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dexed/Source/EngineMkI.cpp

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/*
* Copyright 2014 Pascal Gauthier.
* Copyright 2012 Google Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "EngineMkI.h"
#include <math.h>
#include <cstdlib>
#include "msfa/sin.h"
#include "msfa/exp2.h"
static const uint16_t MKI_BITDEPTH = 8;
static const uint16_t MKI_TABLESIZE = 1<<MKI_BITDEPTH;
static const uint16_t MKI_TABLEFILTER = MKI_TABLESIZE-1;
static const uint16_t NEGATIVE_BIT = 0x8000;
#ifdef _WIN32
__declspec(align(16)) int zeros[N] = {0};
#else
const int32_t __attribute__ ((aligned(16))) zeros[N] = {0};
#endif
static uint16_t sinLogTable[MKI_TABLESIZE];
static uint16_t sinExpTable[MKI_TABLESIZE];
EngineMkI::EngineMkI() {
float bitReso = MKI_TABLESIZE;
for(int i=0;i<MKI_TABLESIZE;i++) {
float x1 = sin(((0.5+i)/bitReso) * M_PI/2.0);
sinLogTable[i] = round(-bitReso * log2(x1));
}
bitReso = MKI_TABLESIZE;
for(int i=0;i<MKI_TABLESIZE;i++) {
float x1 = (pow(2, float(i)/bitReso)-1)*1024;
sinExpTable[i] = round(x1);
}
}
static inline uint16_t sinLog(uint16_t phi) {
const uint16_t index = (phi & MKI_TABLEFILTER);
switch( ( phi & (MKI_TABLESIZE*3) ) ) {
case 0x0000:
// rising quarter wave Shape A
return sinLogTable[index];
case MKI_TABLESIZE:
// falling quarter wave Shape B
return sinLogTable[index ^ MKI_TABLEFILTER];
case (MKI_TABLESIZE*2):
// rising quarter wave -ve Shape C
return sinLogTable[index] | NEGATIVE_BIT;
default:
// falling quarter wave -ve Shape D
return sinLogTable[index ^ MKI_TABLEFILTER] | NEGATIVE_BIT;
}
}
inline int32_t mkiSin(int32_t phase, uint16_t env) {
const uint16_t shift = 22 - MKI_BITDEPTH;
uint16_t expVal = sinLog(phase >> shift) + (env << 3);
const bool isSigned = expVal & NEGATIVE_BIT;
expVal &= ~NEGATIVE_BIT;
// expVal: 0..2137+511*8 = 0..6225
// result: 0..1018+1024
uint16_t result = 0x0400 + sinExpTable[( expVal & MKI_TABLEFILTER ) ^ MKI_TABLEFILTER];
result <<= 1;
result >>= ( expVal >> 8 ); // exp
uint32_t ret;
if( isSigned ) {
// -1 for one's complement
ret = -result - 1;
} else {
ret = result;
}
return ret << shift;
}
void EngineMkI::compute(int32_t *output, const int32_t *input,
int32_t phase0, int32_t freq,
int32_t gain1, int32_t gain2, bool add) {
int32_t dgain = (gain2 - gain1 + (N >> 1)) >> LG_N;
int32_t gain = gain1;
int32_t phase = phase0;
const int32_t *adder = add ? output : zeros;
for (int i = 0; i < N; i++) {
gain += dgain;
int32_t y = mkiSin((phase+input[i]), gain);
output[i] = y + adder[i];
phase += freq;
}
}
void EngineMkI::compute_pure(int32_t *output, int32_t phase0, int32_t freq,
int32_t gain1, int32_t gain2, bool add) {
int32_t dgain = (gain2 - gain1 + (N >> 1)) >> LG_N;
int32_t gain = gain1;
int32_t phase = phase0;
const int32_t *adder = add ? output : zeros;
for (int i = 0; i < N; i++) {
gain += dgain;
int32_t y = mkiSin(phase , gain);
output[i] = y + adder[i];
phase += freq;
}
}
void EngineMkI::compute_fb(int32_t *output, int32_t phase0, int32_t freq,
int32_t gain1, int32_t gain2,
int32_t *fb_buf, int fb_shift, bool add) {
int32_t dgain = (gain2 - gain1 + (N >> 1)) >> LG_N;
int32_t gain = gain1;
int32_t phase = phase0;
const int32_t *adder = add ? output : zeros;
int32_t y0 = fb_buf[0];
int32_t y = fb_buf[1];
for (int i = 0; i < N; i++) {
gain += dgain;
int32_t scaled_fb = (y0 + y) >> (fb_shift + 1);
y0 = y;
y = mkiSin((phase+scaled_fb), gain);
output[i] = y + adder[i];
phase += freq;
}
fb_buf[0] = y0;
fb_buf[1] = y;
}
// exclusively used for ALGO 6 with feedback
void EngineMkI::compute_fb2(int32_t *output, FmOpParams *parms, int32_t gain01, int32_t gain02, int32_t *fb_buf, int fb_shift) {
int32_t dgain[2];
int32_t gain[2];
int32_t phase[2];
int32_t y0 = fb_buf[0];
int32_t y = fb_buf[1];
phase[0] = parms[0].phase;
phase[1] = parms[1].phase;
gain[0] = gain01;
gain[1] = parms[1].gain_out;
dgain[0] = (gain02 - gain01 + (N >> 1)) >> LG_N;
parms[1].gain_out = Exp2::lookup(parms[1].level_in - (14 * (1 << 24)));
dgain[1] = (parms[1].gain_out - gain[1] + (N >> 1)) >> LG_N;
for (int i = 0; i < N; i++) {
// op 0
gain[0] += dgain[0];
int32_t scaled_fb = (y0 + y) >> (fb_shift + 2); // tsk tsk tsk: this needs some tuning
y0 = y;
y = Sin::lookup(phase[0] + scaled_fb);
y = ((int64_t)y * (int64_t)gain[0]) >> 24;
phase[0] += parms[0].freq;
// op 1
gain[1] += dgain[1];
y = Sin::lookup(phase[1] + y);
y = ((int64_t)y * (int64_t)gain[1]) >> 24;
output[i] = y;
phase[1] += parms[1].freq;
}
fb_buf[0] = y0;
fb_buf[1] = y;
}
const FmAlgorithm EngineMkI::algo2[32] = {
{ { 0xc1, 0x11, 0x11, 0x14, 0x01, 0x14 } }, // 1
{ { 0x01, 0x11, 0x11, 0x14, 0xc1, 0x14 } }, // 2
{ { 0xc1, 0x11, 0x14, 0x01, 0x11, 0x14 } }, // 3
{ { 0xc4, 0x00, 0x00, 0x01, 0x11, 0x14 } }, // 4 ** EXCEPTION VIA CODE
{ { 0xc1, 0x14, 0x01, 0x14, 0x01, 0x14 } }, // 5
{ { 0xc4, 0x00, 0x01, 0x14, 0x01, 0x14 } }, // 6 ** EXCEPTION VIA CODE
{ { 0xc1, 0x11, 0x05, 0x14, 0x01, 0x14 } }, // 7
{ { 0x01, 0x11, 0xc5, 0x14, 0x01, 0x14 } }, // 8
{ { 0x01, 0x11, 0x05, 0x14, 0xc1, 0x14 } }, // 9
{ { 0x01, 0x05, 0x14, 0xc1, 0x11, 0x14 } }, // 10
{ { 0xc1, 0x05, 0x14, 0x01, 0x11, 0x14 } }, // 11
{ { 0x01, 0x05, 0x05, 0x14, 0xc1, 0x14 } }, // 12
{ { 0xc1, 0x05, 0x05, 0x14, 0x01, 0x14 } }, // 13
{ { 0xc1, 0x05, 0x11, 0x14, 0x01, 0x14 } }, // 14
{ { 0x01, 0x05, 0x11, 0x14, 0xc1, 0x14 } }, // 15
{ { 0xc1, 0x11, 0x02, 0x25, 0x05, 0x14 } }, // 16
{ { 0x01, 0x11, 0x02, 0x25, 0xc5, 0x14 } }, // 17
{ { 0x01, 0x11, 0x11, 0xc5, 0x05, 0x14 } }, // 18
{ { 0xc1, 0x14, 0x14, 0x01, 0x11, 0x14 } }, // 19
{ { 0x01, 0x05, 0x14, 0xc1, 0x14, 0x14 } }, // 20
{ { 0x01, 0x14, 0x14, 0xc1, 0x14, 0x14 } }, // 21
{ { 0xc1, 0x14, 0x14, 0x14, 0x01, 0x14 } }, // 22
{ { 0xc1, 0x14, 0x14, 0x01, 0x14, 0x04 } }, // 23
{ { 0xc1, 0x14, 0x14, 0x14, 0x04, 0x04 } }, // 24
{ { 0xc1, 0x14, 0x14, 0x04, 0x04, 0x04 } }, // 25
{ { 0xc1, 0x05, 0x14, 0x01, 0x14, 0x04 } }, // 26
{ { 0x01, 0x05, 0x14, 0xc1, 0x14, 0x04 } }, // 27
{ { 0x04, 0xc1, 0x11, 0x14, 0x01, 0x14 } }, // 28
{ { 0xc1, 0x14, 0x01, 0x14, 0x04, 0x04 } }, // 29
{ { 0x04, 0xc1, 0x11, 0x14, 0x04, 0x04 } }, // 30
{ { 0xc1, 0x14, 0x04, 0x04, 0x04, 0x04 } }, // 31
{ { 0xc4, 0x04, 0x04, 0x04, 0x04, 0x04 } }, // 32
};
// exclusively used for ALGO 4 with feedback
void EngineMkI::compute_fb3(int32_t *output, FmOpParams *parms, int32_t gain01, int32_t gain02, int32_t *fb_buf, int fb_shift) {
int32_t dgain[3];
int32_t gain[3];
int32_t phase[3];
int32_t y0 = fb_buf[0];
int32_t y = fb_buf[1];
phase[0] = parms[0].phase;
phase[1] = parms[1].phase;
phase[2] = parms[2].phase;
gain[0] = gain01;
gain[1] = parms[1].gain_out;
gain[2] = parms[2].gain_out;
dgain[0] = (gain02 - gain01 + (N >> 1)) >> LG_N;
parms[1].gain_out = Exp2::lookup(parms[1].level_in - (14 * (1 << 24)));
dgain[1] = (parms[1].gain_out - gain[1] + (N >> 1)) >> LG_N;
parms[2].gain_out = Exp2::lookup(parms[2].level_in - (14 * (1 << 24)));
dgain[2] = (parms[1].gain_out - gain[2] + (N >> 1)) >> LG_N;
for (int i = 0; i < N; i++) {
// op 0
gain[0] += dgain[0];
int32_t scaled_fb = (y0 + y) >> (fb_shift + 6); // tsk tsk tsk: this needs some tuning
y0 = y;
y = Sin::lookup(phase[0] + scaled_fb);
y = ((int64_t)y * (int64_t)gain[0]) >> 24;
phase[0] += parms[0].freq;
// op 1
gain[1] += dgain[1];
y = Sin::lookup(phase[1] + y);
y = ((int64_t)y * (int64_t)gain[1]) >> 24;
phase[1] += parms[1].freq;
// op 2
gain[2] += dgain[2];
y = Sin::lookup(phase[2] + y);
y = ((int64_t)y * (int64_t)gain[2]) >> 24;
output[i] = y;
phase[2] += parms[2].freq;
}
fb_buf[0] = y0;
fb_buf[1] = y;
}
void EngineMkI::render(int32_t *output, FmOpParams *params, int algorithm,
int32_t *fb_buf, int feedback_shift) {
const int kLevelThresh = 507; // really ????
const FmAlgorithm alg = algorithms[algorithm];
bool has_contents[3] = { true, false, false };
for (int op = 0; op < 6; op++) {
int flags = alg.ops[op];
bool add = (flags & OUT_BUS_ADD) != 0;
FmOpParams &param = params[op];
int inbus = (flags >> 4) & 3;
int outbus = flags & 3;
int32_t *outptr = (outbus == 0) ? output : buf_[outbus - 1].get();
int32_t gain1 = param.gain_out == 0 ? 511 : param.gain_out;
int32_t gain2 = 512-(param.level_in >> 19);
param.gain_out = gain2;
if (gain1 <= kLevelThresh || gain2 <= kLevelThresh) {
if (!has_contents[outbus]) {
add = false;
}
if (inbus == 0 || !has_contents[inbus]) {
// todo: more than one op in a feedback loop
if ((flags & 0xc0) == 0xc0 && feedback_shift < 16) {
// cout << op << " fb " << inbus << outbus << add << endl;
compute_fb(outptr, param.phase, param.freq,
gain1, gain2,
fb_buf, feedback_shift, add);
} else {
// cout << op << " pure " << inbus << outbus << add << endl;
compute_pure(outptr, param.phase, param.freq,
gain1, gain2, add);
}
} else {
// cout << op << " normal " << inbus << outbus << " " << param.freq << add << endl;
compute(outptr, buf_[inbus - 1].get(),
param.phase, param.freq, gain1, gain2, add);
}
has_contents[outbus] = true;
} else if (!add) {
has_contents[outbus] = false;
}
param.phase += param.freq << LG_N;
}
}
/*
void EngineMkI::render(int32_t *output, FmOpParams *params, int algorithm, int32_t *fb_buf, int feedback_shift) {
const int kLevelThresh = 507;
const FmAlgorithm alg = algo2[algorithm];
bool has_contents[3] = { true, false, false };
for (int op = 0; op < 6; op++) {
int flags = alg.ops[op];
bool add = (flags & OUT_BUS_ADD) != 0;
FmOpParams &param = params[op];
int inbus = (flags >> 4) & 3;
int outbus = flags & 3;
int32_t *outptr = (outbus == 0) ? output : buf_[outbus - 1].get();
int32_t gain1 = param.gain_out == 0 ? 511 : param.gain_out;
int32_t gain2 = 512-(param.level_in >> 19);
param.gain_out = gain2;
if (gain1 >= kLevelThresh || gain2 >= kLevelThresh) {
if (!has_contents[outbus]) {
add = false;
}
if (inbus == 0 || !has_contents[inbus]) {
// PG: this is my 'dirty' implementation of FB for 2 and 3 operators...
// still needs some tuning...
if ((flags & 0xc0) == 0xc0 && feedback_shift < 16) {
switch ( algorithm ) {
// two operator feedback, process exception for ALGO 6
case 5 :
//compute_fb2(outptr, params, gain1, gain2, fb_buf, feedback_shift, controllers);
params[1].phase += params[1].freq << LG_N; // yuk, hack, we already processed op-5
op++; // ignore next operator;
break;
// three operator feedback, process exception for ALGO 4
case 3 :
//compute_fb3(outptr, params, gain1, gain2, fb_buf, feedback_shift, controllers);
params[1].phase += params[1].freq << LG_N; // hack, we already processed op-5 - op-4
params[2].phase += params[2].freq << LG_N; // yuk yuk
op += 2; // ignore the 2 other operators
break;
default:
// one operator feedback, normal proces
//cout << "\t" << op << " fb " << inbus << outbus << add << endl;
compute_fb(outptr, param.phase, param.freq,gain1, gain2, fb_buf, feedback_shift, add);
break;
}
} else {
// cout << op << " pure " << inbus << outbus << add << endl;
compute_pure(outptr, param.phase, param.freq, gain1, gain2, add);
}
} else {
// cout << op << " normal " << inbus << outbus << " " << param.freq << add << endl;
compute(outptr, buf_[inbus - 1].get(), param.phase, param.freq, gain1, gain2, add);
}
has_contents[outbus] = true;
} else if (!add) {
has_contents[outbus] = false;
}
param.phase += param.freq << LG_N;
}
}
*/