adjustable filter envelope and vca gate

plugin/module.cpp

@@ -18,6 +18,8 @@
 
 #include "module.hpp"
 
+#include <stdio.h>
+
 #include "tables.hpp"
 
 Module::Module() {
@@ -31,11 +33,21 @@ void Module::run(Voice* voice) {
     d = decayTable[patchRam.env_d];   // decay time coeff looked up in table
     r = decayTable[patchRam.env_r];   // release time coeff looked up in table
     s = patchRam.env_s << 7;          // scale 0x00-0x7f to 0x0000-0x3f80
+
+    square = (patchRam.switch2 & 0x08) ? 0.63 : 0;
+    saw = (patchRam.switch2 & 0x10) ? 0.8 : 0;
+    sub = patchRam.sub / 127.0f;
+
+    // printf("%f %f %f %02x\n", square, saw, sub, patchRam.switch2);
+
     // work out the "master" cutoff
-    vcfCutoff = patchRam.vcfFreq / 127.0f;
-    vcfCutoff += lfo * (patchRam.vcfLfo/127.0f);
+    // vcfCutoff = patchRam.vcfFreq / 127.0f;
+    // vcfCutoff += lfo * (patchRam.vcfLfo / 127.0f);
     // also needs pitch bend amount for the base level
 
+    int16_t vcf = (patchRam.vcfEnv << 7) * ((patchRam.switch2 & 0x02) ? -1 : 1);
+   // int16_t vca = (patchRam.vcfEnv << 7) * (patchRam.switch2 & 0x01) ? -1 : 1;
+
     for (uint32_t i = 0; i < NUM_VOICES; i++) {
         switch (voice[i].envPhase) {
             case 0:                                       // release phase FIXME use an enum I guess
@@ -53,5 +65,13 @@ void Module::run(Voice* voice) {
             voice[i].envPhase = 2;  // flip to decay
         }
         // per voice we need to calculate the key follow amount and envelope amount
+        voice[i].vcfCut = (patchRam.vcfFreq << 7) + ((vcf * voice[i].env) >> 16);
+
+        if (voice[i].vcfCut > 0x3fff) voice[i].vcfCut = 0x3fff;
+        if (voice[i].vcfCut < 0) voice[i].vcfCut = 0;
+
+
+        voice[i].vcaEnv = (patchRam.switch2 & 0x04) ? (voice[i].envPhase ? 0x3fff : 0) : voice[i].env;
+    
     }
 }

plugin/module.hpp

@@ -35,31 +35,37 @@ class Module {
     float lfo = 0, lfoTheta = 0;
 
     // precomputed values for all voices
-    float pw, saw, square, sub;
+    float pw;//, saw, square, sub;
 
     // "internal state" values for patch parameters
     uint16_t a, d, s, r;
 
+    float saw = 0, square = 0, sub = 0, noise = 0;
+
     struct {
         uint8_t lfoRate = 0x30;  // lookup value defaults to 0x0200
         uint8_t lfoDelay = 0x00;
         uint8_t vcoLfo = 0x0a;
         uint8_t pwmLfo = 0x30;
         uint8_t noise = 0x00;
-        uint8_t vcfFreq = 0x3c;  // 0x3f80
+        uint8_t vcfFreq = 0x4c;  // 0x3f80
         uint8_t vcfReso = 0x00;
-        uint8_t vcfEnv = 0x2e;
+        uint8_t vcfEnv = 0x4e;
         uint8_t vcfLfo = 0;
         uint8_t vcfKey = 0x47;
         uint8_t vca = 0x28;
-        uint8_t env_a = 0x1b;
+        uint8_t env_a = 0x00;
         uint8_t env_d = 0x39;
         uint8_t env_s = 0x39;  // 0x3f80
         uint8_t env_r = 0x30;
-        uint8_t sub = 0x00;
+        uint8_t sub = 0x7f;
         uint8_t switch1 = 0x1a;
         uint8_t switch2 = 0x18;
     } patchRam;
+
+   private:
+    // controls
+    float subRC = 0, outRC = 0, pwmRC = 0, resRC = 0, noiseRC = 0;
 };
 
 class Voice {
@@ -70,9 +76,14 @@ class Voice {
     void run(Module* m, float* buffer, uint32_t samples);
     uint8_t envPhase = 0;
     int16_t env = 0;  // output amplitude
+    int16_t vcfCut;
+    int16_t vcaEnv;
 
    private:
-    float omega = 0, theta = 0;   // phase increment and angle
+    // control
+    float vcaRC = 0, vcfRC = 0;
+
+    float omega = 0, theta = 0;   // phase increment and angle FIXME better names
     float delay = 0, lastpw = 0;  // delay slots for antialiasing
     uint8_t pulseStage = 1;       // pulse wave phase
     float subosc = 1;             // sub oscillator flipflop output

plugin/voice.cpp

@@ -51,14 +51,17 @@ void Voice::run(Module* m, float* buffer, uint32_t samples) {
     // carry out per-voice calculations for each block of samples
     float out, t, fb, res;
 
-    float cut = 0.00513 + 0.0000075*env;
+    //float cut = 0.00513 + 0.0000075*env;
+
+    // calculate cutoff frequency
+    float cut = 248.0f * (powf(2, (vcfCut - 0x1880) / 1143.0f));
+    cut = 0.25 * 6.2832 * cut / 48000.0f;    // FIXME hardcoded values
+    cut = cut/(1+cut);  // correct tuning warp
+
     // printf("%f ", delay);
-    m->saw = 1;
-    m->square = 1;
-    m->sub = .5;
      m->pw = 0.5;
 
-    float amp = env / 4096.0f;
+    float amp = vcaEnv / 4096.0f;
 
     for (uint32_t i = 0; i < samples; i++) {
         out = delay;
@@ -101,14 +104,14 @@ void Voice::run(Module* m, float* buffer, uint32_t samples) {
             if (fb > 1) fb = 1;
             if (fb < -1) fb = -1;
 
-            fb = out - (fb * 2);
+            fb = out - (fb * 1.7);
             b1 = ((fb - b1) * cut) + b1;
             b2 = ((b1 - b2) * cut) + b2;
             b3 = ((b2 - b3) * cut) + b3;
             b4 = ((b3 - b4) * cut) + b4;
         }
 
-        buffer[i] += 0.125 * amp * b4;
+        buffer[i] += 0.0625 * amp * b4;
         lastpw = m->pw;
     }
     // buffer[0] += 1;