otomatalabs/furnace
8
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

Use bsr() in frequency shift calculations

Browse source
This commit is contained in:
Natt Akuma 2024-09-18 13:05:45 +07:00
parent 9905981e61
commit 6a58797669
6 changed files with 77 additions and 145 deletions
Download patch file Download diff file Expand all files Collapse all files

42
src/engine/platform/opll.cpp
View file

@ -19,6 +19,7 @@
#include "opll.h"
#include "../engine.h"
#include "../bsr.h"
#include "../../ta-log.h"
#include <string.h>
#include <math.h>
@ -352,44 +353,15 @@ void DivPlatformOPLL::tick(bool sysTick) {
#define OPLL_C_NUM 343
int DivPlatformOPLL::octave(int freq) {
if (freq>=OPLL_C_NUM*64) {
return 128;
} else if (freq>=OPLL_C_NUM*32) {
return 64;
} else if (freq>=OPLL_C_NUM*16) {
return 32;
} else if (freq>=OPLL_C_NUM*8) {
return 16;
} else if (freq>=OPLL_C_NUM*4) {
return 8;
} else if (freq>=OPLL_C_NUM*2) {
return 4;
} else if (freq>=OPLL_C_NUM) {
return 2;
} else {
return 1;
}
return 1;
freq/=OPLL_C_NUM;
if (freq==0) return 1;
return 1<<bsr(freq);
}
int DivPlatformOPLL::toFreq(int freq) {
if (freq>=OPLL_C_NUM*64) {
return 0xe00|((freq>>7)&0x1ff);
} else if (freq>=OPLL_C_NUM*32) {
return 0xc00|((freq>>6)&0x1ff);
} else if (freq>=OPLL_C_NUM*16) {
return 0xa00|((freq>>5)&0x1ff);
} else if (freq>=OPLL_C_NUM*8) {
return 0x800|((freq>>4)&0x1ff);
} else if (freq>=OPLL_C_NUM*4) {
return 0x600|((freq>>3)&0x1ff);
} else if (freq>=OPLL_C_NUM*2) {
return 0x400|((freq>>2)&0x1ff);
} else if (freq>=OPLL_C_NUM) {
return 0x200|((freq>>1)&0x1ff);
} else {
return freq&0x1ff;
}
int block=freq/OPLL_C_NUM;
if (block>0) block=bsr(block);
return (block<<9)|((freq>>block)&0x1ff);
}
void DivPlatformOPLL::muteChannel(int ch, bool mute) {