+++ /dev/null
-\r
-// This file is part of the PicoDrive Megadrive Emulator\r
-\r
-// Copyright (c) 2011 FinalDave (emudave (at) gmail.com)\r
-\r
-// This code is licensed under the GNU General Public License version 2.0 and the MAME License.\r
-// You can choose the license that has the most advantages for you.\r
-\r
-// SVN repository can be found at http://code.google.com/p/cyclone68000/\r
-\r
-#include "PicoInt.h"\r
-\r
-#ifdef MSOUND\r
-extern "C"\r
-{\r
-int YM2612UpdateReq(int) { return 0; }\r
-void *errorlog=NULL;\r
-}\r
-#endif\r
-\r
-int PsndRate=0,PsndLen=0;\r
-short *PsndOut=NULL;\r
-\r
-// An operator is a single sine wave generator\r
-struct Operator\r
-{\r
- unsigned short angle; // 0-0xffff\r
- unsigned short freq; // Converted frequency\r
- unsigned char key;\r
- unsigned char state; // 1=attack, 2=decay, 3=sustain, 4=release\r
- int vol;\r
- int delta; // Change in volume per sample\r
- int limit; // Next volume limit\r
-};\r
-\r
-struct Channel\r
-{\r
- struct Operator op[4]; // 4 operators for the channel\r
- unsigned short note; // Written to 0xa4 and 0xa0\r
-};\r
-\r
-static struct Channel Chan[8];\r
-\r
-unsigned char PicoSreg[0x200];\r
-\r
-static int WriteReg(int side,int a,int d)\r
-{\r
- struct Channel *pc=NULL;\r
-\r
- PicoSreg[(side<<8)|a]=(unsigned char)d;\r
-\r
- if (a==0x28)\r
- {\r
- pc=Chan+(d&7);\r
- // Key On/Key Off\r
- if (d&0xf0) pc->op[0].state=1; // Attack\r
- else pc->op[0].state=4; // Release\r
-\r
- return 0;\r
- }\r
-\r
- // Find channel:\r
- pc=Chan+(a&3); if (side) pc+=4;\r
-\r
- if ((a&0xf0)==0xa0)\r
- {\r
- int n=0,f=0,mult=2455;\r
-\r
- if (PsndRate>0) mult=44100*2455/PsndRate;\r
-\r
- if (a&4) pc->note =(unsigned short)(d<<8);\r
- else pc->note|=d;\r
-\r
- // Convert to an actual frequency:\r
- n=pc->note; f=(n&0x7ff)<<((n>>11)&7);\r
-\r
- pc->op[0].freq=(unsigned short)((f*mult)>>16);\r
- return 0;\r
- }\r
-\r
- return 0;\r
-}\r
-\r
-int PsndReset()\r
-{\r
- int i=0;\r
- memset(&Chan,0,sizeof(Chan));\r
- memset(PicoSreg,0,sizeof(PicoSreg));\r
-\r
-// Change Sine wave into a square wave\r
- for (i=0x00; i<0x080; i++) Sine[i]= 0x2000;\r
- for (i=0x80; i<0x100; i++) Sine[i]=-0x2000;\r
-\r
- return 0;\r
-}\r
-\r
-int PsndFm(int a,int d)\r
-{\r
- int side=0;\r
-\r
-#ifdef MSOUND\r
- YM2612Write(0,a&3,(unsigned char)d);\r
-#endif\r
-\r
- a&=3; side=a>>1; // Which side: channels 0-2 or 3-5\r
-\r
- if (a&1) WriteReg(side,Pico.s.fmsel[side],d); // Write register\r
- else Pico.s.fmsel[side]=(unsigned char)d; // Select register\r
-\r
- return 0;\r
-}\r
-\r
-static void BlankSound(short *dest,int len)\r
-{\r
- short *end=NULL;\r
-\r
- end=dest+(len<<1);\r
-\r
- // Init sound to silence:\r
- do { *dest=0; dest++; } while (dest<end);\r
-}\r
-\r
-// Add to output and clip:\r
-static inline void AddClip(short *targ,int d)\r
-{\r
- int total=*targ+d;\r
- if ((total+0x8000)&0xffff0000)\r
- {\r
- if (total>0) total=0x7fff; else total=-0x8000;\r
- }\r
- *targ=(short)total;\r
-}\r
-\r
-static void OpNewState(int c)\r
-{\r
- struct Operator *op=Chan[c].op;\r
- int off=0;\r
-\r
- off=((c&4)<<6)|(c&3);\r
-\r
- switch (op->state)\r
- {\r
- case 1:\r
- {\r
- // Attack:\r
- int ar=PicoSreg[0x50|off];\r
- ar&=0x1f; if (ar) ar+=0x10;\r
- op->delta=ar<<7; op->limit=0x1000000; break;\r
- }\r
- case 2:\r
- {\r
- // Decay:\r
- int d1r=PicoSreg[0x60|off];\r
- d1r&=0x1f; if (d1r) d1r+=0x10;\r
- op->delta=-(d1r<<5); op->limit=0;\r
- }\r
- break;\r
- case 3:\r
- {\r
- // Sustain:\r
- int d2r=0,rr=0;\r
- \r
- d2r=PicoSreg[0x70|off];\r
- d2r&=0x1f; if (d2r) d2r+=0x10;\r
- rr =PicoSreg[0x80|off];\r
- rr>>=4;\r
-\r
- op->delta=-(d2r<<5); op->limit=rr<<20;\r
- }\r
- break;\r
- case 4:\r
- // Release:\r
- int rr=PicoSreg[0x80|off];\r
- rr&=0x0f; rr<<=1; rr+=0x10;\r
- op->delta=-(rr<<5); op->limit=0;\r
- break;\r
- }\r
-}\r
-\r
-// Merely adding this code in seems to bugger up the N-Gage???\r
-static void UpdateOp(int c)\r
-{\r
- struct Operator *op=Chan[c].op;\r
-\r
- op->angle=(unsigned short)(op->angle+op->freq);\r
- op->vol+=op->delta;\r
-\r
- switch (op->state)\r
- {\r
- case 1:\r
- if (op->vol>=op->limit) { op->vol=op->limit; op->state++; OpNewState(c); }\r
- break;\r
- case 2: case 3: // Decay/Sustain\r
- if (op->vol< op->limit) { op->vol=op->limit; op->state++; OpNewState(c); }\r
- break;\r
- case 4:\r
- if (op->vol< op->limit) { op->vol=op->limit; }\r
- break;\r
- }\r
-}\r
-\r
-static void AddChannel(int c,short *dest,int len)\r
-{\r
- struct Channel *pc=Chan+c;\r
- struct Operator *op=pc->op;\r
- short *end=NULL;\r
-\r
- // Work out volume delta for this operator:\r
- OpNewState(c);\r
-\r
- end=dest+len;\r
- do\r
- {\r
- int d=0;\r
- d=Sine[(op->angle>>8)&0xff]>>2;\r
-\r
- d*=(op->vol>>8); d>>=16;\r
-\r
- // Add to output:\r
- AddClip(dest,d);\r
- UpdateOp(c);\r
-\r
- dest++;\r
- }\r
- while (dest<end);\r
-}\r
-\r
-int PsndRender()\r
-{\r
- int i=0;\r
-\r
- if (PsndOut==NULL) return 1; // Not rendering sound\r
-\r
-#ifdef MSOUND\r
- if (PicoOpt&1)\r
- {\r
- short *wave[2]={NULL,NULL};\r
- wave[0]=PsndOut;\r
- wave[1]=PsndOut+PsndLen;\r
- YM2612UpdateOne(0,wave,PsndLen);\r
- }\r
-#endif\r
-\r
- if ((PicoOpt&1)==0)\r
- {\r
- BlankSound(PsndOut,PsndLen);\r
- for (i=0;i<7;i++)\r
- {\r
- if (i!=3) AddChannel(i,PsndOut,PsndLen);\r
- }\r
- }\r
-\r
- return 0;\r
-}\r
notaz.gp2x.de / cyclone68000.git / blobdiff