bettering

2 files changed, 78 insertions, 61 deletions

diff --git a/matleap.cpp b/matleap.cpp
index 4a24d3d..7f109c9 100644
--- a/matleap.cpp
+++ b/matleap.cpp
@@ -252,7 +252,7 @@ void matleap::frame_grabber::open_connection() {
 }
 
 void matleap::frame_grabber::close_connection() {
-    mexPrintf("Good bye.");
+    mexPrintf("Good bye.\n");
 }
 
 matleap::frame_grabber::~frame_grabber() {
diff --git a/theremin.m b/theremin.m
index 22f9991..3a1ebfe 100644
--- a/theremin.m
+++ b/theremin.m
@@ -1,33 +1,37 @@
 clear;
 
-%%%%%%%%
+show_graphs = false;
+
+%%%%%%%%%%%%%%%
 % "constants" %
-%%%%%%%%
+%%%%%%%%%%%%%%%
 
 % how many updates per second, determines the length of audio snippets
 const_frames_per_second = 100;
 
-const_Fs = 44100;  % sampling rate in Hz
+const_Fs = 44100;  % sample rate in Hz
 const_te = 1/const_frames_per_second; % signal duration in seconds
 const_samples_per_frame = ceil(const_Fs * const_te);
 const_sample_range = 0:const_samples_per_frame-1;
 
-% factor the last read frame is multiplied by
+% the smaller the value, the quicker the fade out
 const_fade_speed = 0.975;
 
-% signal "generator"
-signal = @(freq) (freq ./ const_Fs .* 2 .* pi .* const_sample_range);
+% signal "generator" - only gives the input for sin()
+%  it does not apply the sin function yet, see below for reasoning
+signal_f = @(freq) (freq ./ const_Fs .* 2 .* pi .* const_sample_range);
 
 % dimensions to use for detecting number of hands in frame
 zero_hands = size(NaN(0,0));
-one_hand = size(NaN(1,1));
-two_hands = size(NaN(1,2));
+one_hand   = size(NaN(1,1));
+two_hands  = size(NaN(1,2));
 
-deviceWriter = audioDeviceWriter('SampleRate', const_Fs, 'SupportVariableSizeInput', true, 'BufferSize', 3 * const_samples_per_frame);
+deviceWriter = audioDeviceWriter('SampleRate', const_Fs, ...
+    'SupportVariableSizeInput', true, 'BufferSize', 3 * const_samples_per_frame);
 
-%%%%%%%%%%%%%%%%%%%
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 % init matleap by calling for first frame %
-%%%%%%%%%%%%%%%%%%%
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 matleap_frame;
 
 % runtime variables
@@ -38,18 +42,16 @@ done = false;
 frequency_pos = 0;
 height_pos = 0;
 
-offset_one = 0;
-offset_two = 0;
+offset = 0;
 
-signal_one = sin(signal(0));
-signal_two = sin(signal(0));
+signal = sin(signal_f(0));
 
-full_signal = signal_one + signal_two;
-complete_signal = full_signal;
+complete_signal = signal;
 
 % time gestures, used for program termination
 gesture_count = 0;
 
+% main loop
 while gesture_count < const_frames_per_second
     frame = matleap_frame;
     handCount = size(frame.hands);
@@ -95,17 +97,15 @@ while gesture_count < const_frames_per_second
     end
     
     % play current sound
-    [signal_one, offset_one] = get_theremin_sound_bit(frequency_pos, height_pos, offset_one, signal);
-    %[signal_two, offset_two] = get_theremin_sound_bit(x_two, y_two, offset_two, signal);
-    full_signal = signal_one;% + signal_two;
+    [signal, offset] = get_theremin_sound_bit(frequency_pos, height_pos, offset, signal_f);
     
-    buffer_under_flow = deviceWriter(full_signal(:)); 
+    buffer_under_flow = deviceWriter(signal(:)); 
     
     if buffer_under_flow ~= 0
         disp("Buffer ran empty!");
     end
     
-    complete_signal = [complete_signal full_signal];
+    complete_signal = [complete_signal signal];
 end
 
 release(deviceWriter)
@@ -113,50 +113,67 @@ release(deviceWriter)
 %theremin_player = audioplayer(complete_signal, const_Fs);
 %play(theremin_player);
 
-% extract values
-x = P(:,1); % links (-) rechts (+) (LED zu uns)
-y = P(:,2); % oben unten
-z = P(:,3); % vorne (+) hinten (-) (LED zu uns)
-
-% plot
-figure("Position",[0,0, 1200, 2400]);
-t = tiledlayout(4,1);
-
-nexttile;
-plot(x);
-ylabel('left right');
-
-nexttile;
-plot(y);
-ylabel('height');
-
-nexttile;
-plot(z);
-ylabel('depth');
+if show_graphs == true
+    % extract values
+    x = P(:,1); % links (-) rechts (+) (LED zu uns)
+    y = P(:,2); % oben unten
+    z = P(:,3); % vorne (+) hinten (-) (LED zu uns)
+
+    % plot
+    figure("Position",[0,0, 1200, 2400]);
+    t = tiledlayout(4,1);
+
+    nexttile;
+    plot(x);
+    ylabel('left right');
+
+    nexttile;
+    plot(y);
+    ylabel('height');
+
+    nexttile;
+    plot(z);
+    ylabel('depth');
+
+    nexttile;
+    plot3(z,x,y);
+    xlabel('depth');
+    ylabel('left right');
+    zlabel('height');
+
+    %{
+    % Plot both audio channels
+    N = size(complete_signal,2); % Determine total number of samples in audio file
+    figure;
+    subplot(1,1,1);
+    stem(1:N, complete_signal(1,:));
+    title('Audio Channel');
+    % Plot the spectrum
+    df = const_Fs / N;
+    w = (-(N/2):(N/2)-1)*df;
+    y = fft(complete_signal(1,:), N) / N; % For normalizing, but not needed for our analysis
+    y2 = fftshift(y);
+    figure;
+    plot(w,abs(y2));
+    %}
+end
 
-nexttile;
-plot3(z,x,y);
-xlabel('depth');
-ylabel('left right');
-zlabel('height');
+disp('If you want to save your audio, run `audiowrite(<.wav filename>, complete_signal, const_Fs)`');
 
 function [sound,offset] = get_theremin_sound_bit(x, y, offset, generator)
-    % finding ranges for x and y:
-    %'x'
-    %min(x)
-    %max(x)
-    %'y'
-    %min(y)
-    %max(y)
-    % --> 50 < x < 270
-    % --> 90 < y < 350
-    
-    volume = (y) / 1300;
-    frequency = max(0.003, (x - 50) / 220) * 1000; % https://web.physics.ucsb.edu/~lecturedemonstrations/Composer/Pages/60.17.html # How it works
-
+    % the values used here are mostly empirical
+    volume = y / 1300;
+    % How it works:
+    %  https://web.physics.ucsb.edu/~lecturedemonstrations/Composer/Pages/60.17.html
+    frequency = max(0.003, (x - 50) / 220) * 1000; % have at least 3Hz
+
+    % here we generate the array to put into sin(), but offset it with the
+    %  the previous frames offset..
     base = generator(frequency) + offset;
     
+    % ..which we take from here - doing so stops us from phase jumping
     offset = base(end);
     
+    % at last, apply the volume
     sound = sin(base) .* volume;
 end
\ No newline at end of file