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Copy pathwavetable.cpp
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150 lines (133 loc) · 5.51 KB
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// ============================================================
// CardputerGroovebox - wavetable.cpp
// ============================================================
#include "wavetable.h"
#include "sampler.h" // reuse WAV parsing helpers
#include <SD.h>
#include <math.h>
#include <string.h>
int16_t g_wavetables[NUM_WT_TOTAL][WT_SIZE];
char g_wtNames[NUM_WT_TOTAL][WT_NAME_LEN];
uint8_t g_numWavetables = 0;
static void normalizeTable(float* buf) {
float peak = 0.0001f;
for (int i = 0; i < WT_SIZE; i++) {
float a = fabsf(buf[i]);
if (a > peak) peak = a;
}
float g = 0.98f / peak;
for (int i = 0; i < WT_SIZE; i++) buf[i] *= g;
}
static void commitTable(int slot, const float* buf, const char* name) {
for (int i = 0; i < WT_SIZE; i++)
g_wavetables[slot][i] = (int16_t)(buf[i] * 32767.0f);
strncpy(g_wtNames[slot], name, WT_NAME_LEN - 1);
g_wtNames[slot][WT_NAME_LEN - 1] = 0;
}
void wavetableInitBuiltins() {
float buf[WT_SIZE];
float ph;
// 0: ORGAN - harmonics 1,2,4,8
for (int i = 0; i < WT_SIZE; i++) {
ph = TWO_PI_F * (float)i / WT_SIZE;
buf[i] = sinf(ph) + 0.5f * sinf(2*ph) + 0.35f * sinf(4*ph) + 0.2f * sinf(8*ph);
}
normalizeTable(buf); commitTable(0, buf, "ORGAN");
// 1: SOFTSAW - band-limited saw (8 harmonics)
for (int i = 0; i < WT_SIZE; i++) {
ph = TWO_PI_F * (float)i / WT_SIZE;
float s = 0;
for (int h = 1; h <= 8; h++) s += sinf(h * ph) / (float)h;
buf[i] = s;
}
normalizeTable(buf); commitTable(1, buf, "SOFTSAW");
// 2: PWM25 - band-limited 25% pulse (odd/even mix via harmonic series)
for (int i = 0; i < WT_SIZE; i++) {
ph = TWO_PI_F * (float)i / WT_SIZE;
float s = 0;
for (int h = 1; h <= 10; h++)
s += (2.0f / (h * 3.14159f)) * sinf(h * 3.14159f * 0.25f) * cosf(h * ph);
buf[i] = s;
}
normalizeTable(buf); commitTable(2, buf, "PWM25");
// 3: BELL - inharmonic partials
for (int i = 0; i < WT_SIZE; i++) {
ph = TWO_PI_F * (float)i / WT_SIZE;
buf[i] = sinf(ph) + 0.6f * sinf(2.76f * ph) + 0.4f * sinf(5.4f * ph) + 0.25f * sinf(8.93f * ph);
}
normalizeTable(buf); commitTable(3, buf, "BELL");
// 4: FORMANT - vowel-ish resonant bumps
for (int i = 0; i < WT_SIZE; i++) {
ph = TWO_PI_F * (float)i / WT_SIZE;
buf[i] = sinf(ph) + 0.7f * sinf(3*ph) * (0.5f + 0.5f * sinf(ph))
+ 0.5f * sinf(5*ph) * (0.5f + 0.5f * cosf(2*ph));
}
normalizeTable(buf); commitTable(4, buf, "FORMANT");
// 5: METAL - high odd partials, gritty
for (int i = 0; i < WT_SIZE; i++) {
ph = TWO_PI_F * (float)i / WT_SIZE;
buf[i] = sinf(ph) + 0.8f * sinf(7*ph) + 0.6f * sinf(11*ph) + 0.4f * sinf(13*ph);
}
normalizeTable(buf); commitTable(5, buf, "METAL");
// 6: FOLDSIN - waveshaped (folded) sine, rich and warm
for (int i = 0; i < WT_SIZE; i++) {
ph = TWO_PI_F * (float)i / WT_SIZE;
buf[i] = sinf(1.8f * sinf(ph) * 3.14159f * 0.5f);
}
normalizeTable(buf); commitTable(6, buf, "FOLDSIN");
// 7: GRIT - fixed pseudo-random cycle (deterministic seed), lo-fi digital
{
uint32_t seed = 0xC0FFEE42;
float last = 0;
for (int i = 0; i < WT_SIZE; i++) {
seed = seed * 1664525u + 1013904223u;
float n = ((float)(seed >> 16) / 32768.0f) - 1.0f;
last = last * 0.7f + n * 0.3f; // slight smoothing
buf[i] = last + 0.5f * sinf(TWO_PI_F * (float)i / WT_SIZE);
}
// remove DC
float dc = 0; for (int i = 0; i < WT_SIZE; i++) dc += buf[i];
dc /= WT_SIZE; for (int i = 0; i < WT_SIZE; i++) buf[i] -= dc;
normalizeTable(buf); commitTable(7, buf, "GRIT");
}
g_numWavetables = NUM_BUILTIN_WT;
}
void wavetableLoadUserFromSD() {
File dir = SD.open(DIR_WAVETABLES);
if (!dir || !dir.isDirectory()) return;
// temp buffer for decoded wav (single cycle files are small; cap 4096 frames)
const int MAXF = 4096;
static int16_t tmp[MAXF];
File f = dir.openNextFile();
while (f && g_numWavetables < NUM_WT_TOTAL) {
String nm = f.name();
int slash = nm.lastIndexOf('/');
if (slash >= 0) nm = nm.substring(slash + 1);
if (!f.isDirectory() && (nm.endsWith(".wav") || nm.endsWith(".WAV"))) {
uint32_t frames = 0, rate = 0;
if (wavDecodeToMono16(f, tmp, MAXF, frames, rate) && frames >= 8) {
// resample whole file (assumed single cycle) to WT_SIZE
float buf[WT_SIZE];
for (int i = 0; i < WT_SIZE; i++) {
float pos = (float)i * (float)frames / (float)WT_SIZE;
uint32_t a = (uint32_t)pos;
float fr = pos - a;
uint32_t b = (a + 1 < frames) ? a + 1 : 0;
buf[i] = ((float)tmp[a] * (1.0f - fr) + (float)tmp[b] * fr) / 32768.0f;
}
// remove DC + normalize
float dc = 0; for (int i = 0; i < WT_SIZE; i++) dc += buf[i];
dc /= WT_SIZE; for (int i = 0; i < WT_SIZE; i++) buf[i] -= dc;
normalizeTable(buf);
// strip extension for name
int dot = nm.lastIndexOf('.');
String base = (dot > 0) ? nm.substring(0, dot) : nm;
commitTable(g_numWavetables, buf, base.c_str());
g_numWavetables++;
}
}
f.close();
f = dir.openNextFile();
}
dir.close();
}