/* * Adplug - Replayer for many OPL2/OPL3 audio file formats. * Copyright (C) 1999 - 2010 Simon Peter, , et al. * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * 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 * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA * * surroundopl.cpp - Wrapper class to provide a surround/harmonic effect * for another OPL emulator, by Adam Nielsen * * Stereo harmonic algorithm by Adam Nielsen * Please give credit if you use this algorithm elsewhere :-) */ #include // for pow() #include "surroundopl.h" //#include "debug.h" CSurroundopl::CSurroundopl(Copl *a, Copl *b, bool use16bit, double opl_freq, double freq_offset) : a(a), b(b), freq_offset(freq_offset), opl_freq(opl_freq), bufsize(4096), use16bit(use16bit) { currType = TYPE_OPL2; this->lbuf = new short[this->bufsize]; this->rbuf = new short[this->bufsize]; }; CSurroundopl::~CSurroundopl() { delete[] this->rbuf; delete[] this->lbuf; delete a; delete b; } void CSurroundopl::update(short *buf, int samples) { if (samples * 2 > this->bufsize) { // Need to realloc the buffer delete[] this->rbuf; delete[] this->lbuf; this->bufsize = samples * 2; this->lbuf = new short[this->bufsize]; this->rbuf = new short[this->bufsize]; } a->update(this->lbuf, samples); b->update(this->rbuf, samples); // Copy the two mono OPL buffers into the stereo buffer for (int i = 0; i < samples; i++) { if (this->use16bit) { buf[i * 2] = this->lbuf[i]; buf[i * 2 + 1] = this->rbuf[i]; } else { ((char *)buf)[i * 2] = ((char *)this->lbuf)[i]; ((char *)buf)[i * 2 + 1] = ((char *)this->rbuf)[i]; } } } // template methods void CSurroundopl::write(int reg, int val) { a->write(reg, val); // Transpose the other channel to produce the harmonic effect int iChannel = -1; int iRegister = reg; // temp int iValue = val; // temp if ((iRegister >> 4 == 0xA) || (iRegister >> 4 == 0xB)) iChannel = iRegister & 0x0F; // Remember the FM state, so that the harmonic effect can access // previously assigned register values. /*if (((iRegister >> 4 == 0xB) && (iValue & 0x20) && !(this->iFMReg[iRegister] & 0x20)) || (iRegister == 0xBD) && ( ((iValue & 0x01) && !(this->iFMReg[0xBD] & 0x01)) )) { this->iFMReg[iRegister] = iValue; }*/ this->iFMReg[iRegister] = iValue; if ((iChannel >= 0)) {// && (i == 1)) { unsigned char iBlock = (this->iFMReg[0xB0 + iChannel] >> 2) & 0x07; unsigned short iFNum = ((this->iFMReg[0xB0 + iChannel] & 0x03) << 8) | this->iFMReg[0xA0 + iChannel]; //double dbOriginalFreq = 50000.0 * (double)iFNum * pow(2, iBlock - 20); double dbOriginalFreq = opl_freq * (double)iFNum * pow(2.0, iBlock - 20); unsigned char iNewBlock = iBlock; unsigned short iNewFNum; // Adjust the frequency and calculate the new FNum //double dbNewFNum = (dbOriginalFreq+(dbOriginalFreq/FREQ_OFFSET)) / (50000.0 * pow(2.0, iNewBlock - 20)); //#define calcFNum() ((dbOriginalFreq+(dbOriginalFreq/FREQ_OFFSET)) / (50000.0 * pow(2.0, iNewBlock - 20))) #define calcFNum() ((dbOriginalFreq + (dbOriginalFreq / freq_offset)) / (opl_freq * pow(2.0, iNewBlock - 20))) double dbNewFNum = calcFNum(); // Make sure it's in range for the OPL chip if (dbNewFNum > 1023 - NEWBLOCK_LIMIT) { // It's too high, so move up one block (octave) and recalculate if (iNewBlock > 6) { // Uh oh, we're already at the highest octave! // AdPlug_LogWrite("OPL WARN: FNum %d/B#%d would need block 8+ after being transposed (new FNum is %d)\n", // iFNum, iBlock, (int)dbNewFNum); // The best we can do here is to just play the same note out of the second OPL, so at least it shouldn't // sound *too* bad (hopefully it will just miss out on the nice harmonic.) iNewBlock = iBlock; iNewFNum = iFNum; } else { iNewBlock++; iNewFNum = (unsigned short)calcFNum(); } } else if (dbNewFNum < 0 + NEWBLOCK_LIMIT) { // It's too low, so move down one block (octave) and recalculate if (iNewBlock == 0) { // Uh oh, we're already at the lowest octave! // AdPlug_LogWrite("OPL WARN: FNum %d/B#%d would need block -1 after being transposed (new FNum is %d)!\n", // iFNum, iBlock, (int)dbNewFNum); // The best we can do here is to just play the same note out of the second OPL, so at least it shouldn't // sound *too* bad (hopefully it will just miss out on the nice harmonic.) iNewBlock = iBlock; iNewFNum = iFNum; } else { iNewBlock--; iNewFNum = (unsigned short)calcFNum(); } } else { // Original calculation is within range, use that iNewFNum = (unsigned short)dbNewFNum; } // Sanity check if (iNewFNum > 1023) { // Uh oh, the new FNum is still out of range! (This shouldn't happen) // AdPlug_LogWrite("OPL ERR: Original note (FNum %d/B#%d is still out of range after change to FNum %d/B#%d!\n", // iFNum, iBlock, iNewFNum, iNewBlock); // The best we can do here is to just play the same note out of the second OPL, so at least it shouldn't // sound *too* bad (hopefully it will just miss out on the nice harmonic.) iNewBlock = iBlock; iNewFNum = iFNum; } if ((iRegister >= 0xB0) && (iRegister <= 0xB8)) { // Overwrite the supplied value with the new F-Number and Block. iValue = (iValue & ~0x1F) | (iNewBlock << 2) | ((iNewFNum >> 8) & 0x03); this->iCurrentTweakedBlock[iChannel] = iNewBlock; // save it so we don't have to update register 0xB0 later on this->iCurrentFNum[iChannel] = (unsigned char)iNewFNum; if (this->iTweakedFMReg[0xA0 + iChannel] != (iNewFNum & 0xFF)) { // Need to write out low bits unsigned char iAdditionalReg = 0xA0 + iChannel; unsigned char iAdditionalValue = iNewFNum & 0xFF; b->write(iAdditionalReg, iAdditionalValue); this->iTweakedFMReg[iAdditionalReg] = iAdditionalValue; } } else if ((iRegister >= 0xA0) && (iRegister <= 0xA8)) { // Overwrite the supplied value with the new F-Number. iValue = iNewFNum & 0xFF; // See if we need to update the block number, which is stored in a different register unsigned char iNewB0Value = (this->iFMReg[0xB0 + iChannel] & ~0x1F) | (iNewBlock << 2) | ((iNewFNum >> 8) & 0x03); if ( (iNewB0Value & 0x20) && // but only update if there's a note currently playing (otherwise we can just wait (this->iTweakedFMReg[0xB0 + iChannel] != iNewB0Value) // until the next noteon and update it then) ) { // AdPlug_LogWrite("OPL INFO: CH%d - FNum %d/B#%d -> FNum %d/B#%d == keyon register update!\n", // iChannel, iFNum, iBlock, iNewFNum, iNewBlock); // The note is already playing, so we need to adjust the upper bits too unsigned char iAdditionalReg = 0xB0 + iChannel; b->write(iAdditionalReg, iNewB0Value); this->iTweakedFMReg[iAdditionalReg] = iNewB0Value; } // else the note is not playing, the upper bits will be set when the note is next played } // if (register 0xB0 or 0xA0) } // if (a register we're interested in) // Now write to the original register with a possibly modified value b->write(iRegister, iValue); this->iTweakedFMReg[iRegister] = iValue; }; void CSurroundopl::init() { a->init(); b->init(); }