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YM2612: early full linear pitch experiment

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tildearrow 2022-05-10 16:22:40 -05:00
parent c79e5e8081
commit aad5d818f2
3 changed files with 44 additions and 34 deletions
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71
src/engine/engine.cpp
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@ -995,46 +995,55 @@ double DivEngine::calcBaseFreq(double clock, double divider, int note, bool peri
base*(divider/clock);
}
#define CONVERT_FNUM_BLOCK(bf,bits,note) \
double tuning=song.tuning; \
if (tuning<400.0) tuning=400.0; \
if (tuning>500.0) tuning=500.0; \
int boundaryBottom=tuning*pow(2.0,0.25)*(divider/clock); \
int boundaryTop=2.0*tuning*pow(2.0,0.25)*(divider/clock); \
int block=(note)/12; \
if (block<0) block=0; \
if (block>7) block=7; \
bf>>=block; \
if (bf<0) bf=0; \
/* octave boundaries */ \
while (bf>0 && bf<boundaryBottom && block>0) { \
bf<<=1; \
block--; \
} \
if (bf>boundaryTop) { \
while (block<7 && bf>boundaryTop) { \
bf>>=1; \
block++; \
} \
if (bf>((1<<bits)-1)) { \
bf=(1<<bits)-1; \
} \
} \
/* logV("f-num: %d block: %d",bf,block); */ \
return bf|(block<<bits);
unsigned short DivEngine::calcBaseFreqFNumBlock(double clock, double divider, int note, int bits) {
if (song.linearPitch==2) { // full linear
return (note<<7);
}
double tuning=song.tuning;
if (tuning<400.0) tuning=400.0;
if (tuning>500.0) tuning=500.0;
int bf=calcBaseFreq(clock,divider,note,false);
int boundaryBottom=tuning*pow(2.0,0.25)*(divider/clock);
int boundaryTop=2.0*tuning*pow(2.0,0.25)*(divider/clock);
int block=note/12;
if (block<0) block=0;
if (block>7) block=7;
bf>>=block;
if (bf<0) bf=0;
// octave boundaries
while (bf>0 && bf<boundaryBottom && block>0) {
bf<<=1;
block--;
}
if (bf>boundaryTop) {
while (block<7 && bf>boundaryTop) {
bf>>=1;
block++;
}
if (bf>((1<<bits)-1)) {
bf=(1<<bits)-1;
}
}
//logV("f-num: %d block: %d",bf,block);
return bf|(block<<bits);
CONVERT_FNUM_BLOCK(bf,bits,note)
}
int DivEngine::calcFreq(int base, int pitch, bool period, int octave, int pitch2, double clock, double divider) {
int DivEngine::calcFreq(int base, int pitch, bool period, int octave, int pitch2, double clock, double divider, int blockBits) {
if (song.linearPitch==2) {
// do frequency calculation here
double fbase=(period?(song.tuning*0.0625):song.tuning)*pow(2.0,(float)(base+pitch+384)/(128.0*12.0));
return period?
(clock/fbase)/divider:
fbase*(divider/clock);
int nbase=base+pitch+pitch2;
double fbase=(period?(song.tuning*0.0625):song.tuning)*pow(2.0,(float)(nbase+384)/(128.0*12.0));
int bf=period?
(clock/fbase)/divider:
fbase*(divider/clock);
if (blockBits>0) {
CONVERT_FNUM_BLOCK(bf,blockBits,nbase>>7)
} else {
return bf;
}
}
if (song.linearPitch==1) {
// global pitch multiplier