1 files changed, 49 insertions, 0 deletions
diff --git a/src/adsr.c b/src/adsr.c
index 4336bb5..439d7b1 100644
--- a/src/adsr.c
+++ b/src/adsr.c
@@ -45,3 +45,52 @@ adsr_amplitude(adsr_t *adsr, float noteOn, float noteOff, unsigned long long ela
 
   return clamp(mod, -1, 1);
 }
+
+float
+fix_adsr(adsr_t *adsr, float noteOn, float noteOff, unsigned long long elapsed, unsigned long long noteOffSample)
+{
+  // convert to samples
+  unsigned long long attack = adsr->a * SAMPLE_RATE + 1;
+  unsigned long long decay = adsr->d * SAMPLE_RATE + 1;
+  unsigned long long sustain = adsr->s * SAMPLE_RATE + 1;
+  unsigned long long release = adsr->r * SAMPLE_RATE + 1;
+
+  float mod = 0.0f;
+  
+  // if note is pressed
+  if (noteOn != 0 && noteOff == 0) {
+    if (elapsed < attack) {
+      // we are in the attack phase
+      mod = ((float)elapsed / attack) * adsr->peak;
+    }
+    else if (/* elapsed >= attack && */ elapsed < attack + decay) {
+      // we are in the decay phase
+      mod = ((float)(elapsed - attack) / decay) * (adsr->s - adsr->peak) + adsr->peak;
+    }
+    else {// sustain
+      mod = adsr->s;
+    }
+  }
+  else { // note is not pressed
+    if (elapsed < noteOffSample + release) {
+      // we are on the release
+
+      // reuse previous block to find starting value
+      if (noteOffSample < attack) {
+        mod = ((float)noteOffSample / attack) * adsr->peak;
+      }
+      else if (/* elapsed >= attack && */ noteOffSample < attack + decay) {
+        mod = ((float)(noteOffSample - attack) / decay) * (adsr->s - adsr->peak) + adsr->peak;
+      }
+      else {
+        mod = adsr->s;
+      }
+
+      mod = (0 - mod) / (float)release * (elapsed - noteOffSample) + mod;
+    }
+    //printf("el: %ld, att: %ld MOD: %f, on %f, off %f\n", elapsed, attack, mod, noteOn, noteOff);
+  }
+
+
+  return mod;
+}