% MKS_02 - WAVETABLE SYNTHESIZER
%
% Navazuje na MKS_01:
%   - hrajeme stejnymi klavesami
%   - zachovavame magnetofon REC / STOP / PLAY / SAVE WAV
%
% Nove:
%   WAVETABLE: SINUS / BANJO / VLASTNI
%   ENVELOPE : EXP / ADSR
%
% Pri kazdem stisku klavesy se ton vytvori z aktualne zvolene
% wavetable a aktualne zvolene obalky.
%
% Pro volbu BANJO je potreba soubor banjo.wav ve stejne slozce.

clear all
close all
clc

%-------------------------------------------------------------
% zakladni nastaveni
%-------------------------------------------------------------

keyboardType = 'QWERTZ';

if strcmpi(keyboardType,'QWERTZ')
    notes = 'awsedftgzhujk';
else
    notes = 'awsedftgyhujk';
end

Fe = 22050;
f0 = 220;
ht = 2^(1/12);
fr = ht.^(0:12)*f0;

T = 0.7;

%-------------------------------------------------------------
% WAVETABLES
%-------------------------------------------------------------

% 1) sinus - jedna perioda
Ntable = 128;
P_sinus = sin(2*pi*(0:Ntable-1)/Ntable);

% 2) banjo - jedna perioda z realne nahravky
[xBanjo,fsBanjo] = audioread('banjo.wav');

if size(xBanjo,2) > 1
    xBanjo = mean(xBanjo,2);
end

% stejny usek jako ve starsim SYN LAB
P_banjo = xBanjo(144:172)';
P_banjo = P_banjo - mean(P_banjo);

% 3) vlastni wavetable
% ZMENTE JI PODLE SEBE:
P_user = sawtooth(2*pi*(0:Ntable-1)/Ntable);

%-------------------------------------------------------------
% okno
%-------------------------------------------------------------

fig = figure( ...
    'Name','MKS 02 - WAVETABLE SYNTHESIZER', ...
    'NumberTitle','off', ...
    'MenuBar','none', ...
    'ToolBar','none', ...
    'Position',[400 250 760 430], ...
    'WindowKeyPressFcn',@keyPressed);

axis([0 1 0 1])
axis off

text(0.5,0.92,'MKS 02 - WAVETABLE SYNTHESIZER', ...
    'HorizontalAlignment','center','FontSize',18,'FontWeight','bold');

text(0.5,0.82,upper(notes), ...
    'HorizontalAlignment','center','FontSize',14);

text(0.5,0.76,'Hrajte přímo na klávesnici', ...
    'HorizontalAlignment','center','FontSize',10);

%-------------------------------------------------------------
% panel WAVETABLE
%-------------------------------------------------------------

waveGroup = uibuttongroup(fig, ...
    'Title','WAVETABLE', ...
    'FontWeight','bold', ...
    'Position',[0.12 0.36 0.30 0.30], ...
    'SelectionChangedFcn',@waveChanged);

uicontrol(waveGroup,'Style','radiobutton', ...
    'String','SINUS', ...
    'Position',[25 75 120 25], ...
    'Tag','sinus', ...
    'Value',1);

uicontrol(waveGroup,'Style','radiobutton', ...
    'String','BANJO', ...
    'Position',[25 45 120 25], ...
    'Tag','banjo');

uicontrol(waveGroup,'Style','radiobutton', ...
    'String','VLASTNÍ', ...
    'Position',[25 15 120 25], ...
    'Tag','user');

%-------------------------------------------------------------
% panel ENVELOPE
%-------------------------------------------------------------

envGroup = uibuttongroup(fig, ...
    'Title','ENVELOPE', ...
    'FontWeight','bold', ...
    'Position',[0.58 0.36 0.30 0.30], ...
    'SelectionChangedFcn',@envChanged);

uicontrol(envGroup,'Style','radiobutton', ...
    'String','EXP', ...
    'Position',[25 60 120 25], ...
    'Tag','exp', ...
    'Value',1);

uicontrol(envGroup,'Style','radiobutton', ...
    'String','ADSR', ...
    'Position',[25 25 120 25], ...
    'Tag','adsr');

%-------------------------------------------------------------
% magnetofon
%-------------------------------------------------------------

uicontrol(fig,'Style','pushbutton', ...
    'String','REC', ...
    'Position',[145 45 90 35], ...
    'Callback',@recButton);

uicontrol(fig,'Style','pushbutton', ...
    'String','STOP', ...
    'Position',[250 45 90 35], ...
    'Callback',@stopButton);

uicontrol(fig,'Style','pushbutton', ...
    'String','PLAY', ...
    'Position',[355 45 90 35], ...
    'Callback',@playButton);

uicontrol(fig,'Style','pushbutton', ...
    'String','SAVE WAV', ...
    'Position',[460 45 110 35], ...
    'Callback',@saveButton);

statusText = uicontrol(fig,'Style','text', ...
    'String','MAGNETOFON: připraven', ...
    'Position',[205 92 350 25], ...
    'FontSize',10);

%-------------------------------------------------------------
% data programu
%-------------------------------------------------------------

data.notes = notes;
data.fr = fr;
data.Fe = Fe;
data.T = T;

data.P_sinus = P_sinus;
data.P_banjo = P_banjo;
data.P_user = P_user;

data.waveType = 'sinus';
data.envType = 'exp';

data.recording = false;
data.recordStart = [];
data.events = {};            % kazdy zaznam obsahuje cas + hotovy ton
data.recordedSignal = [];

data.statusText = statusText;

guidata(fig,data);


%==========================================================================
% lokalni funkce
%==========================================================================

function keyPressed(src,event)

data = guidata(src);

key = lower(event.Character);

if numel(key) ~= 1
    return
end

k = find(data.notes == key,1);

if isempty(k)
    return
end

%-------------------------------------------------------------
% zvolena wavetable
%-------------------------------------------------------------

switch data.waveType
    case 'sinus'
        P = data.P_sinus;

    case 'banjo'
        P = data.P_banjo;

    case 'user'
        P = data.P_user;
end

%-------------------------------------------------------------
% vytvoreni tonu
%-------------------------------------------------------------

tone = wavetableTone(P,data.fr(k),data.T,data.Fe,data.envType);

sound(tone,data.Fe)

%-------------------------------------------------------------
% pokud bezi zaznam, ulozime CAS + HOTOVY TON
% tim se zachovaji i zmeny WAVETABLE a ENVELOPE behem hrani
%-------------------------------------------------------------

if data.recording

    tNow = toc(data.recordStart);

    data.events{end+1,1} = tNow;
    data.events{end,2} = tone;

    guidata(src,data);
end

end


function out = wavetableTone(P,f,T,fs,envType)

%-------------------------------------------------------------
% WAVETABLE SYNTHESIS
%-------------------------------------------------------------

P = P(:)';
N = length(P);

n = 0:round(T*fs)-1;

% spojita pozice v tabulce
ind = mod(n*f*N/fs,N) + 1;

% linearni interpolace
i1 = floor(ind);
i2 = mod(i1,N) + 1;
a = ind-i1;

out = (1-a).*P(i1) + a.*P(i2);

%-------------------------------------------------------------
% ENVELOPE
%-------------------------------------------------------------

t = (0:length(out)-1)/fs;

switch envType

    case 'exp'

        tau = 0.18;
        envelope = exp(-t/tau);

    case 'adsr'

        % prednastavene hodnoty ADSR
        A = 0.08;        % attack [s]
        D = 0.12;        % decay  [s]
        S = 0.65;        % sustain level
        R = 0.18;        % release [s]

        envelope = ADSR(length(out),fs,A,D,S,R);
end

out = envelope .* out;

% bezpecna normalizace
m = max(abs(out));

if m > 1
    out = out/m;
end

end


function envelope = ADSR(N,fs,A,D,S,R)

NA = round(A*fs);
ND = round(D*fs);
NR = round(R*fs);

% zbytek tonu je sustain
NS = N - NA - ND - NR;

if NS < 0
    % kdyby byl ton prilis kratky, zkratime jednotlive faze
    scale = N/(NA+ND+NR);
    NA = floor(NA*scale);
    ND = floor(ND*scale);
    NR = floor(NR*scale);
    NS = N - NA - ND - NR;
end

attack  = linspace(0,1,max(NA,1));
decay   = linspace(1,S,max(ND,1));
sustain = S*ones(1,max(NS,0));
release = linspace(S,0,max(NR,1));

envelope = [attack decay sustain release];

% presna delka N
if length(envelope) > N
    envelope = envelope(1:N);
elseif length(envelope) < N
    envelope(end+1:N) = 0;
end

end


function waveChanged(src,event)

fig = ancestor(src,'figure');
data = guidata(fig);

data.waveType = event.NewValue.Tag;

guidata(fig,data);

end


function envChanged(src,event)

fig = ancestor(src,'figure');
data = guidata(fig);

data.envType = event.NewValue.Tag;

guidata(fig,data);

end


function recButton(src,~)

fig = ancestor(src,'figure');
data = guidata(fig);

data.recording = true;
data.recordStart = tic;
data.events = {};
data.recordedSignal = [];

set(data.statusText,'String','MAGNETOFON: ● REC');

guidata(fig,data);

end


function stopButton(src,~)

fig = ancestor(src,'figure');
data = guidata(fig);

data.recording = false;

if isempty(data.events)
    set(data.statusText,'String','MAGNETOFON: žádný záznam');
    guidata(fig,data);
    return
end

%-------------------------------------------------------------
% slozeni zaznamu
%-------------------------------------------------------------

lastStart = data.events{end,1};
lastTone = data.events{end,2};

N = round(lastStart*data.Fe) + length(lastTone);

y = zeros(1,N);

for n = 1:size(data.events,1)

    t0 = data.events{n,1};
    tone = data.events{n,2};

    i1 = round(t0*data.Fe) + 1;
    i2 = min(i1 + length(tone) - 1,N);

    L = i2-i1+1;

    y(i1:i2) = y(i1:i2) + tone(1:L);
end

% normalizace pri soubehu tonu
m = max(abs(y));

if m > 1
    y = y/m;
end

data.recordedSignal = y;

set(data.statusText,'String','MAGNETOFON: ■ STOP');

guidata(fig,data);

end


function playButton(src,~)

fig = ancestor(src,'figure');
data = guidata(fig);

if isempty(data.recordedSignal)
    set(data.statusText,'String','MAGNETOFON: nejprve nahrajte sekvenci');
    return
end

set(data.statusText,'String','MAGNETOFON: ▶ PLAY');

sound(data.recordedSignal,data.Fe);

end


function saveButton(src,~)

fig = ancestor(src,'figure');
data = guidata(fig);

if isempty(data.recordedSignal)
    set(data.statusText,'String','MAGNETOFON: není co uložit');
    return
end

audiowrite('MKS_02_recording.wav',data.recordedSignal,data.Fe);

set(data.statusText,'String','MAGNETOFON: uloženo MKS_02_recording.wav');

end