Document the extension and improve exposed API

This also adds some minor fixes and validity
checks where appropriate. Some bigger changes
have been identified which will come in follow-up
commits.

Closes #3.

.gitignore

@@ -4,6 +4,7 @@ bin/*
 !bin/*.gdextension
 example/bin/
 example/export/
+src/**/*.gen.cpp
 
 ### Godot project development ###
 

README.md

@@ -36,14 +36,14 @@ If you need the most recent fixes, you can also download the _[latest unstable](
 4. Restart the editor, and start using the synth!
 
 > [!TIP]
-> You can type "SiON" in the search bar of the editor's built-in help to find available classes. Complete class and method descriptions are coming once _Godot 4.3_ reaches a more stable state (the ability to create class reference has been added very recently).
+> You can type "SiON" in the search bar of the editor's built-in help to find available classes.
 
 ## Usage
 
 First, you need to create a `SiONDriver` instance and add it to the scene tree. **Only one driver** can exist at the same time. (Some internal global objects are stateful and having multiple drivers can lead to conflicts.)
 
 ```gdscript
-var driver := SiONDriver.new()
+var driver := SiONDriver.create()
 add_child(driver)
 ```
 

SConstruct

@@ -45,8 +45,16 @@ def _register_library(name, path):
     env.Append(CPPPATH=["#{}/".format(path)])
     env.library_sources = []
 
+    # Recursively iterate through sub configs in source folders and perform steps defined there.
     SConscript("{}/SCsub".format(path))
 
+    # Add documentation to the list of sources as well.
+    if env["target"] in ["editor", "template_debug"]:
+        doc_data = env.GodotCPPDocData("{}/gen/doc_data.gen.cpp".format(path), source=Glob("doc_classes/*.xml"))
+        env.library_sources.append(doc_data)
+
+    # Finally, register the library to be built.
+
     if env["platform"] == "macos":
         library = env.SharedLibrary(
             "{}/{}.{}.{}.framework/{}.{}.{}".format(

doc_classes/BeatsPerMinute.xml

@@ -0,0 +1,11 @@
+<?xml version="1.0" encoding="UTF-8" ?>
+<class name="BeatsPerMinute" inherits="RefCounted" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="https://raw.githubusercontent.com/godotengine/godot/master/doc/class.xsd">
+	<brief_description>
+		Helper class for manipulating BPM data.
+	</brief_description>
+	<description>
+		[b]Warning:[/b] This class currently has no intended use in the API. If you need this class and its unexposed methods in your project, please [b][url=https://github.com/YuriSizov/gdsion/issues]create a feature request with your use case[/url][/b]!
+	</description>
+	<tutorials>
+	</tutorials>
+</class>

doc_classes/MMLData.xml

@@ -0,0 +1,11 @@
+<?xml version="1.0" encoding="UTF-8" ?>
+<class name="MMLData" inherits="RefCounted" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="https://raw.githubusercontent.com/godotengine/godot/master/doc/class.xsd">
+	<brief_description>
+		Container for the state data of the internal processing. Base class of [SiMMLData] and [SiONData].
+	</brief_description>
+	<description>
+		[b]Warning:[/b] This class currently has no intended use in the API. If you need this class and its unexposed methods in your project, please [b][url=https://github.com/YuriSizov/gdsion/issues]create a feature request with your use case[/url][/b]!
+	</description>
+	<tutorials>
+	</tutorials>
+</class>

doc_classes/MMLEvent.xml

@@ -0,0 +1,11 @@
+<?xml version="1.0" encoding="UTF-8" ?>
+<class name="MMLEvent" inherits="Object" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="https://raw.githubusercontent.com/godotengine/godot/master/doc/class.xsd">
+	<brief_description>
+		Container for event information of the internal sequencer.
+	</brief_description>
+	<description>
+		[b]Warning:[/b] This class currently has no intended use in the API. If you need this class and its unexposed methods in your project, please [b][url=https://github.com/YuriSizov/gdsion/issues]create a feature request with your use case[/url][/b]!
+	</description>
+	<tutorials>
+	</tutorials>
+</class>

doc_classes/MMLSequencer.xml

@@ -0,0 +1,11 @@
+<?xml version="1.0" encoding="UTF-8" ?>
+<class name="MMLSequencer" inherits="Object" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="https://raw.githubusercontent.com/godotengine/godot/master/doc/class.xsd">
+	<brief_description>
+		Internal sequencer. Base class of [SiMMLSequencer].
+	</brief_description>
+	<description>
+		[b]Warning:[/b] This class currently has no intended use in the API. If you need this class and its unexposed methods in your project, please [b][url=https://github.com/YuriSizov/gdsion/issues]create a feature request with your use case[/url][/b]!
+	</description>
+	<tutorials>
+	</tutorials>
+</class>

doc_classes/MMLSystemCommand.xml

@@ -0,0 +1,11 @@
+<?xml version="1.0" encoding="UTF-8" ?>
+<class name="MMLSystemCommand" inherits="RefCounted" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="https://raw.githubusercontent.com/godotengine/godot/master/doc/class.xsd">
+	<brief_description>
+		Container for system commands of the internal sequencer.
+	</brief_description>
+	<description>
+		[b]Warning:[/b] This class currently has no intended use in the API. If you need this class and its unexposed methods in your project, please [b][url=https://github.com/YuriSizov/gdsion/issues]create a feature request with your use case[/url][/b]!
+	</description>
+	<tutorials>
+	</tutorials>
+</class>

doc_classes/SiControllableFilterBase.xml

@@ -0,0 +1,30 @@
+<?xml version="1.0" encoding="UTF-8" ?>
+<class name="SiControllableFilterBase" inherits="SiEffectBase" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="https://raw.githubusercontent.com/godotengine/godot/master/doc/class.xsd">
+	<brief_description>
+		Base class for all controllable filters.
+	</brief_description>
+	<description>
+		Controllable filters allow to set their parameters directly without preprocessing.
+	</description>
+	<tutorials>
+	</tutorials>
+	<methods>
+		<method name="set_params">
+			<return type="void" />
+			<param index="0" name="cutoff" type="int" default="255" />
+			<param index="1" name="resonance" type="int" default="255" />
+			<param index="2" name="fps" type="float" default="20" />
+			<description>
+				Sets filter parameters.
+			</description>
+		</method>
+		<method name="set_params_manually">
+			<return type="void" />
+			<param index="0" name="cutoff" type="float" />
+			<param index="1" name="resonance" type="float" />
+			<description>
+				Sets filter parameters directly.
+			</description>
+		</method>
+	</methods>
+</class>

doc_classes/SiControllableFilterHighPass.xml

@@ -0,0 +1,11 @@
+<?xml version="1.0" encoding="UTF-8" ?>
+<class name="SiControllableFilterHighPass" inherits="SiControllableFilterBase" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="https://raw.githubusercontent.com/godotengine/godot/master/doc/class.xsd">
+	<brief_description>
+		Controllable version of the high pass filter.
+	</brief_description>
+	<description>
+		See also [SiFilterHighPass].
+	</description>
+	<tutorials>
+	</tutorials>
+</class>

doc_classes/SiControllableFilterLowPass.xml

@@ -0,0 +1,11 @@
+<?xml version="1.0" encoding="UTF-8" ?>
+<class name="SiControllableFilterLowPass" inherits="SiControllableFilterBase" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="https://raw.githubusercontent.com/godotengine/godot/master/doc/class.xsd">
+	<brief_description>
+		Controllable version of the low pass filter.
+	</brief_description>
+	<description>
+		See also [SiFilterLowPass].
+	</description>
+	<tutorials>
+	</tutorials>
+</class>

doc_classes/SiEffectAutopan.xml

@@ -0,0 +1,20 @@
+<?xml version="1.0" encoding="UTF-8" ?>
+<class name="SiEffectAutopan" inherits="SiEffectBase" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="https://raw.githubusercontent.com/godotengine/godot/master/doc/class.xsd">
+	<brief_description>
+		Automatic panning effect.
+	</brief_description>
+	<description>
+	</description>
+	<tutorials>
+	</tutorials>
+	<methods>
+		<method name="set_params">
+			<return type="void" />
+			<param index="0" name="frequency" type="float" default="1" />
+			<param index="1" name="stereo_width" type="float" default="1" />
+			<description>
+				Sets effect parameters.
+			</description>
+		</method>
+	</methods>
+</class>

doc_classes/SiEffectBase.xml

@@ -0,0 +1,10 @@
+<?xml version="1.0" encoding="UTF-8" ?>
+<class name="SiEffectBase" inherits="RefCounted" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="https://raw.githubusercontent.com/godotengine/godot/master/doc/class.xsd">
+	<brief_description>
+		Base class for all effects and filters.
+	</brief_description>
+	<description>
+	</description>
+	<tutorials>
+	</tutorials>
+</class>

doc_classes/SiEffectComposite.xml

@@ -0,0 +1,31 @@
+<?xml version="1.0" encoding="UTF-8" ?>
+<class name="SiEffectComposite" inherits="SiEffectBase" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="https://raw.githubusercontent.com/godotengine/godot/master/doc/class.xsd">
+	<brief_description>
+		Composite effect built from other effects and filters.
+	</brief_description>
+	<description>
+		A composite effect can have up to [code]8[/code] slots, each containing a chain of effects. Slot at the index [code]0[/code] has a special meaning as the master slot.
+		When processing, first secondary slots are calculated and mixed, and then the master slot is calculated and mixed.
+	</description>
+	<tutorials>
+	</tutorials>
+	<methods>
+		<method name="set_slot_effects">
+			<return type="void" />
+			<param index="0" name="slot" type="int" />
+			<param index="1" name="effects" type="SiEffectBase[]" />
+			<description>
+				Sets a collection of effects for the given slot, overriding existing effects.
+			</description>
+		</method>
+		<method name="set_slot_levels">
+			<return type="void" />
+			<param index="0" name="slot" type="int" />
+			<param index="1" name="send_level" type="float" />
+			<param index="2" name="mix_level" type="float" />
+			<description>
+				Sets send and mix levels for the given slot.
+			</description>
+		</method>
+	</methods>
+</class>

doc_classes/SiEffectCompressor.xml

@@ -0,0 +1,24 @@
+<?xml version="1.0" encoding="UTF-8" ?>
+<class name="SiEffectCompressor" inherits="SiEffectBase" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="https://raw.githubusercontent.com/godotengine/godot/master/doc/class.xsd">
+	<brief_description>
+		Compressor effect.
+	</brief_description>
+	<description>
+	</description>
+	<tutorials>
+	</tutorials>
+	<methods>
+		<method name="set_params">
+			<return type="void" />
+			<param index="0" name="threshold" type="float" default="0.7" />
+			<param index="1" name="window_time" type="float" default="50" />
+			<param index="2" name="attack_time" type="float" default="20" />
+			<param index="3" name="release_time" type="float" default="20" />
+			<param index="4" name="max_gain" type="float" default="-6" />
+			<param index="5" name="mixing_level" type="float" default="0.5" />
+			<description>
+				Sets effect parameters.
+			</description>
+		</method>
+	</methods>
+</class>

doc_classes/SiEffectDistortion.xml

@@ -0,0 +1,22 @@
+<?xml version="1.0" encoding="UTF-8" ?>
+<class name="SiEffectDistortion" inherits="SiEffectBase" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="https://raw.githubusercontent.com/godotengine/godot/master/doc/class.xsd">
+	<brief_description>
+		Distortion effect.
+	</brief_description>
+	<description>
+	</description>
+	<tutorials>
+	</tutorials>
+	<methods>
+		<method name="set_params">
+			<return type="void" />
+			<param index="0" name="pre_gain" type="float" default="-60" />
+			<param index="1" name="post_gain" type="float" default="18" />
+			<param index="2" name="lpf_frequency" type="float" default="2400" />
+			<param index="3" name="lpf_slope" type="float" default="1" />
+			<description>
+				Sets effect parameters.
+			</description>
+		</method>
+	</methods>
+</class>

doc_classes/SiEffectDownsampler.xml

@@ -0,0 +1,21 @@
+<?xml version="1.0" encoding="UTF-8" ?>
+<class name="SiEffectDownsampler" inherits="SiEffectBase" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="https://raw.githubusercontent.com/godotengine/godot/master/doc/class.xsd">
+	<brief_description>
+		Downsampler effect.
+	</brief_description>
+	<description>
+	</description>
+	<tutorials>
+	</tutorials>
+	<methods>
+		<method name="set_params">
+			<return type="void" />
+			<param index="0" name="frequency_shift" type="int" default="0" />
+			<param index="1" name="bitrate" type="int" default="16" />
+			<param index="2" name="channel_count" type="int" default="2" />
+			<description>
+				Sets effect parameters.
+			</description>
+		</method>
+	</methods>
+</class>

doc_classes/SiEffectEqualizer.xml

@@ -0,0 +1,23 @@
+<?xml version="1.0" encoding="UTF-8" ?>
+<class name="SiEffectEqualizer" inherits="SiEffectBase" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="https://raw.githubusercontent.com/godotengine/godot/master/doc/class.xsd">
+	<brief_description>
+		Equalizer effect.
+	</brief_description>
+	<description>
+	</description>
+	<tutorials>
+	</tutorials>
+	<methods>
+		<method name="set_params">
+			<return type="void" />
+			<param index="0" name="low_gain" type="float" default="1" />
+			<param index="1" name="mid_gain" type="float" default="1" />
+			<param index="2" name="high_gain" type="float" default="1" />
+			<param index="3" name="low_frequency" type="float" default="880" />
+			<param index="4" name="high_frequency" type="float" default="5000" />
+			<description>
+				Sets effect parameters.
+			</description>
+		</method>
+	</methods>
+</class>

doc_classes/SiEffectSpeakerSimulator.xml

@@ -0,0 +1,19 @@
+<?xml version="1.0" encoding="UTF-8" ?>
+<class name="SiEffectSpeakerSimulator" inherits="SiEffectBase" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="https://raw.githubusercontent.com/godotengine/godot/master/doc/class.xsd">
+	<brief_description>
+		Piezoelectric speaker simulator effect.
+	</brief_description>
+	<description>
+	</description>
+	<tutorials>
+	</tutorials>
+	<methods>
+		<method name="set_params">
+			<return type="void" />
+			<param index="0" name="hardness" type="float" default="0.2" />
+			<description>
+				Sets effect parameters.
+			</description>
+		</method>
+	</methods>
+</class>

doc_classes/SiEffectStereoChorus.xml

@@ -0,0 +1,24 @@
+<?xml version="1.0" encoding="UTF-8" ?>
+<class name="SiEffectStereoChorus" inherits="SiEffectBase" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="https://raw.githubusercontent.com/godotengine/godot/master/doc/class.xsd">
+	<brief_description>
+		Stereo chorus effect.
+	</brief_description>
+	<description>
+	</description>
+	<tutorials>
+	</tutorials>
+	<methods>
+		<method name="set_params">
+			<return type="void" />
+			<param index="0" name="delay_time" type="float" default="20" />
+			<param index="1" name="feedback" type="float" default="0.2" />
+			<param index="2" name="frequency" type="float" default="4" />
+			<param index="3" name="depth" type="float" default="20" />
+			<param index="4" name="wet" type="float" default="0.5" />
+			<param index="5" name="invert_phase" type="bool" default="true" />
+			<description>
+				Sets effect parameters.
+			</description>
+		</method>
+	</methods>
+</class>

doc_classes/SiEffectStereoDelay.xml

@@ -0,0 +1,22 @@
+<?xml version="1.0" encoding="UTF-8" ?>
+<class name="SiEffectStereoDelay" inherits="SiEffectBase" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="https://raw.githubusercontent.com/godotengine/godot/master/doc/class.xsd">
+	<brief_description>
+		Stereo delay effect.
+	</brief_description>
+	<description>
+	</description>
+	<tutorials>
+	</tutorials>
+	<methods>
+		<method name="set_params">
+			<return type="void" />
+			<param index="0" name="delay_time" type="float" default="250" />
+			<param index="1" name="feedback" type="float" default="0.25" />
+			<param index="2" name="is_cross" type="bool" default="false" />
+			<param index="3" name="wet" type="float" default="0.25" />
+			<description>
+				Sets effect parameters.
+			</description>
+		</method>
+	</methods>
+</class>