Files
ProSystem-Core/core/Pokey.cpp
T
clobber 6d1f51397e Initial port
Still needs sound. Note: won't run with optimizations so release build
is -O0
2013-07-30 02:31:40 -05:00

365 lines
12 KiB
C++
Executable File

// ----------------------------------------------------------------------------
// ___ ___ ___ ___ ___ ____ ___ _ _
// /__/ /__/ / / /__ /__/ /__ / /_ / |/ /
// / / \ /__/ ___/ ___/ ___/ / /__ / / emulator
//
// ----------------------------------------------------------------------------
// Copyright 2005 Greg Stanton
//
// 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., 675 Mass Ave, Cambridge, MA 02139, USA.
// ----------------------------------------------------------------------------
// PokeySound is Copyright(c) 1997 by Ron Fries
//
// This library is free software; you can redistribute it and/or modify it
// under the terms of version 2 of the GNU Library General Public License
// as published by the Free Software Foundation.
//
// This library 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 Library
// General Public License for more details.
// To obtain a copy of the GNU Library General Public License, write to the
// Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
//
// Any permitted reproduction of these routines, in whole or in part, must
// bear this legend.
// ----------------------------------------------------------------------------
// Pokey.cpp
// ----------------------------------------------------------------------------
#include <stdlib.h>
#include "Pokey.h"
#define POKEY_NOTPOLY5 0x80
#define POKEY_POLY4 0x40
#define POKEY_PURE 0x20
#define POKEY_VOLUME_ONLY 0x10
#define POKEY_VOLUME_MASK 0x0f
#define POKEY_POLY9 0x80
#define POKEY_CH1_179 0x40
#define POKEY_CH3_179 0x20
#define POKEY_CH1_CH2 0x10
#define POKEY_CH3_CH4 0x08
#define POKEY_CH1_FILTER 0x04
#define POKEY_CH2_FILTER 0x02
#define POKEY_CLOCK_15 0x01
#define POKEY_DIV_64 28
#define POKEY_DIV_15 114
#define POKEY_POLY4_SIZE 0x000f
#define POKEY_POLY5_SIZE 0x001f
#define POKEY_POLY9_SIZE 0x01ff
#define POKEY_POLY17_SIZE 0x0001ffff
#define POKEY_CHANNEL1 0
#define POKEY_CHANNEL2 1
#define POKEY_CHANNEL3 2
#define POKEY_CHANNEL4 3
#define POKEY_SAMPLE 4
byte pokey_buffer[POKEY_BUFFER_SIZE] = {0};
uint pokey_size = 524;
static uint pokey_frequency = 1787520;
static uint pokey_sampleRate = 31440;
static uint pokey_soundCntr = 0;
static byte pokey_audf[4];
static byte pokey_audc[4];
static byte pokey_audctl;
static byte pokey_output[4];
static byte pokey_outVol[4];
static byte pokey_poly04[POKEY_POLY4_SIZE] = {1,1,0,1,1,1,0,0,0,0,1,0,1,0,0};
static byte pokey_poly05[POKEY_POLY5_SIZE] = {0,0,1,1,0,0,0,1,1,1,1,0,0,1,0,1,0,1,1,0,1,1,1,0,1,0,0,0,0,0,1};
static byte pokey_poly17[POKEY_POLY17_SIZE];
static uint pokey_poly17Size;
static uint pokey_polyAdjust;
static uint pokey_poly04Cntr;
static uint pokey_poly05Cntr;
static uint pokey_poly17Cntr;
static uint pokey_divideMax[4];
static uint pokey_divideCount[4];
static uint pokey_sampleMax;
static uint pokey_sampleCount[2];
static uint pokey_baseMultiplier;
// ----------------------------------------------------------------------------
// Reset
// ----------------------------------------------------------------------------
void pokey_Reset( ) {
for(int index = 0; index < POKEY_POLY17_SIZE; index++) {
pokey_poly17[index] = rand( ) & 1;
}
pokey_polyAdjust = 0;
pokey_poly04Cntr = 0;
pokey_poly05Cntr = 0;
pokey_poly17Cntr = 0;
pokey_sampleMax = ((uint)pokey_frequency << 8) / pokey_sampleRate;
pokey_sampleCount[0] = 0;
pokey_sampleCount[1] = 0;
pokey_poly17Size = POKEY_POLY17_SIZE;
for(int channel = POKEY_CHANNEL1; channel <= POKEY_CHANNEL4; channel++) {
pokey_outVol[channel] = 0;
pokey_output[channel] = 0;
pokey_divideCount[channel] = 0;
pokey_divideMax[channel] = 0x7fffffffL;
pokey_audc[channel] = 0;
pokey_audf[channel] = 0;
}
pokey_audctl = 0;
pokey_baseMultiplier = POKEY_DIV_64;
}
// ----------------------------------------------------------------------------
// SetRegister
// ----------------------------------------------------------------------------
void pokey_SetRegister(word address, byte value) {
byte channelMask;
switch(address) {
case POKEY_AUDF1:
pokey_audf[POKEY_CHANNEL1] = value;
channelMask = 1 << POKEY_CHANNEL1;
if(pokey_audctl & POKEY_CH1_CH2) {
channelMask |= 1 << POKEY_CHANNEL2;
}
break;
case POKEY_AUDC1:
pokey_audc[POKEY_CHANNEL1] = value;
channelMask = 1 << POKEY_CHANNEL1;
break;
case POKEY_AUDF2:
pokey_audf[POKEY_CHANNEL2] = value;
channelMask = 1 << POKEY_CHANNEL2;
break;
case POKEY_AUDC2:
pokey_audc[POKEY_CHANNEL2] = value;
channelMask = 1 << POKEY_CHANNEL2;
break;
case POKEY_AUDF3:
pokey_audf[POKEY_CHANNEL3] = value;
channelMask = 1 << POKEY_CHANNEL3;
if(pokey_audctl & POKEY_CH3_CH4) {
channelMask |= 1 << POKEY_CHANNEL4;
}
break;
case POKEY_AUDC3:
pokey_audc[POKEY_CHANNEL3] = value;
channelMask = 1 << POKEY_CHANNEL3;
break;
case POKEY_AUDF4:
pokey_audf[POKEY_CHANNEL4] = value;
channelMask = 1 << POKEY_CHANNEL4;
break;
case POKEY_AUDC4:
pokey_audc[POKEY_CHANNEL4] = value;
channelMask = 1 << POKEY_CHANNEL4;
break;
case POKEY_AUDCTL:
pokey_audctl = value;
channelMask = 15;
if(pokey_audctl & POKEY_POLY9) {
pokey_poly17Size = POKEY_POLY9_SIZE;
}
else {
pokey_poly17Size = POKEY_POLY17_SIZE;
}
if(pokey_audctl & POKEY_CLOCK_15) {
pokey_baseMultiplier = POKEY_DIV_15;
}
else {
pokey_baseMultiplier = POKEY_DIV_64;
}
break;
default:
channelMask = 0;
break;
}
uint newValue = 0;
if(channelMask & (1 << POKEY_CHANNEL1)) {
if(pokey_audctl & POKEY_CH1_179) {
newValue = pokey_audf[POKEY_CHANNEL1] + 4;
}
else {
newValue = (pokey_audf[POKEY_CHANNEL1] + 1) * pokey_baseMultiplier;
}
if(newValue != pokey_divideMax[POKEY_CHANNEL1]) {
pokey_divideMax[POKEY_CHANNEL1] = newValue;
if(pokey_divideCount[POKEY_CHANNEL1] > newValue) {
pokey_divideCount[POKEY_CHANNEL1] = 0;
}
}
}
if(channelMask & (1 << POKEY_CHANNEL2)) {
if(pokey_audctl & POKEY_CH1_CH2) {
if(pokey_audctl & POKEY_CH1_179) {
newValue = pokey_audf[POKEY_CHANNEL2] * 256 + pokey_audf[POKEY_CHANNEL1] + 7;
}
else {
newValue = (pokey_audf[POKEY_CHANNEL2] * 256 + pokey_audf[POKEY_CHANNEL1] + 1) * pokey_baseMultiplier;
}
}
else {
newValue = (pokey_audf[POKEY_CHANNEL2] + 1) * pokey_baseMultiplier;
}
if(newValue != pokey_divideMax[POKEY_CHANNEL2]) {
pokey_divideMax[POKEY_CHANNEL2] = newValue;
if(pokey_divideCount[POKEY_CHANNEL2] > newValue) {
pokey_divideCount[POKEY_CHANNEL2] = newValue;
}
}
}
if(channelMask & (1 << POKEY_CHANNEL3)) {
if(pokey_audctl & POKEY_CH3_179) {
newValue = pokey_audf[POKEY_CHANNEL3] + 4;
}
else {
newValue= (pokey_audf[POKEY_CHANNEL3] + 1) * pokey_baseMultiplier;
}
if(newValue!= pokey_divideMax[POKEY_CHANNEL3]) {
pokey_divideMax[POKEY_CHANNEL3] = newValue;
if(pokey_divideCount[POKEY_CHANNEL3] > newValue) {
pokey_divideCount[POKEY_CHANNEL3] = newValue;
}
}
}
if(channelMask & (1 << POKEY_CHANNEL4)) {
if(pokey_audctl & POKEY_CH3_CH4) {
if(pokey_audctl & POKEY_CH3_179) {
newValue = pokey_audf[POKEY_CHANNEL4] * 256 + pokey_audf[POKEY_CHANNEL3] + 7;
}
else {
newValue = (pokey_audf[POKEY_CHANNEL4] * 256 + pokey_audf[POKEY_CHANNEL3] + 1) * pokey_baseMultiplier;
}
}
else {
newValue = (pokey_audf[POKEY_CHANNEL4] + 1) * pokey_baseMultiplier;
}
if(newValue != pokey_divideMax[POKEY_CHANNEL4]) {
pokey_divideMax[POKEY_CHANNEL4] = newValue;
if(pokey_divideCount[POKEY_CHANNEL4] > newValue) {
pokey_divideCount[POKEY_CHANNEL4] = newValue;
}
}
}
for(byte channel = POKEY_CHANNEL1; channel <= POKEY_CHANNEL4; channel++) {
if(channelMask & (1 << channel)) {
if((pokey_audc[channel] & POKEY_VOLUME_ONLY) || ((pokey_audc[channel] & POKEY_VOLUME_MASK) == 0) || (pokey_divideMax[channel] < (pokey_sampleMax >> 8))) {
pokey_outVol[channel] = pokey_audc[channel] & POKEY_VOLUME_MASK;
pokey_divideCount[channel] = 0x7fffffff;
pokey_divideMax[channel] = 0x7fffffff;
}
}
}
}
// ----------------------------------------------------------------------------
// Process
// ----------------------------------------------------------------------------
void pokey_Process(uint length) {
byte* buffer = pokey_buffer + pokey_soundCntr;
uint* sampleCntrPtr = (uint*)((byte*)(&pokey_sampleCount[0]) + 1);
uint size = length;
while(length) {
byte currentValue;
byte nextEvent = POKEY_SAMPLE;
uint eventMin = *sampleCntrPtr;
byte channel;
for(channel = POKEY_CHANNEL1; channel <= POKEY_CHANNEL4; channel++) {
if(pokey_divideCount[channel] <= eventMin) {
eventMin = pokey_divideCount[channel];
nextEvent = channel;
}
}
for(channel = POKEY_CHANNEL1; channel <= POKEY_CHANNEL4; channel++) {
pokey_divideCount[channel] -= eventMin;
}
*sampleCntrPtr -= eventMin;
pokey_polyAdjust += eventMin;
if(nextEvent != POKEY_SAMPLE) {
pokey_poly04Cntr = (pokey_poly04Cntr + pokey_polyAdjust) % POKEY_POLY4_SIZE;
pokey_poly05Cntr = (pokey_poly05Cntr + pokey_polyAdjust) % POKEY_POLY5_SIZE;
pokey_poly17Cntr = (pokey_poly17Cntr + pokey_polyAdjust) % pokey_poly17Size;
pokey_polyAdjust = 0;
pokey_divideCount[nextEvent] += pokey_divideMax[nextEvent];
if((pokey_audc[nextEvent] & POKEY_NOTPOLY5) || pokey_poly05[pokey_poly05Cntr]) {
if(pokey_audc[nextEvent] & POKEY_PURE) {
pokey_output[nextEvent] = !pokey_output[nextEvent];
}
else if (pokey_audc[nextEvent] & POKEY_POLY4) {
pokey_output[nextEvent] = pokey_poly04[pokey_poly04Cntr];
}
else {
pokey_output[nextEvent] = pokey_poly17[pokey_poly17Cntr];
}
}
if(pokey_output[nextEvent]) {
pokey_outVol[nextEvent] = pokey_audc[nextEvent] & POKEY_VOLUME_MASK;
}
else {
pokey_outVol[nextEvent] = 0;
}
}
else {
*pokey_sampleCount += pokey_sampleMax;
currentValue = 0;
for(channel = POKEY_CHANNEL1; channel <= POKEY_CHANNEL4; channel++) {
currentValue += pokey_outVol[channel];
}
currentValue = (currentValue << 2) + 8;
*buffer++ = currentValue;
length--;
}
}
pokey_soundCntr += size;
if(pokey_soundCntr >= pokey_size) {
pokey_soundCntr = 0;
}
}
// ----------------------------------------------------------------------------
// Clear
// ----------------------------------------------------------------------------
void pokey_Clear( ) {
for(int index = 0; index < POKEY_BUFFER_SIZE; index++) {
pokey_buffer[index] = 0;
}
}