Add README files to audio demos

audio/bpm_sync/README.md

@@ -0,0 +1,18 @@
+# Audio BPM Sync
+
+A demo of how to sync the audio playback with the time for a consistent BPM.
+
+Language: GDScript
+
+Renderer: GLES 2
+
+## How does it work?
+
+For the sound clock, it uses methods in
+[`AudioServer`](https://docs.godotengine.org/en/latest/classes/class_audioserver.html)
+to sync the audio playback.
+For the system clock, it uses `OS.get_ticks_usec()`.
+
+## Screenshots
+
+![Screenshot](screenshots/bpm.png)

audio/bpm_sync/bpm_sync.gd

@@ -7,10 +7,12 @@ var playing = false
 const COMPENSATE_FRAMES = 2
 const COMPENSATE_HZ = 60.0
 
-const SYNC_SOURCE_SYSTEM_CLOCK = 0
-const SYNC_SOURCE_SOUND_CLOCK = 1
+enum SyncSource {
+	SYSTEM_CLOCK,
+	SOUND_CLOCK,
+}
 
-var sync_source = SYNC_SOURCE_SYSTEM_CLOCK
+var sync_source = SyncSource.SYSTEM_CLOCK
 
 # Used by system clock.
 var time_begin
@@ -25,16 +27,16 @@ func strsec(secs):
 
 
 func _process(_delta):
-	if (!playing or !$Player.playing):
+	if !playing or !$Player.playing:
 		return
 	
 	var time = 0.0
-	if (sync_source == SYNC_SOURCE_SYSTEM_CLOCK): 
+	if sync_source == SyncSource.SYSTEM_CLOCK: 
 		# Obtain from ticks.
 		time = (OS.get_ticks_usec() - time_begin) / 1000000.0
 		# Compensate.
 		time -= time_delay
-	elif (sync_source == SYNC_SOURCE_SOUND_CLOCK):
+	elif sync_source == SyncSource.SOUND_CLOCK:
 		time = $Player.get_playback_position() + AudioServer.get_time_since_last_mix() - AudioServer.get_output_latency() + (1 / COMPENSATE_HZ) * COMPENSATE_FRAMES
 	
 	var beat = int(time * BPM / 60.0)
@@ -44,7 +46,7 @@ func _process(_delta):
 
 
 func _on_PlaySystem_pressed():
-	sync_source = SYNC_SOURCE_SYSTEM_CLOCK
+	sync_source = SyncSource.SYSTEM_CLOCK
 	time_begin = OS.get_ticks_usec()
 	time_delay = AudioServer.get_time_to_next_mix() + AudioServer.get_output_latency()
 	playing = true
@@ -52,6 +54,6 @@ func _on_PlaySystem_pressed():
 
 
 func _on_PlaySound_pressed():
-	sync_source = SYNC_SOURCE_SOUND_CLOCK
+	sync_source = SyncSource.SOUND_CLOCK
 	playing = true
 	$Player.play()

audio/bpm_sync/icon.png.import

@@ -0,0 +1,34 @@
+[remap]
+
+importer="texture"
+type="StreamTexture"
+path="res://.import/icon.png-487276ed1e3a0c39cad0279d744ee560.stex"
+metadata={
+"vram_texture": false
+}
+
+[deps]
+
+source_file="res://icon.png"
+dest_files=[ "res://.import/icon.png-487276ed1e3a0c39cad0279d744ee560.stex" ]
+
+[params]
+
+compress/mode=0
+compress/lossy_quality=0.7
+compress/hdr_mode=0
+compress/bptc_ldr=0
+compress/normal_map=0
+flags/repeat=0
+flags/filter=true
+flags/mipmaps=false
+flags/anisotropic=false
+flags/srgb=2
+process/fix_alpha_border=true
+process/premult_alpha=false
+process/HDR_as_SRGB=false
+process/invert_color=false
+stream=false
+size_limit=0
+detect_3d=true
+svg/scale=1.0

audio/bpm_sync/project.godot

@@ -17,6 +17,7 @@ _global_script_class_icons={
 
 config/name="BPM Sync Demo"
 run/main_scene="res://bpm_sync.tscn"
+config/icon="res://icon.png"
 
 [rendering]
 

audio/device_changer/Changer.gd

@@ -1,36 +1,37 @@
 extends Control
 
-onready var itemList = get_node("ItemList")
+onready var item_list = get_node("ItemList")
 
 
 func _ready():
 	for item in AudioServer.get_device_list():
-		itemList.add_item(item)
+		item_list.add_item(item)
 	
 	var device = AudioServer.get_device()
-	for i in range(itemList.get_item_count()):
-		if device == itemList.get_item_text(i):
-			itemList.select(i)
+	for i in range(item_list.get_item_count()):
+		if device == item_list.get_item_text(i):
+			item_list.select(i)
 			break
 
 
 func _process(_delta):
-	var speakerMode = "Stereo"
+	var speaker_mode_text = "Stereo"
+	var speaker_mode = AudioServer.get_speaker_mode()
 	
-	if AudioServer.get_speaker_mode() == AudioServer.SPEAKER_SURROUND_31:
-		speakerMode = "Surround 3.1"
-	elif AudioServer.get_speaker_mode() == AudioServer.SPEAKER_SURROUND_51:
-		speakerMode = "Surround 5.1"
-	elif AudioServer.get_speaker_mode() == AudioServer.SPEAKER_SURROUND_71:
-		speakerMode = "Surround 7.1"
+	if speaker_mode == AudioServer.SPEAKER_SURROUND_31:
+		speaker_mode_text = "Surround 3.1"
+	elif speaker_mode == AudioServer.SPEAKER_SURROUND_51:
+		speaker_mode_text = "Surround 5.1"
+	elif speaker_mode == AudioServer.SPEAKER_SURROUND_71:
+		speaker_mode_text = "Surround 7.1"
 	
 	$DeviceInfo.text = "Current Device: " + AudioServer.get_device() + "\n"
-	$DeviceInfo.text += "Speaker Mode: " + speakerMode
+	$DeviceInfo.text += "Speaker Mode: " + speaker_mode_text
 
 
 func _on_Button_button_down():
-	for item in itemList.get_selected_items():
-		var device = itemList.get_item_text(item)
+	for item in item_list.get_selected_items():
+		var device = item_list.get_item_text(item)
 		AudioServer.set_device(device)
 
 

audio/device_changer/README.md

@@ -0,0 +1,18 @@
+# Audio Device Changer
+
+This is a demo showing how the audio output device can be changed from Godot.
+
+Language: GDScript
+
+Renderer: GLES 2
+
+## How does it work?
+
+It uses the `set_device()` method in
+[`AudioServer`](https://docs.godotengine.org/en/latest/classes/class_audioserver.html)
+to change the audio device.
+The list of devices is populated using `get_device_list()`.
+
+## Screenshots
+
+![Screenshot](screenshots/device_changer.png)

audio/generator/README.md

@@ -0,0 +1,16 @@
+# Audio Generator
+
+This is a demo showing how one can generate and
+play audio samples from GDScript.
+It plays a simple 440 Hz sine wave at 22050 Hz.
+
+Language: GDScript
+
+Renderer: GLES 2
+
+## How does it work?
+
+It uses the `push_frame()` method on an [`AudioStreamGeneratorPlayback`](https://docs.godotengine.org/en/latest/classes/class_audiostreamgeneratorplayback.html)
+object, which is inside of an
+[`AudioStreamPlayer`](https://docs.godotengine.org/en/latest/classes/class_audiostreamplayer.html)
+node, to generate audio frame-by-frame based on `pulse_hz`.

audio/generator/generator_demo.gd

@@ -10,10 +10,10 @@ func _fill_buffer():
 	var increment = pulse_hz / sample_hz
 	
 	var to_fill = playback.get_frames_available()
-	while (to_fill > 0):
+	while to_fill > 0:
 		playback.push_frame(Vector2.ONE * sin(phase * TAU)) # Audio frames are stereo.
 		phase = fmod(phase + increment, 1.0)
-		to_fill -= 1;
+		to_fill -= 1
 
 
 func _process(_delta):

audio/mic_record/README.md

@@ -0,0 +1,8 @@
+# Audio Mic Record
+
+This is an example showing how one can record audio from
+the microphone and later play it back or save it to a file.
+
+Language: GDScript
+
+Renderer: GLES 2

audio/mic_record/project.godot

@@ -15,7 +15,7 @@ _global_script_class_icons={
 
 [application]
 
-config/name="Mic Record Demo"
+config/name="Audio Mic Record Demo"
 run/main_scene="res://MicRecord.tscn"
 config/icon="res://icon.png"
 

audio/spectrum/README.md

@@ -0,0 +1,12 @@
+# Audio Spectrum
+
+This is a demo showing how a spectrum analyzer
+can be built using Godot.
+
+Language: GDScript
+
+Renderer: GLES 2
+
+## Screenshots
+
+![Screenshot](screenshots/spectrum.png)

audio/spectrum/icon.png.import

@@ -0,0 +1,34 @@
+[remap]
+
+importer="texture"
+type="StreamTexture"
+path="res://.import/icon.png-487276ed1e3a0c39cad0279d744ee560.stex"
+metadata={
+"vram_texture": false
+}
+
+[deps]
+
+source_file="res://icon.png"
+dest_files=[ "res://.import/icon.png-487276ed1e3a0c39cad0279d744ee560.stex" ]
+
+[params]
+
+compress/mode=0
+compress/lossy_quality=0.7
+compress/hdr_mode=0
+compress/bptc_ldr=0
+compress/normal_map=0
+flags/repeat=0
+flags/filter=true
+flags/mipmaps=false
+flags/anisotropic=false
+flags/srgb=2
+process/fix_alpha_border=true
+process/premult_alpha=false
+process/HDR_as_SRGB=false
+process/invert_color=false
+stream=false
+size_limit=0
+detect_3d=true
+svg/scale=1.0

audio/spectrum/project.godot

@@ -17,6 +17,7 @@ _global_script_class_icons={
 
 config/name="Audio Spectrum Demo"
 run/main_scene="res://show_spectrum.tscn"
+config/icon="res://icon.png"
 
 [rendering]