676 lines
28 KiB
C++
676 lines
28 KiB
C++
#include "synth_engine.h"
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#include <math.h>
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#include <utility>
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#include <string.h>
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// A simple sine lookup table for the sine oscillator
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const int SINE_TABLE_SIZE = 256;
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static int16_t sine_table[SINE_TABLE_SIZE];
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static bool sine_table_filled = false;
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/**
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* @brief Fills the global sine table. Called once on startup.
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*/
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void fill_sine_table() {
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if (sine_table_filled) return;
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for (int i = 0; i < SINE_TABLE_SIZE; ++i) {
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// M_PI is not standard C++, but it's common. If it fails, use 3.1415926535...
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sine_table[i] = static_cast<int16_t>(sin(2.0 * M_PI * i / SINE_TABLE_SIZE) * 32767.0);
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}
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sine_table_filled = true;
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}
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SynthEngine::SynthEngine(uint32_t sampleRate)
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: grid{},
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_sampleRate(sampleRate),
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_phase(0),
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_increment(0),
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_volume(0.5f),
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_waveform(SAWTOOTH),
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_isGateOpen(false),
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_rngState(12345)
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{
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fill_sine_table();
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// Initialize with a default frequency
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setFrequency(440.0f);
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// Initialize SINK
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grid[GRID_W / 2][GRID_H - 1].type = GridCell::SINK;
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rebuildProcessingOrder();
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}
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SynthEngine::~SynthEngine() {
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}
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void SynthEngine::exportGrid(uint8_t* buffer) {
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SynthLockGuard<SynthMutex> lock(gridMutex);
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size_t idx = 0;
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for(int y=0; y<GRID_H; ++y) {
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for(int x=0; x<GRID_W; ++x) {
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GridCell& c = grid[x][y];
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buffer[idx++] = (uint8_t)c.type;
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buffer[idx++] = (uint8_t)(c.param * 255.0f);
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buffer[idx++] = (uint8_t)c.rotation;
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}
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}
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}
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void SynthEngine::importGrid(const uint8_t* buffer) {
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SynthLockGuard<SynthMutex> lock(gridMutex);
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size_t idx = 0;
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for(int y=0; y<GRID_H; ++y) {
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for(int x=0; x<GRID_W; ++x) {
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GridCell& c = grid[x][y];
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uint8_t t = buffer[idx++];
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uint8_t p = buffer[idx++];
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uint8_t r = buffer[idx++];
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GridCell::Type newType = (GridCell::Type)t;
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c.type = newType;
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c.param = (float)p / 255.0f;
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c.rotation = r;
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}
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}
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rebuildProcessingOrder_locked();
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}
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void SynthEngine::clearGrid() {
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SynthLockGuard<SynthMutex> lock(gridMutex);
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for (int x = 0; x < GRID_W; ++x) {
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for (int y = 0; y < GRID_H; ++y) {
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GridCell& c = grid[x][y];
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if (c.type == GridCell::SINK) continue;
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c.type = GridCell::EMPTY;
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c.param = 0.5f;
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c.rotation = 0;
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c.value = 0.0f;
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c.phase = 0.0f;
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c.next_value = 0.0f;
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}
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}
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rebuildProcessingOrder_locked();
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}
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void SynthEngine::loadPreset(int preset) {
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clearGrid();
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SynthLockGuard<SynthMutex> lock(gridMutex);
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auto placeOp = [&](int x, int y, float ratio, float att, float rel) {
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// Layout:
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// (x, y) : G-IN (South)
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// (x, y+1) : WIRE (East) -> Feeds envelope chain
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// (x+1, y+1): ATT (East) ->
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// (x+2, y+1): REL (East)
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// (x+3, y+1): VCA (South) -> Output is here. Gets audio from OSC, gain from envelope.
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// (x+3, y) : OSC (South) -> Audio source. Gets FM from its back (x+3, y-1).
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grid[x][y].type = GridCell::GATE_INPUT; grid[x][y].rotation = 2; // S
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grid[x][y+1].type = GridCell::WIRE; grid[x][y+1].rotation = 1; // E
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grid[x+1][y+1].type = GridCell::ADSR_ATTACK; grid[x+1][y+1].rotation = 1; // E
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grid[x+1][y+1].param = att;
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grid[x+2][y+1].type = GridCell::ADSR_RELEASE; grid[x+2][y+1].rotation = 1; // E
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grid[x+2][y+1].param = rel;
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grid[x+3][y+1].type = GridCell::VCA; grid[x+3][y+1].rotation = 2; // S
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grid[x+3][y+1].param = 0.0f; // Controlled by Env
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grid[x+3][y].type = GridCell::INPUT_OSCILLATOR; grid[x+3][y].rotation = 2; // S
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grid[x+3][y].param = (ratio > 1.0f) ? 0.5f : 0.0f;
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};
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int sinkY = GRID_H - 1;
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int sinkX = GRID_W / 2;
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if (preset == 1) { // Based on DX7 Algorithm 32
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placeOp(0, 0, 1.0f, 0.01f, 0.5f); // Op 1
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placeOp(4, 0, 1.0f, 0.05f, 0.3f); // Op 2
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placeOp(8, 0, 2.0f, 0.01f, 0.2f); // Op 3
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grid[3][2].type = GridCell::WIRE; grid[3][2].rotation = 2;
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grid[3][3].type = GridCell::WIRE; grid[3][3].rotation = 1; // E
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grid[4][3].type = GridCell::WIRE; grid[4][3].rotation = 1; // E
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grid[5][3].type = GridCell::WIRE; grid[5][3].rotation = 1; // E
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grid[6][3].type = GridCell::WIRE; grid[6][3].rotation = 2; // S
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grid[7][2].type = GridCell::WIRE; grid[7][2].rotation = 2;
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grid[7][3].type = GridCell::WIRE; grid[7][3].rotation = 3; // W
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grid[11][2].type = GridCell::WIRE; grid[11][2].rotation = 2;
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grid[11][3].type = GridCell::WIRE; grid[11][3].rotation = 3; // W
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grid[10][3].type = GridCell::WIRE; grid[10][3].rotation = 3; // W
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grid[9][3].type = GridCell::WIRE; grid[9][3].rotation = 3; // W
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grid[8][3].type = GridCell::WIRE; grid[8][3].rotation = 3; // W
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for(int y=4; y<sinkY; ++y) {
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grid[6][y].type = GridCell::WIRE; grid[6][y].rotation = 2;
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}
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} else if (preset == 2) { // Algo 1: Stack (FM)
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placeOp(4, 0, 2.0f, 0.01f, 0.2f); // Modulator
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placeOp(4, 2, 1.0f, 0.01f, 0.8f); // Carrier
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grid[7][4].type = GridCell::WIRE; grid[7][4].rotation = 3; // W
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grid[6][4].type = GridCell::WIRE; grid[6][4].rotation = 2; // S
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for(int y=5; y<sinkY; ++y) {
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grid[6][y].type = GridCell::WIRE; grid[6][y].rotation = 2;
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}
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} else if (preset == 3) { // Algo 2
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placeOp(4, 2, 1.0f, 0.01f, 0.8f);
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placeOp(4, 0, 2.0f, 0.01f, 0.2f);
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placeOp(0, 0, 1.0f, 0.01f, 0.5f);
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grid[7][4].type = GridCell::WIRE; grid[7][4].rotation = 3; // W
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grid[3][2].type = GridCell::WIRE; grid[3][2].rotation = 1; // E
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grid[4][2].type = GridCell::WIRE; grid[4][2].rotation = 1; // E
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grid[5][2].type = GridCell::WIRE; grid[5][2].rotation = 1; // E
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grid[sinkX][2].type = GridCell::WIRE; grid[sinkX][2].rotation = 2; // S
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grid[sinkX][3].type = GridCell::WIRE; grid[sinkX][3].rotation = 2; // S
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grid[sinkX][4].type = GridCell::WIRE; grid[sinkX][4].rotation = 2; // S
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for(int y=5; y<sinkY; ++y) {
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grid[sinkX][y].type = GridCell::WIRE; grid[sinkX][y].rotation = 2;
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}
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} else if (preset == 4) { // Algo 4
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placeOp(4, 4, 1.0f, 0.01f, 0.8f);
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placeOp(4, 2, 2.0f, 0.01f, 0.2f);
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placeOp(4, 0, 4.0f, 0.01f, 0.1f);
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grid[7][6].type = GridCell::WIRE; grid[7][6].rotation = 3; // W
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grid[sinkX][6].type = GridCell::WIRE; grid[sinkX][6].rotation = 2; // S
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for(int y=7; y<sinkY; ++y) {
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grid[sinkX][y].type = GridCell::WIRE; grid[sinkX][y].rotation = 2;
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}
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} else if (preset == 5) { // Algo 5
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placeOp(4, 4, 1.0f, 0.01f, 0.8f);
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placeOp(4, 2, 2.0f, 0.01f, 0.2f);
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placeOp(4, 0, 4.0f, 0.01f, 0.1f);
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placeOp(0, 0, 0.5f, 0.01f, 0.5f);
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grid[7][6].type = GridCell::WIRE; grid[7][6].rotation = 3; // W
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grid[3][2].type = GridCell::WIRE; grid[3][2].rotation = 2; // S
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grid[3][3].type = GridCell::WIRE; grid[3][3].rotation = 1; // E
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grid[4][3].type = GridCell::WIRE; grid[4][3].rotation = 1; // E
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grid[5][3].type = GridCell::WIRE; grid[5][3].rotation = 1; // E
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grid[6][3].type = GridCell::WIRE; grid[6][3].rotation = 2; // S
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grid[sinkX][4].type = GridCell::WIRE; grid[sinkX][4].rotation = 2; // S
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grid[sinkX][5].type = GridCell::WIRE; grid[sinkX][5].rotation = 2; // S
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grid[sinkX][6].type = GridCell::WIRE; grid[sinkX][6].rotation = 2; // S
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for(int y=7; y<sinkY; ++y) {
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grid[sinkX][y].type = GridCell::WIRE; grid[sinkX][y].rotation = 2;
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}
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}
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rebuildProcessingOrder_locked();
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}
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void SynthEngine::setFrequency(float freq) {
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// Calculate the phase increment for a given frequency.
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// The phase accumulator is a 32-bit unsigned integer (0 to 2^32-1).
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// One full cycle of the accumulator represents one cycle of the waveform.
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// increment = (frequency * 2^32) / sampleRate
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// The original calculation was incorrect for float frequencies.
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_increment = static_cast<uint32_t>((double)freq * (4294967296.0 / (double)_sampleRate));
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}
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void SynthEngine::setVolume(float vol) {
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if (vol < 0.0f) vol = 0.0f;
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if (vol > 1.0f) vol = 1.0f;
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_volume = vol;
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}
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void SynthEngine::setWaveform(Waveform form) {
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_waveform = form;
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}
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void SynthEngine::setGate(bool isOpen) {
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_isGateOpen = isOpen;
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}
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float SynthEngine::getFrequency() const {
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return (float)((double)_increment * (double)_sampleRate / 4294967296.0);
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}
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float SynthEngine::_random() {
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// Simple Linear Congruential Generator
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_rngState = _rngState * 1664525 + 1013904223;
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return (float)_rngState / 4294967296.0f;
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}
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void SynthEngine::rebuildProcessingOrder_locked() {
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_processing_order.clear();
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bool visited[GRID_W][GRID_H] = {false};
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std::vector<std::pair<int, int>> q;
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// Start BFS from the SINK backwards
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q.push_back({GRID_W / 2, GRID_H - 1});
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visited[GRID_W / 2][GRID_H - 1] = true;
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int head = 0;
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while(head < (int)q.size()) {
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std::pair<int, int> curr = q[head++];
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int cx = curr.first;
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int cy = curr.second;
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// Check neighbors to see if they output to (cx, cy)
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int nx_offsets[4] = {0, 1, 0, -1};
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int ny_offsets[4] = {-1, 0, 1, 0};
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for(int i=0; i<4; ++i) {
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int tx = cx + nx_offsets[i];
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int ty = cy + ny_offsets[i];
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if (tx >= 0 && tx < GRID_W && ty >= 0 && ty < GRID_H && !visited[tx][ty]) {
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GridCell& neighbor = grid[tx][ty];
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bool pointsToCurr = false;
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if (neighbor.type != GridCell::EMPTY && neighbor.type != GridCell::SINK) {
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int dx = cx - tx;
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int dy = cy - ty;
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int dir = -1;
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if (dx == 0 && dy == -1) dir = 0; // N
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else if (dx == 1 && dy == 0) dir = 1; // E
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else if (dx == 0 && dy == 1) dir = 2; // S
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else if (dx == -1 && dy == 0) dir = 3; // W
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if (neighbor.type == GridCell::FORK) {
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int leftOut = (neighbor.rotation + 3) % 4;
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int rightOut = (neighbor.rotation + 1) % 4;
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if (dir == leftOut || dir == rightOut) pointsToCurr = true;
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} else {
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if (neighbor.rotation == dir) pointsToCurr = true;
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}
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}
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if (pointsToCurr) {
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visited[tx][ty] = true;
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q.push_back({tx, ty});
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}
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}
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}
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}
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_processing_order = q;
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}
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void SynthEngine::rebuildProcessingOrder() {
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SynthLockGuard<SynthMutex> lock(gridMutex);
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rebuildProcessingOrder_locked();
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}
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float SynthEngine::processGridStep() {
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auto isConnected = [&](int tx, int ty, int from_x, int from_y) -> bool {
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if (from_x < 0 || from_x >= GRID_W || from_y < 0 || from_y >= GRID_H) return false;
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GridCell& n = grid[from_x][from_y];
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bool connects = false;
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if (n.type == GridCell::WIRE || n.type == GridCell::FIXED_OSCILLATOR || n.type == GridCell::INPUT_OSCILLATOR || n.type == GridCell::WAVETABLE || n.type == GridCell::NOISE || n.type == GridCell::LFO || n.type == GridCell::GATE_INPUT || n.type == GridCell::ADSR_ATTACK || n.type == GridCell::ADSR_DECAY || n.type == GridCell::ADSR_SUSTAIN || n.type == GridCell::ADSR_RELEASE || n.type == GridCell::LPF || n.type == GridCell::HPF || n.type == GridCell::VCA || n.type == GridCell::BITCRUSHER || n.type == GridCell::DISTORTION || n.type == GridCell::RECTIFIER || n.type == GridCell::PITCH_SHIFTER || n.type == GridCell::GLITCH || n.type == GridCell::OPERATOR || n.type == GridCell::DELAY || n.type == GridCell::REVERB) {
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// Check rotation
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// 0:N (y-1), 1:E (x+1), 2:S (y+1), 3:W (x-1)
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if (n.rotation == 0 && from_y - 1 == ty && from_x == tx) connects = true;
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if (n.rotation == 1 && from_x + 1 == tx && from_y == ty) connects = true;
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if (n.rotation == 2 && from_y + 1 == ty && from_x == tx) connects = true;
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if (n.rotation == 3 && from_x - 1 == tx && from_y == ty) connects = true;
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} else if (n.type == GridCell::FORK) {
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// Fork outputs to Left (rot+3) and Right (rot+1) relative to its rotation
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// n.rotation is "Forward"
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int dx = tx - from_x;
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int dy = ty - from_y;
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int dir = -1;
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if (dx == 0 && dy == -1) dir = 0; // N
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if (dx == 1 && dy == 0) dir = 1; // E
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if (dx == 0 && dy == 1) dir = 2; // S
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if (dx == -1 && dy == 0) dir = 3; // W
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int leftOut = (n.rotation + 3) % 4;
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int rightOut = (n.rotation + 1) % 4;
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if (dir == leftOut || dir == rightOut) connects = true;
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}
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return connects;
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};
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// Helper to get input from a neighbor
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auto getInput = [&](int tx, int ty, int from_x, int from_y) -> float {
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if (!isConnected(tx, ty, from_x, from_y)) return 0.0f;
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GridCell& n = grid[from_x][from_y];
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if (n.type == GridCell::FORK) {
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int dx = tx - from_x;
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int dy = ty - from_y;
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int dir = -1;
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if (dx == 0 && dy == -1) dir = 0; // N
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if (dx == 1 && dy == 0) dir = 1; // E
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if (dx == 0 && dy == 1) dir = 2; // S
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if (dx == -1 && dy == 0) dir = 3; // W
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int leftOut = (n.rotation + 3) % 4;
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int rightOut = (n.rotation + 1) % 4;
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if (dir == leftOut) return n.value * (1.0f - n.param) * 2.0f;
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if (dir == rightOut) return n.value * n.param * 2.0f;
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}
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return n.value;
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};
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// Helper to sum inputs excluding the output direction
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auto getSummedInput = [&](int x, int y, GridCell& c) -> float {
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float sum = 0.0f;
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int outDir = c.rotation; // 0:N, 1:E, 2:S, 3:W
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if (outDir != 0) sum += getInput(x, y, x, y-1);
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if (outDir != 1) sum += getInput(x, y, x+1, y);
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if (outDir != 2) sum += getInput(x, y, x, y+1);
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if (outDir != 3) sum += getInput(x, y, x-1, y);
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return sum;
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};
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auto getInputFromTheBack = [&](int x, int y, GridCell& c) -> float {
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int inDir = (c.rotation + 2) % 4;
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int dx=0, dy=0;
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if(inDir==0) dy=-1; else if(inDir==1) dx=1; else if(inDir==2) dy=1; else dx=-1;
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return getInput(x, y, x+dx, y+dy);
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};
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auto getSideInputGain = [&](int x, int y, GridCell& c) -> float {
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float gain = 0.0f;
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bool hasSide = false;
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// Left (rot+3)
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int lDir = (c.rotation + 3) % 4;
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int ldx=0, ldy=0; if(lDir==0) ldy=-1; else if(lDir==1) ldx=1; else if(lDir==2) ldy=1; else ldx=-1;
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if (isConnected(x, y, x+ldx, y+ldy)) { hasSide = true; gain += getInput(x, y, x+ldx, y+ldy); }
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// Right (rot+1)
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int rDir = (c.rotation + 1) % 4;
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int rdx=0, rdy=0; if(rDir==0) rdy=-1; else if(rDir==1) rdx=1; else if(rDir==2) rdy=1; else rdx=-1;
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if (isConnected(x, y, x+rdx, y+rdy)) { hasSide = true; gain += getInput(x, y, x+rdx, y+rdy); }
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return hasSide ? gain : 1.0f;
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};
|
|
|
|
// 1. Calculate next values for active cells
|
|
for (const auto& cell_coord : _processing_order) {
|
|
int x = cell_coord.first;
|
|
int y = cell_coord.second;
|
|
GridCell& c = grid[x][y];
|
|
float val = 0.0f;
|
|
|
|
if (c.type == GridCell::EMPTY) {
|
|
val = 0.0f;
|
|
} else if (c.type == GridCell::FIXED_OSCILLATOR) {
|
|
// Gather inputs for modulation
|
|
float mod = getInputFromTheBack(x, y, c);
|
|
|
|
// Freq 10 to 1000 Hz
|
|
float freq = 10.0f + c.param * 990.0f + (mod * 500.0f); // FM
|
|
if (freq < 1.0f) freq = 1.0f;
|
|
|
|
float inc = freq * (float)SINE_TABLE_SIZE / (float)_sampleRate;
|
|
c.phase += inc;
|
|
if (c.phase >= SINE_TABLE_SIZE) c.phase -= SINE_TABLE_SIZE;
|
|
val = (float)sine_table[(int)c.phase] / 32768.0f;
|
|
val *= getSideInputGain(x, y, c);
|
|
} else if (c.type == GridCell::INPUT_OSCILLATOR) {
|
|
float mod = getInputFromTheBack(x, y, c);
|
|
|
|
// Freq based on current note + octave param (1-5)
|
|
float baseFreq = getFrequency();
|
|
int octave = 1 + (int)(c.param * 4.99f); // Map 0.0-1.0 to 1-5
|
|
float freq = baseFreq * (float)(1 << (octave - 1)); // 2^(octave-1)
|
|
freq += (mod * 500.0f); // Apply FM
|
|
if (freq < 1.0f) freq = 1.0f; // Protect against negative/zero freq
|
|
float inc = freq * (float)SINE_TABLE_SIZE / (float)_sampleRate;
|
|
c.phase += inc;
|
|
if (c.phase >= SINE_TABLE_SIZE) c.phase -= SINE_TABLE_SIZE;
|
|
val = (float)sine_table[(int)c.phase] / 32768.0f;
|
|
val *= getSideInputGain(x, y, c);
|
|
} else if (c.type == GridCell::WAVETABLE) {
|
|
float mod = getInputFromTheBack(x, y, c);
|
|
|
|
// Track current note frequency + FM
|
|
float freq = getFrequency() + (mod * 500.0f);
|
|
if (freq < 1.0f) freq = 1.0f;
|
|
|
|
float inc = freq * (float)SINE_TABLE_SIZE / (float)_sampleRate;
|
|
c.phase += inc;
|
|
if (c.phase >= SINE_TABLE_SIZE) c.phase -= SINE_TABLE_SIZE;
|
|
|
|
float phase_norm = c.phase / (float)SINE_TABLE_SIZE; // 0.0 to 1.0
|
|
int wave_select = (int)(c.param * 7.99f);
|
|
|
|
switch(wave_select) {
|
|
case 0: val = (float)sine_table[(int)c.phase] / 32768.0f; break;
|
|
case 1: val = (phase_norm * 2.0f) - 1.0f; break; // Saw
|
|
case 2: val = (phase_norm < 0.5f) ? 1.0f : -1.0f; break; // Square
|
|
case 3: val = (phase_norm < 0.5f) ? (phase_norm * 4.0f - 1.0f) : (3.0f - phase_norm * 4.0f); break; // Triangle
|
|
case 4: val = 1.0f - (phase_norm * 2.0f); break; // Ramp
|
|
case 5: val = (phase_norm < 0.25f) ? 1.0f : -1.0f; break; // Pulse 25%
|
|
case 6: // Distorted Sine
|
|
val = sin(phase_norm * 2.0 * M_PI) + sin(phase_norm * 4.0 * M_PI) * 0.3f;
|
|
val /= 1.3f; // Normalize
|
|
break;
|
|
case 7: // Organ-like
|
|
val = sin(phase_norm * 2.0 * M_PI) * 0.6f +
|
|
sin(phase_norm * 4.0 * M_PI) * 0.2f +
|
|
sin(phase_norm * 8.0 * M_PI) * 0.1f;
|
|
val /= 0.9f; // Normalize
|
|
break;
|
|
}
|
|
val *= getSideInputGain(x, y, c);
|
|
} else if (c.type == GridCell::NOISE) {
|
|
float mod = getInputFromTheBack(x, y, c);
|
|
|
|
float white = _random() * 2.0f - 1.0f;
|
|
int shade = (int)(c.param * 4.99f);
|
|
switch(shade) {
|
|
case 0: // Brown (Leaky integrator)
|
|
c.phase = (c.phase + white * 0.1f) * 0.95f;
|
|
val = c.phase * 3.0f; // Gain up
|
|
break;
|
|
case 1: // Pink (Approx: LPF)
|
|
c.phase = 0.5f * c.phase + 0.5f * white;
|
|
val = c.phase;
|
|
break;
|
|
case 2: // White
|
|
val = white;
|
|
break;
|
|
case 3: // Yellow (HPF)
|
|
val = white - c.phase;
|
|
c.phase = white; // Store last sample
|
|
break;
|
|
case 4: // Green (BPF approx)
|
|
c.phase = (c.phase + white) * 0.5f; // LPF
|
|
val = white - c.phase; // HPF result
|
|
break;
|
|
}
|
|
|
|
// Apply Amplitude Modulation (AM) from input
|
|
val *= (1.0f + mod);
|
|
val *= getSideInputGain(x, y, c);
|
|
} else if (c.type == GridCell::LFO) {
|
|
// Low Frequency Oscillator (0.1 Hz to 20 Hz)
|
|
float freq = 0.1f + c.param * 19.9f;
|
|
float inc = freq * (float)SINE_TABLE_SIZE / (float)_sampleRate;
|
|
c.phase += inc;
|
|
if (c.phase >= SINE_TABLE_SIZE) c.phase -= SINE_TABLE_SIZE;
|
|
// Output full range -1.0 to 1.0
|
|
val = (float)sine_table[(int)c.phase] / 32768.0f;
|
|
} else if (c.type == GridCell::FORK) {
|
|
// Sum inputs from "Back" (Input direction)
|
|
val = getInputFromTheBack(x, y, c);
|
|
} else if (c.type == GridCell::GATE_INPUT) {
|
|
// Outputs 1.0 when gate is open (key pressed), 0.0 otherwise
|
|
val = _isGateOpen ? 1.0f : 0.0f;
|
|
} else if (c.type == GridCell::ADSR_ATTACK) {
|
|
// Slew Limiter (Up only)
|
|
float in = getInputFromTheBack(x, y, c);
|
|
float rate = 1.0f / (0.001f + c.param * 2.0f * _sampleRate); // 0.001s to 2s
|
|
if (in > c.value) {
|
|
c.value += rate;
|
|
if (c.value > in) c.value = in;
|
|
} else {
|
|
c.value = in;
|
|
}
|
|
val = c.value;
|
|
} else if (c.type == GridCell::ADSR_DECAY || c.type == GridCell::ADSR_RELEASE) {
|
|
// Slew Limiter (Down only)
|
|
float in = getInputFromTheBack(x, y, c);
|
|
float rate = 1.0f / (0.001f + c.param * 2.0f * _sampleRate);
|
|
if (in < c.value) {
|
|
c.value -= rate;
|
|
if (c.value < in) c.value = in;
|
|
} else {
|
|
c.value = in;
|
|
}
|
|
val = c.value;
|
|
} else if (c.type == GridCell::ADSR_SUSTAIN) {
|
|
// Attenuator
|
|
float in = getInputFromTheBack(x, y, c);
|
|
val = in * c.param;
|
|
} else if (c.type == GridCell::WIRE) {
|
|
// Sum inputs from all neighbors that point to me
|
|
float sum = getSummedInput(x, y, c);
|
|
val = sum;
|
|
} else if (c.type == GridCell::LPF) {
|
|
// Input from Back
|
|
float in = getInputFromTheBack(x, y, c);
|
|
|
|
// Simple one-pole LPF
|
|
// Cutoff mapping: Exponential-ish 20Hz to 15kHz
|
|
float cutoff = 20.0f + c.param * c.param * 15000.0f;
|
|
float alpha = 2.0f * M_PI * cutoff / (float)_sampleRate;
|
|
if (alpha > 1.0f) alpha = 1.0f;
|
|
|
|
// c.phase stores previous output
|
|
val = c.phase + alpha * (in - c.phase);
|
|
c.phase = val;
|
|
} else if (c.type == GridCell::HPF) {
|
|
// Input from Back
|
|
float in = getInputFromTheBack(x, y, c);
|
|
|
|
float cutoff = 20.0f + c.param * c.param * 15000.0f;
|
|
float alpha = 2.0f * M_PI * cutoff / (float)_sampleRate;
|
|
if (alpha > 1.0f) alpha = 1.0f;
|
|
|
|
// HPF = Input - LPF
|
|
// c.phase stores LPF state
|
|
float lpf = c.phase + alpha * (in - c.phase);
|
|
c.phase = lpf;
|
|
val = in - lpf;
|
|
} else if (c.type == GridCell::VCA) {
|
|
// Input from Back
|
|
float in = getInputFromTheBack(x, y, c);
|
|
|
|
// Mod from other directions (sum)
|
|
float mod = getSummedInput(x, y, c);
|
|
mod -= in; // Remove signal input from mod sum (it was included in getInput calls)
|
|
|
|
// Gain = Param + Mod
|
|
float gain = c.param + mod;
|
|
if (gain < 0.0f) gain = 0.0f;
|
|
val = in * gain;
|
|
} else if (c.type == GridCell::BITCRUSHER) {
|
|
float in = getInputFromTheBack(x, y, c);
|
|
|
|
// Bit depth reduction
|
|
float bits = 1.0f + c.param * 15.0f; // 1 to 16 bits
|
|
float steps = powf(2.0f, bits);
|
|
val = roundf(in * steps) / steps;
|
|
} else if (c.type == GridCell::DISTORTION) {
|
|
float in = getInputFromTheBack(x, y, c);
|
|
|
|
// Soft clipping
|
|
float drive = 1.0f + c.param * 20.0f;
|
|
float x_driven = in * drive;
|
|
// Simple soft clip: x / (1 + |x|)
|
|
val = x_driven / (1.0f + fabsf(x_driven));
|
|
} else if (c.type == GridCell::RECTIFIER) {
|
|
float in = getInputFromTheBack(x, y, c);
|
|
// Mix between original and rectified based on param
|
|
float rect = fabsf(in);
|
|
val = in * (1.0f - c.param) + rect * c.param;
|
|
} else if (c.type == GridCell::GLITCH) {
|
|
float in = getInputFromTheBack(x, y, c);
|
|
// Param controls probability of glitch
|
|
float chance = c.param * 0.2f; // 0 to 20% chance per sample
|
|
if (_random() < chance) {
|
|
int mode = (int)(_random() * 3.0f);
|
|
if (mode == 0) val = in * 50.0f; // Massive gain (clipping)
|
|
else if (mode == 1) val = _random() * 2.0f - 1.0f; // White noise burst
|
|
else val = 0.0f; // Drop out
|
|
} else {
|
|
val = in;
|
|
}
|
|
} else if (c.type == GridCell::OPERATOR || c.type == GridCell::SINK) {
|
|
// Gather inputs
|
|
float inputs[4];
|
|
int count = 0;
|
|
int outDir = (c.type == GridCell::SINK) ? -1 : c.rotation;
|
|
|
|
float iN = (outDir != 0) ? getInput(x, y, x, y-1) : 0.0f; if(iN!=0) inputs[count++] = iN;
|
|
float iE = (outDir != 1) ? getInput(x, y, x+1, y) : 0.0f; if(iE!=0) inputs[count++] = iE;
|
|
float iS = (outDir != 2) ? getInput(x, y, x, y+1) : 0.0f; if(iS!=0) inputs[count++] = iS;
|
|
float iW = (outDir != 3) ? getInput(x, y, x-1, y) : 0.0f; if(iW!=0) inputs[count++] = iW;
|
|
|
|
if (c.type == GridCell::SINK) {
|
|
// Sink just sums everything
|
|
val = 0.0f;
|
|
for(int k=0; k<count; ++k) val += inputs[k];
|
|
} else {
|
|
// Operator
|
|
int opType = (int)(c.param * 5.99f);
|
|
if (count == 0) val = 0.0f;
|
|
else {
|
|
val = inputs[0];
|
|
for (int i=1; i<count; ++i) {
|
|
switch(opType) {
|
|
case 0: val += inputs[i]; break; // ADD
|
|
case 1: val *= inputs[i]; break; // MUL
|
|
case 2: val -= inputs[i]; break; // SUB
|
|
case 3: if(inputs[i]!=0) val /= inputs[i]; break; // DIV
|
|
case 4: if(inputs[i]<val) val = inputs[i]; break; // MIN
|
|
case 5: if(inputs[i]>val) val = inputs[i]; break; // MAX
|
|
}
|
|
}
|
|
}
|
|
}
|
|
} // End of big switch
|
|
c.next_value = val;
|
|
} // End of for loop over _processing_order
|
|
|
|
// 2. Update current values from next values for active cells
|
|
for (const auto& cell_coord : _processing_order) {
|
|
int x = cell_coord.first;
|
|
int y = cell_coord.second;
|
|
grid[x][y].value = grid[x][y].next_value;
|
|
}
|
|
|
|
return grid[GRID_W / 2][GRID_H - 1].value;
|
|
}
|
|
|
|
void SynthEngine::process(int16_t* buffer, uint32_t numFrames) {
|
|
// Lock grid mutex to prevent UI from changing grid structure mid-process
|
|
SynthLockGuard<SynthMutex> lock(gridMutex);
|
|
|
|
for (uint32_t i = 0; i < numFrames; ++i) {
|
|
// The grid is now the primary sound source.
|
|
// The processGridStep() returns a float in the approx range of -1.0 to 1.0.
|
|
float sampleF = processGridStep();
|
|
|
|
// Soft clip grid sample to avoid harsh distortion before filtering.
|
|
if (sampleF > 1.0f) sampleF = 1.0f;
|
|
if (sampleF < -1.0f) sampleF = -1.0f;
|
|
|
|
// The filters were designed for a signal in the int16 range.
|
|
// We scale the grid's float output to match this expected range.
|
|
sampleF *= 32767.0f;
|
|
|
|
// Apply Master Volume and write to buffer
|
|
buffer[i] = static_cast<int16_t>(sampleF * _volume);
|
|
}
|
|
} |