Descent3/README.md

![d3 (1)](https://github.com/DescentDevelopers/Descent3/assets/47716344/82ba0911-ee32-4565-84ee-b432c215ab95)

This is the Descent 3 open source engine, licensed under [GPL-3.0](https://github.com/DescentDevelopers/Descent3?tab=GPL-3.0-1-ov-file). It includes the '1.5' patch written by Kevin Bentley and Jeff Slutter several years ago and brought to a stable condition by the Descent community.

In order to use this, you must provide your own game files. See the **Usage** section for details.

## Version 1.5 Notes
There is no "release" yet. The current milestone is "1.5 Stable", which is meant to more or less be Descent 3 as it might have been if the 1.5 patch had made it to retail years ago. Artifacts can be downloaded from the [Actions](https://github.com/DescentDevelopers/Descent3/actions) tab.
The milestone needs testing on all platforms. Please report issues when found.

## Usage
1. Make sure that you have a copy of Descent 3. You can purchase a copy of Descent 3 from [GOG](https://www.gog.com/game/descent_3_expansion) or [Steam](https://store.steampowered.com/app/273590/Descent_3/).
2. Install Descent 3.

    - **Note for Steam users:** If you own Descent 3 on Steam, then it’s recommended that you install the Windows version of the game even if you’re running macOS or Linux, otherwise movies will not work due to [current lack of Ogv support](https://github.com/DescentDevelopers/Descent3/issues/240). You can use either [Steam Play](https://help.steampowered.com/en/faqs/view/08F7-5D56-9654-39AF) or [SteamCMD](https://developer.valvesoftware.com/wiki/SteamCMD#Cross-Platform_Installation) to install the Windows version of the game on macOS or Linux.

    - **Note for non-Windows users:** If you have the Windows version of the game on CDs but you don’t want to use Windows to install them, then you can follow these instructions:

        <details>
        <summary>How to install the Windows Dual-Jewel version of Descent 3 in Wine</summary>

        <ol type="1">
            <li>Make sure that you have <a href="https://www.winehq.org">Wine</a> installed.</li>
            <li><i>(Recommended)</i> Run <code>winecfg</code> and make sure that “Emulate a virtual desktop” is enabled.</li>
            <li>
                <p><i>(Optional)</i> Determine if you’re going to be affected by a bug with Descent 3’s installer, and potentially apply a workaround:</p>
                <ol type="a">
                    <li>Download <a href="https://codeberg.org/JasonYundt/environment-size-checker">Environment Size Checker</a>.</li>
                    <li>Run <code>wine environment-size-checker.exe</code>.</li>
                    <li>If that program tells you that your environment is more than 32,724 bytes large, then you’ll need to unset or shorten environment variables before running Descent 3’s installer. If you don’t, then the installer will page fault.</li>
                </ol>
            </li>
            <li>
                <p>Install Descent 3:</p>
                <ol type="a">
                    <li>Insert disc 1.</li>
                    <li>Make sure that disc 1 is mounted.</li>
                    <li>Determine which drive letter Wine is using for your CD drive. (Hint: try running <code>wine explorer</code>).</li>
                    <li>Run <code>wine '&lt;drive-letter&gt;:\Setup.exe'</code>.</li>
                    <li>Follow the installation wizard’s instructions until it asks you to choose a “Setup Type”.</li>
                    <li>Select the “Full” Setup Type, then click “Next”.
                    <li>Continue following the installation wizard’s instructions until it asks you to insert disc 2.</li>
                    <li>
                        <p>Switch to disc 2:</p>
                        <!-- This really should be an <ol>, but I couldn’t get the numbering/lettering to work right: <https://github.com/orgs/community/discussions/124850> -->
                        <ul>
                            <li>Run <code>wine eject &lt;drive-letter&gt;:</code>.</li>
                            <li>Make sure that the disc was unmounted and ejected.</li>
                            <li>Insert disc 2.</li>
                            <li>Mount disc 2.</li>
                        </ul>
                    </li>
                    <li>Continue following the installation wizard’s instructions until it asks you to insert disc 1 again.</li>
                    <li>Switch back to disc 1. Follow a similar procedure to the one that you used to switch to disc 2.</li>
                    <li>Finish the going through the installation wizard.</li>
                    <li>When the installation wizard finishes, it will open an explorer window. Close out of that window.</li>
                    <li>Unmount the disc.</li>
                    <li>Eject the disc.</li>
                </ol>
            <li>
                <p>Install Descent 3: Mercenary:</p>
                <ol type="a">
                    <li>Insert disc 3.</li>
                    <li>Make sure that disc 3 is mounted.</li>
                    <li>Run <code>wine start /d &lt;drive-letter&gt;: setup.exe -autorun</code>.</li>
                    <li>Follow the instructions in the installation wizard.</li>
                </ol>
            </li>
        </ol>

        </details>

3. If your version of Descent 3 is older than v1.4, then [update it to v1.4](http://descent3.com/downloads.php).
4. Create a new folder named `D3-open-source`.
5. Copy the following files from your installation of Descent 3 to `D3-open-source`:
    - All `.hog` files
    - The `missions` folder
    - _(Optional)_ All `.pld` files
    - _(Optional)_ The `demo` folder
    - _(Optional)_ The `movies` folder
6. Create the following folders in `D3-open-source`:
    - `custom/`
    - `custom/cache/`
7. Obtain new Descent 3 engine files:
    - If you want to use pre-built binaries, then download one of the artifacts from our latest CI run. You can find a list of CI runs [here](https://github.com/DescentDevelopers/Descent3/actions/workflows/build.yml?query=branch%3Amain).
    - If you want to build the engine files yourself, the follow [these instructions](#building). Once you build the engine files, they’ll be put in `builds/<platform>/Descent3/<build-type>/`. For example, if you’re using Linux and you create a “Release” build, then the files will be located at `builds/linux/Descent3/Release`.
8. Copy all of the new engine files into `D3-open-source` and overwrite any conflicts.
9. Run the game:
    - On Windows, run `D3-open-source\Descent3.exe`.
    - On other platforms, run `D3-open-source/Descent3`.
10. Special notes:
    - D3 Open Source compiles level scripts in their own hogfiles. Make sure you copy and overwrite `d3-{platform}.hog`.

## Building
### Dependencies
The build process uses [**CMake**](https://cmake.org/) and, by default, [**Ninja**](https://ninja-build.org/). You must install these; the project cannot locate them for you. The source code depends on [**SDL2**](https://github.com/libsdl-org/SDL/tree/SDL2) and [**zlib**](https://github.com/madler/zlib). You can supply these dependencies yourself via your system's library management tools, or the build system can locate the dependencies for you using [vcpkg](https://github.com/microsoft/vcpkg), a cross-platform dependency-management system developed by Microsoft. The official builds source their dependencies from vcpkg.

### Installing and using vcpkg
* When building for Windows, vcpkg is already installed and configured when using any of the Visual Studio command prompts (either actual Command Prompt, or PowerShell).
* For Android, Linux or Mac (or non-standard-Windows) configurations, you will need to install vcpkg locally by cloning https://github.com/microsoft/vcpkg and setting your `VCPKG_ROOT` env var to the repository location. With this environment variable set, the build will automatically locate its dependencies.

### Building - Windows
1. **Install the prerequisite build tools.**

    Make sure that you have Git and Visual Studio 2022 with the “Desktop development with C++” workload and the “C++ MFC for latest v143 build tools (x86 & x64)” component. If you don’t already have those installed or you aren’t sure, then open an elevated Command Prompt and run:
    <!--
    The following code block specifies the full path to the Visual Studio Installer because the Visual Studio Installer doesn’t add itself to the user’s Path. The installer is guaranteed to be in a specific location on 64-bit systems [1]. The installer will be in a different location on 32-bit systems [2], but Visual Studio 2022 doesn’t support 32-bit systems [3] so we can ignore that detail.

    [1]: <https://learn.microsoft.com/en-us/visualstudio/install/use-command-line-parameters-to-install-visual-studio?view=vs-2022>
    [2]: <https://github.com/microsoft/vswhere/wiki#installing>
    [3]: <https://learn.microsoft.com/en-us/answers/questions/1689898/does-visual-studio-build-tools-2022-support-32-bit>
    -->
    ```batch
    winget install Git.Git Microsoft.VisualStudio.2022.Community

    "%ProgramFiles(x86)%\Microsoft Visual Studio\Installer\setup.exe" modify^
        --passive^
        --channelId VisualStudio.17.Release^
        --productId Microsoft.VisualStudio.Product.Community^
        --add Microsoft.VisualStudio.Workload.NativeDesktop;includeRecommended^
        --add Microsoft.VisualStudio.Component.VC.ATLMFC
    ```

    **NOTE:**
    Builds _must_ be performed in one of the Visual Studio-provided **x64 Native Tools** command prompts ("x64 Native Tools Command Prompt" or "x64 Native Tools PowerShell"), _not_ a standard Command Prompt or PowerShell. The VS prompts will already have vcpkg installed and configured for use, so no dependency management is needed.

2. **Clone the Descent3 source code.**

    Open a "x64 Native Tools Command Prompt" or "x64 Native Tools PowerShell" and run:
    ```batch
    git clone https://github.com/DescentDevelopers/Descent3
    ```

4. **Build Descent3.**

    ```batch
    cd Descent3
    cmake --preset win
    cmake --build --preset win --config [Debug|Release]
    ```
    See [Build Options](#build-options) below for more information on `Debug` vs `Release`.

Once CMake finishes, the built files will be put in `builds\win\Descent3\Debug` or `builds\win\Descent3\Release`.

### Building - macOS
1. **Install the prerequisite build tools.**

    * Make sure that [Xcode](https://developer.apple.com/xcode) is installed.
    * Make sure that [Homebrew](https://brew.sh) is installed.

2. **Acquire the library dependencies.**

    * If you would like to use vcpkg:
        ```sh
        git clone https://github.com/microsoft/vcpkg
        export VCPKG_ROOT="$PWD/vcpkg"
        ```
        **NOTE:**
        You will need `$VCPKG_ROOT` defined in the environment for all build runs. It is a good idea to set this in your `.bashrc` or equivalent.
    * If you would like to manage the code dependencies yourself:
        ```sh
        brew install sdl2 zlib googletest
        ```

3. **Clone the Descent3 source code.**

    ```sh
    git clone https://github.com/DescentDevelopers/Descent3
    ```

4. **Build Descent3.**

    ```sh
    cd Descent3
    brew bundle install
    cmake --preset mac
    cmake --build --preset mac --config [Debug|Release]
    ```
    See [Build Options](#build-options) below for more information on `Debug` vs `Release`.

Once CMake finishes, the built files will be put in `builds/mac/Descent3/Debug` or `builds/mac/Descent3/Release`.

### Building - Linux
1. **Install the prerequisite build tools.**

    * APT users (Debian, Ubuntu)
        ```sh
        sudo apt update
        sudo apt install -y --no-install-recommends git ninja-build cmake g++
        ```
    * DNF users (Red Hat, Fedora)
        ```sh
        sudo dnf update --refresh
        sudo dnf install -y git ninja-build cmake gcc-c++
        ```

2. **Acquire the library dependencies.**

    * If you would like to use vcpkg:
        1. Clone vcpkg:
            ```sh
            git clone https://github.com/microsoft/vcpkg
            export VCPKG_ROOT="$PWD/vcpkg"
            ```
            **NOTE:**
            You will need `$VCPKG_ROOT` defined in the environment for all build runs. It is a good idea to set this in your `.bashrc` or equivalent.
        2. Install vcpkg-needed build tools and dependencies:
            * APT users
                ```sh
                sudo apt install -y --no-install-recommends curl pkg-config autoconf automake libtool libltdl-dev make python3-jinja2 libx11-dev libxft-dev libxext-dev libwayland-dev libxkbcommon-dev libegl1-mesa-dev libibus-1.0-dev libasound2-dev libpulse-dev libaudio-dev libjack-dev libsndio-dev
                ```
            * DNF users
                ```sh
                sudo dnf install -y autoconf automake libtool perl-open perl-FindBin python-jinja2 libX11-devel libXft-devel libXext-devel wayland-devel libxkbcommon-devel mesa-libEGL-devel ibus-devel alsa-lib-devel pulseaudio-libs-devel
                ```
    * If you would like to manage the code dependencies yourself:
        * APT users
            ```sh
            sudo apt install -y --no-install-recommends libsdl2-dev zlib1g-dev libgtest-dev
            ```
        * DNF users
            ```sh
            sudo dnf install -y SDL2-devel zlib-devel gtest
            ```

3. **Clone the Descent3 source code.**

    ```sh
    git clone https://github.com/DescentDevelopers/Descent3
    ```

4. **Build Descent3.**

    ```sh
    cd Descent3
    cmake --preset linux
    cmake --build --preset linux --config [Debug|Release]
    ```
    See [Build Options](#build-options) below for more information on `Debug` vs `Release`.

Once CMake finishes, the built files will be put in `builds/linux/Descent3/Debug` or `builds/linux/Descent3/Release`.

### Build Options

The Descent3 build can be customized by [setting CMake variables on the command line](https://cmake.org/cmake/help/latest/manual/cmake.1.html#cmdoption-cmake-D) during its "Configuration" phase (the command without the `--build` option). To set a variable, you prepend the variable name with `-D` and then append the value, all as one single parameter. For example:
```sh
cmake --preset linux -DENABLE_LOGGER=ON
```

**NOTE:** CMake variables, or more technically _CMake cache entries_, will persist in their values until they are explicitly cleared. So, if you set a variable and then run another CMake command _without_ that variable specified, the variable will still be set. Variables must be explicitly unset, or the `builds/` directory cleaned, in order to be cleared.

| Option | Description | Default |
| ------ | ----------- | ------- |
| `CMAKE_BUILD_TYPE`<br/>(or just [`--config`](https://cmake.org/cmake/help/latest/manual/cmake.1.html#cmdoption-cmake-build-config), without the `-D` syntax) | <p>`Debug` builds are generally larger, slower and contain extra correctness checks that will validate game data and interrupt gameplay when problems are detected.</p><p>`Release` builds are optimized for size and speed and do not include debugging information, which makes it harder to find problems.</p> | `Debug` |
| `BUILD_EDITOR` | _(Windows-only)_ Build internal editor. | `OFF` |
| `BUILD_TESTING` | Enable testing. Requires GTest. | `OFF` |
| `ENABLE_LOGGER` | Enable logging to the terminal. | `OFF` |
| `ENABLE_MEM_RTL` | Enable Real-time library memory management functions (disable to verbose memory allocations). | `ON` |
| `FORCE_COLORED_OUTPUT` | Always produce ANSI-colored compiler warnings/errors (GCC/Clang only; esp. useful with Ninja). | `OFF` |
| `FORCE_PORTABLE_INSTALL` | Install all files into local directory defined by `CMAKE_INSTALL_PREFIX`. | `ON` |
| `USE_VCPKG` | Explicitly control whether or not to use vcpkg for dependency resolution. `ON` requires the environment variable `VCPKG_ROOT` to be set. | Determined by the existence of `VCPKG_ROOT` in the environment: If it exists, vcpkg is used. |

## Contributing
Anyone can contribute! We have an active Discord presence at [Descent Developer Network](https://discord.gg/GNy5CUQ). If you are interested in maintaining the project on a regular basis, please contact Kevin Bentley.