[BGM] Rudimentary Pitch Slide

Need to dig deeper on the reset conditions, these are wrong for many songs.
Also slides in general need to have the actual end sample for slides that finish mid-note-event.

scripts/MusicRenderer.gd

@@ -12,10 +12,12 @@ class NoteEvent:
 	var p_end: int
 	var instrument: int
 	var pitch: int = 0
+	var pitch_slide: float
+	var pitch_slide_end: float
 	var velocity: float = 0.0
 	var velocity_end: float = 0.0
-	var pan: int
+	var pan: float
-	var pan_end: int
+	var pan_end: float
 	var adsr_attack_rate: int
 	var adsr_decay_rate: int
 	var adsr_decay_total_periods: int
@@ -44,9 +46,13 @@ class TrackCurve:  # built-in Curve class is too restrictive for this
 					self.entries.insert(i, entry)
 					break
 
-	func add_slide(pulse_start: int, duration: int, value: float) -> void:
+	func add_slide(pulse_start: int, duration: int, value: float, zero_is_256: bool = false) -> void:
 		if duration == 0:
-			duration = 256
+			if zero_is_256:
+				duration = 256
+			else:
+				self.add_point(pulse_start, value)
+				return
 		self.add_point(pulse_start, self.get_pulse(pulse_start), true)
 		self.add_point(pulse_start + duration, value)
 
@@ -158,6 +164,7 @@ static func render_channels(tracks: Array, inst_map: Array, _debug_name := 'none
 		var curve_pan_lfo_depth := TrackCurve.new()
 		var curve_noise_on := TrackCurve.new()  # [0.0, 1.0] for now
 		var curve_noise_freq := TrackCurve.new()
+		var curve_pitch_slide := TrackCurve.new()
 		var curve_pitchmod_on := TrackCurve.new()  # [0.0, 1.0] for now
 		var curve_echo_on := TrackCurve.new()  # [0.0, 1.0] for now
 		var curve_echo_volume := TrackCurve.new()
@@ -226,6 +233,8 @@ static func render_channels(tracks: Array, inst_map: Array, _debug_name := 'none
 					note_event.instrument = current_instrument
 					note_event.pan = curve_pan.get_pulse(p)
 					note_event.pan_end = curve_pan.get_pulse(curve_p_end)
+					note_event.pitch_slide = curve_pitch_slide.get_pulse(p)
+					note_event.pitch_slide_end = curve_pitch_slide.get_pulse(curve_p_end)
 					note_event.adsr_attack_rate = current_adsr_attack_rate
 					note_event.adsr_decay_rate = current_adsr_decay_rate
 					note_event.adsr_decay_total_periods = current_adsr_decay_total_periods
@@ -237,6 +246,7 @@ static func render_channels(tracks: Array, inst_map: Array, _debug_name := 'none
 						note_event.pitch = note  # pitch_idx  #* curve_fine_tuning
 						note_event.velocity = curve_velocity.get_pulse(p)  # current_velocity
 						note_event.velocity_end = curve_velocity.get_pulse(curve_p_end)
+						curve_pitch_slide.add_point(p, 0)  # Reset pitch slide
 					elif note == music.NOTE_IS_TIE:
 						if last_note_pretransform_pitch >= 0:
 							note = last_note_pretransform_pitch + (12 * current_octave) + current_transpose
@@ -244,25 +254,28 @@ static func render_channels(tracks: Array, inst_map: Array, _debug_name := 'none
 							note_event.pitch = note  # pitch_idx  #* curve_fine_tuning
 							note_event.velocity = curve_velocity.get_pulse(p)
 							note_event.velocity_end = curve_velocity.get_pulse(curve_p_end)
+					else:
+						curve_pitch_slide.add_point(p, 0)  # Reset pitch slide on rest
 					channel_note_events.append(note_event)
 					p += duration
 				EventType.VOLUME:
 					var new_velocity: float = event[1]/255.0
-					curve_velocity.add_point(p, new_velocity, false)
+					curve_velocity.add_point(p, new_velocity)
 				EventType.VOLUME_SLIDE:
 					var slide_duration: int = event[1]
 					var new_velocity: float = event[2]/255.0
 					curve_velocity.add_slide(p, slide_duration, new_velocity)
 				EventType.PAN:
 					var new_pan = 1.0 - event[1]/127.5
-					curve_pan.add_point(p, new_pan, false)
+					curve_pan.add_point(p, new_pan)
 				EventType.PAN_SLIDE:
 					var new_pan = 1.0 - event[2]/127.5
 					var slide_duration: int = event[1]
 					curve_pan.add_slide(p, slide_duration, new_pan)
-				EventType.PITCH_SLIDE:  # TODO: implement slides
+				EventType.PITCH_SLIDE:
 					var slide_duration: int = event[1]
-					var target_pitch: int = event[2]  # Signed
+					var target_pitch: int = event[2] + curve_pitch_slide.get_pulse(p) # Signed and relative
+					curve_pitch_slide.add_slide(p, slide_duration, target_pitch)
 				EventType.OCTAVE:
 					current_octave = event[1]
 				EventType.OCTAVE_UP:
@@ -282,6 +295,7 @@ static func render_channels(tracks: Array, inst_map: Array, _debug_name := 'none
 						scale = fine_tune/255.0
 					curve_fine_tuning.add_point(p, scale)
 				EventType.PROGCHANGE:
+					curve_pitch_slide.add_point(p, 0)  # Reset pitch slide
 					current_instrument = event[1]
 					if current_instrument >= 0x20:
 						current_instrument = inst_map[current_instrument-0x20] - 1 + SoundLoader.SFX_NUM
@@ -450,7 +464,8 @@ static func render_channels(tracks: Array, inst_map: Array, _debug_name := 'none
 			midi_events_bytes_adsr.put_u8(event.adsr_sustain_rate)
 			midi_events_bytes4.put_u8(int((event.pan+1.0) * 127.5))
 			midi_events_bytes4.put_u8(int((event.pan_end+1.0) * 127.5))
-			midi_events_bytes4.put_u16(0)
+			midi_events_bytes4.put_u8(int((event.pitch_slide*5))+128)
+			midi_events_bytes4.put_u8(int((event.pitch_slide_end*5))+128)
 
 			event_ptr += 1
 			num_notes += 1

shaders/audio_renderer.gdshader

@@ -253,6 +253,8 @@ highp vec4 render_song(highp sampler2D tex, highp int smp) {
 				highp float pitch_idx = tex2.y * 255.0;
 				highp float velocity = mix(tex2.z, tex2.w, event_progress);
 				highp float pan = mix(tex4.x, tex4.y, event_progress);
+				highp float pitchslide = ((mix(tex4.z, tex4.w, event_progress)*255.0) - 128.0)/5.0;
+				pitch_idx += pitchslide;
 				highp ivec4 adsr = ivec4(tex3 * 255.0);
 				// ====================At some point I'll look back into packing floats====================
 				// TBD = note_event_supplement.zw; - tremolo/vibrato/noise/pan_lfo/pitchbend/echo remain