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Diffstat (limited to 'src/fake86/adlib.c')
| -rwxr-xr-x | src/fake86/adlib.c | 240 |
1 files changed, 240 insertions, 0 deletions
diff --git a/src/fake86/adlib.c b/src/fake86/adlib.c new file mode 100755 index 0000000..cf17584 --- /dev/null +++ b/src/fake86/adlib.c @@ -0,0 +1,240 @@ +/* + Fake86: A portable, open-source 8086 PC emulator. + Copyright (C)2010-2013 Mike Chambers + + This program is free software; you can redistribute it and/or + modify it under the terms of the GNU General Public License + as published by the Free Software Foundation; either version 2 + of the License, or (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software + Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. +*/ + +/* adlib.c: very ugly Adlib OPL2 emulation for Fake86. very much a work in progress. :) */ + +#include "config.h" +#include <SDL/SDL.h> +#include <stdint.h> +#include <stdio.h> + +extern void set_port_write_redirector (uint16_t startport, uint16_t endport, void *callback); +extern void set_port_read_redirector (uint16_t startport, uint16_t endport, void *callback); + +extern int32_t usesamplerate; + +double samprateadjust = 1.0; +uint8_t optable[0x16] = { 0, 0, 0, 1, 1, 1, 255, 255, 0, 0, 0, 1, 1, 1, 255, 255, 0, 0, 0, 1, 1, 1 }; +uint16_t adlibregmem[0xFF], adlibaddr = 0; + +int8_t waveform[4][64] = { + { 1, 8, 13, 20, 26, 31, 37, 41, 47, 49, 54, 58, 58, 62, 63, 63, 64, 63, 62, 61, 58, 55, 52, 47, 45, 38, 34, 27, 23, 17, 10, 4,-2,-8,-15,-21,-26,-34,-36,-42,-48,-51,-54,-59,-60,-62,-64,-65,-65,-63,-64,-61,-59,-56,-53,-48,-46,-39,-36,-28,-24,-17,-11,-6 }, + { 1, 8, 13, 20, 25, 32, 36, 42, 46, 50, 54, 57, 60, 61, 62, 64, 63, 65, 61, 61, 58, 55, 51, 49, 44, 38, 34, 28, 23, 16, 11, 3, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 }, + { 1, 8, 13, 21, 25, 31, 36, 43, 45, 50, 54, 57, 59, 62, 63, 63, 63, 64, 63, 59, 59, 55, 52, 48, 44, 38, 34, 28, 23, 16, 10, 4, 2, 7, 14, 20, 26, 31, 36, 42, 45, 51, 54, 56, 60, 62, 62, 63, 65, 63, 62, 60, 58, 55, 52, 48, 44, 38, 34, 28, 23, 17, 10, 3 }, + { 1, 8, 13, 20, 26, 31, 36, 42, 46, 51, 53, 57, 60, 62, 61, 66, 16, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 7, 13, 21, 25, 32, 36, 41, 47, 50, 54, 56, 60, 62, 61, 67, 15, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 } +}; + +int8_t oplwave[4][256] = { + { + 0, 1, 3, 4, 6, 7, 9, 11, 12, 14, 15, 17, 18, 20, 22, 23, 24, 26, 27, 29, 30, 31, 33, 34, 36, 37, 38, 40, 40, 42, 43, 44, 46, 46, 48, 49, 50, 51, 51, 53, + 53, 54, 55, 56, 57, 57, 58, 59, 59, 60, 61, 61, 62, 62, 63, 63, 63, 64, 64, 64, 116, 116, 116, 116, 116, 116, 116, 116, 116, 64, 64, 64, 63, 63, 63, 62, 62, 61, 61, 60, + 59, 59, 58, 57, 57, 56, 55, 54, 53, 53, 51, 51, 50, 49, 48, 46, 46, 44, 43, 42, 40, 40, 38, 37, 36, 34, 33, 31, 30, 29, 27, 26, 24, 23, 22, 20, 18, 17, 15, 14, + 12, 11, 9, 7, 6, 4, 3, 1, 0, -1, -3, -4, -6, -7, -9, -11, -12, -14, -15, -17, -18, -20, -22, -23, -24, -26, -27, -29, -30, -31, -33, -34, -36, -37, -38, -40, -40, -42, -43, -44, + -46, -46, -48, -49, -50, -51, -51, -53, -53, -54, -55, -56, -57, -57, -58, -59, -59, -60, -61, -61, -62, -62, -63, -63, -63, -64, -64, -64, -116, -116, -116, -116, -116, -116, -116, -116, -116, -64, -64, -64, + -63, -63, -63, -62, -62, -61, -61, -60, -59, -59, -58, -57, -57, -56, -55, -54, -53, -53, -51, -51, -50, -49, -48, -46, -46, -44, -43, -42, -40, -40, -38, -37, -36, -34, -33, -31, -30, -29, -27, -26, + -24, -23, -22, -20, -18, -17, -15, -14, -12, -11, -9, -7, -6, -4, -3, -1 + }, + + { + 0, 1, 3, 4, 6, 7, 9, 11, 12, 14, 15, 17, 18, 20, 22, 23, 24, 26, 27, 29,30, 31, 33, 34, 36, 37, 38, 40, 40, 42, 43, 44, 46, 46, 48, 49, 50, 51, 51, 53, + 53, 54, 55, 56, 57, 57, 58, 59, 59, 60, 61, 61, 62, 62, 63, 63, 63, 64, 64, 64, 116, 116, 116, 116, 116, 116, 116, 116, 116, 64, 64, 64, 63, 63, 63, 62, 62, 61, 61, 60, + 59, 59, 58, 57, 57, 56, 55, 54, 53, 53, 51, 51, 50, 49, 48, 46, 46, 44, 43, 42, 40, 40, 38, 37, 36, 34, 33, 31, 30, 29, 27, 26, 24, 23, 22, 20, 18, 17, 15, 14, + 12, 11, 9, 7, 6, 4, 3, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 + }, + + + { + 0, 1, 3, 4, 6, 7, 9, 11, 12, 14, 15, 17, 18, 20, 22, 23, 24, 26, 27, 29, 30, 31, 33, 34, 36, 37, 38, 40, 40, 42, 43, 44, 46, 46, 48, 49, 50, 51, 51, 53, + 53, 54, 55, 56, 57, 57, 58, 59, 59, 60, 61, 61, 62, 62, 63, 63, 63, 64, 64, 64, 116, 116, 116, 116, 116, 116, 116, 116, 116, 64, 64, 64, 63, 63, 63, 62, 62, 61, 61, 60, + 59, 59, 58, 57, 57, 56, 55, 54, 53, 53, 51, 51, 50, 49, 48, 46, 46, 44, 43, 42, 40, 40, 38, 37, 36, 34, 33, 31, 30, 29, 27, 26, 24, 23, 22, 20, 18, 17, 15, 14, + 12, 11, 9, 7, 6, 4, 3, 1, 0, 1, 3, 4, 6, 7, 9, 11, 12, 14, 15, 17, 18, 20, 22, 23, 24, 26, 27, 29, 30, 31, 33, 34, 36, 37, 38, 40, 40, 42, 43, 44, + 46, 46, 48, 49, 50, 51, 51, 53, 53, 54, 55, 56, 57, 57, 58, 59, 59, 60, 61, 61, 62, 62, 63, 63, 63, 64, 64, 64, 116, 116, 116, 116, 116, 116, 116, 116, 116, 64, 64, 64, + 63, 63, 63, 62, 62, 61, 61, 60, 59, 59, 58, 57, 57, 56, 55, 54, 53, 53, 51, 51, 50, 49, 48, 46, 46, 44, 43, 42, 40, 40, 38, 37, 36, 34, 33, 31, 30, 29, 27, 26, + 24, 23, 22, 20, 18, 17, 15, 14, 12, 11, 9, 7, 6, 4, 3, 1 + }, + + + { + 0, 1, 3, 4, 6, 7, 9, 11, 12, 14, 15, 17, 18, 20, 22, 23, 24, 26, 27, 29, 30, 31, 33, 34, 36, 37, 38, 40, 40, 42, 43, 44, 46, 46, 48, 49, 50, 51, 51, 53, + 53, 54, 55, 56, 57, 57, 58, 59, 59, 60, 61, 61, 62, 62, 63, 63, 63, 64, 64, 64, 116, 116, 116, 116, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 3, 4, 6, 7, 9, 11, 12, 14, 15, 17, 18, 20, 22, 23, 24, 26, 27, 29, 30, 31, 33, 34, 36, 37, 38, 40, 40, 42, 43, 44, + 46, 46, 48, 49, 50, 51, 51, 53, 53, 54, 55, 56, 57, 57, 58, 59, 59, 60, 61, 61, 62, 62, 63, 63, 63, 64, 64, 64, 116, 116, 116, 116, 0, 0, 0, 0, 0, 0, 0, 0, + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 + } + +}; + +uint8_t oplstep[9] = { 0, 0, 0, 0, 0, 0, 0, 0, 0 }; + +struct structadlibop { + uint8_t wave; +} adlibop[9][2]; + +struct structadlibchan { + uint16_t freq; + double convfreq; + uint8_t keyon; + uint16_t octave; + uint8_t wavesel; +} adlibch[9]; + +double attacktable[16] = { 1.0003, 1.00025, 1.0002, 1.00015, 1.0001, 1.00009, 1.00008, 1.00007, 1.00006, 1.00005, 1.00004, 1.00003, 1.00002, 1.00001, 1.000005 }; //1.003, 1.05, 1.01, 1.015, 1.02, 1.025, 1.03, 1.035, 1.04, 1.045, 1.05, 1.055, 1.06, 1.065, 1.07, 1.075 }; +double decaytable[16] = { 0.99999, 0.999985, 0.99998, 0.999975, 0.99997, 0.999965, 0.99996, 0.999955, 0.99995, 0.999945, 0.99994, 0.999935, 0.99994, 0.999925, 0.99992, 0.99991 }; +double adlibenv[9], adlibdecay[9], adlibattack[9]; +uint8_t adlibdidattack[9], adlibpercussion = 0, adlibstatus = 0; + +uint16_t adlibport = 0x388; + +void outadlib (uint16_t portnum, uint8_t value) { + if (portnum==adlibport) { + adlibaddr = value; + return; + } + portnum = adlibaddr; + adlibregmem[portnum] = value; + switch (portnum) { + case 4: //timer control + if (value&0x80) { + adlibstatus = 0; + adlibregmem[4] = 0; + } + break; + case 0xBD: + if (value & 0x10) adlibpercussion = 1; + else adlibpercussion = 0; + break; + } + if ( (portnum >= 0x60) && (portnum <= 0x75) ) { //attack/decay + portnum &= 15; + adlibattack[portnum] = attacktable[15- (value>>4) ]*1.006; + adlibdecay[portnum] = decaytable[value&15]; + } + else if ( (portnum >= 0xA0) && (portnum <= 0xB8) ) { //octave, freq, key on + portnum &= 15; + if (!adlibch[portnum].keyon && ( (adlibregmem[0xB0+portnum]>>5) &1) ) { + adlibdidattack[portnum] = 0; + adlibenv[portnum] = 0.0025; + } + adlibch[portnum].freq = adlibregmem[0xA0+portnum] | ( (adlibregmem[0xB0+portnum]&3) <<8); + adlibch[portnum].convfreq = ( (double) adlibch[portnum].freq * 0.7626459); + adlibch[portnum].keyon = (adlibregmem[0xB0+portnum]>>5) &1; + adlibch[portnum].octave = (adlibregmem[0xB0+portnum]>>2) &7; + } + else if ( (portnum >= 0xE0) && (portnum <= 0xF5) ) { //waveform select + portnum &= 15; + if (portnum<9) adlibch[portnum].wavesel = value&3; + } +} + +uint8_t inadlib (uint16_t portnum) { + if (!adlibregmem[4]) adlibstatus = 0; + else adlibstatus = 0x80; + adlibstatus = adlibstatus + (adlibregmem[4]&1) *0x40 + (adlibregmem[4]&2) *0x10; + return (adlibstatus); +} + +uint16_t adlibfreq (uint8_t chan) { + uint16_t tmpfreq; + if (!adlibch[chan].keyon) return (0); + tmpfreq = (uint16_t) adlibch[chan].convfreq; + switch (adlibch[chan].octave) { + case 0: + tmpfreq = tmpfreq >> 4; + break; + case 1: + tmpfreq = tmpfreq >> 3; + break; + case 2: + tmpfreq = tmpfreq >> 2; + break; + case 3: + tmpfreq = tmpfreq >> 1; + break; + case 5: + tmpfreq = tmpfreq << 1; + break; + case 6: + tmpfreq = tmpfreq << 2; + break; + case 7: + tmpfreq = tmpfreq << 3; + } + + return (tmpfreq); +} + +uint64_t fullstep, adlibstep[9]; +double adlibenv[9], adlibdecay[9], adlibattack[9]; +uint8_t adlibdidattack[9]; + +extern SDL_AudioSpec wanted; +int32_t adlibsample (uint8_t curchan) { + int32_t tempsample; + double tempstep; + + if (adlibpercussion && (curchan>=6) && (curchan<=8) ) return (0); + + fullstep = usesamplerate/adlibfreq (curchan); + + tempsample = (int32_t) oplwave[adlibch[curchan].wavesel][ (uint8_t) ( (double) adlibstep[curchan]/ ( (double) fullstep/ (double) 256) ) ]; + tempstep = adlibenv[curchan]; + if (tempstep>1.0) tempstep = 1; + tempsample = (int32_t) ( (double) tempsample * tempstep * 2.0); + + adlibstep[curchan]++; + if (adlibstep[curchan]>fullstep) adlibstep[curchan] = 0; + return (tempsample); +} + +int16_t adlibgensample() { + uint8_t curchan; + int16_t adlibaccum; + adlibaccum = 0; + for (curchan=0; curchan<9; curchan++) { + if (adlibfreq (curchan) !=0) { + adlibaccum += (int16_t) adlibsample (curchan); + } + } + return (adlibaccum); +} + +void tickadlib() { + uint8_t curchan; + for (curchan=0; curchan<9; curchan++) { + if (adlibfreq (curchan) !=0) { + if (adlibdidattack[curchan]) { + adlibenv[curchan] *= adlibdecay[curchan]; + } + else { + adlibenv[curchan] *= adlibattack[curchan]; + if (adlibenv[curchan]>=1.0) adlibdidattack[curchan] = 1; + } + } + } +} + +void initadlib (uint16_t baseport) { + set_port_write_redirector (baseport, baseport + 1, &outadlib); + set_port_read_redirector (baseport, baseport + 1, &inadlib); +} |