furnace/src/engine/platform/dummy.cpp
2022-02-14 22:12:20 -05:00

118 lines
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3.1 KiB
C++

/**
* Furnace Tracker - multi-system chiptune tracker
* Copyright (C) 2021-2022 tildearrow and contributors
*
* 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.
*/
#include "dummy.h"
#include "../engine.h"
#include <stdio.h>
#include <math.h>
void DivPlatformDummy::acquire(short* bufL, short* bufR, size_t start, size_t len) {
for (size_t i=start; i<start+len; i++) {
bufL[i]=0;
for (unsigned char j=0; j<chans; j++) {
if (chan[j].active) {
if (!isMuted[j]) bufL[i]+=(((signed short)chan[j].pos)*chan[j].amp*chan[j].vol)>>13;
chan[j].pos+=chan[j].freq;
}
}
}
}
void DivPlatformDummy::muteChannel(int ch, bool mute) {
isMuted[ch]=mute;
}
void DivPlatformDummy::tick() {
for (unsigned char i=0; i<chans; i++) {
chan[i].amp-=3;
if (chan[i].amp<16) chan[i].amp=16;
if (chan[i].freqChanged) {
chan[i].freqChanged=false;
chan[i].freq=parent->calcFreq(chan[i].baseFreq,chan[i].pitch);
}
}
}
void* DivPlatformDummy::getChanState(int ch) {
return &chan[ch];
}
int DivPlatformDummy::dispatch(DivCommand c) {
switch (c.cmd) {
case DIV_CMD_NOTE_ON:
if (c.value!=DIV_NOTE_NULL) {
chan[c.chan].baseFreq=65.6f*pow(2.0f,((float)c.value/12.0f));
chan[c.chan].freqChanged=true;
}
chan[c.chan].active=true;
chan[c.chan].amp=64;
break;
case DIV_CMD_NOTE_OFF:
chan[c.chan].active=false;
break;
case DIV_CMD_VOLUME:
chan[c.chan].vol=c.value;
if (chan[c.chan].vol>15) chan[c.chan].vol=15;
break;
case DIV_CMD_GET_VOLUME:
return chan[c.chan].vol;
break;
case DIV_CMD_PITCH:
chan[c.chan].pitch=c.value;
chan[c.chan].freqChanged=true;
break;
case DIV_CMD_LEGATO:
chan[c.chan].baseFreq=65.6f*pow(2.0f,((float)c.value/12.0f));
chan[c.chan].freqChanged=true;
break;
case DIV_CMD_GET_VOLMAX:
return 15;
break;
default:
break;
}
return 1;
}
void DivPlatformDummy::reset() {
for (int i=0; i<chans; i++) {
chan[i]=DivPlatformDummy::Channel();
chan[i].vol=0x0f;
}
}
int DivPlatformDummy::init(DivEngine* p, int channels, int sugRate, unsigned int flags) {
parent=p;
dumpWrites=false;
skipRegisterWrites=false;
for (int i=0; i<DIV_MAX_CHANS; i++) {
isMuted[i]=false;
}
rate=65536;
chans=channels;
reset();
return channels;
}
void DivPlatformDummy::quit() {
}
DivPlatformDummy::~DivPlatformDummy() {
}