54 lines
989 B
Plaintext
Executable File
54 lines
989 B
Plaintext
Executable File
function eval_adsr(Ta, Td, Vs, Tr, ks)
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% eval_adsr(0.1, 0.2, 0.2, 0.2)
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fs = 1000;
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a_a = -log(1-ks)/(Ta*fs);
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a_d = 5/(Td*fs);
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a_r = 5/(Tr*fs);
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state = 0;
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s = 0;
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tol = 1E-4;
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n = 1;
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p = 0;
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k = 1/ks;
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while (1),
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if state == 0 % Attack
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s = a_a + (1-a_a)*s;
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y(n) = k*s;
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if s >= (ks-tol)
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state = 1;
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s = 1-ks;
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end;
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end;
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if state == 1 % Decay
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s = (1-a_d)*s;
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y(n) = s/(1-ks);
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if s <= (Vs+tol)
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state = 2;
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p = 0;
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end;
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end;
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if state == 2 % sustain
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y(n) = Vs;
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if p >= 1*fs
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state = 3;
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s = Vs;
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end;
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p = p + 1;
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end;
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if state == 3 % Release
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s = (1-a_r)*s;
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y(n) = s;
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if s <= (tol)
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break;
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end;
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end;
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n = n + 1;
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end;
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plot((0:n-1)/fs, y); grid;
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set(gca,'xtick',[0:0.1:(n-1)/fs])
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