refactor: formatting

implemented in c++ to improve readability and simplify maintenance

Co-authored-by: HiveBeats <e1lama@protonmail.com>
Reviewed-on: #13

.clang-format

@@ -0,0 +1,216 @@
+---
+Language:        Cpp
+# BasedOnStyle:  LLVM
+AccessModifierOffset: -2
+AlignAfterOpenBracket: Align
+AlignArrayOfStructures: None
+AlignConsecutiveAssignments:
+  Enabled:         false
+  AcrossEmptyLines: false
+  AcrossComments:  false
+  AlignCompound:   false
+  PadOperators:    true
+AlignConsecutiveBitFields:
+  Enabled:         false
+  AcrossEmptyLines: false
+  AcrossComments:  false
+  AlignCompound:   false
+  PadOperators:    false
+AlignConsecutiveDeclarations:
+  Enabled:         false
+  AcrossEmptyLines: false
+  AcrossComments:  false
+  AlignCompound:   false
+  PadOperators:    false
+AlignConsecutiveMacros:
+  Enabled:         false
+  AcrossEmptyLines: false
+  AcrossComments:  false
+  AlignCompound:   false
+  PadOperators:    false
+AlignEscapedNewlines: Right
+AlignOperands:   Align
+AlignTrailingComments: true
+AllowAllArgumentsOnNextLine: true
+AllowAllParametersOfDeclarationOnNextLine: true
+AllowShortEnumsOnASingleLine: true
+AllowShortBlocksOnASingleLine: Never
+AllowShortCaseLabelsOnASingleLine: false
+AllowShortFunctionsOnASingleLine: All
+AllowShortLambdasOnASingleLine: All
+AllowShortIfStatementsOnASingleLine: Never
+AllowShortLoopsOnASingleLine: false
+AlwaysBreakAfterDefinitionReturnType: None
+AlwaysBreakAfterReturnType: None
+AlwaysBreakBeforeMultilineStrings: false
+AlwaysBreakTemplateDeclarations: MultiLine
+AttributeMacros:
+  - __capability
+BinPackArguments: true
+BinPackParameters: true
+BraceWrapping:
+  AfterCaseLabel:  false
+  AfterClass:      false
+  AfterControlStatement: Never
+  AfterEnum:       false
+  AfterFunction:   false
+  AfterNamespace:  false
+  AfterObjCDeclaration: false
+  AfterStruct:     false
+  AfterUnion:      false
+  AfterExternBlock: false
+  BeforeCatch:     false
+  BeforeElse:      false
+  BeforeLambdaBody: false
+  BeforeWhile:     false
+  IndentBraces:    false
+  SplitEmptyFunction: true
+  SplitEmptyRecord: true
+  SplitEmptyNamespace: true
+BreakBeforeBinaryOperators: None
+BreakBeforeConceptDeclarations: Always
+BreakBeforeBraces: Attach
+BreakBeforeInheritanceComma: false
+BreakInheritanceList: BeforeColon
+BreakBeforeTernaryOperators: true
+BreakConstructorInitializersBeforeComma: false
+BreakConstructorInitializers: BeforeColon
+BreakAfterJavaFieldAnnotations: false
+BreakStringLiterals: true
+ColumnLimit:     80
+CommentPragmas:  '^ IWYU pragma:'
+QualifierAlignment: Leave
+CompactNamespaces: false
+ConstructorInitializerIndentWidth: 4
+ContinuationIndentWidth: 4
+Cpp11BracedListStyle: true
+DeriveLineEnding: true
+DerivePointerAlignment: false
+DisableFormat:   false
+EmptyLineAfterAccessModifier: Never
+EmptyLineBeforeAccessModifier: LogicalBlock
+ExperimentalAutoDetectBinPacking: false
+PackConstructorInitializers: BinPack
+BasedOnStyle:    ''
+ConstructorInitializerAllOnOneLineOrOnePerLine: false
+AllowAllConstructorInitializersOnNextLine: true
+FixNamespaceComments: true
+ForEachMacros:
+  - foreach
+  - Q_FOREACH
+  - BOOST_FOREACH
+IfMacros:
+  - KJ_IF_MAYBE
+IncludeBlocks:   Preserve
+IncludeCategories:
+  - Regex:           '^"(llvm|llvm-c|clang|clang-c)/'
+    Priority:        2
+    SortPriority:    0
+    CaseSensitive:   false
+  - Regex:           '^(<|"(gtest|gmock|isl|json)/)'
+    Priority:        3
+    SortPriority:    0
+    CaseSensitive:   false
+  - Regex:           '.*'
+    Priority:        1
+    SortPriority:    0
+    CaseSensitive:   false
+IncludeIsMainRegex: '(Test)?$'
+IncludeIsMainSourceRegex: ''
+IndentAccessModifiers: false
+IndentCaseLabels: true
+IndentCaseBlocks: false
+IndentGotoLabels: true
+IndentPPDirectives: None
+IndentExternBlock: AfterExternBlock
+IndentRequiresClause: true
+IndentWidth: 4
+IndentWrappedFunctionNames: false
+InsertBraces:    false
+InsertTrailingCommas: None
+JavaScriptQuotes: Leave
+JavaScriptWrapImports: true
+KeepEmptyLinesAtTheStartOfBlocks: true
+LambdaBodyIndentation: Signature
+MacroBlockBegin: ''
+MacroBlockEnd:   ''
+MaxEmptyLinesToKeep: 1
+NamespaceIndentation: None
+ObjCBinPackProtocolList: Auto
+ObjCBlockIndentWidth: 2
+ObjCBreakBeforeNestedBlockParam: true
+ObjCSpaceAfterProperty: false
+ObjCSpaceBeforeProtocolList: true
+PenaltyBreakAssignment: 2
+PenaltyBreakBeforeFirstCallParameter: 19
+PenaltyBreakComment: 300
+PenaltyBreakFirstLessLess: 120
+PenaltyBreakOpenParenthesis: 0
+PenaltyBreakString: 1000
+PenaltyBreakTemplateDeclaration: 10
+PenaltyExcessCharacter: 1000000
+PenaltyReturnTypeOnItsOwnLine: 60
+PenaltyIndentedWhitespace: 0
+PointerAlignment: Left
+PPIndentWidth:   -1
+ReferenceAlignment: Pointer
+ReflowComments:  true
+RemoveBracesLLVM: false
+RequiresClausePosition: OwnLine
+SeparateDefinitionBlocks: Leave
+ShortNamespaceLines: 1
+SortIncludes:    CaseSensitive
+SortJavaStaticImport: Before
+SortUsingDeclarations: true
+SpaceAfterCStyleCast: false
+SpaceAfterLogicalNot: false
+SpaceAfterTemplateKeyword: true
+SpaceBeforeAssignmentOperators: true
+SpaceBeforeCaseColon: false
+SpaceBeforeCpp11BracedList: false
+SpaceBeforeCtorInitializerColon: true
+SpaceBeforeInheritanceColon: true
+SpaceBeforeParens: ControlStatements
+SpaceBeforeParensOptions:
+  AfterControlStatements: true
+  AfterForeachMacros: true
+  AfterFunctionDefinitionName: false
+  AfterFunctionDeclarationName: false
+  AfterIfMacros:   true
+  AfterOverloadedOperator: false
+  AfterRequiresInClause: false
+  AfterRequiresInExpression: false
+  BeforeNonEmptyParentheses: false
+SpaceAroundPointerQualifiers: Default
+SpaceBeforeRangeBasedForLoopColon: true
+SpaceInEmptyBlock: false
+SpaceInEmptyParentheses: false
+SpacesBeforeTrailingComments: 1
+SpacesInAngles:  Never
+SpacesInConditionalStatement: false
+SpacesInContainerLiterals: true
+SpacesInCStyleCastParentheses: false
+SpacesInLineCommentPrefix:
+  Minimum:         1
+  Maximum:         -1
+SpacesInParentheses: false
+SpacesInSquareBrackets: false
+SpaceBeforeSquareBrackets: false
+BitFieldColonSpacing: Both
+Standard:        Latest
+StatementAttributeLikeMacros:
+  - Q_EMIT
+StatementMacros:
+  - Q_UNUSED
+  - QT_REQUIRE_VERSION
+TabWidth:        8
+UseCRLF:         false
+UseTab:          Never
+WhitespaceSensitiveMacros:
+  - STRINGIZE
+  - PP_STRINGIZE
+  - BOOST_PP_STRINGIZE
+  - NS_SWIFT_NAME
+  - CF_SWIFT_NAME
+...
+

.vscode/launch.json

@@ -0,0 +1,16 @@
+{
+    // Use IntelliSense to learn about possible attributes.
+    // Hover to view descriptions of existing attributes.
+    // For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
+    "version": "0.2.0",
+    "configurations": [
+        {
+            "type": "lldb",
+            "request": "launch",
+            "name": "Debug",
+            "program": "${workspaceFolder}/bin/main",
+            "args": [],
+            "cwd": "${workspaceFolder}"
+        }
+    ]
+}

.vscode/settings.json

@@ -7,7 +7,64 @@
         "__bit_reference": "c",
         "bitset": "c",
         "chrono": "c",
-        "unordered_map": "c"
+        "unordered_map": "c",
+        "__bits": "cpp",
+        "__config": "cpp",
+        "__debug": "cpp",
+        "__errc": "cpp",
+        "__hash_table": "cpp",
+        "__locale": "cpp",
+        "__mutex_base": "cpp",
+        "__node_handle": "cpp",
+        "__split_buffer": "cpp",
+        "__threading_support": "cpp",
+        "__tuple": "cpp",
+        "__verbose_abort": "cpp",
+        "array": "cpp",
+        "atomic": "cpp",
+        "bit": "cpp",
+        "cctype": "cpp",
+        "clocale": "cpp",
+        "cmath": "cpp",
+        "complex": "cpp",
+        "cstdarg": "cpp",
+        "cstddef": "cpp",
+        "cstdint": "cpp",
+        "cstdio": "cpp",
+        "cstdlib": "cpp",
+        "cstring": "cpp",
+        "ctime": "cpp",
+        "cwchar": "cpp",
+        "cwctype": "cpp",
+        "exception": "cpp",
+        "initializer_list": "cpp",
+        "ios": "cpp",
+        "iosfwd": "cpp",
+        "istream": "cpp",
+        "limits": "cpp",
+        "locale": "cpp",
+        "memory": "cpp",
+        "mutex": "cpp",
+        "new": "cpp",
+        "optional": "cpp",
+        "ostream": "cpp",
+        "ratio": "cpp",
+        "sstream": "cpp",
+        "stdexcept": "cpp",
+        "streambuf": "cpp",
+        "string": "cpp",
+        "string_view": "cpp",
+        "system_error": "cpp",
+        "tuple": "cpp",
+        "type_traits": "cpp",
+        "typeinfo": "cpp",
+        "variant": "cpp",
+        "vector": "cpp",
+        "__nullptr": "cpp",
+        "__string": "cpp",
+        "compare": "cpp",
+        "concepts": "cpp",
+        "numeric": "cpp"
     },
     "FSharp.suggestGitignore": false,
 }

.vscode/tasks.json

@@ -3,24 +3,12 @@
         {
             "type": "cppbuild",
             "label": "C/C++: clang сборка активного файла",
-            "command": "/usr/bin/clang",
+            "command": "sh",
             "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}"
+                "${workspaceFolder}/build.sh"
             ],
             "options": {
-                "cwd": "${fileDirname}"
+                "cwd": "${workspaceFolder}"
             },
             "problemMatcher": [
                 "$gcc"

build.sh

@@ -1,3 +1,5 @@
 #!/bin/bash
-CC="${CXX:-cc}"
-$CC -Wall -std=c11 ./main.c ./utils.c ./ring_buffer.c ./oscillator.c ./parser.c ./export.c -lm -lraylib -o ./bin/main
+CC="${CXX:-c++}"
+LL="-lm -lraylib"
+FLAGS="-Wall -std=c++17 -I./inc/ -g"
+$CC $FLAGS $(find ./src -type f -iregex ".*\.cpp") $LL -o ./bin/main

docs/ADSR.md

@@ -26,6 +26,7 @@ release_samples = int(release_time * sample_rate)
 
 # Attack phase
 envelope[:attack_samples] = np.linspace(0, 1, num=attack_samples)
+# 1/n * count;
 
 # Decay phase
 decay_slope = (1 - sustain_level) / decay_samples

export.c

@@ -1,74 +0,0 @@
-#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

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

inc/ADSR.h

@@ -0,0 +1,37 @@
+#pragma once
+#include "Effect.h"
+#include "Ramp.h"
+#include <cstddef>
+
+struct ADSRParameters {
+    float attack_time;   // Attack time in seconds
+    float decay_time;    // Decay time in seconds
+    float sustain_level; // Sustain level (0 to 1)
+    float release_time;
+};
+
+enum ADSRState { Off, Attack, Decay, Sustain, Release };
+
+class ADSR : public Effect {
+  private:
+    ADSRParameters m_parameters;
+    ADSRState m_state;
+    Ramp* m_ramp;
+
+    void process_sample(float* sample);
+    bool is_attack_elapsed();
+    bool is_decay_elapsed();
+    bool is_release_elapsed();
+    void recheck_state();
+
+  public:
+    ADSR(/* args */);
+    ADSR(ADSRParameters param);
+    ~ADSR();
+    void OnSetNote() override;
+    void OnUnsetNote() override;
+    // void RetriggerState() override;
+    void Process(std::vector<float>& samples) override;
+    void Reset();
+    void SetParameters(float attack, float decay, float sustain, float release);
+};

inc/Adder.h

@@ -0,0 +1,26 @@
+#pragma once
+
+#include "Oscillator.h"
+#include "Settings.h"
+#include <numeric>
+#include <vector>
+
+struct Adder {
+    static void SumOscillators(const std::vector<Oscillator*>& oscillators,
+                               std::vector<float>& signal) {
+        size_t sample_count =
+            STREAM_BUFFER_SIZE; //(size_t)(1.f/FPS * SAMPLE_RATE);
+
+        // std::vector<float>* output = new std::vector<float>();
+        // output->reserve(sample_count);
+
+        for (size_t i = 0; i < sample_count; i++) {
+            float sample = 0.0f;
+            for (Oscillator* osc : oscillators) {
+                sample += osc->GenerateSample(1.f);
+            }
+
+            signal[i] = sample;
+        }
+    }
+};

inc/Application.h

@@ -0,0 +1,26 @@
+#pragma once
+#include "Note.h"
+#include "Renderer.h"
+#include "Synth.h"
+#include "SynthGuiState.h"
+#include "raylib.h"
+
+class Application {
+  private:
+    Synth m_synth;
+    SynthGuiState m_synth_gui_state;
+    AudioStream m_synth_stream;
+    int m_sound_played_count;
+    Note* m_current_note;
+    Renderer m_renderer;
+    bool detect_note_pressed(Note* note);
+    void init_synth();
+    void init_audio();
+    void update_on_note_input();
+    void play_buffered_audio();
+
+  public:
+    Application(/* args */);
+    ~Application();
+    void Run();
+};

inc/Effect.h

@@ -0,0 +1,13 @@
+#pragma once
+#include <vector>
+class Effect {
+  private:
+    /* data */
+  public:
+    Effect(/* args */){};
+    ~Effect(){};
+    virtual void OnSetNote(){};
+    virtual void OnUnsetNote(){};
+    // virtual void RetriggerState(){};
+    virtual void Process(std::vector<float>& samples){};
+};

inc/KeyBoard.h

@@ -0,0 +1,78 @@
+#pragma once
+#include "Settings.h"
+#include <cmath>
+#include <cstdlib>
+#include <cstring>
+#include <string>
+
+class KeyBoard {
+  private:
+    /* data */
+    static int get_semitone_shift_internal(const char* root_note,
+                                           char* target_note) {
+        const char* pitch_classes[12] = {"C",  "C#", "D",  "D#", "E",  "F",
+                                         "F#", "G",  "G#", "A",  "A#", "B"};
+
+        // Extract the note number and pitch class for the root note
+        int root_note_num = (int)root_note[strlen(root_note) - 1] - '0';
+
+        char* root_pitch_class_str =
+            (char*)malloc((strlen(root_note) - 1) * sizeof(char));
+        strncpy(root_pitch_class_str, root_note, strlen(root_note) - 1);
+
+        int root_pitch_class = -1;
+
+        for (int i = 0; i < 12; i++) {
+            if (strcmp(pitch_classes[i], root_pitch_class_str) == 0) {
+                root_pitch_class = i;
+                break;
+            }
+        }
+
+        free(root_pitch_class_str);
+
+        // Extract the note number and pitch class for the target note
+        int target_note_num = (int)target_note[strlen(target_note) - 1] - '0';
+
+        char* target_pitch_class_str =
+            (char*)malloc((strlen(target_note) - 1) * sizeof(char));
+        strncpy(target_pitch_class_str, target_note, strlen(target_note) - 1);
+
+        int target_pitch_class = -1;
+
+        for (int i = 0; i < 12; i++) {
+            if (strcmp(pitch_classes[i], target_pitch_class_str) == 0) {
+                target_pitch_class = i;
+                break;
+            }
+        }
+
+        free(target_pitch_class_str);
+
+        // Calculate the semitone shift using the formula
+        return (target_note_num - root_note_num) * 12 +
+               (target_pitch_class - root_pitch_class);
+    }
+
+  public:
+    KeyBoard(/* args */);
+    ~KeyBoard();
+
+    static float GetHzBySemitone(int semitone) {
+        return PITCH_STANDARD * powf(powf(2.f, (1.f / 12.f)), semitone);
+    }
+
+    static int GetSemitoneShift(const std::string& target_note) {
+        char* target_note_cstr = new char[target_note.length() + 1];
+        strcpy(target_note_cstr, target_note.c_str());
+
+        int result = get_semitone_shift_internal("A4", target_note_cstr);
+
+        delete[] target_note_cstr;
+        return result;
+    }
+};
+
+KeyBoard::KeyBoard(/* args */) {}
+
+KeyBoard::~KeyBoard() {}

inc/Logger.h

@@ -0,0 +1,6 @@
+#pragma once
+#include "cstdio"
+
+#define write_log(format,args...) do { \
+        printf(format, ## args); \
+    } while(0)

inc/Note.h

@@ -0,0 +1,8 @@
+#pragma once
+
+#include <string>
+
+struct Note {
+    std::string& name;
+    int length;
+};

inc/Oscillator.h

@@ -0,0 +1,35 @@
+#pragma once
+#include "OscillatorType.h"
+#include <vector>
+
+class Oscillator {
+  private:
+    OscillatorType m_osc;
+    float m_freq;
+    float m_volume;
+    float m_phase;
+    float m_phase_dt;
+    float (Oscillator::*m_osc_function)(void);
+    float (Oscillator::*m_dt_function)(float freq);
+    void sine_osc_phase_incr();
+    void saw_osc_phase_incr();
+    float calc_saw_phase_delta(float freq);
+    float calc_sine_phase_delta(float freq);
+    float sawosc();
+    float triangleosc();
+    float squareosc();
+    float sign(float v);
+    float sineosc();
+
+  public:
+    Oscillator(OscillatorType osc, float freq, float volume);
+    ~Oscillator();
+    OscillatorType GetType() { return m_osc; }
+    void SetType(OscillatorType osc);
+    float GetVolume() { return m_volume; }
+    void SetVolume(float volume) { m_volume = volume; }
+    float GetFreq() { return m_freq; }
+    void SetFreq(float freq);
+    void Reset();
+    float GenerateSample(float duration);
+};

inc/OscillatorType.h

@@ -0,0 +1,2 @@
+#pragma once
+typedef enum { Sine, Triangle, Saw, Square } OscillatorType;

inc/Ramp.h

@@ -0,0 +1,16 @@
+#pragma once
+
+class Ramp {
+  private:
+    float m_level;
+    float m_sample_rate;
+    float m_increment;
+    int m_counter;
+
+  public:
+    Ramp(float starting_level, float sample_rate);
+    ~Ramp();
+    void RampTo(float value, float time);
+    float Process();
+    bool IsCompleted();
+};

inc/Renderer.h

@@ -0,0 +1,29 @@
+#pragma once
+#include "ADSR.h"
+#include "Synth.h"
+#include "SynthGuiState.h"
+#include "raylib.h"
+#include <vector>
+
+class Renderer {
+  private:
+    void draw_main_panel(const Rectangle& panel_bounds);
+    void draw_add_oscillator_button(Synth& synth, SynthGuiState& synth_gui,
+                                    Rectangle panel_bounds);
+    float draw_oscillators_panels(
+        const std::vector<Oscillator*>& oscillators,
+        const std::vector<OscillatorGuiState*>& gui_oscillators,
+        const Rectangle& panel_bounds);
+    void draw_oscillators_shape_inputs(
+        const std::vector<Oscillator*>& oscillators,
+        const std::vector<OscillatorGuiState*>& guiOscillators);
+    void draw_ui(Synth& synth, SynthGuiState& synth_gui);
+    void draw_signal(Synth& synth, SynthGuiState& synth_gui);
+    void draw_adsr_panel(ADSR* adsr, ADSRGuiState& gui_adsr,
+                         const Rectangle& panel_bounds, float panel_y_offset);
+
+  public:
+    Renderer(/* args */);
+    ~Renderer();
+    void Draw(Synth& synth, SynthGuiState& synth_gui);
+};

inc/RingBuffer.h

@@ -0,0 +1,115 @@
+#pragma once
+#include "Logger.h"
+#include <cstddef>
+template <typename T> class RingBuffer {
+  private:
+    T* m_items; /* data */
+    std::size_t m_head;
+    std::size_t m_tail;
+    bool m_is_full;
+    bool m_is_empty;
+    std::size_t m_size;
+    void advance_pointer();
+    void retreat_pointer();
+
+  public:
+    RingBuffer(std::size_t size);
+    ~RingBuffer();
+    bool IsFull() { return m_is_full; }
+    bool IsEmpty() { return m_is_empty; }
+    std::size_t GetSize();
+    std::size_t GetCapacity() { return m_size; }
+    void Reset();
+    void Write(T* data, size_t count);
+    bool Read(T* output, size_t count);
+    void Print();
+};
+
+template <typename T> RingBuffer<T>::RingBuffer(std::size_t size) {
+    m_items = new T[size];
+    m_head = 0;
+    m_tail = 0;
+    m_is_full = 0;
+    m_is_empty = 1;
+    m_size = size;
+}
+
+template <typename T> RingBuffer<T>::~RingBuffer() { delete[] m_items; }
+
+template <typename T> void RingBuffer<T>::Reset() {
+    m_head = 0;
+    m_tail = 0;
+    m_is_full = 0;
+}
+
+template <typename T> void RingBuffer<T>::advance_pointer() {
+    if (m_is_full) {
+        m_tail++;
+        if (m_tail == m_size) {
+            m_tail = 0;
+        }
+    }
+    m_head++;
+    if (m_head == m_size) {
+        m_head = 0;
+    }
+    std::size_t p_is_full = m_head == m_tail ? 1 : 0;
+    m_is_full = p_is_full;
+}
+
+template <typename T> void RingBuffer<T>::retreat_pointer() {
+    m_is_full = 0;
+    m_tail++;
+    if (m_tail == m_size) {
+        m_tail = 0;
+    }
+}
+
+template <typename T> void RingBuffer<T>::Write(T* data, std::size_t count) {
+    if (m_is_full || m_head + count > m_size) {
+        write_log("[WARN] Trying to overfill the ring buffer: "
+                  "\n\tIsFull:%d\n\tHead:%zu\n\tCount:%zu\n\t",
+                  m_is_full, m_head, count);
+        return;
+    }
+    m_is_empty = 0;
+
+    for (std::size_t i = 0; i < count; i++) {
+        m_items[m_head] = data[i];
+        advance_pointer();
+    }
+    // m_is_empty = m_is_full && (m_head == m_tail);
+}
+
+template <typename T> bool RingBuffer<T>::Read(T* output, std::size_t count) {
+    if (m_is_empty) {
+        write_log("[WARN] Trying to read empty buffer");
+        return 0;
+    }
+
+    for (std::size_t i = 0; i < count; i++) {
+        output[i] = m_items[m_tail];
+        retreat_pointer();
+    }
+    m_is_empty = !m_is_full && (m_head == m_tail);
+    return 1;
+}
+
+template <typename T> std::size_t RingBuffer<T>::GetSize() {
+    size_t p_size = m_size;
+    if (!m_is_full) {
+        if (m_head >= m_tail) {
+            p_size = (m_head - m_tail);
+        } else {
+            p_size = (m_size + m_head - m_tail);
+        }
+    }
+
+    return p_size;
+}
+
+template <typename T> void RingBuffer<T>::Print() {
+    write_log("[INFO] The ring buffer: "
+              "\n\tIsFull:%d\n\tIsEmpty:%d\n\tHead:%zu\n\tTail:%zu\n\t",
+              m_is_full, m_is_empty, m_head, m_tail);
+}

inc/Settings.h

@@ -1,19 +1,17 @@
-#ifndef SETTINGS_H
-#define SETTINGS_H
+#pragma once
 
-#define SAMPLE_RATE 48000.f
+#define SAMPLE_RATE 44100.f
 #define BPM 120.f
-#define BEAT_DURATION 60.f/BPM
+#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 STREAM_BUFFER_SIZE 1024
+#define FPS 60
 
 #define SYNTH_PI 3.1415926535f
 #define SYNTH_VOLUME 0.5f
 
 #define WINDOW_WIDTH 640
 #define WINDOW_HEIGHT 480
-#define OSCILLATOR_PANEL_WIDTH 200
-
-#endif
+#define OSCILLATOR_PANEL_WIDTH 200

inc/Synth.h

@@ -0,0 +1,37 @@
+#pragma once
+
+#include "ADSR.h"
+#include "Adder.h"
+#include "Effect.h"
+#include "Note.h"
+#include "Oscillator.h"
+#include "Settings.h"
+#include <vector>
+
+class Synth {
+  private:
+    bool is_note_triggered;
+    std::vector<Oscillator*> m_oscillators;
+    std::vector<Effect*> m_effects;
+    // OscillatorUI* ui_oscillators;
+    // Note m_current_note;
+    std::vector<float> m_out_signal;
+    void zero_signal();
+    void get_note();
+    void trigger_note_on_effects();
+    void untrigger_note_on_effects();
+    void apply_effects();
+
+  public:
+    Synth(/* args */);
+    ~Synth();
+    void TriggerNote(Note input);
+    void ProduceSound();
+    void StopSound();
+    void AddOscillator();
+    void AddEffect(Effect* fx);
+    const std::vector<float>& GetOutSignal() { return m_out_signal; }
+    const std::vector<Oscillator*>& GetOscillators() { return m_oscillators; }
+    const bool& GetIsNoteTriggered() { return is_note_triggered; }
+    ADSR* GetADSR() { return (ADSR*)m_effects[0]; }
+};

inc/SynthGuiState.h

@@ -0,0 +1,24 @@
+#pragma once
+#include "OscillatorType.h"
+#include "raygui.h"
+#include <vector>
+
+struct OscillatorGuiState {
+    float volume;
+    float freq; // todo: remove or change to pitch shift
+    OscillatorType waveshape;
+    bool is_dropdown_open;
+    Rectangle shape_dropdown_rect;
+};
+
+struct ADSRGuiState {
+    float attack;
+    float decay;
+    float sustain;
+    float release;
+};
+
+struct SynthGuiState {
+    std::vector<OscillatorGuiState*> oscillators;
+    ADSRGuiState adsr;
+};

main.c

@@ -1,471 +0,0 @@
-#include "stdlib.h"
-#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 RAYGUI_IMPLEMENTATION
-#include "raygui.h"
-
-//------------------------------------------------------------------------------------
-// Synth
-//------------------------------------------------------------------------------------
-
-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" };
-
-    // Extract the note number and pitch class for the root note
-    int root_note_num = (int)root_note[strlen(root_note) - 1] - '0';
-
-    char* root_pitch_class_str = malloc((strlen(root_note) - 1) * sizeof(char));
-    strncpy(root_pitch_class_str, root_note, strlen(root_note) - 1);
-
-    int root_pitch_class = -1;
-
-    for (int i = 0; i < 12; i++) {
-        if (strcmp(pitch_classes[i], root_pitch_class_str) == 0) {
-            root_pitch_class = i;
-            break;
-        }
-    }
-
-    free(root_pitch_class_str);
-
-    // Extract the note number and pitch class for the target note
-    int target_note_num = (int)target_note[strlen(target_note) - 1] - '0';
-
-    char* target_pitch_class_str =
-        malloc((strlen(target_note) - 1) * sizeof(char));
-    strncpy(target_pitch_class_str, target_note, strlen(target_note) - 1);
-
-    int target_pitch_class = -1;
-
-    for (int i = 0; i < 12; i++) {
-        if (strcmp(pitch_classes[i], target_pitch_class_str) == 0) {
-            target_pitch_class = i;
-            break;
-        }
-    }
-
-    free(target_pitch_class_str);
-
-    // Calculate the semitone shift using the formula
-    return (target_note_num - root_note_num) * 12 +
-        (target_pitch_class - root_pitch_class);
-}
-
-static float get_hz_by_semitone(int semitone) {
-    return PITCH_STANDARD * powf(powf(2.f, (1.f / 12.f)), semitone);
-}
-
-int get_semitone_shift(char* target_note) {
-    return get_semitone_shift_internal("A4", target_note);
-}
-
-static OscillatorArray init_osc_array() {
-    Oscillator first = {
-        .osc = Square,
-        .freq = 440.f,
-        .volume = VOLUME
-    };
-
-    Oscillator* oscArray = malloc(sizeof(Oscillator*) * 1);
-    assert(oscArray);
-    
-    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;
-    
-    // will change after oscillator starts to be more autonomous
-    for (size_t i = 0; i < synth->oscillators.count; i++) {
-        osc_set_freq(&synth->oscillators.array[i], hz);
-    }
-
-    return freq(duration, synth->oscillators);
-}
-
-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 note_on(Synth *synth, Note *note) {
-	
-}
-
-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];
-        assert(ui_osc);
-
-        Oscillator* osc = &synth->oscillators.array[ui_osc_i];
-        assert(osc);
-
-        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];
-        assert(ui_osc);
-
-        Oscillator* osc = &synth->oscillators.array[ui_osc_i];
-        assert(osc);
-
-        // 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) {
-    InitWindow(WINDOW_WIDTH, WINDOW_HEIGHT, "SeeSynth - v0.2");
-    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];
-        assert(ui);
-
-        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 Audio states
-        //----------------------------------------------------------------------------------
-        // Fill ring buffer from current sound
-        SynthSound* sound = synth.out_signal;
-        assert(sound);
-
-        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:%d\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
-        //----------------------------------------------------------------------------------
-        BeginDrawing();
- 
-            ClearBackground(RAYWHITE);
-            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);
-
-    NoteArray note_array = parse_notes(buf, strlen(buf));
-    SynthSound* sounds = malloc(sizeof(SynthSound) * note_array.count);
-    assert(sounds);
-
-    for (size_t i = 0; i < note_array.count; i++) {
-        Note note = note_array.notes[i];
-        sounds[i] = get_note_sound(&synth, note);
-    }
-
-    SynthSound song = concat_sounds(sounds, note_array.count);
-    uint16_t* song_pcm = malloc(sizeof(uint16_t) * song.sample_count);
-    assert(song_pcm);
-
-    for (size_t i = 0; i < song.sample_count; i++) {
-        song_pcm[i] = toInt16Sample(song.samples[i]);
-    }
-
-    pack(song_pcm, song.sample_count);
-
-    // De-Initialization
-    //--------------------------------------------------------------------------------------
-    StopAudioStream(synth_stream);
-    UnloadAudioStream(synth_stream);    
-    CloseAudioDevice();
-    CloseWindow();        // Close window and OpenGL context
-    //--------------------------------------------------------------------------------------
-
-    return 0;
-}

oscillator.c

@@ -1,167 +0,0 @@
-#include "oscillator.h"
-#include "settings.h"
-#include "math.h"
-#include "stdlib.h"
-
-#define TWO_PI 2*SYNTH_PI
-
-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 void sine_osc_phase_incr(Oscillator* osc) {
-    osc->phase += osc->phase_dt;
-    if (osc->phase >= TWO_PI)
-        osc->phase -= TWO_PI;
-}
-
-static void saw_osc_phase_incr(Oscillator* osc) {
-    osc->phase += osc->phase_dt;
-    if (osc->phase >= 1.0f)
-        osc->phase -= 1.0f;
-}
-
-static float calc_saw_phase_delta(float freq) {
-    return freq / SAMPLE_RATE;
-}
-
-static float calc_sine_phase_delta(float freq) {
-    return (TWO_PI * freq) / SAMPLE_RATE;
-}
-
-static float sineosc(Oscillator* osc) {
-    float result = sinf(osc->phase);
-    sine_osc_phase_incr(osc);
-    return result;
-}
-
-static float sign(float v) {
-    return (v > 0.0) ? 1.f : -1.f;
-}
-
-static float squareosc(Oscillator* osc) {
-    return sign(sineosc(osc));
-}
-
-static float triangleosc(Oscillator* osc) {
-    float result = 1.f - fabsf(osc->phase - 0.5f) * 4.f;
-    saw_osc_phase_incr(osc);
-    return result;
-}
-
-static float sawosc(Oscillator* osc) {
-    float result = osc->phase * 2.f - 1.f;
-    saw_osc_phase_incr(osc);
-    return result;
-}
-
-void osc_set_freq(Oscillator* osc, float freq) {
-    osc->freq = freq;
-    osc->phase = 0;
-    switch (osc->osc)
-    {
-        case Sine:
-            osc->phase_dt = calc_sine_phase_delta(freq);
-            break;
-        case Square:
-            osc->phase_dt = calc_sine_phase_delta(freq);
-            break;
-        case Triangle:
-            osc->phase_dt = calc_saw_phase_delta(freq);
-            break;
-        case Saw:
-            osc->phase_dt = calc_saw_phase_delta(freq);
-            break;
-        default:
-            break;
-    }
-}
-
-void osc_reset(Oscillator* osc) {
-    osc->volume = 0;
-    osc->phase = 0;
-    osc->phase_dt = 0;
-}
-
-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];
-        assert(osc);
-        
-        switch (osc->osc) {
-            case Sine:
-                osc_sample += sineosc(osc) * osc->volume;
-                break;
-            case Triangle:
-                osc_sample += triangleosc(osc) * osc->volume;
-                break;
-            case Square:
-                osc_sample += squareosc(osc) * osc->volume;
-                break;
-            case Saw:
-                osc_sample += sawosc(osc) * osc->volume;
-                break;
-        }
-    }
-
-    return osc_sample;
-}
-
-SynthSound freq(float duration, OscillatorArray osc) {
-    size_t sample_count = (size_t)(duration * SAMPLE_RATE);
-    
-    float* output = malloc(sizeof(float) * sample_count);
-    for (size_t i = 0; i < sample_count; i++) {
-        OscillatorGenerationParameter param = {
-            .oscillators = osc
-        };
-        output[i] = multiosc(param);
-    }
-    
-    SynthSound res = {
-        .samples = output,
-        .sample_count = 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

@@ -1,37 +0,0 @@
-#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;
-    float phase;
-    float phase_dt;
-} Oscillator;
-
-typedef struct OscillatorArray {
-    Oscillator* array;
-    size_t count;
-} OscillatorArray;
-
-typedef struct OscillatorGenerationParameter {
-    OscillatorArray oscillators;
-} OscillatorGenerationParameter;
-
-void osc_set_freq(Oscillator* osc, float freq);
-void osc_reset(Oscillator* osc);
-float multiosc(OscillatorGenerationParameter param);
-SynthSound freq(float duration, OscillatorArray osc);
-
-
-
-#endif

parser.c

@@ -1,94 +0,0 @@
-#include "parser.h"
-#include "string.h"
-#include "stdio.h"
-
-struct StringArray {
-    char** array;
-    size_t count;
-};
-
-static void trim(char* str) {
-    size_t len = strlen(str);
-    while (len > 0 && (str[len - 1] == '\n' || str[len - 1] == ' ')) {
-        str[--len] = '\0';
-    }
-}
-
-static struct StringArray parse_note_parts(char* input) {
-    size_t count = 0;
-    size_t i = 0;
-    while (input[i] != '\0') {
-        if (input[i] == ' ')
-            count++;
-
-        i++;
-    }
-
-    char** array = malloc(sizeof(char*) * count);
-
-    char* sep = " ";
-    char* line = strtok(input, sep);
-    i = 0;
-    while (line != NULL) {
-        array[i] = strdup(line);
-        line = strtok(NULL, sep);
-        i++;
-    }
-
-    struct StringArray result = {
-        .array = array,
-        .count = count
-    };
-
-    return result;
-}
-
-NoteArray parse_notes(char* input, size_t len) {
-    struct StringArray note_strings = parse_note_parts(input);
-    
-    NoteArray notes;
-    notes.count = note_strings.count;
-
-    char* end;
-    for (size_t i = 0; i < note_strings.count; i++) {
-        char* line = note_strings.array[i];
-        trim(line);
-        
-        char* note_name = strtok(line, "-");
-        char* note_length_str = strtok(NULL, "-");
-
-        int note_length = strtol(note_length_str, &end, 10);
-        if (*end != '\0') {
-            fprintf(stderr,
-                "Failed to parse note length: %s\n", note_length_str);
-            return notes;
-        }
-        
-        char* buf = malloc(strlen(note_name) + 1);
-        strcpy(buf, note_name);
-        
-        Note note = {
-            .length = note_length,
-            .name = buf
-        };
-
-        notes.notes[i] = note;
-    }
-
-    return notes;
-}
-
-/*
-static int test(int argc, char **argv) {
-    char* input = "A4-4 A4-2 C5-8 C5-4 ";
-    char* buf = malloc(strlen(input) + 1);
-    strcpy(buf, input);
-
-    NoteArray note_array = parse_notes(buf, strlen(buf));
-    for (size_t i = 0; i < note_array.count; i++) {
-        Note note = note_array.notes[i];
-    }
-
-    return 0;
-}
-*/

parser.h

@@ -1,20 +0,0 @@
-#ifndef PARSER_H
-#define PARSER_H
-
-#include "stdlib.h"
-
-#define MAX_NOTES 1024
-
-typedef struct Note {
-    char* name;
-    int length;
-} Note;
-
-typedef struct NoteArray {
-    Note notes[MAX_NOTES];
-    size_t count;
-} NoteArray;
-
-NoteArray parse_notes(char* input, size_t len);
-
-#endif

ring_buffer.c

@@ -1,99 +0,0 @@
-#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

@@ -1,22 +0,0 @@
-#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

src/ADSR.cpp

@@ -0,0 +1,97 @@
+#include "ADSR.h"
+#include "Logger.h"
+#include "Settings.h"
+
+ADSR::ADSR(/* args */) {
+    m_parameters.attack_time = 1.f;
+    m_parameters.decay_time = 0.4f;
+    m_parameters.sustain_level = 0.6f;
+    m_parameters.release_time = 0.8f;
+    m_ramp = new Ramp(0, SAMPLE_RATE);
+}
+
+ADSR::ADSR(ADSRParameters param) { m_parameters = param; }
+
+ADSR::~ADSR() { delete m_ramp; }
+
+bool ADSR::is_attack_elapsed() {
+    return m_state == Attack && m_ramp->IsCompleted();
+}
+
+bool ADSR::is_decay_elapsed() {
+    return m_state == Decay && m_ramp->IsCompleted();
+}
+
+bool ADSR::is_release_elapsed() {
+    return m_state == Release && m_ramp->IsCompleted();
+}
+
+void ADSR::recheck_state() {
+    switch (m_state) {
+        case Attack:
+            if (is_attack_elapsed()) {
+                m_state = Decay;
+                m_ramp->RampTo(m_parameters.sustain_level,
+                               m_parameters.decay_time);
+            }
+            break;
+        case Decay:
+            if (is_decay_elapsed()) {
+                m_state = Sustain;
+            }
+            break;
+        case Release:
+            if (is_release_elapsed()) {
+                m_state = Off;
+            }
+            break;
+        default:
+            break;
+    }
+}
+
+void ADSR::process_sample(float* sample) {
+    if (m_state == Off) {
+        (*sample) = 0;
+    } else if (m_state == Attack) {
+        (*sample) = (*sample) * m_ramp->Process();
+    } else if (m_state == Decay) {
+        (*sample) = (*sample) * m_ramp->Process();
+    } else if (m_state == Sustain) {
+        (*sample) = (*sample) * m_parameters.sustain_level;
+    } else if (m_state == Release) {
+        (*sample) = (*sample) * m_ramp->Process();
+    }
+}
+
+void ADSR::OnSetNote() {
+    write_log("Set ADSR\n");
+    if (m_state == Off) {
+        m_state = Attack;
+    } else if (m_state == Release) {
+        m_state = Attack;
+    };
+
+    m_ramp->RampTo(1, m_parameters.attack_time);
+}
+
+void ADSR::OnUnsetNote() {
+    write_log("Unset ADSR\n");
+    m_state = Release;
+    m_ramp->RampTo(0, m_parameters.release_time);
+}
+
+void ADSR::Process(std::vector<float>& samples) {
+    for (std::size_t i = 0; i < samples.size(); i++) {
+        recheck_state();
+        process_sample(&samples[i]);
+    }
+}
+
+void ADSR::SetParameters(float attack, float decay, float sustain,
+                         float release) {
+    m_parameters.attack_time = attack;
+    m_parameters.decay_time = decay;
+    m_parameters.sustain_level = sustain;
+    m_parameters.release_time = release;
+}

src/Application.cpp

@@ -0,0 +1,131 @@
+#include "Application.h"
+#include "Logger.h"
+#include "Settings.h"
+#include <string>
+
+Application::Application(/* args */) {
+    init_synth();
+    init_audio();
+}
+
+Application::~Application() {
+    StopAudioStream(m_synth_stream);
+    UnloadAudioStream(m_synth_stream);
+    CloseAudioDevice();
+    CloseWindow();
+    // todo: move to gui state class destructor (make it a class)
+    for (int i = 0; i < m_synth_gui_state.oscillators.size(); i++) {
+        delete m_synth_gui_state.oscillators[i];
+    }
+}
+
+void Application::init_audio() {
+    m_sound_played_count = 0;
+
+    InitAudioDevice();
+    SetMasterVolume(SYNTH_VOLUME);
+    SetAudioStreamBufferSizeDefault(STREAM_BUFFER_SIZE);
+    m_synth_stream = LoadAudioStream(SAMPLE_RATE, sizeof(float) * 8, 1);
+    SetAudioStreamVolume(m_synth_stream, 0.5f);
+
+    PlayAudioStream(m_synth_stream);
+}
+
+void Application::init_synth() {
+    // todo: move that variables to Synth declaration
+    std::string* nameString = new std::string(std::string(new char[3]));
+    m_current_note = new Note{.length = 1, .name = (*nameString)};
+    m_current_note->name.assign("G4");
+    // todo: move somewhere in initialization
+    std::vector<Oscillator*> oscillators = m_synth.GetOscillators();
+    m_synth_gui_state.oscillators.reserve(oscillators.size());
+    for (size_t i = 0; i < oscillators.size(); i++) {
+        Oscillator* osc = oscillators[i];
+        assert(osc);
+
+        OscillatorGuiState* ui =
+            new OscillatorGuiState{.freq = osc->GetFreq(),
+                                   .waveshape = osc->GetType(),
+                                   .volume = osc->GetVolume()};
+        m_synth_gui_state.oscillators.push_back(ui);
+    }
+}
+
+bool Application::detect_note_pressed(Note* note) {
+    std::size_t is_pressed = 0;
+    note->length = 8;
+    if (IsKeyDown(KEY_A)) {
+        note->name.assign("A2");
+        is_pressed = 1;
+    }
+    if (IsKeyDown(KEY_B)) {
+        note->name.assign("B2");
+        is_pressed = 1;
+    }
+    if (IsKeyDown(KEY_C)) {
+        note->name.assign("C2");
+        is_pressed = 1;
+    }
+    if (IsKeyDown(KEY_D)) {
+        note->name.assign("D2");
+        is_pressed = 1;
+    }
+    if (IsKeyDown(KEY_E)) {
+        note->name.assign("E2");
+        is_pressed = 1;
+    }
+    if (IsKeyDown(KEY_F)) {
+        note->name.assign("F2");
+        is_pressed = 1;
+    }
+    if (IsKeyDown(KEY_G)) {
+        note->name.assign("G2");
+        is_pressed = 1;
+    }
+    return is_pressed == 1;
+}
+
+bool is_note_up() {
+    return IsKeyUp(KEY_A) || IsKeyUp(KEY_B) ||
+           IsKeyUp(KEY_C) || IsKeyUp(KEY_D) ||
+           IsKeyUp(KEY_E) || IsKeyUp(KEY_F) || IsKeyUp(KEY_G);
+}
+
+// Update On Input
+void Application::update_on_note_input() {
+    if (detect_note_pressed(m_current_note)) {
+
+        if (!m_synth.GetIsNoteTriggered()) {
+            m_synth.TriggerNote((*m_current_note));
+        }
+
+        // m_sound_played_count = 0;
+        write_log("Note played: %s\n", m_current_note->name.c_str());
+    } else if (is_note_up() && m_synth.GetIsNoteTriggered()) {
+        m_synth.StopSound();
+    }
+    // will produce 0 signal if ADSR is in off state
+    m_synth.ProduceSound();
+}
+
+// Play ring-buffered audio
+void Application::play_buffered_audio() {
+    if (IsAudioStreamProcessed(m_synth_stream)) {
+        // const float audio_frame_start_time = GetTime();
+        update_on_note_input();
+        UpdateAudioStream(m_synth_stream, m_synth.GetOutSignal().data(),
+                          STREAM_BUFFER_SIZE);
+        // const float audio_freme_duration = GetTime() -
+        // audio_frame_start_time; write_log("Frame time: %.3f%% \n", 100.0f /
+        // ((1.0f / audio_freme_duration) /
+        // ((float)SAMPLE_RATE/STREAM_BUFFER_SIZE)));
+    }
+}
+
+void Application::Run() {
+    // Main game loop
+    while (!WindowShouldClose()) {
+        play_buffered_audio();
+        m_renderer.Draw(m_synth, m_synth_gui_state);
+    }
+}

src/Oscillator.cpp

@@ -0,0 +1,92 @@
+#include "Oscillator.h"
+#include "Settings.h"
+
+#define TWO_PI 2 * SYNTH_PI
+
+Oscillator::Oscillator(OscillatorType osc, float freq, float volume) {
+    SetType(osc);
+    m_freq = freq;
+    m_volume = volume;
+}
+
+Oscillator::~Oscillator() {}
+
+void Oscillator::Reset() {
+    m_volume = 0;
+    m_phase = 0;
+    m_phase_dt = 0;
+}
+
+void Oscillator::SetType(OscillatorType osc) {
+    m_osc = osc;
+    switch (m_osc) {
+        case Sine:
+            m_osc_function = &Oscillator::sineosc;
+            m_dt_function = &Oscillator::calc_sine_phase_delta;
+            break;
+        case Triangle:
+            m_osc_function = &Oscillator::triangleosc;
+            m_dt_function = &Oscillator::calc_saw_phase_delta;
+            break;
+        case Square:
+            m_osc_function = &Oscillator::squareosc;
+            m_dt_function = &Oscillator::calc_sine_phase_delta;
+            break;
+        case Saw:
+            m_osc_function = &Oscillator::sawosc;
+            m_dt_function = &Oscillator::calc_saw_phase_delta;
+            break;
+    }
+}
+
+void Oscillator::SetFreq(float freq) {
+    m_freq = freq;
+    m_phase = 0;
+    m_phase_dt = (this->*m_dt_function)(freq);
+}
+
+float Oscillator::GenerateSample(float duration) {
+    return (this->*m_osc_function)() * m_volume;
+}
+
+void Oscillator::sine_osc_phase_incr() {
+    m_phase += m_phase_dt;
+    if (m_phase >= TWO_PI)
+        m_phase -= TWO_PI;
+}
+
+void Oscillator::saw_osc_phase_incr() {
+    m_phase += m_phase_dt;
+    if (m_phase >= 1.0f)
+        m_phase -= 1.0f;
+}
+
+float Oscillator::calc_saw_phase_delta(float freq) {
+    return freq / SAMPLE_RATE;
+}
+
+float Oscillator::calc_sine_phase_delta(float freq) {
+    return (TWO_PI * freq) / SAMPLE_RATE;
+}
+
+float Oscillator::sineosc() {
+    float result = sinf(m_phase);
+    sine_osc_phase_incr();
+    return result;
+}
+
+float Oscillator::sign(float v) { return (v > 0.0) ? 1.f : -1.f; }
+
+float Oscillator::squareosc() { return sign(sineosc()); }
+
+float Oscillator::triangleosc() {
+    float result = 1.f - fabsf(m_phase - 0.5f) * 4.f;
+    saw_osc_phase_incr();
+    return result;
+}
+
+float Oscillator::sawosc() {
+    float result = m_phase * 2.f - 1.f;
+    saw_osc_phase_incr();
+    return result;
+}

src/Ramp.cpp

@@ -0,0 +1,27 @@
+#include "Ramp.h"
+#include "Logger.h"
+
+Ramp::Ramp(float starting_level, float sample_rate) {
+    m_level = starting_level;
+    m_sample_rate = sample_rate;
+}
+
+Ramp::~Ramp() {}
+
+void Ramp::RampTo(float val, float time) {
+    m_increment = (val - m_level) / (m_sample_rate * time);
+    m_counter = (int)(m_sample_rate * time);
+    write_log("Ramping from: %.1f to: %.1f by: %lf for: %d\n", m_level, val,
+              m_increment, m_counter);
+}
+
+float Ramp::Process() {
+    if (m_counter > 0) {
+        m_counter--;
+        m_level += m_increment;
+    }
+
+    return m_level;
+}
+
+bool Ramp::IsCompleted() { return m_counter == 0; }

src/Renderer.cpp

@@ -0,0 +1,245 @@
+#include "Renderer.h"
+#define RAYGUI_IMPLEMENTATION
+#include "Logger.h"
+#include "Settings.h"
+
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wunused-but-set-variable"
+#pragma clang diagnostic ignored "-Wunused-variable"
+#pragma clang diagnostic ignored "-Wdeprecated-declarations"
+#include "raygui.h"
+#pragma clang diagnostic pop
+
+Renderer::Renderer(/* args */) {
+    InitWindow(WINDOW_WIDTH, WINDOW_HEIGHT, "SeeSynth - v0.2");
+    SetTargetFPS(FPS);
+}
+
+Renderer::~Renderer() {}
+
+void Renderer::Draw(Synth& synth, SynthGuiState& synth_gui) {
+    BeginDrawing();
+
+    ClearBackground(RAYWHITE);
+    // todo: implement renderer
+    draw_ui(synth, synth_gui);
+    draw_signal(synth, synth_gui);
+    // DrawText("Congrats! You created your first window!", 190, 200, 20,
+    // LIGHTGRAY); DrawFPS(0,0);
+
+    EndDrawing();
+}
+
+void Renderer::draw_signal(Synth& synth, SynthGuiState& synth_gui) {
+    GuiGrid((Rectangle){0, 0, WINDOW_WIDTH, WINDOW_HEIGHT}, "",
+            WINDOW_HEIGHT / 8, 2);
+    auto signal = synth.GetOutSignal();
+    Vector2* signal_points = new Vector2[signal.size()];
+    const float screen_vertical_midpoint = (WINDOW_HEIGHT / 2);
+    for (int point_idx = 0; point_idx < signal.size(); point_idx++) {
+        signal_points[point_idx].x = (float)point_idx + OSCILLATOR_PANEL_WIDTH;
+        signal_points[point_idx].y =
+            screen_vertical_midpoint + (int)(signal[point_idx] * 300);
+    }
+    DrawLineStrip(signal_points, signal.size(), RED);
+    delete[] signal_points;
+}
+
+void Renderer::draw_oscillators_shape_inputs(
+    const std::vector<Oscillator*>& oscillators,
+    const std::vector<OscillatorGuiState*>& gui_oscillators) {
+#define WAVE_SHAPE_OPTIONS "Sine;Triangle;Sawtooth;Square"
+
+    // DRAW OSCILLATOR SHAPE INPUTS
+    for (int i = 0; i < oscillators.size(); i += 1) {
+        OscillatorGuiState* ui_osc = gui_oscillators[i];
+        assert(ui_osc);
+
+        Oscillator* osc = oscillators[i];
+        assert(osc);
+
+        // 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) {
+            write_log("Dropdown clicked!\n");
+            ui_osc->is_dropdown_open = !ui_osc->is_dropdown_open;
+            ui_osc->waveshape = (OscillatorType)(shape_index);
+            // APPLY STATE TO REAL OSC
+            osc->SetType(ui_osc->waveshape);
+        }
+        if (ui_osc->is_dropdown_open)
+            break;
+    }
+}
+
+float Renderer::draw_oscillators_panels(
+    const std::vector<Oscillator*>& oscillators,
+    const std::vector<OscillatorGuiState*>& gui_oscillators,
+    const Rectangle& panel_bounds) {
+    float panel_y_offset = 0;
+    for (int i = 0; i < oscillators.size(); i++) {
+        OscillatorGuiState* ui_osc = gui_oscillators[i];
+        assert(ui_osc);
+
+        Oscillator* osc = oscillators[i];
+        assert(osc);
+
+        const bool has_shape_param = (ui_osc->waveshape == Square);
+
+        // Draw Oscillator Panel
+        const int osc_panel_width = panel_bounds.width - 20;
+        const int osc_panel_height = has_shape_param ? 130 : 100;
+        const int osc_panel_x = panel_bounds.x + 10;
+        const int osc_panel_y = panel_bounds.y + 50 + panel_y_offset;
+        panel_y_offset += osc_panel_height + 5;
+        GuiPanel((Rectangle){(float)osc_panel_x, (float)osc_panel_y,
+                             (float)osc_panel_width, (float)osc_panel_height},
+                 "");
+
+        const float slider_padding = 50.f;
+        const float el_spacing = 5.f;
+        Rectangle el_rect = {.x = (float)osc_panel_x + slider_padding + 30,
+                             .y = (float)osc_panel_y + 10,
+                             .width =
+                                 (float)osc_panel_width - (slider_padding * 2),
+                             .height = 25.f};
+
+        // Volume slider
+        float decibels = (20.f * log10f(osc->GetVolume()));
+        char amp_slider_label[32];
+        snprintf(amp_slider_label, 7, "%.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->SetVolume(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;
+        }
+    }
+
+    return panel_y_offset;
+}
+
+void Renderer::draw_main_panel(const Rectangle& panel_bounds) {
+    GuiPanel(panel_bounds, "");
+}
+
+void Renderer::draw_add_oscillator_button(Synth& synth,
+                                          SynthGuiState& synth_gui,
+                                          Rectangle panel_bounds) {
+    //clang-format off
+    bool click_add_oscillator =
+        GuiButton((Rectangle){panel_bounds.x + 10, panel_bounds.y + 10,
+                              panel_bounds.width - 20, 25.f},
+                  "Add Oscillator");
+    //clang-format on
+
+    if (click_add_oscillator) {
+        synth.AddOscillator();
+        Oscillator* osc = synth.GetOscillators().back();
+
+        OscillatorGuiState* ui =
+            new OscillatorGuiState{.freq = osc->GetFreq(),
+                                   .waveshape = osc->GetType(),
+                                   .volume = osc->GetVolume()};
+        synth_gui.oscillators.push_back(ui);
+    }
+}
+
+void Renderer::draw_ui(Synth& synth, SynthGuiState& synth_gui) {
+    Rectangle panel_bounds = {.x = 0,
+                              .y = 0,
+                              .width = OSCILLATOR_PANEL_WIDTH,
+                              .height = WINDOW_HEIGHT};
+    draw_main_panel(panel_bounds);
+    draw_add_oscillator_button(synth, synth_gui, panel_bounds);
+    // Draw Oscillators
+    std::vector<Oscillator*> oscillators = synth.GetOscillators();
+    std::vector<OscillatorGuiState*> gui_oscillators = synth_gui.oscillators;
+
+    float panel_y_offset =
+        draw_oscillators_panels(oscillators, gui_oscillators, panel_bounds);
+    draw_oscillators_shape_inputs(oscillators, gui_oscillators);
+
+    draw_adsr_panel(synth.GetADSR(), synth_gui.adsr, panel_bounds,
+                    panel_y_offset);
+}
+
+void Renderer::draw_adsr_panel(ADSR* adsr, ADSRGuiState& gui_adsr,
+                               const Rectangle& panel_bounds,
+                               float panel_y_offset) {
+    // Draw ADSR Panel
+    const int osc_panel_width = panel_bounds.width - 20;
+    const int osc_panel_height = 120;
+    const int osc_panel_x = panel_bounds.x + 10;
+    const int osc_panel_y = panel_bounds.y + 50 + panel_y_offset;
+    panel_y_offset += osc_panel_height + 5;
+    GuiPanel((Rectangle){(float)osc_panel_x, (float)osc_panel_y,
+                         (float)osc_panel_width, (float)osc_panel_height},
+             "ADSR");
+
+    const float slider_padding = 50.f;
+    const float el_spacing = 5.f;
+    Rectangle el_rect = {.x = (float)osc_panel_x + slider_padding + 30,
+                         .y = (float)osc_panel_y + 10,
+                         .width = (float)osc_panel_width - (slider_padding * 2),
+                         .height = 25.f};
+
+    // Attack slider
+    float attack = gui_adsr.attack;
+    char attack_slider_label[32];
+    snprintf(attack_slider_label, 7, "%.1f s", attack);
+    attack = GuiSlider(el_rect, attack_slider_label, "", attack, 0.0f, 2.0f);
+    gui_adsr.attack = attack;
+    el_rect.y += el_rect.height + el_spacing;
+
+    // Decay slider
+    float decay = gui_adsr.decay;
+    char decay_slider_label[32];
+    snprintf(decay_slider_label, 7, "%.1f s", decay);
+    decay = GuiSlider(el_rect, decay_slider_label, "", decay, 0.0f, 1.0f);
+    gui_adsr.decay = decay;
+    el_rect.y += el_rect.height + el_spacing;
+
+    // Sustain slider
+    float sustain = gui_adsr.sustain;
+    char sustain_slider_label[32];
+    snprintf(sustain_slider_label, 7, "%.1f u", sustain);
+    sustain = GuiSlider(el_rect, sustain_slider_label, "", sustain, 0.0f, 1.0f);
+    gui_adsr.sustain = sustain;
+    el_rect.y += el_rect.height + el_spacing;
+
+    // Release slider
+    float release = gui_adsr.release;
+    char release_slider_label[32];
+    snprintf(release_slider_label, 7, "%.1f s", release);
+    release = GuiSlider(el_rect, release_slider_label, "", release, 0.0f, 5.0f);
+    gui_adsr.release = release;
+    el_rect.y += el_rect.height + el_spacing;
+
+    // apply values to real one
+    adsr->SetParameters(gui_adsr.attack, gui_adsr.decay, gui_adsr.sustain,
+                        gui_adsr.release);
+}

src/SeeSynth.cpp

@@ -0,0 +1,8 @@
+#include "Application.h"
+
+int main() {
+    Application* app = new Application();
+    app->Run();
+
+    delete app;
+}

src/Synth.cpp

@@ -0,0 +1,83 @@
+#include "Synth.h"
+#include "ADSR.h"
+#include "KeyBoard.h"
+#include "Logger.h"
+#include "OscillatorType.h"
+#include "Settings.h"
+
+Synth::Synth(/* args */) {
+    AddOscillator();
+    AddEffect(new ADSR());
+    for (size_t i = 0; i < STREAM_BUFFER_SIZE; i++) {
+        float sample = 0.0f;
+        m_out_signal.push_back(sample);
+    }
+    zero_signal();
+}
+
+Synth::~Synth() {
+    m_oscillators.clear();
+    m_effects.clear();
+    m_out_signal.clear();
+}
+
+void Synth::zero_signal() {
+    float sample = 0.0f;
+    for (size_t i = 0; i < STREAM_BUFFER_SIZE; i++) {
+        m_out_signal[i] = sample;
+    }
+}
+
+void Synth::get_note() {
+    zero_signal();
+    Adder::SumOscillators(m_oscillators, m_out_signal);
+}
+
+void Synth::apply_effects() {
+    for (Effect* effect : m_effects) {
+        effect->Process(m_out_signal);
+    }
+}
+
+void Synth::trigger_note_on_effects() {
+    for (Effect* effect : m_effects) {
+        effect->OnSetNote();
+    }
+}
+
+void Synth::untrigger_note_on_effects() {
+    for (Effect* effect : m_effects) {
+        effect->OnUnsetNote();
+    }
+}
+
+void Synth::TriggerNote(Note input) {
+    int semitone_shift = KeyBoard::GetSemitoneShift(input.name);
+    float hz = KeyBoard::GetHzBySemitone(semitone_shift);
+
+    // will change after oscillator starts to be more autonomous
+    for (Oscillator* osc : m_oscillators) {
+        osc->SetFreq(hz);
+    }
+    is_note_triggered = true;
+    trigger_note_on_effects();
+}
+
+void Synth::ProduceSound() {
+    get_note();
+    apply_effects();
+}
+
+// todo: rename to something like untrigger note
+void Synth::StopSound() {
+    zero_signal();
+    is_note_triggered = false;
+    untrigger_note_on_effects();
+}
+
+void Synth::AddOscillator() {
+    m_oscillators.push_back(
+        new Oscillator(OscillatorType::Sine, 440.f, VOLUME));
+}
+
+void Synth::AddEffect(Effect* fx) { m_effects.push_back(fx); }

utils.c

@@ -1,30 +0,0 @@
-#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

@@ -1,23 +0,0 @@
-#ifndef UTILS_H
-#define UTILS_H
-
-#include "stdio.h"
-#include "assert.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