Added basic usage information to the readme.

README.md

@@ -1,3 +1,218 @@
 # PMLPP Sample Project
 
 Sample project / testbed for the https://github.com/Relintai/pmlpp pandemonium engine module.
+
+## Opening the project
+
+Compile the engine itself, and then open the project inside the `game` folder.
+
+After the initial import it might need an editor restart, however everything should work after that.
+
+## Compiling
+
+First make sure, that you have everything installed to be able to compile the engine. 
+See the [official docs](https://github.com/Relintai/pandemonium_engine_docs/tree/master/development/compiling) or the [official Godot docs](https://docs.godotengine.org/en/3.4/development/compiling/index.html) for more info.
+
+My setup/compile script uses the same tools, so you don't need to install anything else.
+
+Even though the project doesn't use godot anymore, their docs are still sufficient.
+
+Now let's clone this repository:
+
+``` git clone https://github.com/Relintai/pmlpp_sample ```
+
+cd into the new folder:
+
+``` cd pmlpp_sample ```
+
+Now let's run the project's setup script, by calling scons without arguments.
+
+``` scons ```
+
+This will clone and setup the engine, and all of the required modules into a new `pandemonium_engine` folder inside the project, using http.
+
+(If you want to use the github's ssh links append `repository_type=ssh` like ``` scons repository_type=ssh ```)
+
+Once it is done you can compile the engine.
+
+To build the editor on windows with 4 threads run the following command:
+
+``` scons bew -j4 ```
+
+To build the editor on linux with 4 threads run the following command:
+
+``` scons bel -j4 ```
+
+I call this feature of the setup script build words. [See](#build-words).
+
+Once the build finishes you can find the editor executable inside the `./engine/bin/` folder.
+
+For convenience there is a provided `editor.sh`, or `editor.bat` for running it from the project's folder.
+These will create a copy, so you can even compile while the editor is running.
+
+Alternatively if you don't want to use build words, you can also just go into the engine folder:
+
+``` cd pandemonium_engine ```
+
+And compile godot as per the [official docs](https://docs.godotengine.org/en/latest/development/compiling/index.html).
+
+### Build words
+
+The project's setup script contains support for "build words". These can be used from the root of this project.
+
+For example to build the editor for windows with 4 threads you can use:
+
+``` scons bew -j4 ```
+
+The first argument must start with b (build), then it needs to be followed by a few abbreviations (the order does not matters)
+
+The rest of the arguments will be passed directly to godot's scons script.
+
+#### Editor
+
+Append `e` to build with `tools=yes` a.k.a. the editor.
+
+``` scons bew -j4 ```
+
+if you omit `e`, the system will build the export template for you. For example:
+
+``` scons bw -j4 ```
+
+This will be the `release_debug` windows export template.
+
+#### Platform abbreviations
+
+`l`: linux \
+`w`: windows \
+`a`: android \
+`j`: Javascript \
+`i`: iphone (Not yet finished, use `build_ios.sh`, and `build_ios_release.sh`) \
+Mac OSX: Not yet finished, use `build_osx.sh`
+
+#### Target abbreviations
+
+By default the system builds in release_debug.
+
+Append `d` for debug, or `r` for release.
+
+``` scons bewd -j4 ```
+
+build editor windows debug
+
+``` scons bwr -j4 ```
+
+build windows release (this will build the windows release export template)
+
+#### Shared modules
+
+Note: This only works on linux!
+
+append `s` to the build string. 
+
+Optionally you can also make the build system only build a target module, by appending one of these:
+
+`E`: Entity Spell System \
+`T`: Texture Packer \
+`V`: Voxelman \
+`W`: World Generator \
+`P`: Procedural Animations
+
+Example:
+
+``` scons belsE -j4 ```
+
+build editor linux shared (Entity Spell System) with 4 threads
+
+Note: to easily run the editor you can use the `editor.sh` or `editor.bat` in the root of the project.
+
+#### Other
+
+Append `v` to pass the `vsproj=yes` parameter to the build script. This will generate Visual Studio project files.\
+Append `c` to pass the `compiledb=yes` parameter to the build script. This is a new feature in 3.x to have this disabled by default to lessen compile times.
+
+#### Postfixes
+
+There are a few postfixes for the build words. These are more complex options. You have to append them to your build word with an underscore.
+
+You can use as many as you want.
+
+For example:
+
+``` scons bel_slim_latomic -j4 ```
+
+##### slim
+
+With this postfix you can build a slimmed down version of the engine. This disables quite a few unneeded modules.
+
+``` scons bel_slim -j4 ```
+
+##### latomic
+
+If you get linker errors while building the game/editor about undefined referenced with atomic related functions you can use this postfix.
+It will add the ` -latomic ` command line switch to the linker flags.
+
+I ran into this issue while building on a raspberry pi 4 with the x11 platform. It might be related to the recent reworks to threading.
+
+``` scons bel_latomic -j4 ```
+
+##### strip
+
+Appends `debug_symbols=no` to the build command, which will strip the resulting binary from debug symbols.
+
+``` scons bel_strip -j4 ```
+
+##### threads
+
+Appends `threads_enabled=yes` to the build command. Useful for building the editor for html.
+
+``` scons bej_threads -j4 ```
+
+#### Scons cache, and sdk locations
+
+In order to use scons cache and to tell the build system where some of the required sdks are located you usually 
+have to use environment variables. Most of the time you might just want to add them globally, 
+howewer this is sometimes unfeasible (e.g. you don't have administrator access, or you just want to have
+multiple sdk versions installed).
+
+In order to solve this a build config file was added.
+
+If you want to use the config simply rename the provided `build.config.example` to `build.config`, and customize 
+the settings inside.
+
+### Manual Setup
+
+If you you don't want to use the setup script (or just want to know what it actually does), 
+this section will explain how to set everything up manually.
+
+First clone the engine:
+
+``` git clone https://github.com/Relintai/pandemonium_engine ```
+
+Now if you look at the [HEADS file](https://github.com/Relintai/broken_seals/blob/master/HEADS).
+
+It contains the commit hashes for that particular revision for every module and the engine.
+The engine now contains all the modules, so at the moment only worry about the engine's commit hash.
+
+You need to go and checkout the proper commit for it.
+
+Now you can go ahead and compile the engine normally.
+
+## Pulling upstream changes
+
+First pull the changes by calling
+
+``` git pull orgin master ```
+
+Then just run `scons`, to will update the modules.
+
+## Upgrading the modules
+
+Note: this is how to update the HEADS file. Normally you don't need to do this.
+
+If you want to update the modules, and the engine to the latest, you can use (`action=update`):
+
+``` scons a=u ``` 
+
+You can also update different targets: `all`, `engine`, `modules`, `all_addons`, `addons`, `third_party_addons`
+
+For example to update the engine to the latest: ``` scons a=u target=engine ```