Wiki/wiki-rtd/docs/wiki_experiments/external-emulator/external-emulator.md

# Launching External Emulator 

<img src="../dolphin-result.png" width="800">

This experiment was initiated by the user **TopHatCat** and later expanded upon by the RetroDECK Team. **TopHatCats** goal was to explore the possibility of launching games against external Emulators from within RetroDECK (limited to the systems ES-DE supports). 

**However, doing this defeats the entire purpose of RetroDECK** 

You will not get any of the RetroDECK features for these systems, such as: 

- Hotkeys
- Working Inputs 
- Configurator
- Unified Folders
- Preconfigured 
- Backups
- and everything else!

Essentially, you are creating an Anti-RetroDECK / Bizzaro-RetroDECK / Absolute Heresy inside of RetroDECK. 

Your system will be cluttered, and you will be bound by each emulator's defaults, which you will need to change to your liking.

**There is no good reason to launch external emulators via RetroDECK**

Instead, you can install ES-DE from their website and set up the emulators as usual. 

Note that the `es_find_rules.xml` and `es_systems.xml` files you are editing will be overwritten when RetroDECK updates, so you'll need to reapply your changes after each update.


### Disclaimer on Experiments 

These experiments are created by the RetroDECK Team and/or Community. The guides are intended for people with technical knowledge and a passion for tinkering. Using these guides *might* put RetroDECK and your data at risk. The RetroDECK Team can't provide any support for these experiments or fix any issues they might cause on your system or RetroDECK installation.


## Prerequisites

### Flatpak Spawn Permission

**Information:**

This experiment requires the `flatpak-spawn` permission, which breaks the sandbox environment that RetroDECK operates in. Therefore, we do not recommend attempting this unless you are confident in your understanding of the process and its implications.

You can enable it by running this command in the terminal.

```
flatpak override --user --talk-name=org.freedesktop.Flatpak net.retrodeck.retrodeck
```

### Add RetroDECK to Steam

We also recommend that you add RetroDECK to Steam to utilize Steam Input if you need to rebind the system hotkeys manually.

## Folder Structure

The Flatpak paths for RetroDECK vary based on how you installed it. You can install it as either a system or user application.

**Note:**  If you installed RetroDECK as a system application, you will need increased privileges to edit the files.


| Type    | Folder                 |          Comment     | 
|  :---:  | :---:                  |             :---:     |
| **User Application:** ES-DE Linux Folder |`~/.local/share/flatpak/app/net.retrodeck.retrodeck/current/active/files/share/es-de/resources/systems/linux/` | `es_find_rules.xml` `es_systems.xml` |  
| **System Application:** ES-DE Linux Folder  |`/var/lib/flatpak/app/net.retrodeck.retrodeck/current/active/files/share/es-de/resources/systems/linux/` | `es_find_rules.xml` `es_systems.xml` |  

## Requirement: Add the FLATPAKSPAWN System

**Edit the es_find_rules.xml**

1. Go to the ES-DE Linux Folder via the path above (depending on how you installed RetroDECK).

2. Find and open `es_find_rules.xml`.

3. Edit `es_find_rules.xml`:

    - At the end of the file but before `</ruleList>`, add a new system `FLATPAKSPAWN`:
    - Copy & paste:
      ```
      <emulator name="FLATPAKSPAWN">
          <rule type="systempath">
              <entry>flatpak-spawn</entry>
          </rule>
      </emulator>
      ```
4. Save and close the file.


## How-to: Edit es_systems.xml file

### Step 1: Open es_systems.xml

1. Go to the ES-DE Linux Folder via the path above (depending on how you installed RetroDECK).

2. Find and open `es_systems.xml`.

3. Search for and find the system entry you want to add an external system to.

**Example:** GameCube

```
    <system>
        <name>gc</name>
        <fullname>Nintendo GameCube</fullname>
        <path>%ROMPATH%/gc</path>
        <extension>.ciso .CISO .dff .DFF .dol .DOL .elf .ELF .gcm .GCM .gcz .GCZ .iso .ISO .json .JSON .m3u .M3U .rvz .RVZ .tgc .TGC .wad .WAD .wbfs .WBFS .wia .WIA .7z .7Z .zip .ZIP</extension>
        <command label="Dolphin (Standalone)">%INJECT%=%BASENAME%.esprefix %EMULATOR_DOLPHIN% -b -e %ROM%</command>
        <command label="Dolphin">%EMULATOR_RETROARCH% -L %CORE_RETROARCH%/dolphin_libretro.so %ROM%</command>
        <command label="PrimeHack (Standalone)">%INJECT%=%BASENAME%.esprefix %EMULATOR_PRIMEHACK% -b -e %ROM%</command>
        <!-- <command label="Triforce (Standalone)">%INJECT%=%BASENAME%.esprefix %EMULATOR_TRIFORCE% -b -e %ROM%</command> -->
        <platform>gc</platform>
        <theme>gc</theme>
    </system>
```

### Step 2: Modify es_systems.xml

1. Copy and paste one of <command label=> entries and add one or more additional entries.

2. Modify the command labels values:

    - Point it towards the `%EMULATOR_FLATPAKSPAWN% --host` system.
    - Add the `Launch Command` of the external emulator (check How-to). 
    - Change the label="" so it ends with (External) or any other name you want.
    
3. Save and close the file.

##### How-to: Finding the Launch Command

<img src="../dolphin-emu-flatpak.png" width="800">

**Note:** This was done in KDE.

The easiest way is just to:

- Open the `Application Launcher Menu` (Start Menu).
- `Right Click` in on the Application in the `Application Launcher Menu` and press `Edit Application`.
- `Command-line arguments` should contain the `Launch Command`.

#### Examples & Results



**Dolphin (Native Application)**

- Launch Command: `/usr/bin/dolphin-emu`

New command label: 

`<command label="Dolphin (External Native)"> %EMULATOR_FLATPAKSPAWN% --host /usr/bin/dolphin-emu -b -e %ROM% </command>`

**Dolphin (Flatpak Application)**

- You need to add `flatpak` infront of `run` in the `Launch Command`.

- Launch Command: `flatpak run --branch=stable --arch=x86_64 --command=/app/bin/dolphin-emu-wrapper org.DolphinEmu.dolphin-emu`

New command label:  

`<command label="Dolphin (External Flatpak)"> %EMULATOR_FLATPAKSPAWN% --host flatpak run --branch=stable --arch=x86_64 --command=/app/bin/dolphin-emu-wrapper org.DolphinEmu.dolphin-emu -b -e %ROM% </command>`



**Combined Results**

```
    <system>
        <name>gc</name>
        <fullname>Nintendo GameCube</fullname>
        <path>%ROMPATH%/gc</path>
        <extension>.ciso .CISO .dff .DFF .dol .DOL .elf .ELF .gcm .GCM .gcz .GCZ .iso .ISO .json .JSON .m3u .M3U .rvz .RVZ .tgc .TGC .wad .WAD .wbfs .WBFS .wia .WIA .7z .7Z .zip .ZIP</extension>
        <command label="Dolphin (Standalone)">%INJECT%=%BASENAME%.esprefix %EMULATOR_DOLPHIN% -b -e %ROM%</command>
        <command label="Dolphin">%EMULATOR_RETROARCH% -L %CORE_RETROARCH%/dolphin_libretro.so %ROM%</command>
        <command label="PrimeHack (Standalone)">%INJECT%=%BASENAME%.esprefix %EMULATOR_PRIMEHACK% -b -e %ROM%</command>
        <command label="Dolphin (External Flatpak)"> %EMULATOR_FLATPAKSPAWN% --host flatpak run --branch=stable --arch=x86_64 --command=/app/bin/dolphin-emu-wrapper org.DolphinEmu.dolphin-emu -b -e %ROM% </command>
        <command label="Dolphin (External Native)"> %EMULATOR_FLATPAKSPAWN% --host /usr/bin/dolphin-emu -b -e %ROM% </command>
        <!-- <command label="Triforce (Standalone)">%INJECT%=%BASENAME%.esprefix %EMULATOR_TRIFORCE% -b -e %ROM%</command> -->
        <platform>gc</platform>
        <theme>gc</theme>
    </system>
```

### Step 3: Launch RetroDECK

**Note:** If you make an error, close RetroDECK before editing the `es_find_rules.xml` or `es_systems.xml` files. Save the files and relaunch RetroDECK, as the files are loaded when the application starts.

1. Launch RetroDECK.

2. Check the [ES-DE Frontend: General Guide](../../wiki_system_guides/es-de/esde-guide.md) on How-to set alternative emulators either per game or per system.

3. If everything is correct, the game should launch with the External System. You will need to manually configure it, considering all the drawbacks listed.