commit 0ceccb0d5d60e968439a65aeedfb999741899ed5
Author: Raimon Zamora <jaildoctor@gmail.com>
Date:   Thu Sep 2 22:22:01 2021 +0200

    first commit

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..90dfd1c
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,3 @@
+.vscode/*
+*.dll
+*.exe
diff --git a/audio.h b/audio.h
new file mode 100755
index 0000000..9a43d23
--- /dev/null
+++ b/audio.h
@@ -0,0 +1,8 @@
+#pragma once
+
+#define AUDIO_FORMAT AUDIO_S16
+#define AUDIO_FORMAT_TYPE Sint16
+#define AUDIO_FORMAT_SIZE sizeof(AUDIO_FORMAT_TYPE)
+#define AUDIO_FORMAT_MAX_VALUE 32767
+
+#define SAMPLES_PER_SECOND 44100
diff --git a/font.bmp b/font.bmp
new file mode 100644
index 0000000..d46476a
Binary files /dev/null and b/font.bmp differ
diff --git a/main.cpp b/main.cpp
new file mode 100755
index 0000000..095ac3e
--- /dev/null
+++ b/main.cpp
@@ -0,0 +1,88 @@
+#include <SDL2/SDL.h>
+#include "tonegen.h"
+#include "audio.h"
+
+#define SOUND_DURATION 0.25f
+#define SOUND_NUM_SAMPLES SOUND_DURATION*SAMPLES_PER_SECOND
+#define SOUND_SIZE_IN_BYTES SOUND_NUM_SAMPLES*AUDIO_FORMAT_SIZE
+
+SDL_AudioSpec audioSpec{SAMPLES_PER_SECOND, AUDIO_FORMAT, 1, 0, 512, 0, 0, NULL, NULL};
+
+int main(int argc, char* argv[]) {
+    SDL_Init(SDL_INIT_EVERYTHING);
+    SDL_AudioDeviceID sdlAudioDevice = SDL_OpenAudioDevice(NULL, 0, &audioSpec, NULL, 0);
+
+    AUDIO_FORMAT_TYPE beeps[int(SOUND_NUM_SAMPLES*8)];
+    AUDIO_FORMAT_TYPE beeps2[int(SOUND_NUM_SAMPLES*8)];
+    AUDIO_FORMAT_TYPE *pointer = beeps;
+
+    toneGen tonegen(SOUND_NUM_SAMPLES);
+
+    tonegen.setup(22, CHIPTUNE_INSTRUMENT_TRIANGLE, 13, CHIPTUNE_EFFECT_DROP);
+    int numSamples = tonegen.getSamples(SOUND_NUM_SAMPLES, pointer); pointer += int(SOUND_NUM_SAMPLES);
+    tonegen.setup(32, CHIPTUNE_INSTRUMENT_SQUARE, 0, CHIPTUNE_EFFECT_NONE);
+    numSamples = tonegen.getSamples(SOUND_NUM_SAMPLES, pointer); pointer += int(SOUND_NUM_SAMPLES);
+    tonegen.setup(32, CHIPTUNE_INSTRUMENT_NOISE, 4, CHIPTUNE_EFFECT_FADEOUT);
+    numSamples = tonegen.getSamples(SOUND_NUM_SAMPLES, pointer); pointer += int(SOUND_NUM_SAMPLES);
+    tonegen.setup(32, CHIPTUNE_INSTRUMENT_SQUARE, 0, CHIPTUNE_EFFECT_NONE);
+    numSamples = tonegen.getSamples(SOUND_NUM_SAMPLES, pointer); pointer += int(SOUND_NUM_SAMPLES);
+    tonegen.setup(22, CHIPTUNE_INSTRUMENT_TRIANGLE, 13, CHIPTUNE_EFFECT_DROP);
+    numSamples = tonegen.getSamples(SOUND_NUM_SAMPLES, pointer); pointer += int(SOUND_NUM_SAMPLES);
+    tonegen.setup(22, CHIPTUNE_INSTRUMENT_TRIANGLE, 13, CHIPTUNE_EFFECT_DROP);
+    numSamples = tonegen.getSamples(SOUND_NUM_SAMPLES, pointer); pointer += int(SOUND_NUM_SAMPLES);
+    tonegen.setup(32, CHIPTUNE_INSTRUMENT_NOISE, 4, CHIPTUNE_EFFECT_FADEOUT);
+    numSamples = tonegen.getSamples(SOUND_NUM_SAMPLES, pointer); pointer += int(SOUND_NUM_SAMPLES);
+    tonegen.setup(32, CHIPTUNE_INSTRUMENT_SQUARE, 0, CHIPTUNE_EFFECT_NONE);
+    numSamples = tonegen.getSamples(SOUND_NUM_SAMPLES, pointer); pointer += int(SOUND_NUM_SAMPLES);
+
+    pointer = beeps2;
+    tonegen.setup(35, CHIPTUNE_INSTRUMENT_SQUARE, 1, CHIPTUNE_EFFECT_NONE);
+    numSamples = tonegen.getSamples(SOUND_NUM_SAMPLES, pointer); pointer += int(SOUND_NUM_SAMPLES);
+    tonegen.setup(37, CHIPTUNE_INSTRUMENT_SQUARE, 1, CHIPTUNE_EFFECT_NONE);
+    numSamples = tonegen.getSamples(SOUND_NUM_SAMPLES, pointer); pointer += int(SOUND_NUM_SAMPLES);
+    tonegen.setup(39, CHIPTUNE_INSTRUMENT_SQUARE, 1, CHIPTUNE_EFFECT_NONE);
+    numSamples = tonegen.getSamples(SOUND_NUM_SAMPLES, pointer); pointer += int(SOUND_NUM_SAMPLES);
+    tonegen.setup(40, CHIPTUNE_INSTRUMENT_SQUARE, 1, CHIPTUNE_EFFECT_NONE);
+    numSamples = tonegen.getSamples(SOUND_NUM_SAMPLES, pointer); pointer += int(SOUND_NUM_SAMPLES);
+    tonegen.setup(42, CHIPTUNE_INSTRUMENT_SQUARE, 1, CHIPTUNE_EFFECT_NONE);
+    numSamples = tonegen.getSamples(SOUND_NUM_SAMPLES, pointer); pointer += int(SOUND_NUM_SAMPLES);
+    tonegen.setup(44, CHIPTUNE_INSTRUMENT_SQUARE, 1, CHIPTUNE_EFFECT_NONE);
+    numSamples = tonegen.getSamples(SOUND_NUM_SAMPLES, pointer); pointer += int(SOUND_NUM_SAMPLES);
+    tonegen.setup(46, CHIPTUNE_INSTRUMENT_SQUARE, 1, CHIPTUNE_EFFECT_NONE);
+    numSamples = tonegen.getSamples(SOUND_NUM_SAMPLES, pointer); pointer += int(SOUND_NUM_SAMPLES);
+    tonegen.setup(47, CHIPTUNE_INSTRUMENT_SQUARE, 1, CHIPTUNE_EFFECT_NONE);
+    numSamples = tonegen.getSamples(SOUND_NUM_SAMPLES, pointer); pointer += int(SOUND_NUM_SAMPLES);
+
+    for (int i=0; i<SOUND_NUM_SAMPLES*8;++i) {
+        beeps[i] += beeps2[i];
+    }
+
+    SDL_Window *sdlWindow = SDL_CreateWindow("Mus", SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED, 1102, 700, SDL_WINDOW_SHOWN);
+    SDL_Renderer *sdlRenderer = SDL_CreateRenderer(sdlWindow, -1, 0);
+
+    SDL_SetRenderDrawColor(sdlRenderer, 255, 255, 255, 255);
+
+    int last_x = 0, last_y = 120;
+    for (int x=0; x<1102; ++x) {
+        int y = 700 - (350+300*(float(beeps[x*10])/float(AUDIO_FORMAT_MAX_VALUE)));
+        SDL_RenderDrawLine(sdlRenderer, x, y, last_x, last_y);
+        last_x = x; last_y = y;
+    }
+    SDL_RenderPresent(sdlRenderer);
+
+    SDL_QueueAudio(sdlAudioDevice, &beeps[0], SOUND_SIZE_IN_BYTES*8);
+    SDL_PauseAudioDevice(sdlAudioDevice, 0);
+
+    bool exit = false;
+    SDL_Event sdlEvent;
+    while (!exit) {
+        while (SDL_PollEvent(&sdlEvent)) {
+            if (sdlEvent.type == SDL_QUIT) { exit = true; break;}
+        }
+    }
+    
+    SDL_DestroyRenderer(sdlRenderer);
+    SDL_DestroyWindow(sdlWindow);
+    SDL_Quit();
+    return 0;
+}
\ No newline at end of file
diff --git a/tonegen.cpp b/tonegen.cpp
new file mode 100755
index 0000000..ae7a3fe
--- /dev/null
+++ b/tonegen.cpp
@@ -0,0 +1,93 @@
+#include "tonegen.h"
+#include "audio.h"
+#include <math.h>
+
+Sint16 notes[64];
+
+toneGen::toneGen(const int note_length) {
+    this->note_length = note_length;
+    this->current_pos = 0;
+
+    this->note = 32;
+    this->instrument = CHIPTUNE_INSTRUMENT_NOISE;
+    this->volume = 15;
+    this->effect = CHIPTUNE_EFFECT_FADEOUT;
+
+    this->current_volume = this->nominal_volume = 1.0f;
+
+    for (int i=0; i<64; ++i) {
+        const float NOTE_FREQ = 440 * pow(1.059463094359, i-32);
+        notes[i] = 65536 / int(SAMPLES_PER_SECOND/NOTE_FREQ);
+    }
+
+    this->old_df = this->df = notes[this->note];
+    this->f = -AUDIO_FORMAT_MAX_VALUE;
+}
+
+void toneGen::setup(const uint8_t note, const uint8_t instrument, const uint8_t volume, const uint8_t effect) {
+    this->current_pos = 0;
+
+    this->note = note;
+    this->instrument = instrument;
+    this->volume = volume;
+    this->effect = effect;
+
+    this->nominal_volume =  float(volume) / 15.0f;
+    this->current_volume = this->effect == CHIPTUNE_EFFECT_FADEIN ? 0.0f : this->nominal_volume;
+
+    this->old_df = this->df;
+    this->df = notes[this->note];
+    this->f = -AUDIO_FORMAT_MAX_VALUE * this->current_volume;
+}
+
+void toneGen::setup(const uint16_t tracker_note) {
+    setup(tracker_note >> 10, (tracker_note >> 8) & 0x03, (tracker_note >> 4) & 0x0F, tracker_note & 0x0F );
+}
+
+const int toneGen::getSamples(const int numSamples, Sint16 *buffer) {
+    const int actual_samples_generated = SDL_min(numSamples, this->note_length-this->current_pos);
+
+    for (int i=0; i<actual_samples_generated;++i) {
+        f += df;
+
+        switch (this->effect) {
+            case CHIPTUNE_EFFECT_NONE:
+                break;
+            case CHIPTUNE_EFFECT_VIBRATO:
+                f += SDL_sinf((i+this->current_pos)/1000)*15;
+                break;
+            case CHIPTUNE_EFFECT_DROP:
+                if (((i+this->current_pos)%15)==0 && df != 0) { df--; if (df < 100) this->current_volume = this->nominal_volume*df*0.01f; }
+                if (df == 0) { buffer[i] = 0; continue; }
+                break;
+            case CHIPTUNE_EFFECT_FADEOUT:
+                if (this->current_volume > 0) this->current_volume -= (this->nominal_volume/float(this->note_length));
+                break;
+            case CHIPTUNE_EFFECT_FADEIN:
+                if (this->current_volume < this->nominal_volume) this->current_volume += (this->nominal_volume/float(this->note_length));
+                break;
+        }
+
+        buffer[i] = f;
+
+        Sint32 temp;
+        switch (this->instrument) {
+            case CHIPTUNE_INSTRUMENT_SAWTOOTH:
+                break;
+            case CHIPTUNE_INSTRUMENT_SQUARE:
+                buffer[i] = buffer[i] > 0 ? AUDIO_FORMAT_MAX_VALUE : -AUDIO_FORMAT_MAX_VALUE;
+                break;
+            case CHIPTUNE_INSTRUMENT_TRIANGLE:
+                temp = buffer[i];
+                buffer[i] = buffer[i] < 0 ? ((temp+AUDIO_FORMAT_MAX_VALUE)*2)-AUDIO_FORMAT_MAX_VALUE : (AUDIO_FORMAT_MAX_VALUE*2-temp*2)-AUDIO_FORMAT_MAX_VALUE;
+                break;
+            case CHIPTUNE_INSTRUMENT_NOISE:
+                buffer[i] = (rand()*2)-AUDIO_FORMAT_MAX_VALUE;
+                break;
+        }
+        buffer[i] *= this->current_volume;
+    }
+
+    this->current_pos += actual_samples_generated;
+    return actual_samples_generated;
+}
diff --git a/tonegen.h b/tonegen.h
new file mode 100755
index 0000000..ddc3f44
--- /dev/null
+++ b/tonegen.h
@@ -0,0 +1,30 @@
+#pragma once
+
+#include <SDL2/SDL.h>
+
+#define CHIPTUNE_EFFECT_NONE    0
+#define CHIPTUNE_EFFECT_SLIDE   1
+#define CHIPTUNE_EFFECT_VIBRATO 2
+#define CHIPTUNE_EFFECT_DROP    3
+#define CHIPTUNE_EFFECT_FADEIN  4
+#define CHIPTUNE_EFFECT_FADEOUT 5
+
+#define CHIPTUNE_INSTRUMENT_SAWTOOTH 0
+#define CHIPTUNE_INSTRUMENT_SQUARE   1
+#define CHIPTUNE_INSTRUMENT_TRIANGLE 2
+#define CHIPTUNE_INSTRUMENT_NOISE    3
+
+class toneGen {
+    public:
+        toneGen(const int note_length);
+        void setup(const uint8_t note, const uint8_t instrument, const uint8_t volume, const uint8_t effect);
+        void setup(const uint16_t tracker_note);
+        const int getSamples(const int numSamples, Sint16 *buffer);
+
+    private:
+        uint8_t note, instrument, volume, effect;
+        float nominal_volume, current_volume;
+        Sint16 df, old_df, f;
+        int note_length;
+        int current_pos;
+};