feat: update synth version

Waveshape and volume implemented. Added Signal drawing

Todo: explore possibility to separate ui and applying state changes

Co-authored-by: HiveBeats <e1lama@protonmail.com>
Reviewed-on: #9

.gitignore

@@ -1,4 +1,6 @@
 /bin
 .DS_Store
 /Debug/
-*.wav
+*.wav
+*.dSYM
+/lib

.vscode/settings.json

@@ -3,6 +3,11 @@
         "readability/casting"
     ],
     "files.associations": {
-        "algorithm": "c"
-    }
+        "algorithm": "c",
+        "__bit_reference": "c",
+        "bitset": "c",
+        "chrono": "c",
+        "unordered_map": "c"
+    },
+    "FSharp.suggestGitignore": false,
 }

.vscode/tasks.json

@@ -0,0 +1,36 @@
+{
+    "tasks": [
+        {
+            "type": "cppbuild",
+            "label": "C/C++: clang сборка активного файла",
+            "command": "/usr/bin/clang",
+            "args": [
+                "-fcolor-diagnostics",
+                "-fansi-escape-codes",
+                "-g",
+                "${file}",
+                "${fileDirname}/utils.c",
+                "${fileDirname}/ring_buffer.c",
+                "${fileDirname}/oscillator.c",
+                "${fileDirname}/parser.c",
+                "${fileDirname}/export.c",
+                "-lm",
+                "-lraylib",
+                "-o",
+                "${fileDirname}/bin/${fileBasenameNoExtension}"
+            ],
+            "options": {
+                "cwd": "${fileDirname}"
+            },
+            "problemMatcher": [
+                "$gcc"
+            ],
+            "group": {
+                "kind": "build",
+                "isDefault": true
+            },
+            "detail": "Задача создана отладчиком."
+        }
+    ],
+    "version": "2.0.0"
+}

build.sh

@@ -1,3 +1,3 @@
 #!/bin/bash
 CC="${CXX:-cc}"
-$CC -Wall -std=c11 ./main.c ./parser.c -lm -lraylib -o ./bin/main
+$CC -Wall -std=c11 ./main.c ./utils.c ./ring_buffer.c ./oscillator.c ./parser.c ./export.c -lm -lraylib -o ./bin/main

export.c

@@ -0,0 +1,74 @@
+#include "export.h"
+
+#include "stdio.h"
+#include "string.h"
+#include "settings.h"
+
+uint16_t toInt16Sample(float sample) {
+    return (uint16_t)(sample * 32767.f);
+}
+
+static void write_file(char* filename, void* data, int size) {
+    FILE* fp = fopen(filename, "wb");  // open file for writing in binary mode
+    if (fp == NULL) {
+        fprintf(stderr, "Cannot open file: %s\n", filename);
+        exit(1);
+    }
+
+    fwrite(data, size, 1, fp);  // write data to file
+
+    fclose(fp);  // close file
+}
+
+void pack(uint16_t* d, size_t length) {
+    size_t dataLength = length * 2;
+
+    int bytesPerSample = 2;
+    int byteRate = SAMPLE_RATE * bytesPerSample;
+
+    size_t fileSize = 36 + dataLength;
+
+    uint8_t* buffer = (uint8_t*)malloc(fileSize);
+
+    int i = 0;
+
+    // RIFF header
+    memcpy(buffer + i, "RIFF", 4);
+    i += 4;
+    memcpy(buffer + i, &fileSize, 4);
+    i += 4;
+    memcpy(buffer + i, "WAVE", 4);
+    i += 4;
+
+    // fmt subchunk
+    memcpy(buffer + i, "fmt ", 4);
+    i += 4;
+    int fmtSize = 16;
+    memcpy(buffer + i, &fmtSize, 4);
+    i += 4;
+    uint16_t audioFormat = 1;
+    memcpy(buffer + i, &audioFormat, 2);
+    i += 2;
+    uint16_t numChannels = 1;
+    memcpy(buffer + i, &numChannels, 2);
+    i += 2;
+    int sampleRate = (int)SAMPLE_RATE;
+    memcpy(buffer + i, &sampleRate, 4);
+    i += 4;
+    memcpy(buffer + i, &byteRate, 4);
+    i += 4;
+    memcpy(buffer + i, &bytesPerSample, 2);
+    i += 2;
+    int bitsPerSample = bytesPerSample * 8;
+    memcpy(buffer + i, &bitsPerSample, 2);
+    i += 2;
+
+    // data subchunk
+    memcpy(buffer + i, "data", 4);
+    i += 4;
+    memcpy(buffer + i, &dataLength, 4);
+    i += 4;
+    memcpy(buffer + i, d, dataLength);
+
+    write_file("output.wav", buffer, fileSize);
+}

export.h

@@ -0,0 +1,9 @@
+#ifndef EXPORT_H
+#define EXPORT_H
+
+#include "stdlib.h"
+
+uint16_t toInt16Sample(float sample);
+void pack(uint16_t* d, size_t length);
+
+#endif

main.c

@@ -2,221 +2,38 @@
 #include "stdio.h"
 #include "string.h"
 #include "math.h"
+
 #include "parser.h"
+#include "utils.h"
+#include "ring_buffer.h"
+#include "settings.h"
+#include "oscillator.h"
+#include "export.h"
 
 #include "raylib.h"
-
-#define SAMPLE_RATE 48000.f
-#define BPM 120.f
-#define BEAT_DURATION 60.f/BPM
-#define PITCH_STANDARD 440.f
-#define VOLUME 0.5f
-#define ATTACK_MS 100.f
-
-#define SYNTH_PI 3.1415926535f
-
-//------------------------------------------------------------------------------------
-// General SynthSound
-//------------------------------------------------------------------------------------
-
-typedef struct SynthSound {
-    float* samples;
-    size_t sample_count;
-} SynthSound;
-
-// frees the original sounds
-SynthSound concat_sounds(SynthSound* sounds, size_t count) {
-    size_t total_count = 0;
-    for (size_t i = 0; i < count; i++) {
-        total_count += sounds[i].sample_count;
-    }
-    // array to hold the result
-    float* total = malloc(total_count * sizeof(float));
-
-    size_t current_count = 0;
-    for (size_t i = 0; i < count; i++) {
-        memcpy(total + current_count,
-            sounds[i].samples,
-            sounds[i].sample_count * sizeof(float));
-        current_count += sounds[i].sample_count;
-
-        free(sounds[i].samples);
-    }
-
-    SynthSound result = {
-        .samples = total,
-        .sample_count = total_count
-    };
-
-    return result;
-}
-
-//------------------------------------------------------------------------------------
-// Oscillator
-//------------------------------------------------------------------------------------
-
-typedef enum {
-    Sine,
-    Triangle,
-    Saw,
-    Square
-} OscillatorType;
-
-typedef struct OscillatorParameter {
-    OscillatorType osc;
-    float freq;
-} OscillatorParameter;
-
-typedef struct OscillatorParameterList {
-    OscillatorParameter* array;
-    size_t count;
-} OscillatorParameterList;
-
-typedef struct OscillatorGenerationParameter {
-    OscillatorParameterList oscillators;
-    float sample;
-} OscillatorGenerationParameter;
-
-static SynthSound get_init_samples(float duration) {
-    size_t sample_count = (size_t)(duration * SAMPLE_RATE);
-    float* samples = malloc(sizeof(float) * sample_count);
-
-    for (double i = 0.0; i < duration * SAMPLE_RATE; i++) {
-        samples[(int)i] = i;
-    }
-
-    SynthSound res = {
-        .samples = samples,
-        .sample_count = sample_count
-    };
-
-    return res;
-}
-
-static float pos(float hz, float x) {
-    return fmodf(hz * x / SAMPLE_RATE, 1);
-}
-
-float sineosc(float hz, float x) {
-    return sinf(x * (2.f * SYNTH_PI * hz / SAMPLE_RATE));
-}
-
-static float sign(float v) {
-    return (v > 0.0) ? 1.f : -1.f;
-}
-
-float squareosc(float hz, float x) {
-    return sign(sineosc(hz, x));
-}
-
-float triangleosc(float hz, float x) {
-    return 1.f - fabsf(pos(hz, x) - 0.5f) * 4.f;
-}
-
-float sawosc(float hz, float x) {
-    return pos(hz, x) * 2.f - 1.f;
-}
-
-float multiosc(OscillatorGenerationParameter param) {
-    float osc_sample = 0.f;
-    for (size_t i = 0; i < param.oscillators.count; i++) {
-        OscillatorParameter osc = param.oscillators.array[i];
-        switch (osc.osc) {
-            case Sine:
-                osc_sample += sineosc(osc.freq, param.sample);
-                break;
-            case Triangle:
-                osc_sample += triangleosc(osc.freq, param.sample);
-                break;
-            case Square:
-                osc_sample += squareosc(osc.freq, param.sample);
-                break;
-            case Saw:
-                osc_sample += sawosc(osc.freq, param.sample);
-                break;
-        }
-    }
-
-    return osc_sample;
-}
-
-static SynthSound freq(float duration, OscillatorParameterList osc) {
-    SynthSound samples = get_init_samples(duration);
-    // SynthSound attack = get_attack_samples();
-
-    float* output = malloc(sizeof(float) * samples.sample_count);
-    for (int i = 0; i < samples.sample_count; i++) {
-        float sample = samples.samples[i];
-        OscillatorGenerationParameter param = {
-            .oscillators = osc,
-            .sample = sample
-        };
-        output[i] = multiosc(param) * VOLUME;
-    }
-
-    // create attack and release
-    /*
-        let adsrLength = Seq.length output
-        let attackArray = attack |> Seq.take adsrLength
-        let release = Seq.rev attackArray
-    */
-    /*
-     todo: I will change the ADSR approach to an explicit ADSR module(with it's own state)
-    size_t adsr_length = samples.sample_count;
-    float *attackArray = NULL, *releaseArray = NULL;
-
-    if (adsr_length > 0) {
-        //todo: calloc
-        attackArray = malloc(sizeof(float) * adsr_length);
-        size_t attack_length = attack.sample_count < adsr_length
-                ? attack.sample_count
-                : adsr_length;
-        
-        memcpy(attackArray, attack.samples, attack_length);
-        //todo: calloc
-        releaseArray = malloc(sizeof(float) * adsr_length);
-        memcpy(releaseArray, attackArray, attack_length);
-        reverse_array(releaseArray, 0, adsr_length);
-    }
-    */
-
-    // return zipped array
-    SynthSound res = {
-        .samples = output,
-        .sample_count = samples.sample_count
-    };
-
-    return res;
-}
-
-/*
-static SynthSound get_attack_samples() {
-    float attack_time = 0.001 * ATTACK_MS;
-    size_t sample_count = (size_t)(attack_time * SAMPLE_RATE);
-    float* attack = malloc(sizeof(float) * sample_count);
-    float samples_to_rise = SAMPLE_RATE * attack_time;
-    float rising_delta = 1.0 / samples_to_rise;
-    float i = 0.0;
-
-    for (int j = 0; j < sample_count; j++) {
-        i += rising_delta;
-        attack[j] = fmin(i, 1.0);
-    }
-
-    SynthSound res = {
-        .samples = attack,
-        .sample_count = sample_count
-    };
-
-    return res;
-}
-*/
+#define RAYGUI_IMPLEMENTATION
+#include "raygui.h"
 
 //------------------------------------------------------------------------------------
 // Synth
 //------------------------------------------------------------------------------------
 
-static size_t get_semitone_shift_internal(char* root_note, char* target_note) {
+typedef struct OscillatorUI {
+    float volume;
+    float freq;//todo: remove or change to pitch shift
+    OscillatorType waveshape;
+    bool is_dropdown_open;
+    Rectangle shape_dropdown_rect;
+} OscillatorUI;
+
+typedef struct Synth {
+    OscillatorArray oscillators;
+    OscillatorUI* ui_oscillators;
+    Note current_note;
+    SynthSound* out_signal;
+} Synth;
+
+static int get_semitone_shift_internal(char* root_note, char* target_note) {
     char* pitch_classes[12] =
         { "C", "C#", "D", "D#", "E", "F", "F#", "G", "G#", "A", "A#", "B" };
 
@@ -260,139 +77,331 @@ static size_t get_semitone_shift_internal(char* root_note, char* target_note) {
         (target_pitch_class - root_pitch_class);
 }
 
-static float get_hz_by_semitone(size_t semitone) {
+static float get_hz_by_semitone(int semitone) {
     return PITCH_STANDARD * powf(powf(2.f, (1.f / 12.f)), semitone);
 }
 
-size_t get_semitone_shift(char* target_note) {
+int get_semitone_shift(char* target_note) {
     return get_semitone_shift_internal("A4", target_note);
 }
 
-SynthSound note(size_t semitone, float beats) {
+static OscillatorArray init_osc_array() {
+    Oscillator first = {
+        .osc = Square,
+        .freq = 440.f,
+        .volume = VOLUME
+    };
+
+    Oscillator* oscArray = malloc(sizeof(Oscillator*) * 1);
+    oscArray[0] = first;
+
+    OscillatorArray oscillators = {
+        .array = oscArray,
+        .count = 1
+    };
+
+    return oscillators;
+}
+
+SynthSound note(Synth* synth, int semitone, float beats) {
     float hz = get_hz_by_semitone(semitone);
     float duration = beats * BEAT_DURATION;
-
-    OscillatorParameter first = {
-        .osc = Saw,
-        .freq = hz/4.f
-    };
-
-    OscillatorParameter second = {
-        .osc = Saw,
-        .freq = hz + 0.5
-    };
-
-    OscillatorParameter third = {
-        .osc = Saw,
-        .freq = hz - 1.f
-    };
-
-    OscillatorParameter oscArray[] = { first, second, third };
-    OscillatorParameterList parameters = {
-        .array = oscArray,
-        .count = 3
-    };
-
-    return freq(duration, parameters);
-}
-
-SynthSound get_note_sound(Note input) {
-    float length = 1.f / input.length;
-    size_t semitone_shift = get_semitone_shift(input.name);
-    return note(semitone_shift, length);
-}
-
-
-//------------------------------------------------------------------------------------
-// Wav File 
-//------------------------------------------------------------------------------------
-
-static uint16_t toInt16Sample(float sample) {
-    return (uint16_t)(sample * 32767.f);
-}
-
-static void write_file(char* filename, void* data, int size) {
-    FILE* fp = fopen(filename, "wb");  // open file for writing in binary mode
-    if (fp == NULL) {
-        fprintf(stderr, "Cannot open file: %s\n", filename);
-        exit(1);
+    
+    // will change after oscillator starts to be more autonomous
+    for (size_t i = 0; i < synth->oscillators.count; i++) {
+        synth->oscillators.array[i].freq = hz;
     }
 
-    fwrite(data, size, 1, fp);  // write data to file
-
-    fclose(fp);  // close file
+    return freq(duration, synth->oscillators);
 }
 
-void pack(uint16_t* d, size_t length) {
-    size_t dataLength = length * 2;
-
-    int bytesPerSample = 2;
-    int byteRate = SAMPLE_RATE * bytesPerSample;
-
-    size_t fileSize = 36 + dataLength;
-
-    uint8_t* buffer = (uint8_t*)malloc(fileSize);
-
-    int i = 0;
-
-    // RIFF header
-    memcpy(buffer + i, "RIFF", 4);
-    i += 4;
-    memcpy(buffer + i, &fileSize, 4);
-    i += 4;
-    memcpy(buffer + i, "WAVE", 4);
-    i += 4;
-
-    // fmt subchunk
-    memcpy(buffer + i, "fmt ", 4);
-    i += 4;
-    int fmtSize = 16;
-    memcpy(buffer + i, &fmtSize, 4);
-    i += 4;
-    uint16_t audioFormat = 1;
-    memcpy(buffer + i, &audioFormat, 2);
-    i += 2;
-    uint16_t numChannels = 1;
-    memcpy(buffer + i, &numChannels, 2);
-    i += 2;
-    int sampleRate = (int)SAMPLE_RATE;
-    memcpy(buffer + i, &sampleRate, 4);
-    i += 4;
-    memcpy(buffer + i, &byteRate, 4);
-    i += 4;
-    memcpy(buffer + i, &bytesPerSample, 2);
-    i += 2;
-    int bitsPerSample = bytesPerSample * 8;
-    memcpy(buffer + i, &bitsPerSample, 2);
-    i += 2;
-
-    // data subchunk
-    memcpy(buffer + i, "data", 4);
-    i += 4;
-    memcpy(buffer + i, &dataLength, 4);
-    i += 4;
-    memcpy(buffer + i, d, dataLength);
-
-    write_file("output.wav", buffer, fileSize);
+SynthSound get_note_sound(Synth* synth, Note input) {
+    float length = 1.f / input.length;
+    int semitone_shift = get_semitone_shift(input.name);
+    return note(synth, semitone_shift, length);
 }
+//-------------------------------------------------------
+
+size_t detect_note_pressed(Note* note) {
+    size_t is_pressed = 0;
+    note->length = 8;
+    if (IsKeyPressed(KEY_A)) {
+        strcpy(note->name, "A4");
+        is_pressed = 1;
+    }
+    if (IsKeyPressed(KEY_B)) {
+        strcpy(note->name, "B4");
+        is_pressed = 1;
+    }
+    if (IsKeyPressed(KEY_C)) {
+        strcpy(note->name, "C4");
+        is_pressed = 1;
+    }
+    if (IsKeyPressed(KEY_D)) {
+        strcpy(note->name, "D4");
+        is_pressed = 1;
+    }
+    if (IsKeyPressed(KEY_E)) {
+        strcpy(note->name, "E4");
+        is_pressed = 1;
+    }
+    if (IsKeyPressed(KEY_F)) {
+        strcpy(note->name, "F4");
+        is_pressed = 1;
+    }
+    if (IsKeyPressed(KEY_G)) {
+        strcpy(note->name, "G4");
+        is_pressed = 1;
+    }
+    return is_pressed;
+}
+
+//------------------------------------------------------------------------------------
+// GUI
+//------------------------------------------------------------------------------------
+
+void DrawUi(Synth *synth) {
+    const int panel_x_start = 0;
+    const int panel_y_start = 0;
+    const int panel_width = OSCILLATOR_PANEL_WIDTH;
+    const int panel_height = WINDOW_HEIGHT;
+    
+    bool is_shape_dropdown_open = false;
+    int shape_index = 0;
+    
+    
+    GuiPanel((Rectangle){
+                 panel_x_start,
+                 panel_y_start,
+                 panel_width,
+                 panel_height
+             }, 
+            "");
+    
+    bool click_add_oscillator = GuiButton((Rectangle){
+                                              panel_x_start + 10,
+                                              panel_y_start + 10,
+                                              panel_width - 20,
+                                              25
+                                          }, "Add Oscillator");
+    if (click_add_oscillator)
+    {
+        // synth->ui_oscillator_count += 1;
+        // // Set defaults:
+        // UiOscillator *ui_osc = synth->ui_oscillator + (synth->ui_oscillator_count - 1);
+        // ui_osc->shape = WaveShape_SINE;
+        // ui_osc->freq = BASE_NOTE_FREQ;
+        // ui_osc->amplitude_ratio = 0.1f;
+        // ui_osc->shape_parameter_0 = 0.5f;
+    }
+
+    // Draw Oscillators
+    float panel_y_offset = 0;
+    //synth->ui_oscillator_count = 1
+    for (int ui_osc_i = 0; ui_osc_i < synth->oscillators.count; ui_osc_i++)
+    {
+        OscillatorUI* ui_osc = &synth->ui_oscillators[ui_osc_i];
+        Oscillator* osc = &synth->oscillators.array[ui_osc_i];
+        const bool has_shape_param = (ui_osc->waveshape == Square);
+        
+        // Draw Oscillator Panel
+        const int osc_panel_width = panel_width - 20;
+        const int osc_panel_height = has_shape_param ? 130 : 100;
+        const int osc_panel_x = panel_x_start + 10;
+        const int osc_panel_y = panel_y_start + 50 + panel_y_offset;
+        panel_y_offset += osc_panel_height + 5;
+        GuiPanel((Rectangle){
+                     osc_panel_x,
+                     osc_panel_y,
+                     osc_panel_width,
+                     osc_panel_height
+                 },
+                "");
+        
+        const float slider_padding = 50.f;
+        const float el_spacing = 5.f;
+        Rectangle el_rect = {
+            .x = osc_panel_x + slider_padding + 30,
+            .y = osc_panel_y + 10,
+            .width = osc_panel_width - (slider_padding * 2),
+            .height = 25
+        };
+        
+        // Volume slider
+        float decibels = (20.f * log10f(osc->volume));
+        char amp_slider_label[32];
+        sprintf(amp_slider_label, "%.1f dB", decibels);
+        decibels = GuiSlider(el_rect, 
+                             amp_slider_label, 
+                             "", 
+                             decibels, 
+                             -60.0f, 
+                             0.0f
+                             );
+        ui_osc->volume = powf(10.f, decibels * (1.f/20.f));
+        osc->volume = ui_osc->volume;
+
+        el_rect.y += el_rect.height + el_spacing;
+        
+        // Defer shape drop-down box.
+        ui_osc->shape_dropdown_rect = el_rect;
+        el_rect.y += el_rect.height + el_spacing;
+        /*
+        Rectangle delete_button_rect = el_rect;
+        delete_button_rect.x = osc_panel_x + 5;
+        delete_button_rect.y -= el_rect.height + el_spacing;
+        delete_button_rect.width = 30;
+        bool is_delete_button_pressed = GuiButton(delete_button_rect, "X");
+        if (is_delete_button_pressed)
+        {
+            memmove(
+                    synth->ui_oscillator + ui_osc_i, 
+                    synth->ui_oscillator + ui_osc_i + 1, 
+                    (synth->ui_oscillator_count - ui_osc_i) * sizeof(UiOscillator)
+                    );
+            synth->ui_oscillator_count -= 1;
+        }
+        */
+    }
+
+    // DRAW OSCILLATOR SHAPE INPUTS
+    for (int ui_osc_i = 0; ui_osc_i < synth->oscillators.count; ui_osc_i += 1)
+    {
+        OscillatorUI* ui_osc = &synth->ui_oscillators[ui_osc_i];
+        Oscillator* osc = &synth->oscillators.array[ui_osc_i];
+        // Shape select
+        int shape_index = (int)(ui_osc->waveshape);
+        bool is_dropdown_click = GuiDropdownBox(ui_osc->shape_dropdown_rect, 
+                                                WAVE_SHAPE_OPTIONS, 
+                                                &shape_index, 
+                                                ui_osc->is_dropdown_open
+                                                );
+        
+        if (is_dropdown_click)
+        {
+            ui_osc->is_dropdown_open = !ui_osc->is_dropdown_open;
+            ui_osc->waveshape = (OscillatorType)(shape_index);
+            // APPLY STATE TO REAL OSC
+            osc->osc = (OscillatorType)(shape_index);
+        }
+        if (ui_osc->is_dropdown_open) break;
+    }
+}
+
+void DrawSignal(Synth* synth) {
+    GuiGrid((Rectangle){0, 0, WINDOW_WIDTH, WINDOW_HEIGHT}, "", WINDOW_HEIGHT / 8, 2);
+    Vector2* signal_points = malloc(sizeof(Vector2) * synth->out_signal->sample_count);
+    const float screen_vertical_midpoint = (WINDOW_HEIGHT/2);
+    for (int point_idx = 0; point_idx < synth->out_signal->sample_count; point_idx++)
+    {
+        signal_points[point_idx].x = (float)point_idx + OSCILLATOR_PANEL_WIDTH;
+        signal_points[point_idx].y = screen_vertical_midpoint + (int)(synth->out_signal->samples[point_idx] * 300);
+    }
+    DrawLineStrip(signal_points, synth->out_signal->sample_count, RED);
+}
+
 
 //------------------------------------------------------------------------------------
 // Main
 //------------------------------------------------------------------------------------
 
 int main(int argc, char **argv) {
-    const size_t width = 1280;
-    const size_t height = 720;
+    InitWindow(WINDOW_WIDTH, WINDOW_HEIGHT, "SeeSynth - v0.2");
+    SetTargetFPS(60);
 
-    InitWindow(width, height, "SeeSynth - v0.1");
-    //SetTargetFPS(60); 
+    //todo: move that variables to Synth declaration
+    Note g_current_note = {
+        .length = 1,
+        .name = malloc(sizeof(char) * 3)
+    };
 
+    SynthSound g_sound = {
+        .sample_count = 0
+    };
+
+    Synth synth = {
+        .current_note = g_current_note,
+        .out_signal = &g_sound,
+        .oscillators = init_osc_array()
+    };
+    //todo: move somewhere in initialization
+    synth.ui_oscillators = malloc(sizeof(OscillatorUI) * synth.oscillators.count);
+    for (size_t i = 0; i < synth.oscillators.count; i++)
+    {
+        OscillatorUI* ui = &synth.ui_oscillators[i];
+        ui->freq = synth.oscillators.array[i].freq;
+        ui->waveshape = synth.oscillators.array[i].osc;
+        ui->volume = synth.oscillators.array[i].volume;
+    }
+    
+    int sound_played_count = 0;
+    float temp_buffer[STREAM_BUFFER_SIZE];
+    RingBuffer ring_buffer = ring_buffer_init(STREAM_BUFFER_SIZE);
+
+    InitAudioDevice();
+    SetMasterVolume(SYNTH_VOLUME);
+    SetAudioStreamBufferSizeDefault(STREAM_BUFFER_SIZE);
+    AudioStream synth_stream = LoadAudioStream(SAMPLE_RATE, sizeof(float) * 8, 1);
+    SetAudioStreamVolume(synth_stream, 0.5f);
+
+    PlayAudioStream(synth_stream);
+    
     // Main game loop
     while (!WindowShouldClose())    // Detect window close button or ESC key
     {
-        // Update
+        // Update Audio states
         //----------------------------------------------------------------------------------
-        // TODO: Update your variables here
+        // Fill ring buffer from current sound
+        SynthSound* sound = synth.out_signal;
+        size_t size_for_buffer = 0;
+        if (!ring_buffer.is_full && sound->sample_count != sound_played_count) {
+            write_log("[INFO] IsFull:%d Samples:%zu Played:%zu\n", 
+                ring_buffer.is_full, 
+                sound->sample_count, 
+                sound_played_count);
+            
+            // how many samples need write
+            size_t size_to_fill = 0;
+            
+            if ((sound->sample_count - sound_played_count) > ring_buffer.size) {
+                size_to_fill = ring_buffer.size;
+            } else {
+                size_to_fill = sound->sample_count - sound_played_count;
+            }
+
+            write_log("[INFO] SizeToFill:%zu\n", size_to_fill);
+            for (size_t i = 0; i < size_to_fill; i++) {
+                temp_buffer[i] = sound->samples[i];
+            }
+            
+            ring_buffer_write(&ring_buffer, temp_buffer, size_to_fill);
+            sound_played_count += size_to_fill;
+        }
+
+        // Play ring-buffered audio
+        if (IsAudioStreamProcessed(synth_stream) && !ring_buffer.is_empty) {
+                size_t size_to_read = ring_buffer_size(&ring_buffer);
+                
+                write_log("Samples to play:%zu \n", size_to_read);
+                //todo: try to start reading directly from ring buffer, avoiding temp_buffer
+                ring_buffer_read(&ring_buffer, temp_buffer, size_to_read);
+                // can try the SetAudioStreamCallback
+                UpdateAudioStream(synth_stream, temp_buffer, size_to_read);
+                // can overwrite the ring buffer to avoid that
+                if (sound->sample_count == sound_played_count) {
+                    ring_buffer_reset(&ring_buffer);
+                }
+        }
+        //----------------------------------------------------------------------------------
+        
+        // Update On Input
+        //----------------------------------------------------------------------------------
+        Note current_note = synth.current_note;
+        if (detect_note_pressed(&current_note)) {
+            *sound = get_note_sound(&synth, current_note);
+            sound_played_count = 0;
+            write_log("Note played: %s\n", current_note.name);
+        }
         //----------------------------------------------------------------------------------
  
         // Draw
@@ -400,13 +409,15 @@ int main(int argc, char **argv) {
         BeginDrawing();
  
             ClearBackground(RAYWHITE);
- 
-            DrawText("Congrats! You created your first window!", 190, 200, 20, LIGHTGRAY);
+            DrawUi(&synth);
+            DrawSignal(&synth);
+            //DrawText("Congrats! You created your first window!", 190, 200, 20, LIGHTGRAY);
+            //DrawFPS(0,0);
  
         EndDrawing();
         //----------------------------------------------------------------------------------
     }
-
+    
     char* input = "A4-4 A4-4 A4-4 A4-4 A4-2 A4-4 A4-4 A4-4 A4-4 A4-4 A4-2 D5-4 D5-4 D5-4 D5-4 D5-4 D5-4 D5-2 C5-4 C5-4 C5-4 C5-4 C5-4 C5-4 C5-2 G4-2 ";
     char* buf = malloc(strlen(input) + 1);
     strcpy(buf, input);
@@ -415,7 +426,7 @@ int main(int argc, char **argv) {
     SynthSound* sounds = malloc(sizeof(SynthSound) * note_array.count);
     for (size_t i = 0; i < note_array.count; i++) {
         Note note = note_array.notes[i];
-        sounds[i] = get_note_sound(note);
+        sounds[i] = get_note_sound(&synth, note);
     }
 
     SynthSound song = concat_sounds(sounds, note_array.count);
@@ -428,6 +439,9 @@ int main(int argc, char **argv) {
 
     // De-Initialization
     //--------------------------------------------------------------------------------------
+    StopAudioStream(synth_stream);
+    UnloadAudioStream(synth_stream);    
+    CloseAudioDevice();
     CloseWindow();        // Close window and OpenGL context
     //--------------------------------------------------------------------------------------
 

oscillator.c

@@ -0,0 +1,153 @@
+#include "oscillator.h"
+#include "settings.h"
+#include "math.h"
+#include "stdlib.h"
+
+static SynthSound get_init_samples(float duration) {
+    size_t sample_count = (size_t)(duration * SAMPLE_RATE);
+    float* samples = malloc(sizeof(float) * sample_count);
+
+    for (double i = 0.0; i < duration * SAMPLE_RATE; i++) {
+        samples[(int)i] = i;
+    }
+
+    SynthSound res = {
+        .samples = samples,
+        .sample_count = sample_count
+    };
+
+    return res;
+}
+
+static float pos(float hz, float x) {
+    return fmodf(hz * x / SAMPLE_RATE, 1);
+}
+
+static float sineosc(float hz, float x) {
+    return sinf(x * (2.f * SYNTH_PI * hz / SAMPLE_RATE));
+}
+
+static float sign(float v) {
+    return (v > 0.0) ? 1.f : -1.f;
+}
+
+static float squareosc(float hz, float x) {
+    return sign(sineosc(hz, x));
+}
+
+static float triangleosc(float hz, float x) {
+    return 1.f - fabsf(pos(hz, x) - 0.5f) * 4.f;
+}
+
+static float sawosc(float hz, float x) {
+    return pos(hz, x) * 2.f - 1.f;
+}
+
+float multiosc(OscillatorGenerationParameter param) {
+    float osc_sample = 0.f;
+    for (size_t i = 0; i < param.oscillators.count; i++) {
+        Oscillator osc = param.oscillators.array[i];
+        switch (osc.osc) {
+            case Sine:
+                osc_sample += sineosc(osc.freq, param.sample) * osc.volume;
+                break;
+            case Triangle:
+                osc_sample += triangleosc(osc.freq, param.sample) * osc.volume;
+                break;
+            case Square:
+                osc_sample += squareosc(osc.freq, param.sample) * osc.volume;
+                break;
+            case Saw:
+                osc_sample += sawosc(osc.freq, param.sample) * osc.volume;
+                break;
+        }
+    }
+
+    return osc_sample;
+}
+
+SynthSound freq(float duration, OscillatorArray osc) {
+    SynthSound samples = get_init_samples(duration);
+    // SynthSound attack = get_attack_samples();
+
+    float* output = malloc(sizeof(float) * samples.sample_count);
+    for (int i = 0; i < samples.sample_count; i++) {
+        float sample = samples.samples[i];
+        OscillatorGenerationParameter param = {
+            .oscillators = osc,
+            .sample = sample
+        };
+        output[i] = multiosc(param);
+    }
+
+    // create attack and release
+    /*
+        let adsrLength = Seq.length output
+        let attackArray = attack |> Seq.take adsrLength
+        let release = Seq.rev attackArray
+    */
+    /*
+     todo: I will change the ADSR approach to an explicit ADSR module(with it's own state)
+    size_t adsr_length = samples.sample_count;
+    float *attackArray = NULL, *releaseArray = NULL;
+
+    if (adsr_length > 0) {
+        //todo: calloc
+        attackArray = malloc(sizeof(float) * adsr_length);
+        size_t attack_length = attack.sample_count < adsr_length
+                ? attack.sample_count
+                : adsr_length;
+        
+        memcpy(attackArray, attack.samples, attack_length);
+        //todo: calloc
+        releaseArray = malloc(sizeof(float) * adsr_length);
+        memcpy(releaseArray, attackArray, attack_length);
+        reverse_array(releaseArray, 0, adsr_length);
+    }
+    */
+
+    // if (samples.sample_count > 1024) {
+    //     samples.sample_count = 1024;
+    // }
+    // //todo: move to somewhere
+    // for (size_t i = 0; i < 1024; i++) {
+    //     synth_sound.samples[i] = 0.0f;
+    // }
+
+    // for (size_t i = 0; i < samples.sample_count; i++) {
+    //     synth_sound.samples[i] = output[i];
+    // }
+    // synth_sound.sample_count = samples.sample_count;
+
+
+    // return zipped array
+    SynthSound res = {
+        .samples = output,
+        .sample_count = samples.sample_count
+    };
+
+    return res;
+}
+
+/*
+static SynthSound get_attack_samples() {
+    float attack_time = 0.001 * ATTACK_MS;
+    size_t sample_count = (size_t)(attack_time * SAMPLE_RATE);
+    float* attack = malloc(sizeof(float) * sample_count);
+    float samples_to_rise = SAMPLE_RATE * attack_time;
+    float rising_delta = 1.0 / samples_to_rise;
+    float i = 0.0;
+
+    for (int j = 0; j < sample_count; j++) {
+        i += rising_delta;
+        attack[j] = fmin(i, 1.0);
+    }
+
+    SynthSound res = {
+        .samples = attack,
+        .sample_count = sample_count
+    };
+
+    return res;
+}
+*/

oscillator.h

@@ -0,0 +1,34 @@
+#ifndef OSCILLATOR_H
+#define OSCILLATOR_H
+
+#include "utils.h"
+#define WAVE_SHAPE_OPTIONS "Sine;Triangle;Sawtooth;Square"
+typedef enum {
+    Sine,
+    Triangle,
+    Saw,
+    Square
+} OscillatorType;
+
+typedef struct Oscillator {
+    OscillatorType osc;
+    float freq;
+    float volume;
+} Oscillator;
+
+typedef struct OscillatorArray {
+    Oscillator* array;
+    size_t count;
+} OscillatorArray;
+
+typedef struct OscillatorGenerationParameter {
+    OscillatorArray oscillators;
+    float sample;
+} OscillatorGenerationParameter;
+
+float multiosc(OscillatorGenerationParameter param);
+SynthSound freq(float duration, OscillatorArray osc);
+
+
+
+#endif

ring_buffer.c

@@ -0,0 +1,99 @@
+#include "ring_buffer.h"
+#include "utils.h"
+
+RingBuffer ring_buffer_init(size_t buffer_size) {
+    RingBuffer buffer = {
+        .items = calloc(buffer_size, sizeof(float)),
+        .head = 0,
+        .tail = 0,
+        .is_full = 0,
+        .is_empty = 1,
+        .size = buffer_size
+    };
+
+    return buffer;
+}
+
+void ring_buffer_reset(RingBuffer* me) {
+    me->head = 0;
+    me->tail = 0;
+    me->is_full = 0;
+}
+
+// +
+static void advance_pointer(RingBuffer* me) {
+    if(me->is_full) {
+        me->tail++;
+		if (me->tail == me->size) { 
+			me->tail = 0;
+		}
+	}
+    me->head++;
+	if (me->head == me->size) { 
+		me->head = 0;
+	}
+    size_t is_full = me->head == me->tail ? 1 : 0;
+	me->is_full = is_full;
+}
+
+// -
+static void retreat_pointer(RingBuffer* me) {
+	me->is_full = 0;
+    me->tail++;
+	if (me->tail == me->size) { 
+		me->tail = 0;
+	}
+}
+
+void ring_buffer_write(RingBuffer* buffer, float* data, size_t count) {
+    if (buffer->is_full || buffer->head + count > buffer->size) {
+        write_log("[WARN] Trying to overfill the ring buffer: \n\tIsFull:%d\n\tHead:%zu\n\tCount:%zu\n\t", 
+            buffer->is_full,
+            buffer->head, 
+            count);
+        return;
+    }
+    buffer->is_empty = 0;
+
+    for (size_t i = 0; i < count; i++) {
+        buffer->items[buffer->head] = data[i];
+        advance_pointer(buffer);
+    }
+    //me->is_empty = is_full && (me->head == me->tail);
+}
+
+int ring_buffer_read(RingBuffer* buffer, float* output, size_t count) {
+    if (buffer->is_empty) {
+        write_log("[WARN] Trying to read empty buffer");
+        return 0;
+    }
+
+    for (size_t i = 0; i < count; i++) {
+        output[i] = buffer->items[buffer->tail];
+        retreat_pointer(buffer);
+    }
+    buffer->is_empty = !buffer->is_full && (buffer->head == buffer->tail);
+    return 1;
+}
+
+size_t ring_buffer_size(RingBuffer* buffer) {
+	size_t size = buffer->size;
+	if(!buffer->is_full) {
+		if(buffer->head >= buffer->tail) {
+			size = (buffer->head - buffer->tail);
+		}
+		else {
+			size = (buffer->size + buffer->head - buffer->tail);
+		}
+	}
+
+	return size;
+}
+
+void ring_buffer_print(RingBuffer* me) {
+    write_log("[INFO] The ring buffer: \n\tIsFull:%d\n\tIsEmpty:%d\n\tHead:%zu\n\tTail:%zu\n\t", 
+                me->is_full, 
+                me->is_empty, 
+                me->head, 
+                me->tail);
+}

ring_buffer.h

@@ -0,0 +1,22 @@
+#ifndef RING_BUFFER_H
+#define RING_BUFFER_H
+
+#include "stdlib.h"
+
+typedef struct RingBuffer {
+    float* items;
+    size_t head;
+    size_t tail;
+    int is_full;
+    int is_empty;
+    size_t size;
+} RingBuffer;
+
+RingBuffer ring_buffer_init(size_t buffer_size);
+void ring_buffer_reset(RingBuffer* me);
+void ring_buffer_write(RingBuffer* buffer, float* data, size_t count);
+int ring_buffer_read(RingBuffer* buffer, float* output, size_t count);
+size_t ring_buffer_size(RingBuffer* buffer);
+void ring_buffer_print(RingBuffer* me);
+
+#endif

settings.h

@@ -0,0 +1,19 @@
+#ifndef SETTINGS_H
+#define SETTINGS_H
+
+#define SAMPLE_RATE 48000.f
+#define BPM 120.f
+#define BEAT_DURATION 60.f/BPM
+#define PITCH_STANDARD 440.f
+#define VOLUME 0.5f
+#define ATTACK_MS 100.f
+#define STREAM_BUFFER_SIZE 4096
+
+#define SYNTH_PI 3.1415926535f
+#define SYNTH_VOLUME 0.5f
+
+#define WINDOW_WIDTH 640
+#define WINDOW_HEIGHT 480
+#define OSCILLATOR_PANEL_WIDTH 200
+
+#endif

utils.c

@@ -0,0 +1,30 @@
+#include "utils.h"
+#include "stdlib.h"
+#include "string.h"
+
+// frees the original sounds
+SynthSound concat_sounds(SynthSound* sounds, size_t count) {
+    size_t total_count = 0;
+    for (size_t i = 0; i < count; i++) {
+        total_count += sounds[i].sample_count;
+    }
+    // array to hold the result
+    float* total = malloc(total_count * sizeof(float));
+
+    size_t current_count = 0;
+    for (size_t i = 0; i < count; i++) {
+        memcpy(total + current_count,
+            sounds[i].samples,
+            sounds[i].sample_count * sizeof(float));
+        current_count += sounds[i].sample_count;
+
+        free(sounds[i].samples);
+    }
+
+    SynthSound result = {
+        .samples = total,
+        .sample_count = total_count
+    };
+
+    return result;
+}

utils.h

@@ -0,0 +1,22 @@
+#ifndef UTILS_H
+#define UTILS_H
+
+#include "stdio.h"
+
+#define write_log(format,args...) do { \
+        printf(format, ## args); \
+    } while(0)
+
+//------------------------------------------------------------------------------------
+// General SynthSound
+//------------------------------------------------------------------------------------
+
+typedef struct SynthSound {
+    float* samples;
+    size_t sample_count;
+} SynthSound;
+
+// frees the original sounds
+SynthSound concat_sounds(SynthSound* sounds, size_t count);
+
+#endif