From 8f69b4fcf8489fa8e95af3cce0ff422247f601c8 Mon Sep 17 00:00:00 2001
From: Chris <chris@ternar.tech>
Date: Fri, 16 May 2025 13:44:15 +0200
Subject: [PATCH] add optional modulators to synth/voices

---
 synth/ivoice.h          | 3 ++-
 synth/midi_synth.h      | 4 ++--
 synth/tx_voice.h        | 3 ++-
 synth/voice_allocator.h | 4 ++--
 4 files changed, 8 insertions(+), 6 deletions(-)

diff --git a/synth/ivoice.h b/synth/ivoice.h
index 890db6b..e4f6ed2 100644
--- a/synth/ivoice.h
+++ b/synth/ivoice.h
@@ -1,10 +1,11 @@
 #pragma once
+#include <span>
 
 namespace trnr {
 template <typename t_sample>
 struct ivoice {
 	virtual ~ivoice() = default;
-	virtual void process_samples(t_sample** _outputs, int _start_index, int _block_size) = 0;
+    virtual void process_samples(t_sample** _outputs, int _start_index, int _block_size, std::span<std::span<t_sample>> _modulators = {}) = 0;
 	virtual bool is_busy() = 0;
 	virtual void set_samplerate(double samplerate) = 0;
 	virtual void note_on(int _note, float _velocity) = 0;
diff --git a/synth/midi_synth.h b/synth/midi_synth.h
index caecdfa..3e0470f 100644
--- a/synth/midi_synth.h
+++ b/synth/midi_synth.h
@@ -25,7 +25,7 @@ public:
 		voice_allocator<t_voice, t_sample>::set_samplerate(_samplerate);
 	}
 
-	void process_block(t_sample** _outputs, int _n_frames)
+	void process_block(t_sample** _outputs, int _n_frames, std::span<std::span<t_sample>> _modulators = {})
 	{
 		// clear outputs
 		for (auto i = 0; i < 2; i++) { memset(_outputs[i], 0, _n_frames * sizeof(t_sample)); }
@@ -55,7 +55,7 @@ public:
 					m_event_queue.erase(m_event_queue.begin());
 				}
 
-				voice_allocator<t_voice, t_sample>::process_samples(_outputs, start_index, block_size);
+				voice_allocator<t_voice, t_sample>::process_samples(_outputs, start_index, block_size, _modulators);
 
 				samples_remaining -= block_size;
 				start_index += block_size;
diff --git a/synth/tx_voice.h b/synth/tx_voice.h
index 94a1b8e..204c3b0 100644
--- a/synth/tx_voice.h
+++ b/synth/tx_voice.h
@@ -5,6 +5,7 @@
 #include "tx_operator.h"
 #include "tx_sineosc.h"
 #include "tx_parameter_mapping.h"
+#include <span>
 
 namespace trnr {
 
@@ -48,7 +49,7 @@ public:
 	// modulates the pitch in semitones
 	void modulate_pitch(float _pitch) override { this->pitch_mod = _pitch; }
 
-	void process_samples(t_sample** _outputs, int _start_index, int _block_size) override
+	void process_samples(t_sample** _outputs, int _start_index, int _block_size, std::span<std::span<t_sample>> _modulators = {}) override
 	{
 		float frequency = midi_to_frequency(midi_note + pitch_mod + additional_pitch_mod);
 
diff --git a/synth/voice_allocator.h b/synth/voice_allocator.h
index 63d64ad..a985c51 100644
--- a/synth/voice_allocator.h
+++ b/synth/voice_allocator.h
@@ -61,14 +61,14 @@ public:
 		});
 	}
 
-	void process_samples(t_sample** _outputs, int _start_index, int _block_size)
+	void process_samples(t_sample** _outputs, int _start_index, int _block_size, std::span<std::span<t_sample>> _modulators = {})
 	{
 		for (int b = _start_index; b < _start_index + _block_size; b += internal_block_size) {
 
 			// process all events in the block (introduces potential inaccuracy of up to 16 samples)
 			process_events(b, internal_block_size);
 
-			for (const auto& v : voicePtrs) { v->process_samples(_outputs, b, internal_block_size); }
+			for (const auto& v : voicePtrs) { v->process_samples(_outputs, b, internal_block_size, _modulators); }
 		}
 	}