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synthesizer
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note stack

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main
sandyx 1 year ago
parent 47349d3bf7
commit a5e7611495
1 changed files with 139 additions and 68 deletions
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207
src/main.c
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@ -6,7 +6,7 @@
#include <string.h>
#include <stdlib.h>
#define MAX_NOTES 26
#define MAX_NOTES 16
const int window_width = 640;
const int window_height = 480;
@ -34,7 +34,45 @@ typedef struct note {
bool released;
} note;
note scale[MAX_NOTES];
note scale[26];
typedef struct keymap {
int key;
int idx;
} keymap;
typedef struct note_stack {
int nsp; //stack pointer
note notes[MAX_NOTES];
keymap keys[MAX_NOTES];
} note_stack;
//so the stack can be accessed in the callback
note_stack *nsptr;
static inline void push_note(note_stack *ns, note n) {
ns->nsp = ns->nsp % MAX_NOTES;
//printf("%s: %d\n", "push_note", ns->nsp);
ns->notes[ns->nsp] = n;
ns->nsp++;
}
//must come before push_note
static inline void push_key(note_stack *ns, int k) {
ns->keys[ns->nsp % MAX_NOTES].key = k;
ns->keys[ns->nsp % MAX_NOTES].idx = ns->nsp % MAX_NOTES; //might not need
//printf("%s: %d %d %d\n", "push_key", ns->nsp % MAX_NOTES, ns->keys[ns->nsp % MAX_NOTES].key, ns->keys[ns->nsp % MAX_NOTES].idx);
}
static inline void release_note(note_stack *ns, int k) {
for (int i = 0; i < MAX_NOTES; i++) {
if (ns->keys[i].key == k) {
//printf("%s %d %d\n", "release note", k, i);
ns->notes[i].released = true; //try i first
ns->keys[i].key = 0;
}
}
}
float sine_wave(float idx) {
return sinf(2 * PI * idx);
@ -48,43 +86,61 @@ float square_wave(float idx) {
return -0.5f;
}
static inline int count_active_notes(void) {
float saw_wave(float idx) {
return idx - 0.5f;
}
float reverse_saw_wave(float idx) {
return -idx + 0.5f;
}
float semisine_wave(float idx) {
return (idx * idx)/2;
}
//not needed?
static inline int count_active_notes(note_stack *ns) {
int active = 0;
for (size_t i = 0; i < MAX_NOTES; i++) {
if (scale[i].volume > 0.0f)
if (ns->notes[i].volume > 0.0f) {
//printf("%s %f\n", "wtf?:", ns->notes[i].volume);
active++;
}
}
//printf("%s: %d\n", "active notes", active);
return active;
}
static inline float add_notes(void) {
//add each notes index
float m = 0;
int active = count_active_notes();
static inline float add_notes(note_stack *ns) {
float m = 0.0f;
//int active = count_active_notes(ns);
float compress = 0.0f;
for (size_t i = 0; i < MAX_NOTES; i++) {
m += square_wave(scale[i].index) * scale[i].volume;
m += sine_wave(ns->notes[i].index) * ns->notes[i].volume;
m += square_wave(ns->notes[i].index) * ns->notes[i].volume;
compress += scale[i].volume;
}
//don't divide by zero
m = active ? m/active : 0.0f; //compression
//m = m + (1.0f - m) * 0.95f;
return m;
m = compress ? m/compress : 0.0f; //compression
//m = (m - (-1.0f*active)) / (1.0f*active) - (-1.0f*active);
return m * 5;
}
static inline float calc_note_step(note *n) {
return n->frequency/sample_rate;
}
static inline void reset_index(void) {
static inline void reset_index(note_stack *ns) {
for (size_t i = 0; i < MAX_NOTES; i++) {
scale[i].index += scale[i].step;
if (scale[i].index > 1.0f && scale[i].volume > 0.0f) {
scale[i].index -= 1.0f;
ns->notes[i].index += ns->notes[i].step;
if (ns->notes[i].index > 1.0f && ns->notes[i].volume > 0.0f) {
ns->notes[i].index -= 1.0f;
}
}
}
@ -94,26 +150,24 @@ void AudioInputCallback2(void *buffer, uint32_t frames) {
short *d = (short *)buffer;
for (size_t i = 0; i < frames; i++) {
d[i] = (signed short)(pcm_volume * add_notes());;
reset_index();
d[i] = (signed short)(pcm_volume * add_notes(nsptr));
reset_index(nsptr);
}
}
const float volume_release_step = 0.01f;
void key_press(int key, note *n) {
void key_press(int key, note_stack *ns, note n) {
if (IsKeyPressed(key)) {
//keys_pressed++;
n->released = false;
push_key(ns, key);
push_note(ns, n);
//n->released = false;
}
if (IsKeyReleased(key)) {
//keys_pressed--;
n->released = true;
//ns->notes[/*saved idx*/].released = true;
release_note(ns, key);
//n->released = true;
}
//printf("%s\n", "wow");
}
int main(int argc, char *argv[]) {
@ -128,61 +182,78 @@ int main(int argc, char *argv[]) {
PlayAudioStream(stream);
const float volume_attack_step = 0.08f;
const float volume_release_step = 0.08f;
note_stack ns;
ns.nsp = 0;
//init scale
for (int i = 0; i < MAX_NOTES; i++) {
ns.notes[i] = (note){
.volume = 0.0f,
.released = true,
.index = 0.0f,
};
ns.keys[i] = (keymap){0};
}
nsptr = &ns;
const float volume_attack_step = 0.04f;
const float volume_release_step = 0.04f;
//init scale
for (int i = 0; i < 26; i++) {
scale[i].frequency = semitone(i-24);
scale[i].index = 0.0f;
scale[i].volume = 0.0f;
scale[i].volume = 1.0f;
scale[i].step = calc_note_step(&scale[i]);
scale[i].released = true;
scale[i].released = false;
}
while(!WindowShouldClose()) {
key_press(KEY_Z, &scale[0]);
key_press(KEY_X, &scale[1]);
key_press(KEY_C, &scale[2]);
key_press(KEY_V, &scale[3]);
key_press(KEY_B, &scale[4]);
key_press(KEY_N, &scale[5]);
key_press(KEY_M, &scale[6]);
key_press(KEY_A, &scale[7]);
key_press(KEY_S, &scale[8]);
key_press(KEY_D, &scale[9]);
key_press(KEY_F, &scale[10]);
key_press(KEY_G, &scale[11]);
key_press(KEY_H, &scale[12]);
key_press(KEY_J, &scale[13]);
key_press(KEY_K, &scale[14]);
key_press(KEY_L, &scale[15]);
key_press(KEY_Q, &scale[16]);
key_press(KEY_W, &scale[17]);
key_press(KEY_E, &scale[18]);
key_press(KEY_R, &scale[19]);
key_press(KEY_T, &scale[20]);
key_press(KEY_Y, &scale[21]);
key_press(KEY_U, &scale[22]);
key_press(KEY_I, &scale[23]);
key_press(KEY_O, &scale[24]);
key_press(KEY_P, &scale[25]);
key_press(KEY_Z, &ns, scale[0]);
key_press(KEY_X, &ns, scale[1]);
key_press(KEY_C, &ns, scale[2]);
key_press(KEY_V, &ns, scale[3]);
key_press(KEY_B, &ns, scale[4]);
key_press(KEY_N, &ns, scale[5]);
key_press(KEY_M, &ns, scale[6]);
key_press(KEY_A, &ns, scale[7]);
key_press(KEY_S, &ns, scale[8]);
key_press(KEY_D, &ns, scale[9]);
key_press(KEY_F, &ns, scale[10]);
key_press(KEY_G, &ns, scale[11]);
key_press(KEY_H, &ns, scale[12]);
key_press(KEY_J, &ns, scale[13]);
key_press(KEY_K, &ns, scale[14]);
key_press(KEY_L, &ns, scale[15]);
key_press(KEY_Q, &ns, scale[16]);
key_press(KEY_W, &ns, scale[17]);
key_press(KEY_E, &ns, scale[18]);
key_press(KEY_R, &ns, scale[19]);
key_press(KEY_T, &ns, scale[20]);
key_press(KEY_Y, &ns, scale[21]);
key_press(KEY_U, &ns, scale[22]);
key_press(KEY_I, &ns, scale[23]);
key_press(KEY_O, &ns, scale[24]);
key_press(KEY_P, &ns, scale[25]);
for (int i = 0; i < MAX_NOTES; i++) {
if (scale[i].released) {
scale[i].volume -= volume_release_step;
if (scale[i].volume < 0.0f) {
scale[i].volume = 0.0f;
scale[i].index = 0.0f;
if (ns.notes[i].released) {
//printf("lowering volume: %f\n", ns.notes[i].volume);
ns.notes[i].volume -= volume_release_step;
//printf("lowering volume: %f\n", ns.notes[i].volume);
if (ns.notes[i].volume < 0.0f) {
ns.notes[i].volume = 0.0f;
ns.notes[i].index = 0.0f;
}
}
}
for (int i = 0; i < MAX_NOTES; i++) {
if (!scale[i].released) {
scale[i].volume += volume_attack_step;
if (scale[i].volume > 1.0f) {
scale[i].volume = 1.0f;
if (!ns.notes[i].released) {
//printf("%s\n", "bugs?");
ns.notes[i].volume += volume_attack_step;
if (ns.notes[i].volume > 1.0f) {
ns.notes[i].volume = 1.0f;
}
}
}

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