to output_resolution
+
+    nested_resolution = system.config.get_str("gamescope_nested_resolution")
+    if nested_resolution:
+        nested_width, _, nested_height = nested_resolution.partition("x")
+        gamescope_arguments.extend([
+            "-w", nested_width.strip(),
+            "-h", nested_height.strip()
+        ])
+
+    # Retrieve nested refresh rate.
+    # Default is undefined with output refresh forced to 60hz
+    # if nested refresh is defined, output refresh is equal to nested refresh
+    nested_refresh = system.config.get_str("gamescope_nested_refresh")
+    if nested_refresh:
+        gamescope_arguments.extend(["-r", str(nested_refresh)])
+
+    # Upscaler type.
+    # default is stretched if undefined
+    scaler = system.config.get_str("gamescope_scaler")
+    if scaler:
+        gamescope_arguments.extend(["-S", scaler])
+
+    # Upscaler filter.
+    # default is linear if undefined
+    filter = system.config.get_str("gamescope_filter")
+    if filter:
+        gamescope_arguments.extend(["-F", filter])
+
+    # Upscaler sharpness
+    sharpness = system.config.get_str("gamescope_sharpness")
+    if sharpness:
+        gamescope_arguments.extend(["--sharpness", sharpness])
+
+    if system.config.get_bool("gamescope_hdr"):
+        sdr_gamut = system.config.get_str("gamescope_sdr_gamut_wideness")
+        if sdr_gamut:
+            gamescope_arguments.extend(["--sdr-gamut-wideness", sdr_gamut])
+
+        hdr_sdr_nits = system.config.get_str("gamescope_hdr_sdr_content_nits")
+        if hdr_sdr_nits:
+           gamescope_arguments.extend(["--hdr-sdr-content-nits", hdr_sdr_nits])
+
+        if system.config.get_bool("gamescope_hdr_itm_enabled"):
+           gamescope_arguments.append("--hdr-itm-enabled")
+
+        hdr_itm_sdr_nits = system.config.get_str("gamescope_hdr_itm_sdr_nits")
+        if hdr_itm_sdr_nits:
+            gamescope_arguments.extend(["--hdr-itm-sdr-nits", hdr_itm_sdr_nits])
+
+        hdr_itm_target = system.config.get_str("gamescope_hdr_itm_target_nits")
+        if hdr_itm_target:
+            gamescope_arguments.extend(["--hdr-itm-target-nits", hdr_itm_target])
+
+    #always fullscreen
+    gamescope_arguments.append("-f")
+
+    # Reshade effect.
+    reshade_effect = system.config.get_str("gamescope_reshade_effect")
+    if reshade_effect:
+        gamescope_arguments.extend(["--reshade-effect", reshade_effect])
+
+    gamescope_arguments.append("--")
+
+    command.array = gamescope_arguments + command.array