From 202ddac184febe971aa8445da2fabc389df1d64c Mon Sep 17 00:00:00 2001
From: Gordon JC Pearce <gordonjcp@gmail.com>
Date: Sat, 19 Oct 2024 00:19:35 +0100
Subject: [PATCH] noise gen

---
 plugin/ic29.cpp       | 8 +++++++-
 plugin/ic29.hpp       | 6 +++++-
 plugin/oscillator.cpp | 5 +++--
 plugin/peacock.cpp    | 3 ++-
 4 files changed, 17 insertions(+), 5 deletions(-)

diff --git a/plugin/ic29.cpp b/plugin/ic29.cpp
index 5ab2cfe..978aecb 100644
--- a/plugin/ic29.cpp
+++ b/plugin/ic29.cpp
@@ -25,6 +25,7 @@ Synth ic29;
 Synth::Synth() {
     d_debug("initialising synth\n");
     portaCoeff = 0x0;
+    noise = new float [4096];
 }
 
 void Synth::buildTables(double sampleRate) {
@@ -57,9 +58,14 @@ void Synth::run() {
     // 0 sets EA to 0x3fff, 1 adds
     uint16_t pwmVal = 0x2000 - ic29.lfo.lfoOut;
     if (ic29.patchRam.switch2 & 0x01) pwmVal = 0x3fff;
-
     ic29.pwm = 0.5 - pwmVal / 32768.0f * (ic29.patchRam.pwmLfoMod / 106.0f);
 
+    // generate the voices, then
+    for (uint32_t i=0; i<bufferSize; i++) {
+        tr21 = (tr21*519) + 3;
+        noise[i] = (1-(tr21 & 0x00ffffff) / 8388608.0f) * (ic29.patchRam.noiseLevel * 0.0063);
+    }
+
     for (uint8_t i = 0; i < NUM_VOICES; i++) {
         ic29.voices[i].update();
     }
diff --git a/plugin/ic29.hpp b/plugin/ic29.hpp
index d8bdae5..fd940d3 100644
--- a/plugin/ic29.hpp
+++ b/plugin/ic29.hpp
@@ -72,7 +72,7 @@ class Voice {
    public:
     Voice();
     uint8_t note = 0x3c;  // middle C
-    void run(float *buffer, uint32_t samples);
+    void run(float *buffer, uint32_t pos, uint32_t samples);
     void update();
     void on(uint8_t note);
     void off();
@@ -106,6 +106,7 @@ class Synth {
     void buildTables(double sampleRate);
 
     double sampleRate;
+    uint32_t bufferSize;
     uint16_t masterPitch;  // sum of bend and LFO, plus any other pitch-setting value
                            // protected:
     uint16_t envAtk, envDcy, envStn, envRls;
@@ -113,6 +114,8 @@ class Synth {
     bool sustained;
     double pitchTable[104];
 
+    float *noise;
+
     // private:
     uint8_t vcoBend=42;
     uint8_t vcfBend=42;
@@ -123,6 +126,7 @@ class Synth {
     uint8_t modWheel = 0x00;
 
     float pwm;
+    uint32_t tr21;
 
     struct {
         uint8_t lfoRate = 0x3f;
diff --git a/plugin/oscillator.cpp b/plugin/oscillator.cpp
index f6ad088..a3d7f07 100644
--- a/plugin/oscillator.cpp
+++ b/plugin/oscillator.cpp
@@ -27,7 +27,7 @@ static inline float poly3blep1(float t) {
     return -poly3blep0(1 - t);
 }
 
-void Voice::run(float *buffer, uint32_t samples) {
+void Voice::run(float *buffer, uint32_t pos, uint32_t samples) {
     // generate a full block of samples for the oscillator
 
     float y, out, t;
@@ -69,10 +69,11 @@ void Voice::run(float *buffer, uint32_t samples) {
         // the DC correction is important because the hardware synth is AC-coupled effectively high-passing
         // the signal at about 10Hz or so, preventing any PWM rumble from leaking through!
         delay += subosc;
+        delay += ic29.noise[i+pos];
 
         out = y * 0.15;
         lastpw = pwrc;
-        buffer[i] += out * gain;
+        buffer[i + pos] += out * gain;
     }
 
 }
diff --git a/plugin/peacock.cpp b/plugin/peacock.cpp
index 9eb09ac..f1e2874 100644
--- a/plugin/peacock.cpp
+++ b/plugin/peacock.cpp
@@ -26,6 +26,7 @@ START_NAMESPACE_DISTRHO
 Peacock::Peacock() : Plugin(paramCount, 0, 0), sampleRate(getSampleRate()) {
     printf("peacock constructor\n");
     ic29.buildTables(getSampleRate());
+    ic29.bufferSize = getBufferSize();
 }
 
 
@@ -86,7 +87,7 @@ void Peacock::run(const float **, float **outputs, uint32_t frames, const MidiEv
 
         // run every synth voice into the buffer here FIXME
         for (uint8_t i = 0; i < NUM_VOICES; i++) {
-            ic29.voices[i].run(outputs[0] + framePos, sizeThisTime);
+            ic29.voices[i].run(outputs[0], framePos, sizeThisTime);
         }
 
         framePos += sizeThisTime;  // move along the frame