Add Linux wrapper tweak for hybrid gpu systems

Ideally, this should be done through the freedesktop specification (PrefersNonDefaultGPU), but the implementation is currently buggy, or ineffective at the moment on Plasma5 and Plasma6. This is a stopgap fix until we can rely on the frameworks currently in place.

indra/newview/linux_tools/wrapper.sh

@@ -105,6 +105,59 @@ else
     echo "Please install wine to enable full voice functionality."
 fi
 
+# Multiple GPU support
+#TODO: check if running on battery?
+if [[ -z "$AL_NO_OFFLOAD" ]]; then
+    _fallback_to_lspci=0
+    if [[ -d /sys/class/drm/card1 ]]; then
+        # The system registered more than one GPU
+        # TODO: Test if this folder disappears after disconnecting an eGPU
+        if [[ -f /sys/class/drm/card1/device/vendor ]]; then
+            # We have more than one display adapter and it exposes its vendor info
+            # Check if this indeed the non-primary gpus
+            if [[ $(</sys/class/drm/card1/device/boot_vga) == 0 ]]; then
+                if [[ "$(< /sys/class/drm/card1/device/vendor)" == "0x10de" ]]; then
+                    # NVIDIA GPU
+                    export __NV_PRIME_RENDER_OFFLOAD=1
+                    export __GLX_VENDOR_LIBRARY_NAME=nvidia
+                else
+                    echo >&2 'Warning: unknown secondary GPU vendor, please report the following to the Alchemy Viewer support Discord server:'
+                    echo >&2 "Secondary (drm/card1) GPU vendor is '$(/sys/class/drm/card1/device/vendor)'"
+                fi
+            else
+                echo >&2 'Warning: Secondary GPU is the boot GPU! How to handle? Please report to the Alchemy Viewer support Discord server.'
+            fi
+        else
+            echo >&2 "Secondary GPU does not expose its vendor!"
+            _fallback_to_lspci=1
+        fi
+        if [[ "$_fallback_to_lspci" == 1 ]]; then
+            if ! command -v lspci; then
+                echo >&2 "Warning: lspci not found. automatic display adapter selection will not work."
+            else
+                vga_adapters=$(lspci -nn | grep '\[03')
+                adapters_count=$(wc -l <<< "$vga_adapters")
+                if [[ $adapters_count -gt 1 ]]; then
+                    echo 'Multiple graphics adapters detected, attempting to select the best one.'
+                    # TODO: Stuff DRI_PRIME=1 somewhere in there for machines with AMD discrete gpus + integrated graphics
+                    if [[ "${vga_adapters}" =~ "10de" ]] && [[ "${vga_adapters}" =~ "Advanced Micro Devices, Inc" ]]; then
+                            export __NV_PRIME_RENDER_OFFLOAD=1
+                            export __GLX_VENDOR_LIBRARY_NAME=nvidia
+                    else
+                        # if [[ "${vga_adapters}" =~ "Intel" ]]; then
+                        echo >&2 'Warning: Auto-select does not know what to do with your current configuration.'
+                        echo >&2 'Please send the following output to the Alchemy Viewer support Discord server:'
+                        echo >&2 "======"
+                        echo >&2 "$vga_adapters"
+                        echo >&2 "======"
+                    fi
+                fi
+            fi
+        fi
+    fi
+#TODO: gracefully fail if the GPU is stuck sleeping. It can happen.
+fi
+
 # Run the program.
 # Don't quote $LL_WRAPPER because, if empty, it should simply vanish from the
 # command line. But DO quote "${ARGS[@]}": preserve separate args as