Updated docs for gmc.config

docs/gmc/reference/gmc-cfg.md

@@ -6,6 +6,10 @@ title: GMC Configuration File
 
 The *gmc.cfg* configuration file in your Godot project root contains options for customizing GMC behavior. It uses INI formatting and its supported features are documented here.
 
+### Local Overrides
+
+Any configuration options in *gmc.cfg* can be overridden with a local file *gmc.local.cfg* in the Godot User Data folder. This allows you to commit the primary configuration to version control while still having platform-specific configurations (e.g. MPF executable path and logging levels) on each machine.
+
 ## \[filter\]
 
 The filter section configures a shader for the GMC window, applying effects universally to all displays.
@@ -24,7 +28,53 @@ Full documentation can be found on the [Window Effects Filters guide](../guides/
 
 ## \[gmc\]
 
-The gmc section overrides the core GMC scripts for advanced customization of the GMC itself. Only for advanced users.
+The GMC section contains settings related to the GMC itself, including logging.
+
+### `content_root`
+
+Single value, type `String`. Default `None`
+
+In addition to mode subfolders, GMC will look for slides, widgets, and sounds in those respective folders in the Godot project root (e.g. */sounds*, */slides*).
+
+You may wish to consolidate your content in a common subfolder rather than the project root. You can define a content root folder here, which will be prepended to the individual content folders (e.g. */content/sounds*, */content/slides*).
+
+### `exit_on_esc`
+
+If true, the GMC process will exit if the Escape key is pressed during runtime.
+
+### Logging
+
+Logging can be specified in the `\[gmc\]` section with the following components:
+
+  * `logging_global` for all components not otherwise specified
+  * `logging_game` for the MPF.game script, holding all game-related data
+  * `logging_server` for the BCP Server, with all comms between GMC and MPF
+  * `logging_process` for the MPF.process manager, running the MPF subprocess
+  * `logging_media` for the media controller (slides, widgets, and sound)
+  * `logging_sound_player` for the sound player specifically
+
+``` ini
+
+    [gmc]
+    logging_global=20
+    logging_sound_player=10
+```
+
+Each core component's log level can be adjusted here, and any unspecified components will use the global log level. The log levels are stored as integers with the following values:
+
+  * USE_GLOBAL_LEVEL: 0
+  * VERBOSE: 1
+  * DEBUG: 10
+  * INFO: 20
+  * LOG: 25
+  * WARNING: 30
+  * ERROR: 40
+
+By default, debug/editor builds will run at INFO while production builds run at LOG.
+
+### Script Overrides (Advanced)
+
+The gmc section can override the core GMC scripts for advanced customization of the GMC itself. Only for advanced users.
 
 Full documentation can be found on the [Advanced Custom Code guide](../guides/advanced-custom-code.md).
 
@@ -34,6 +84,7 @@ Full documentation can be found on the [Advanced Custom Code guide](../guides/ad
     GMCServer="custom_code/my_custom_bcp.gd"
 ```
 
+
 ## \[keyboard\]
 
 The keyboard section maps key inputs to switches and events for simulating MPF behavior during development.
@@ -51,23 +102,60 @@ Full documentation can be found on the [Keyboard Setup guide](../keyboard.md).
     m=["event", "start_mode_multiball"]
 ```
 
-## \[settings\]
+## \[mpf\]
 
-The settings section is where general customization options are defined.
+The MPF section defines parameters for the GMC-spawned MPF process. The full command for the process will be assembled thus:
 
-``` ini
+``` console
 
-    [settings]
-    content_root="content"
+    <executable_path> <executable_args> <machine_path> <machine_args>
 ```
 
-### `content_root`
+### `executable_args`
 
 Single value, type `String`. Default `None`
 
-In addition to mode subfolders, GMC will look for slides, widgets, and sounds in those respective folders in the Godot project root (e.g. */sounds*, */slides*).
+Additional arguments to pass to the executable. For example, if the executable is a Python interpreter then the executable args may be `-m mpf` to load the MPF module.
+
+Note that MPF-specific command line args should *not* go here, even if the executable is an MPF binary.
+
+
+### `executable_path`
+
+Single value, type `String`. Default `None`.
+
+The path to the executable entry point for the MPF process. It can be a Python interpreter, a symlink to a virtual environment mpf executable, or a precompiled MPF binary.
+
+### `machine_path`
+
+Single value, type `String`. Defaults to the GMC project folder.
+
+The path of the MPF machine folder, i.e. the root folder containing the */config* and */modes* folders for your project. If not specified, the GMC project folder will be used.
+
+### `mpf_args`
+
+Single value, type `String`. Default `None`
+
+Additional arguments to pass to MPF after the machine path. Common values may include `-x` for virtual mode, `-vV` for verbose logging, or `-P` for production mode. Note that values defined specifically for virtal or verbose (see below) will supersede.
+
+### `spawn_mpf`
+
+Single value, type `bool`. Default `false`.
+
+If true, GMC will spawn a subprocess to run MPF when the main project is run.
+
+### `virtual`
+
+Single value, type `bool`. Default `false`.
+
+If true, the MPF process will spawn in virtual mode (i.e. `-x` will be appended to the `mpf_args`).
+
+### `verbose`
+
+Single value, type `bool`. Default `false`.
+
+If true, the MPF process will have verbose logging (i.e. `-vV` will be appended to the `mpf_args`).
 
-You may wish to consolidate your content in a common subfolder rather than the project root. You can define a content root folder here, which will be prepended to the individual content folders (e.g. */content/sounds*, */content/slides*).
 
 ## \[sound_system\]