Improved tutorial for sync audio with music, use two approaches.

Author: reduz

audio/bpm_sync/Control.gd

@@ -7,27 +7,53 @@ var playing = false
 const COMPENSATE_FRAMES = 2
 const COMPENSATE_HZ = 60.0
 
+const SYNC_SOURCE_SYSTEM_CLOCK = 0
+const SYNC_SOURCE_SOUND_CLOCK = 1
+
+var sync_source = SYNC_SOURCE_SYSTEM_CLOCK
+
+
 func strsec(secs):
 	var s = str(secs)
 	if (s.length()==1):
 		s="0"+s
 	return s
 
-# warning-ignore:unused_argument
+# used by system clock
+var time_begin 
+var time_delay
+
 func _process(delta):
 	if (!playing or !$Player.playing):
 		return
 
-	var time = $Player.get_mix_time() + AudioServer.get_time_since_last_mix() - AudioServer.get_output_latency() + (1/COMPENSATE_HZ)*COMPENSATE_FRAMES
+	var time 
+	if (sync_source == SYNC_SOURCE_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):		
+		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)
 	var seconds = int(time)
 	var seconds_total = int($Player.stream.get_length())
 	$Label.text = str("BEAT: ",beat % BARS +1,"/",BARS," TIME: ",seconds/60,":",strsec(seconds%60)," / ",seconds_total/60,":",strsec(seconds_total%60))
 
 
-func _on_Button_pressed():
-	print(AudioServer.get_output_latency())
+
+func _on_PlaySystem_pressed():
+	pass # Replace with function body.
+	sync_source = SYNC_SOURCE_SYSTEM_CLOCK
+	time_begin = OS.get_ticks_usec()
+	time_delay = AudioServer.get_time_to_next_mix() + AudioServer.get_output_latency()
 	playing=true
 	$Player.play()
 
+
+func _on_PlaySound_pressed():
+	sync_source = SYNC_SOURCE_SOUND_CLOCK
+	playing=true
+	$Player.play()
+	

audio/bpm_sync/play_button.png

@@ -2,15 +2,15 @@
 
 importer="texture"
 type="StreamTexture"
-path="res://.import/play_button.png-c6659eb2fbf2022d9e670864776e465a.stex"
+path="res://.import/play_sound_button.png-7e88216154de1a5cb6304cbd3751ed46.stex"
 metadata={
 "vram_texture": false
 }
 
 [deps]
 
-source_file="res://play_button.png"
-dest_files=[ "res://.import/play_button.png-c6659eb2fbf2022d9e670864776e465a.stex" ]
+source_file="res://play_sound_button.png"
+dest_files=[ "res://.import/play_sound_button.png-7e88216154de1a5cb6304cbd3751ed46.stex" ]
 
 [params]
 

audio/bpm_sync/play_button_hl.png

@@ -0,0 +1,34 @@
+[remap]
+
+importer="texture"
+type="StreamTexture"
+path="res://.import/play_sound_button_hl.png-8d86f81fe37a5f2959088b0948283133.stex"
+metadata={
+"vram_texture": false
+}
+
+[deps]
+
+source_file="res://play_sound_button_hl.png"
+dest_files=[ "res://.import/play_sound_button_hl.png-8d86f81fe37a5f2959088b0948283133.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/play_sound_button.png

@@ -2,15 +2,15 @@
 
 importer="texture"
 type="StreamTexture"
-path="res://.import/play_button_hl.png-63644aa33cad39ca169b518c7eed7ae2.stex"
+path="res://.import/play_system_button.png-683c51b4d13189b67bb57e75cbb8ef56.stex"
 metadata={
 "vram_texture": false
 }
 
 [deps]
 
-source_file="res://play_button_hl.png"
-dest_files=[ "res://.import/play_button_hl.png-63644aa33cad39ca169b518c7eed7ae2.stex" ]
+source_file="res://play_system_button.png"
+dest_files=[ "res://.import/play_system_button.png-683c51b4d13189b67bb57e75cbb8ef56.stex" ]
 
 [params]