changed triLFO to do integer bitmask math

Jeffrey Snyder committed 4 years ago

Commit 4c40a1f1 parent c9ae42f2 files · +20 −9Browse files

Unified · Split

2 files

     {
         tMempool mempool;
-        uint32_t phase;
+        int32_t phase;
-        uint32_t inc;
+        int32_t inc;
-        uint32_t prevPhase;
+        int32_t prevPhase;
         float freq;
-        int32_t mask;
         uint8_t phaseDidReset;
         uint32_t invSampleRate;
         float invSampleRateTimesTwoTo32;

     c->phase    =  0;
     c->invSampleRate = leaf->invSampleRate;
     c->invSampleRateTimesTwoTo32 = (c->invSampleRate * TWO_TO_32);
-    c->mask = TRI_TABLE_SIZE - 1;
+    //c->mask = TRI_TABLE_SIZE - 1;
     tTriLFO_setFreq(cy, 220);
 }
 float   tTriLFO_tick(tTriLFO* const cy)
 {
     _tTriLFO* c = *cy;
-    uint32_t idx;
+    //uint32_t idx;
-    float frac, samp0, samp1;
+    //float frac, samp0, samp1;
     // Phasor increment
     c->phase += c->inc;
+    //bitmask fun
+    //
+    uint32_t mask = c->phase >> 31;
+    int32_t val2 = c->phase + mask;
+    int32_t test = val2 ^ mask;
+    float output =( ((float)test * INV_TWO_TO_31)-0.5f) * 2.0f;
+    return output;
+    /*
     // Wavetable synthesis
     idx = c->phase >> 21;
     uint32_t idx2 = (idx + 1) & c->mask;
     float oct0 = (samp0 + (samp1 - samp0) * frac);
     return oct0;
+     */
 }
 void     tTriLFO_setFreq(tTriLFO* const cy, float freq)
     _tSineTriLFO* c = *cy;
     float a = tCycle_tick(&c->sine);
     float b = tTriLFO_tick(&c->tri);
-    return  (1 - c->shape) * a + c->shape * b;
+    return  (1 - c->shape) * a + c->shape * -1.0f * b;
 }
 void    tSineTriLFO_setFreq     (tSineTriLFO* const cy, float freq)
 {

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