added matlab

matlab/env/eval_adsr2.asv

@@ -0,0 +1,52 @@
+function eval_adsr(Ta, Td, Vs, Tr)
+
+% eval_adsr(0.1, 0.2, 0.2, 0.2)
+
+fs = 1000;
+
+a_a = 1/(Ta*fs);
+a_d = -1/(Td*fs/log(Vs))
+a_d = 5/(Td*fs)
+a_r = 5/(Tr*fs)
+state = 0;
+s = 0;
+tol = 1E-4;
+target = 1;
+n = 0;
+p = 0;
+k = 1/0.63;
+while (1),
+    
+    if state == 0       % Attack
+        s = a_a + (1-a_a)*s;
+        if s >= (0.63-tol)
+            state = 1
+            target = Vs;
+        end;
+    end;
+    if state == 1       % Decay
+        s = (1-a_d)*s;
+        if s <= (0.63*Vs+tol)
+            state = 2
+            target = 0;
+            p = 0;
+        end;
+    end;
+    if state == 2       % sustain
+        s = Vs/k;
+        if p >= 1*fs
+            state = 3
+        end;
+        p = p + 1;
+    end;
+    if state == 3       % Release
+        s = (1-a_r)*s;
+        if s <= (target+tol)
+            break;
+        end;
+    end;
+    n = n + 1;
+    y(n) = k*s;
+end;
+
+plot((0:n-1)/fs, y); grid;