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windows build, separation of synth code, 3-op now, modulator feedback

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This commit is contained in:
veclavtalica 2024-06-24 10:58:31 +03:00
parent ce5cfdd95b
commit 561dece028
11 changed files with 139 additions and 62 deletions
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2
Source/Instruments/Trojka/readme.md Normal file
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@ -0,0 +1,2 @@
# Trojka
3-op minimalist FM synth to the mega!

56
Source/Instruments/Trojka/trojka.c Normal file
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@ -0,0 +1,56 @@
#if defined(STFU_MAIN) && !defined(STFU_TROJKA)
#define STFU_TROJKA
#include "../../phaser.c"
#include "../../envelope.c"
#include "../../config.h"
#define STFU_TROJKA_OP_COUNT 3
/* https://multimed.org/student/eim/en/04-FM.pdf */
// todo: A few more algorithm configurations.
// todo: Other oscillators.
struct stfu_trojka {
struct stfu_phaser phasers[STFU_TROJKA_OP_COUNT];
struct stfu_envelope envelopes[STFU_TROJKA_OP_COUNT];
float gains[STFU_TROJKA_OP_COUNT];
float freq_scales[STFU_TROJKA_OP_COUNT];
float key_frequency;
float feedback_gain; // todo: Separate gain for channels?
float left_feedback, right_feedback;
};
static struct stfu_trojka stfu_sample_trojka(struct stfu_trojka synth, float buffer[static 2]) {
for (int i = 0; i < STFU_TROJKA_OP_COUNT; ++i) {
synth.phasers[i] = stfu_pump_phaser(synth.phasers[i]);
synth.envelopes[i] = stfu_pump_envelope(synth.envelopes[i]);
}
float left_modulator_stack = synth.envelopes[1].v * sinf(synth.phasers[1].v + synth.envelopes[0].v * sinf(synth.phasers[0].v)) + synth.left_feedback * synth.feedback_gain;
float right_modulator_stack = synth.envelopes[1].v * sinf(synth.phasers[1].v + synth.envelopes[0].v * sinf(synth.phasers[0].v)) + synth.right_feedback * synth.feedback_gain;
synth.left_feedback = left_modulator_stack;
synth.right_feedback = right_modulator_stack;
float left = synth.envelopes[2].v * sinf(synth.phasers[2].v + left_modulator_stack);
float right =
synth.envelopes[2].v * sinf(synth.phasers[2].v + right_modulator_stack);
buffer[0] = left;
buffer[1] = right;
return synth;
}
static struct stfu_trojka stfu_press_trojka(struct stfu_trojka synth, float key_frequency) {
for (int i = 0; i < STFU_TROJKA_OP_COUNT; ++i) {
synth.phasers[i] = stfu_set_phaser_frequency(synth.phasers[i], key_frequency * synth.freq_scales[i]);
synth.envelopes[i] = stfu_trigger_envelope(synth.envelopes[i]);
}
return synth;
}
#endif

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Source/Maker/Build/stfu-maker.exe Normal file
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1
Source/Maker/Build/windows-clang.bat Normal file
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@ -0,0 +1 @@
clang ../main.c -lkernel32 -luser32 -lshell32 -ld3d11 -ldxgi -lgdi32 -lole32 -DSOKOL_D3D11 -o stfu-maker.exe -O3

78
Source/Maker/main.c
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@ -3,45 +3,27 @@
#include <string.h>
#define SOKOL_IMPL
#define SOKOL_GLCORE
#include "sokol_app.h"
#include "sokol_audio.h"
#include "sokol_log.h"
#define STFU_MAIN
#include "../config.h"
#include "../envelope.c"
// #include "../interp.c"
#include "../oscillators.c"
#include "../phaser.c"
static struct stfu_sinewave sine0;
static struct stfu_phaser phaser0;
static struct stfu_phaser phaser1;
static struct stfu_phaser phaser2;
static struct stfu_envelope envelope;
#include "../Instruments/Trojka/trojka.c"
static float key_frequency = STFU_C4_FREQUENCY;
static struct stfu_trojka synth = {0};
// todo: Separate to playback.c, generic for Player and Maker
#define CROSSFADE_RING_RANGE \
(STFU_CROSSFADE_BUFFER_FRAMES * STFU_AUDIO_CHANNEL_COUNT)
static float crossfade_ring[CROSSFADE_RING_RANGE] = {0};
static size_t crossfade_ring_needle = 0;
static unsigned int crossfade_frames_left = 0;
static void sample(float buffer[static 2]) {
phaser0 = stfu_pump_phaser(phaser0);
phaser1 = stfu_pump_phaser(phaser1);
phaser2 = stfu_pump_phaser(phaser2);
envelope = stfu_pump_envelope(envelope);
float left = envelope.v * sinf(phaser2.v + sinf(phaser0.v + sinf(phaser1.v)));
float right =
envelope.v * sinf(phaser2.v + sinf(phaser0.v + sinf(phaser1.v)));
buffer[0] = left;
buffer[1] = right;
}
static void stream(float *buffer, int num_frames, int num_channels) {
/* Fade away */
for (size_t i = 0; crossfade_frames_left > 0;
@ -58,7 +40,7 @@ static void stream(float *buffer, int num_frames, int num_channels) {
buffer[0] = crossfade_ring[crossfade_ring_needle % CROSSFADE_RING_RANGE];
buffer[1] =
crossfade_ring[(crossfade_ring_needle + 1) % CROSSFADE_RING_RANGE];
sample(&crossfade_ring[crossfade_ring_needle % CROSSFADE_RING_RANGE]);
synth = stfu_sample_trojka(synth, &crossfade_ring[crossfade_ring_needle % CROSSFADE_RING_RANGE]);
buffer = &buffer[2];
crossfade_ring_needle += 2;
}
@ -71,15 +53,19 @@ static void init(void) {
// .stream_cb = stream,
});
// sine0 = stfu_init_sinewave(STFU_A4_FREQUENCY / 2.0f, 0.0f, 0.8f);
phaser0 = stfu_init_phaser(key_frequency);
phaser1 = stfu_init_phaser(key_frequency * 0.25);
phaser2 = stfu_init_phaser(key_frequency * 2.0);
envelope = stfu_init_envelope(
synth.phasers[0] = stfu_init_phaser(220);
synth.phasers[1] = stfu_init_phaser(220 * 0.25);
synth.phasers[2] = stfu_init_phaser(220 * 2.0);
synth.feedback_gain = 0.25;
for (int i = 0; i < STFU_TROJKA_OP_COUNT; ++i) {
synth.envelopes[i] = stfu_init_envelope(
(struct stfu_envelope_point[]){[0] = {.dur = 0.02, .vol = 1.0},
[1] = {.dur = 0.5, .vol = 0.33},
[2] = {.dur = 1.0, .vol = 0}},
3);
synth.gains[i] = 1.0;
synth.freq_scales[i] = 1.0;
}
}
static void cleanup(void) { saudio_shutdown(); }
@ -92,53 +78,38 @@ static void event(const sapp_event *e) {
switch (e->key_code) {
case SAPP_KEYCODE_Z:
key_frequency = STFU_C4_FREQUENCY;
break;
synth = stfu_press_trojka(synth, STFU_SCALE[0]);
case SAPP_KEYCODE_X:
key_frequency = STFU_C4_FREQUENCY * STFU_NOTE_UPSCALE_FACTOR;
synth = stfu_press_trojka(synth, STFU_SCALE[1]);
break;
case SAPP_KEYCODE_C:
key_frequency = STFU_C4_FREQUENCY * STFU_NOTE_UPSCALE_FACTOR *
STFU_NOTE_UPSCALE_FACTOR;
synth = stfu_press_trojka(synth, STFU_SCALE[2]);
break;
case SAPP_KEYCODE_V:
key_frequency = STFU_C4_FREQUENCY * STFU_NOTE_UPSCALE_FACTOR *
STFU_NOTE_UPSCALE_FACTOR * STFU_NOTE_UPSCALE_FACTOR;
synth = stfu_press_trojka(synth, STFU_SCALE[3]);
break;
case SAPP_KEYCODE_B:
key_frequency = STFU_C4_FREQUENCY * STFU_NOTE_UPSCALE_FACTOR *
STFU_NOTE_UPSCALE_FACTOR * STFU_NOTE_UPSCALE_FACTOR *
STFU_NOTE_UPSCALE_FACTOR;
synth = stfu_press_trojka(synth, STFU_SCALE[4]);
break;
case SAPP_KEYCODE_N:
key_frequency = STFU_A4_FREQUENCY * STFU_NOTE_DOWNSCALE_FACTOR *
STFU_NOTE_DOWNSCALE_FACTOR * STFU_NOTE_DOWNSCALE_FACTOR *
STFU_NOTE_DOWNSCALE_FACTOR;
synth = stfu_press_trojka(synth, STFU_SCALE[5]);
break;
case SAPP_KEYCODE_M:
key_frequency = STFU_A4_FREQUENCY * STFU_NOTE_DOWNSCALE_FACTOR *
STFU_NOTE_DOWNSCALE_FACTOR * STFU_NOTE_DOWNSCALE_FACTOR;
synth = stfu_press_trojka(synth, STFU_SCALE[6]);
break;
case SAPP_KEYCODE_COMMA:
key_frequency = STFU_A4_FREQUENCY * STFU_NOTE_DOWNSCALE_FACTOR *
STFU_NOTE_DOWNSCALE_FACTOR;
synth = stfu_press_trojka(synth, STFU_SCALE[7]);
break;
case SAPP_KEYCODE_PERIOD:
key_frequency = STFU_A4_FREQUENCY * STFU_NOTE_DOWNSCALE_FACTOR;
synth = stfu_press_trojka(synth, STFU_SCALE[8]);
break;
case SAPP_KEYCODE_SLASH:
key_frequency = STFU_A4_FREQUENCY;
synth = stfu_press_trojka(synth, STFU_SCALE[9]);
break;
default:
break;
}
phaser0 = stfu_set_phaser_frequency(phaser0, key_frequency);
phaser1 = stfu_set_phaser_frequency(phaser1, key_frequency * 0.25);
phaser2 = stfu_set_phaser_frequency(phaser2, key_frequency * 2.0);
envelope = stfu_trigger_envelope(envelope);
crossfade_frames_left = STFU_CROSSFADE_BUFFER_FRAMES;
break;
}
default:
@ -172,5 +143,6 @@ sapp_desc sokol_main(int argc, char *argv[]) {
.gl_major_version = 2,
.gl_minor_version = 0,
// .swap_interval = 0,
.window_title = "stfu-maker",
};
}

27
Source/config.h
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@ -1,3 +1,5 @@
#if !defined(STFU_CONFIG)
#define STFU_CONFIG
/* Determines output framerate, in times per second. */
#define STFU_AUDIO_FRAME_RATE 44100
@ -10,6 +12,27 @@
/* Introduces delayed buffering for purposes of crossfading channels when notes
* are retriggered, needed for filtering clicks */
#define STFU_CROSSFADE_BUFFER_FRAMES 64
#define STFU_CROSSFADE_BUFFER_FRAMES 32
// todo: Array of precomputed note frequencies?
static const float STFU_SCALE[12] = {
STFU_C4_FREQUENCY,
STFU_C4_FREQUENCY * STFU_NOTE_UPSCALE_FACTOR,
STFU_C4_FREQUENCY * STFU_NOTE_UPSCALE_FACTOR *
STFU_NOTE_UPSCALE_FACTOR,
STFU_C4_FREQUENCY * STFU_NOTE_UPSCALE_FACTOR *
STFU_NOTE_UPSCALE_FACTOR * STFU_NOTE_UPSCALE_FACTOR,
STFU_C4_FREQUENCY * STFU_NOTE_UPSCALE_FACTOR *
STFU_NOTE_UPSCALE_FACTOR * STFU_NOTE_UPSCALE_FACTOR *
STFU_NOTE_UPSCALE_FACTOR,
STFU_A4_FREQUENCY * STFU_NOTE_DOWNSCALE_FACTOR *
STFU_NOTE_DOWNSCALE_FACTOR * STFU_NOTE_DOWNSCALE_FACTOR *
STFU_NOTE_DOWNSCALE_FACTOR,
STFU_A4_FREQUENCY * STFU_NOTE_DOWNSCALE_FACTOR *
STFU_NOTE_DOWNSCALE_FACTOR * STFU_NOTE_DOWNSCALE_FACTOR,
STFU_A4_FREQUENCY * STFU_NOTE_DOWNSCALE_FACTOR *
STFU_NOTE_DOWNSCALE_FACTOR,
STFU_A4_FREQUENCY * STFU_NOTE_DOWNSCALE_FACTOR,
STFU_A4_FREQUENCY,
};
#endif

8
Source/envelope.c
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@ -1,3 +1,6 @@
#if defined(STFU_MAIN) && !defined(STFU_ENVELOPE)
#define STFU_ENVELOPE
#include <stdint.h>
#include <string.h>
@ -29,12 +32,13 @@ struct stfu_envelope {
}
struct stfu_envelope stfu_pump_envelope(struct stfu_envelope envelope) {
envelope.p += 1.0f / STFU_AUDIO_FRAME_RATE;
float d = stfu_get_envelope_duration(envelope);
if (envelope.p >= d)
/* Needs retriggering after that point */
return envelope;
envelope.p += 1.0f / STFU_AUDIO_FRAME_RATE;
float p = 0.0f;
for (uint8_t i = 0;; ++i) {
float ends = p + envelope.pnts[i].dur;
@ -63,3 +67,5 @@ struct stfu_envelope stfu_trigger_envelope(struct stfu_envelope envelope) {
envelope.v = 0.0f;
return envelope;
}
#endif

4
Source/interp.c
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@ -1,4 +1,8 @@
#if defined(STFU_MAIN) && !defined(STFU_INTERP)
#define STFU_INTERP
float stfu_linear_interpolate(float x0, float y0, float x1, float y1, float n) {
return (y0 * (x1 - n) + y1 * (n - x0)) / (x1 - x0);
}
#endif

7
Source/oscillators.c
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@ -1,10 +1,11 @@
#if defined(STFU_MAIN) && !defined(STFU_OSCILLATORS)
#define STFU_OSCILLATORS
#include <math.h>
#include <stdint.h>
#include "config.h"
/* https://multimed.org/student/eim/en/04-FM.pdf */
/* Intended to be executed offline with values then embedded in the binary.
* By having usage of glibc sin and cos functions strictly offline it's easier
* to have it freestanding
@ -76,3 +77,5 @@ struct stfu_sawtooth stfu_pump_sawtooth(struct stfu_sawtooth wave) {
wave.v -= wave.a * 2.f;
return wave;
}
#endif

5
Source/phaser.c
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@ -1,3 +1,6 @@
#if defined(STFU_MAIN) && !defined(STFU_PHASER)
#define STFU_PHASER
#include <math.h>
#include "config.h"
@ -29,3 +32,5 @@ struct stfu_phaser stfu_set_phaser_frequency(struct stfu_phaser phaser,
phaser.a = 2 * ((float)M_PI / (float)STFU_AUDIO_FRAME_RATE) * frequency;
return phaser;
}
#endif

5
Source/timer.c
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@ -1,3 +1,6 @@
#if defined(STFU_MAIN) && !defined(STFU_TIMER)
#define STFU_TIMER
#include <math.h>
#include "config.h"
@ -18,3 +21,5 @@ struct stfu_timer stfu_pump_timer(struct stfu_timer wave) {
wave.v -= 1000;
return wave;
}
#endif