![](https://i.imgur.com/7mECYKU.gif)
![](https://i.imgur.com/ABcJqB5.gif)
+## Dependencies
+
+- [gcc]
+- [cmake]
+- [libsdl2-dev]
+- [libsdl2-mixer-dev]
+- [xqilla]
+- [inotify-tools]
+
+### Ubuntu
+
+```console
+$ sudo apt-get install gcc cmake libsdl2-dev libsdl2-mixer-dev xqilla inotify-tools
+```
+### NixOS
+
+For [NixOS] we have a development environment defined in [default.nix]
+with all of the required dependencies. You can enter the environment
+`nix-shell` command:
+
+```console
+$ nix-shell
+```
+
+### Windows
+
+See [Build on Windows][build-on-windows] section.
+
## Quick Start
```console
-$ nix-shell # Only on NixOS
$ mkdir build
$ cd build/
$ cmake ..
$ make
-$ ./nothing <level-file>
+$ ./nothing ../levels/level-01.txt
$ ./nothing_test
```
+## Controls
+
+### Game
+
+#### Keyboard
+
+| Key | Action |
+|---------|-------------------------------------------------------------|
+| `d` | Move to the right |
+| `a` | Move to the left |
+| `SPACE` | Jump |
+| `c` | Open debug console |
+| `r` | Reload the current level including the Player's position |
+| `q` | Reload the current level preserving the Player's position |
+| `p` | Toggle game pause |
+| `l` | Toggle transparency on objects. Useful for debugging levels |
+
+#### Gamepad
+
+| Button | Action |
+|--------------|------------------------|
+| `Left Stick` | Movement of the Player |
+| `1` | Jump |
+
+### Consolé
+
+| Key | Action |
+|-----------|--------------------------|
+| `ESC` | Exit console |
+| `Enter` | Evaluate the expression |
+| `Up/Down` | Traverse console history |
+
+## Editing Levels
+
+Generally creating a level looks like:
+
+```
+SVG File -> Custom Level File -> Game
+```
+
+To convert SVG to the level file install [xqilla] and run
+[svg2rects.xqe] script:
+
+```console
+$ xqilla ./devtools/svg2rects.xqe -i <svg-file> -o <level-file>
+```
+
+All of the levels reside in the [./levels/] folder. Use
+[./levels/Makefile] to automatically rebuild all levels.
+
+### Level Editing Workflow
+
+1. `$ inkscape ./levels/level.svg &`
+2. `$ ./build/nothing ./levels/level.txt &`
+3. `$ cd ./levels/`
+4. `$ make watch`
+5. Edit Level in Inkscape and Save
+6. Switch to the Game and reload level by pressing Q
+7. Go to 5
+
+### Objects Reference
+
+#### SVG rect node
+
+| Regex of id | Description |
+|--------------|-------------------------------------------------------------------------------------------------------------------|
+| `player` | Defines the **position** of the Player. **Size is ignored**. |
+| `rect.*` | Defines the **size** and **position** of an impenetrable platform block |
+| `box.*` | Defines the **size** and **position** of a rigid box that obeys the physics of the game |
+| `region(.*)` | Defines the **size** and **position** of a region that hides the Goals. `\1` defines the id of the Goal to hide. |
+| `goal(.*)` | Defines the **position** of the goal. **Size is ignored**. `\1` defines the id of the region that hides the goal. |
+| `lava.*` | Defines the **position** and **size** of a lava block. |
+| `background` | Defines the **color** of the background. **Position and size are ignored**. |
+| `backrect.*` | Defines the **size** and **position** of a solid block in the background. |
+
+#### SVG text node
+
+| Regex of id | Description |
+|-------------|----------------------------------------------------------------------------|
+| `label.*` | Defines **position** and **text** of a in-game label. **Size is ignored**. |
+
## Build on Windows
You need to install [conan][] and [Visual Studio 2017][visual-studio].
[conan]: https://www.conan.io/
[conan-sdl2]: https://bintray.com/conan/conan-transit/SDL2%3Alasote/2.0.5%3Astable
[visual-studio]: https://www.visualstudio.com/
+[svg2rects.xqe]: ./devtools/svg2rects.xqe
+[./levels/]: ./levels/
+[./levels/Makefile]: ./levels/Makefile
+[gcc]: https://gcc.gnu.org/
+[cmake]: https://cmake.org/
+[libsdl2-dev]: https://www.libsdl.org/
+[libsdl2-mixer-dev]: https://www.libsdl.org/projects/SDL_mixer/
+[xqilla]: http://xqilla.sourceforge.net/HomePage
+[NixOS]: https://nixos.org/
+[default.nix]: ./default.nix
+[build-on-windows]: #build-on-windows
+[inotify-tools]: https://github.com/rvoicilas/inotify-tools