# engine

Small graphics engine.

## Binaries

-   windows: [engine-win.zip](https://vimene.fr/engine-win.zip)
-   linux: [engine-linux.tar.xz](https://vimene.fr/engine-linux.tar.xz)

## Usage

    :::text
    Usage: ./engine [-htg] [--help] [--term] [--graphical]
      -h, --help        show usage (this)
      -t, --term        terminal mode
      -g, --graphical   graphical mode (default)

You can press `o` to switch between the hardware and the software renderer. You can close the window
by pressing `escape`.

## Building

### Getting the source code

The repository contains autotools files without generated ones. If you don't want to run autotools,
you can download the source code here:
[engine-source.tar.xz](https://vimene.fr/engine-source.tar.xz)

Otherwise, you need to install autotools and run the following commands:

    :::sh
    git clone https://git.vimene.fr/engine.git
    cd engine
    ./bootstrap.sh

### Building for linux

#### Dependencies

Required:

-   `g++` (GNU C++ Compiler) supporting at least C++23
-   `glfw`
-   Vulkan headers and `libvulkan.so`
-   `slangc` compiler

Optional:

-   ncurses (for terminal rendering)

#### Actually building

While inside the directory containing all files:

    :::sh
    mkdir build
    cd build
    ../configure --prefix="$(realpath .)" --with-ncurses
    make
    make install

You should now have an executable in `./share/engine` called `engine`.

The configure script searches for libraries with `pkgconf` but can be overwriten with environment
variables passed to `configure`. You can also set `PKG_CONFIG_PATH` if you have appropriate
`pkgconf` files different from system ones.

More precisely, if `glfw` headers or `libglfw3.so` cannot be found, or if you want to use ones other
than the ones given by `pkgconf`, you have to set both `GLFW3_CFLAGS` and `GLFW3_LIBS` in the
`configure` command line, like so:

    :::sh
    ../configure --prefix="$(realpath .)" --with-ncurses \
      GLFW3_CFLAGS=-I/path/to/glfw/headers \
      GLFW3_LIBS=-L/path/to/glfw/libs -lglfw3

If Vulkan headers or libvulkan.so cannot be found, or if for example you want to use ones given by
LunarG's Vulkan SDK, you have to set both `VULKAN_CFLAGS` and `VULKAN_LIBS` in the `configure`
command line, like so:

    :::sh
    ../configure --prefix="$(realpath .)" --with-ncurses \
      VULKAN_CFLAGS=-I/path/to/vulkan/headers \
      VULKAN_LIBS=-L/path/to/vulkan/libs -lvulkan

If `slangc` cannot be found in path, or if you also want to use the one given by LunarG's Vulkan
SDK, you have to set `SLANGC` to the path of the executable, like so:

    :::sh
    ../configure --prefix="$(realpath .)" --with-ncurses \
      SLANGC=/path/to/slangc

If ncurses headers or libncurses.so cannot be found, or if you want to use ones other than the ones
given by `pkgconf`, you have to set both `NCURSES_CFLAGS` and `NCURSES_LIBS` in the `configure`
command line, like so:

    :::sh
    ../configure --prefix="$(realpath .)" --with-ncurses \
      NCURSES_CFLAGS=-I/path/to/ncurses/headers \
      NCURSES_LIBS=-L/path/to/ncurses/libs -lvulkan

You can, of course, combine as many as you like:

    :::sh
    ../configure --prefix="$(realpath .)" --with-ncurses \
      GLFW3_CFLAGS=-I/path/to/glfw/headers \
      GLFW3_LIBS=-L/path/to/glfw/libs -lglfw3 \
      VULKAN_CFLAGS=-I/path/to/vulkan/headers \
      VULKAN_LIBS=-L/path/to/vulkan/libs -lvulkan \
      SLANGC=/path/to/slangc \
      NCURSES_CFLAGS=-I/path/to/ncurses/headers \
      NCURSES_LIBS=-L/path/to/ncurses/libs -lvulkan

You can also set `PKG_CONFIG_PATH` if you have appropriate `pkgconf` files, different from system
ones, for some or all dependencies. You can find all configure options with `../configure --help`.

### Building for windows from linux

#### Dependencies

Required:

-   MinGW with `g++` (GNU C++ Compiler) supporting at least C++23
-   `glfw` for windows
-   Vulkan headers and `vulkan-1.dll`
-   `slangc` compiler

*Note: ncurses is not supported on windows.*

#### Actually building

While inside the directory containing all files:

    :::sh
    mkdir build
    cd build
    ../configure --prefix="$(realpath .)" \
      --build x86_64-pc-linux-gnu \
      --host x86_64-w64-mingw32
    make
    make install

The `--build` option must be the one of your system, which for example would not be x86\_64 if you
are building on a system with an ARM CPU.

You should now have an executable in `./share/engine` called `engine.exe`.

The configure script searches for libraries with `pkgconf` but can be overwriten with environment
variables passed to `configure`.

More precisely, if `glfw` headers or `glfw3.a` cannot be found, or if you want to use ones other
than the ones given by `pkgconf`, you have to set both `GLFW3_CFLAGS` and `GLFW3_LIBS` in the
`configure` command line, like so:

    :::sh
    ../configure --prefix="$(realpath .)" \
      --build x86_64-pc-linux-gnu \
      --host x86_64-w64-mingw32 \
      GLFW3_CFLAGS=-I/path/to/glfw/headers \
      GLFW3_LIBS=-L/path/to/glfw/libs -lglfw3

If Vulkan headers or vulkan-1.dll cannot be found, or if for example you want to use ones given by
LunarG's Vulkan SDK, you have to set both `VULKAN_CFLAGS` and `VULKAN_LIBS` in the `configure`
command line, like so:

    :::sh
    ../configure --prefix="$(realpath .)" \
      --build x86_64-pc-linux-gnu \
      --host x86_64-w64-mingw32 \
      VULKAN_CFLAGS=-I/path/to/vulkan/headers \
      VULKAN_LIBS=-L/path/to/vulkan/libs -lvulkan-1

If `slangc` cannot be found in path, or if you also want to use the one given by LunarG's Vulkan
SDK, you have to set `SLANGC` to the path of the executable, like so:

    :::sh
    ../configure --prefix="$(realpath .)" \
      --build x86_64-pc-linux-gnu \
      --host x86_64-w64-mingw32 \
      SLANGC=/path/to/slangc

You can, of course, combine as many as you like:

    :::sh
    ../configure --prefix="$(realpath .)" \
      --build x86_64-pc-linux-gnu \
      --host x86_64-w64-mingw32 \
      GLFW3_CFLAGS=-I/path/to/glfw/headers \
      GLFW3_LIBS=-L/path/to/glfw/libs -lglfw3 \
      VULKAN_CFLAGS=-I/path/to/vulkan/headers \
      VULKAN_LIBS=-L/path/to/vulkan/libs -lvulkan-1 \
      SLANGC=/path/to/slangc

You can also set `PKG_CONFIG_PATH` if you have appropriate `pkgconf` files, different from system
ones, for some or all dependencies. You can find all configure options with `../configure --help`.

To be able to run it from windows, you will need to provide `libstdc++-6.dll` and
`libgcc_s_seh-1.dll` alongside the executable.

*Note: glfw is statically built with the executable, therefore you don't need to provide it.*