ref: e8304ea686d212ad118f760dc9e6df5167027272
dir: /it_m_eff.c/
/*
Copyright (C) 2014, Jeffrey Lim. All Rights Reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:
1. Redistributions of source code must retain the above copyright notice,
this list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright notice,
this list of conditions and the following disclaimer in the documentation
and/or other materials provided with the distribution.
3. The name of the author may not be used to endorse or promote products
derived from this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR
BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
POSSIBILITY OF SUCH DAMAGE.
*/
#include "it_struc.h"
uint8_t SlideTable[9] = { 1, 4, 8, 16, 32, 64, 96, 128, 255 };
void InitVolumeEffectH(it_engine *ite, it_host *chn, uint8_t ah);
void InitCommandD7(it_engine *ite, it_host *chn, it_slave *slave);
void InitCommandG11(it_engine *ite, it_host *chn);
void InitCommandX2(it_engine *ite, it_host *chn, uint8_t al);
void CommandD2(it_engine *ite, it_host *chn, it_slave *slave, uint8_t al);
void CommandEChain(it_engine *ite, it_host *chn, int16_t bx);
void CommandFChain(it_engine *ite, it_host *chn, int16_t bx);
void InitVibrato(it_engine *ite, it_host *chn);
void CommandH5(it_engine *ite, it_host *chn, it_slave *slave, int8_t al);
void InitTremelo(it_engine *ite, it_host *chn);
void CommandR2(it_engine *ite, it_host *chn, it_slave *slave, int8_t al);
/*
// Not transcribing further unless there is a good reason to.
int32_t GetC5Speed(uint8_t *ds, uint8_t *es, uint16_t bx)
{
if(*(uint8_t *)(ds + di + 0x0F) == 101)
{
// OK.. we have a MIDI sample
// Check whether the midi sample points to a valid sample
// And if so, use that sample's C5 speed.
uint16_t si = *(uint8_t *)(ds + di + 0x03); // Not a note?
uint32_t ebp = *(uint8_t *)(ds + di + 0x04);
if(ebp != 0) // No sample?
{
si += si;
ebp = *(uint16_t *)(es + 64710 + ebp + ebp);
uint8_t al = *(uint8_t *)(es + ebp + si + 0x40) // AL = note
uint8_t ah = *(uint8_t *)(es + ebp + si + 0x41) // AH = sample.
if(ah != 0) // No sample?
{
si = ah*2;
si = *(uint16_t *)(es + 64910 + si) // Sample offset
if(*(uint8_t *)(es + si + 0x12) == 1)
{
bx = si;
}
}
}
}
return *(uint8_t *)(es + bx + 0x3C); // EAX = C5Spd
}
*/
void InitVolumeEffect(it_engine *ite, it_host *chn) // Done A, B, H
{
if((chn->Msk & 0x44) == 0)
return;
uint8_t al = chn->Vol;
uint8_t ah = al;
al &= 0x7F;
if(al < 65)
return;
al -= 65;
if((ah & 0x80) != 0)
{
al += 60;
}
uint8_t dl = 10;
uint8_t tmpquo = al / dl;
uint8_t tmprem = al % dl;
al = tmpquo; // Effect number
ah = tmprem; // Effect parameter
chn->VCm = al; // Store effect number
// Memory for effects A->D, (EFG)/H dont' share.
// Effects Ax and Bx (fine volume slide up and down) require immediate
// handling. No flags required. (effect 0 and 1)
// Effects Cx, Dx, Ex, Fx (volume/pitch slides) require flag to be
// set (effects 2->5)
// Effects Gx and Hx need init (handling) code + flags.
// (effects 6 and 7).
if(ah != 0)
{
if(al >= 4)
{
if(al < 6)
{
// Ex Fx
chn->EFG = ah<<2;
} else if(al <= 6) {
// Gx
if((ite->hdr.Flags & 0x0020) != 0) // Link command G?
{
chn->GOE = SlideTable[ah-1];
} else {
chn->EFG = SlideTable[ah-1];
}
}
} else {
// Ax Bx Cx Dx
chn->VVal = ah;
}
}
if((chn->Flags & 0x04) != 0)
{
// Channel not on!
// TODO: work out what this comment means and which it applies to
// (I think it applies to this block)
it_slave *slave = &ite->slave[chn->SCOffst];
if(al <= 1)
{
if(al != 1)
{
al = chn->VVal;
al += slave->VS;
if(al > 64)
al = 64;
} else {
al = chn->VVal;
al -= slave->VS;
if((al & 0x80) != 0)
al = 0;
}
CommandD2(ite, chn, slave, al);
return;
} else {
chn->Flags |= 0x0100;
if(al > 6)
{
InitVolumeEffectH(ite, chn, ah);
return;
} else if(al == 6) {
InitCommandG11(ite, chn);
return;
}
return;
}
} else {
if(al == 7)
InitVolumeEffectH(ite, chn, ah);
}
}
void InitVolumeEffectH(it_engine *ite, it_host *chn, uint8_t ah)
{
ah <<= 2;
if(ah != 0)
chn->VDp = ah;
if((chn->Flags & 4) != 0)
InitVibrato(ite, chn);
}
void VolumeCommandC(it_engine *ite, it_host *chn)
{
it_slave *slave = &ite->slave[chn->SCOffst];
uint8_t al = chn->VVal + slave->VS;
if(al > 64)
{
chn->Flags &= ~0x0100; // Turn off effect calling
al = 64;
}
CommandD2(ite, chn, slave, al);
}
void VolumeCommandD(it_engine *ite, it_host *chn)
{
it_slave *slave = &ite->slave[chn->SCOffst];
uint8_t al = slave->VS - chn->VVal;
//if((al & 0x80) != 0) // JNC, not JNS
if(slave->VS < chn->VVal)
{
chn->Flags &= ~0x0100; // Turn off effect calling
al = 0;
}
CommandD2(ite, chn, slave, al);
}
void VolumeCommandE(it_engine *ite, it_host *chn) // Pitch slide down
{
CommandEChain(ite, chn, ((int16_t)(uint16_t)chn->EFG)<<2);
}
void VolumeCommandF(it_engine *ite, it_host *chn)
{
CommandFChain(ite, chn, ((int16_t)(uint16_t)chn->EFG)<<2);
}
void VolumeCommandG(it_engine *ite, it_host *chn)
{
if((chn->Flags & 0x16) == 0)
return;
uint16_t bx = chn->EFG;
if((ite->hdr.Flags & 0x0020) != 0) // Link command G?
bx = chn->GOE;
if(bx == 0)
return;
bx <<= 2;
it_slave *slave = &ite->slave[chn->SCOffst];
if(chn->_42 != 1)
{
// Slide down
PitchSlideDown(ite, chn, slave, bx);
// Check that frequency is above porta
// to frequency.
int32_t eaxs = slave->Frequency;
if(eaxs <= chn->Porta_Frequency)
{
chn->Flags &= ~0x0110; // Turn off calling
slave->Frequency = eaxs = chn->Porta_Frequency;
}
slave->Frequency_Set = eaxs;
} else {
// Slide up!
PitchSlideUp(ite, chn, slave, bx);
// Check that
// 1) Channel is on
// 2) Frequency (set) is below porta to
// frequency
int32_t eaxs = slave->Frequency;
if((slave->Flags & 0x0200) != 0 || eaxs > chn->Porta_Frequency)
{
slave->Flags &= ~0x0200;
chn->Flags |= 0x0004; // Turn on.
chn->Flags &= ~0x0110; // Turn off calling
slave->Frequency = eaxs = chn->Porta_Frequency;
}
slave->Frequency_Set = eaxs;
}
}
void InitNoCommand(it_engine *ite, it_host *chn) // DS:DI points to CIT area.
{
it_slave *slave;
uint8_t cl = chn->Msk; // CL = mask
uint8_t ch = chn->Flags; // CH = channel info.
if((cl & 0x33) == 0)
goto NoOldEffect; // InitCommand1
uint8_t al = chn->Nt2;
// Note here!
// Check for noteoff.
if(al >= 120)
{
if((ch & 0x04) == 0) // Taken if the channel's off.
{
// Jump point.
goto NoOldEffect; // InitNoCommand1
}
slave = &ite->slave[chn->SCOffst];
//if(0)
if(al > 0xFE) // Noteoff
{
slave->Flags |= 0x0004; // Note off
// if(slave->VS == 0) // Volume = 0???
// goto InitNoCommand13;
} else {
//if(al == 0xFE || al == 0xFF)
if(al == 0xFE)
{
ch &= ~4;
if(chn->Smp != 100 && (ite->d.DriverFlags & 2) == 0)
{
slave->Flags = 0x0200;
goto NoOldEffect;
}
// MIDINoteCut:
// ch &= ~4;
slave->Flags |= 0x0200;
} else {
slave->Flags |= 8; // Note fade
goto NoOldEffect;
}
}
} else {
if((ch & 4) != 0 && (cl & 0x11) == 0 && ite->slave[chn->SCOffst].Nte != chn->Nte)
goto NoOldEffect; // InitNoCommand1
if((cl & 0x44) != 0 && chn->Vol >= 193 && chn->Vol <= 202 && (chn->Flags & 4) != 0) {
InitVolumeEffect(ite, chn);
return;
}
slave = AllocateChannel(ite, chn, &ch);
if(slave == NULL)
goto NoOldEffect;
// Channel allocated.
// put volume
slave->Vol = slave->VS = chn->VSe;
it_sample *smp = &ite->smp[slave->SmpOffs];
if((ite->hdr.Flags & 4) == 0 && (smp->DfP & 0x80) != 0)
slave->PS = slave->Pan = chn->CP = smp->DfP & 0x7F;
uint32_t eax = smp->C5Speed;
slave->OldSampleOffset = 0;
slave->SmpErr = 0;
slave->Sample_Offset = 0;
// Calculate frequency.
uint64_t da = (uint64_t)eax * (uint64_t)PitchTable[chn->Nt2];
eax = (uint32_t)(((uint64_t)da)>>(uint64_t)16);
slave->Frequency = slave->Frequency_Set = eax;
ch |= 4;
ch &= ~16;
}
GetLoopInformation(ite, slave);
//InitNoCommand1:
if((cl & (0x22 + 0x44)) == 0)
goto InitNoCommand3;
// Instrument mode and old effects?
if((ite->hdr.Flags & 0x14) != 0x14)
goto NoOldEffect;
if(cl & 0x22)
goto NoOldEffect;
if(chn->Ins == 0xFF)
goto NoOldEffect;
slave->FadeOut = 0x0400;
InitPlayInstrument(ite, chn, slave, chn->Ins);
NoOldEffect:
// TODO: fix this dreadful flow code once everything works --GM
if((cl & 0x44) == 0)
goto InitNoCommand7;
if(chn->Vol <= 64)
{
chn->VSe = chn->Vol;
goto InitNoCommand8; // Volume set...
}
if((chn->Vol & 0x7F) >= 65)
goto InitNoCommand7;
// Panning set!
//InitNoCommandPanning:
chn->Flags = (chn->Flags & 0xFF00) | (0xFF & (uint16_t)ch);
InitCommandX2(ite, chn, chn->Vol - 128); // Destroys (SI), AX
InitNoCommand7:
if((cl & 0x22) == 0) // Instrument present? Change volume
goto InitNoCommand3;
// Get instrument offset.
if(chn->Smp == 0xFF)
goto InitNoCommand3;
chn->VSe = ite->smp[chn->Smp-1].Vol; // Default volume
InitNoCommand8:
if((ch & 4) == 0)
goto InitNoCommand3;
slave = &ite->slave[chn->SCOffst];
slave->Vol = slave->VS = chn->VSe;
slave->Flags |= 0x10; // recalc volume
InitNoCommand3:
// Randomise volume if required.
if((chn->Flags & 0x80) == 0)
{
chn->Flags = (chn->Flags & 0xFF00) | (0xFF & (uint16_t)ch);
InitVolumeEffect(ite, chn);
return;
}
chn->Flags = (chn->Flags & 0xFF00) | (0xFF & (uint16_t)ch);
ApplyRandomValues(ite, chn);
InitVolumeEffect(ite, chn);
}
void InitCommandA(it_engine *ite, it_host *chn)
{
uint16_t ax = chn->CVal;
if(ax != 0)
{
ite->CurrentTick -= ite->CurrentSpeed;
ite->ProcessTick -= ite->CurrentSpeed;
ite->CurrentTick += ax;
ite->ProcessTick += ax;
ite->CurrentSpeed = ax;
}
InitNoCommand(ite, chn);
}
void InitCommandB(it_engine *ite, it_host *chn)
{
uint16_t ax = chn->CVal;
if(ax < ite->CurrentOrder)
ite->StopSong = 1;
ax--;
ite->ProcessOrder = ax;
ite->ProcessRow = 0xFFFE;
InitNoCommand(ite, chn);
}
void InitCommandC(it_engine *ite, it_host *chn)
{
if(ite->PatternLooping == 0)
{
ite->BreakRow = chn->CVal;
ite->ProcessRow = 0xFFFE;
}
InitNoCommand(ite, chn);
}
void InitCommandD(it_engine *ite, it_host *chn)
{
InitNoCommand(ite, chn);
if(chn->CVal != 0)
chn->DKL = chn->CVal;
if((chn->Flags & 4) == 0)
return;
it_slave *slave = &ite->slave[chn->SCOffst];
InitCommandD7(ite, chn, slave);
}
void InitCommandD7(it_engine *ite, it_host *chn, it_slave *slave)
{
// Jmp point for Lxx
slave->Flags |= 16; // Recalc vol
// TODO: verify
if((chn->DKL & 0x0F) == 0) {
// Slide up.
chn->VCh = chn->DKL>>4;
chn->Flags |= 1;
if(chn->VCh == 0x0F) {
CommandD(ite, chn);
return;
}
} else if((chn->DKL & 0xF0) == 0) {
// Slide down
chn->VCh = -chn->DKL;
chn->Flags |= 1;
if(chn->VCh == (uint8_t)-0x0F) {
CommandD(ite, chn);
return;
}
} else if((chn->DKL & 0x0F) == 0x0F) {
// InitCommandD5:
// Slide up (fine)
chn->VCh = 0;
uint8_t al = (chn->DKL >> 4) + slave->VS;
if(al > 64)
al = 64;
slave->Vol = slave->VS = chn->VSe = al;
} else if((chn->DKL & 0xF0) == 0xF0) {
// Slide down (fine)
chn->VCh = 0;
uint8_t al = slave->VS - (chn->DKL & 0x0F);
if((al & 0x80) != 0)
al = 0;
slave->Vol = slave->VS = chn->VSe = al;
}
}
void InitCommandE(it_engine *ite, it_host *chn)
{
InitNoCommand(ite, chn);
if(chn->CVal != 0)
chn->EFG = chn->CVal;
if((chn->Flags & 4) == 0)
return;
it_slave *slave = &ite->slave[chn->SCOffst];
// OK.. now processing is dependent
// upon slide mode.
if(chn->EFG == 0) // still no slide??
return;
if((chn->EFG & 0xF0) >= 0xE0)
{
if((chn->EFG & 0x0F) == 0)
return;
uint8_t al = chn->EFG & 0x0F;
if((chn->EFG & 0xF0) != 0xE0)
al <<= 2;
PitchSlideDown(ite, chn, slave, al);
slave->Frequency_Set = slave->Frequency;
} else {
chn->_40 = ((int16_t)chn->EFG)<<2;
// call update only if necess.
chn->Flags |= 1;
}
}
void InitCommandF(it_engine *ite, it_host *chn)
{
// TODO: verify
InitNoCommand(ite, chn);
if(chn->CVal != 0)
chn->EFG = chn->CVal;
if((chn->Flags & 4) == 0)
return;
it_slave *slave = &ite->slave[chn->SCOffst];
// OK.. now processing is dependent
// upon slide mode.
if(chn->EFG == 0) // still no slide??
return;
if((chn->EFG & 0xF0) >= 0xE0)
{
if((chn->EFG & 0x0F) == 0)
return;
uint8_t al = chn->EFG & 0x0F;
if((chn->EFG & 0xF0) != 0xE0)
al <<= 2;
PitchSlideUp(ite, chn, slave, al);
slave->Frequency_Set = slave->Frequency;
} else {
// note: not negative. this point proves crucial for some things --GM
chn->_40 = (((int16_t)chn->EFG)<<2);
// call update only if necess.
chn->Flags |= 1;
}
}
// InitCommandG15 = InitNoCommand
void InitCommandG(it_engine *ite, it_host *chn)
{
// Check whether channel on/owned
if(chn->CVal != 0)
{
// Compatibility Gxx?
if((ite->hdr.Flags & 0x20) != 0)
chn->GOE = chn->CVal;
else
chn->EFG = chn->CVal;
}
if((chn->Flags & 4) == 0)
{
InitNoCommand(ite, chn);
} else {
InitCommandG11(ite, chn);
}
}
void InitCommandG11(it_engine *ite, it_host *chn)
{
// added some flow comments because, well, the flow is weird --GM
// Jumped to from Lxx
it_slave *slave = &ite->slave[chn->SCOffst];
int skipnote = 0;
if((chn->Msk & 0x22) != 0 && (chn->Smp != 0)) // false -> G13
{
int has_g18 = 0;
// Checking for change of Sample or instrument.
if((ite->hdr.Flags & 0x20) == 0) // false -> GXXCompat1
{
// Don't overwrite note if MIDI!
if(chn->Smp != 101) // false -> G13
{
uint8_t oldsmp = slave->Smp;
uint8_t oldins = slave->Ins;
slave->Nte = chn->Nte;
slave->Ins = chn->Ins;
/*
flow here is kinda odd:
INS SMP
= = -> G13
! = -> G18
= ! -> G16
! ! -> G16
*/
if(oldsmp != chn->Smp-1) // Sample the same?
{
// G16
it_sample *smp = &ite->smp[chn->Smp-1];
slave->Flags = (slave->Flags & 0xFF) | 0x0100;
// Now to update sample info.
slave->SmpOffs = chn->Smp-1;
slave->Smp = chn->Smp-1;
slave->ViDepth = 0; // Reset vibrato..
slave->LpD = 0; // Reset loop direction.
slave->OldSampleOffset = 0;
slave->SmpErr = 0;
slave->Sample_Offset = 0;
slave->SVl = smp->GvL*2;
if((smp->Flg & 1) == 0)
{
slave->Flags = 0x0200;
chn->Flags &= ~4;
return;
}
// 16 bit...
slave->Bit = (smp->Flg & 2);
GetLoopInformation(ite, slave);
// follow onto G18
has_g18 = 1;
} else if(oldins != chn->Ins) { // Ins the same?
// follow onto G18
has_g18 = 1;
}
}
} else {
// GXXCompat1
chn->Smp = slave->Smp+1;
it_sample *smp = &ite->smp[slave->Smp];
slave->SVl = smp->GvL*2;
// follow onto G18
has_g18 = 1;
}
// G18
if(has_g18)
{
if((ite->hdr.Flags & 4) != 0) // Instrument/sample mode?
// false -> G14
{
// Now for instruments
slave->FadeOut = 0x0400;
it_instrument *ins = &ite->ins[chn->Ins-1];
uint16_t oldflags = slave->Flags;
InitPlayInstrument(ite, chn, slave, chn->Ins);
if((oldflags & 1) != 0)
slave->Flags &= ~0x100;
slave->SVl = ((uint16_t)ins->GbV * (uint16_t)slave->SVl)>>7;
// follow onto G14
}
skipnote = 1; // -> G14 common jump
}
}
// G13 (refers to the actual mask condition)
if((skipnote != 0) || (chn->Msk & 0x11) != 0) // false -> G1
{
// G14
// OK. Time to calc freq.
if(chn->Nt2 > 119) // false -> G5
{
if((chn->Flags & 4) != 0) // false -> G1
{
if(chn->Nt2 > 0xFE)
{
// Note off
slave->Flags |= 4;
GetLoopInformation(ite, slave);
} else if(chn->Nt2 != 0xFE) {
slave->Flags |= 8;
} else {
// Note cut!
chn->Flags &= ~4;
slave->Flags = 0x200; // Cut.
}
}
} else {
// Don't overwrite note if MIDI!
if(chn->Smp != 101)
slave->Nte = chn->Nt2;
it_sample *smp = &ite->smp[slave->SmpOffs];
uint64_t c5 = ((uint64_t)smp->C5Speed) * (uint64_t)PitchTable[chn->Nt2];
c5 >>= (uint64_t)16;
chn->Porta_Frequency = c5;
chn->Flags |= 16;
}
}
int revol = -1;
if((chn->Msk & 0x44) != 0)
{
if(chn->Vol <= 64)
{
revol = chn->Vol;
} else if((chn->Vol & 0x7F) < 65) {
// Panning set...
InitCommandX2(ite, chn, chn->Vol - 128);
}
}
if(revol == -1 && (chn->Msk & 0x22) != 0)
revol = ite->smp[slave->SmpOffs].Vol;
if(revol != -1)
{
slave->Flags |= 16; // recalc volume.
chn->VSe = slave->Vol = slave->VS = revol;
}
if((chn->Flags & 16) != 0) // Slide on???
{
// Work out magnitude + dirn
int16_t ax = chn->EFG;
if((ite->hdr.Flags & 0x20) != 0) // Command G memory
ax = chn->GOE;
ax <<= 2;
if(ax != 0)
{
chn->_40 = ax;
if(chn->Porta_Frequency > slave->Frequency_Set)
{
// slide up
chn->_42 = 1 | (chn->_42 & 0xFF00);
if((chn->Flags & 0x100) == 0)
chn->Flags |= 1; // Update effect if necess.
} else if(chn->Porta_Frequency < slave->Frequency_Set) {
// slide down.
chn->_42 = 0 | (chn->_42 & 0xFF00);
if((chn->Flags & 0x100) == 0)
chn->Flags |= 1; // Update effect if necess.
}
// equal?!?!?
// then don't update effect.
}
}
// Don't call volume effects if it has a Gxx!
if((chn->Flags & 0x100) == 0) // comment this out and you'll get a stack overflow on a Gx VE --GM
InitVolumeEffect(ite, chn);
}
void InitCommandH(it_engine *ite, it_host *chn)
{
if((chn->Msk & 0x11) != 0 && chn->Nte <= 119)
{
chn->VPo = 0;
chn->LVi = 0;
}
uint8_t ah = (chn->CVal & 0x0F); // AH = depth
uint8_t al = (chn->CVal & 0xF0); // AL = speed.
if(ah != 0 || al != 0)
{
al >>= 2;
if(al != 0)
chn->VSp = al;
ah <<= 2;
if(ah != 0)
{
if((ite->hdr.Flags & 0x10) != 0)
ah *= 2;
chn->VDp = ah;
}
}
InitNoCommand(ite, chn);
if((chn->Flags & 4) != 0)
{
// Update mode.
chn->Flags |= 1;
InitVibrato(ite, chn);
}
}
void InitCommandI(it_engine *ite, it_host *chn)
{
InitNoCommand(ite, chn);
if(chn->CVal != 0)
chn->I00 = chn->CVal;
if((chn->Flags & 4) != 0)
{
// OK.. now to handle tremor
chn->Flags |= 1;
uint8_t al = chn->I00 & 0x0F; // AL = Offtime
uint8_t ah = chn->I00 >> 4; // AH = ontime
if((ite->hdr.Flags & 16) != 0)
{
al++;
ah++;
}
uint16_t ax = (uint16_t)al | (((uint16_t)ah)<<8);
chn->_40 = ax; // fucking hell Jeff ;_; --GM
CommandI(ite, chn);
}
}
void InitCommandJ(it_engine *ite, it_host *chn)
{
InitNoCommand(ite, chn);
chn->_40 = 0;
if(chn->CVal != 0)
chn->J00 = chn->CVal;
if((chn->Flags & 4) != 0)
{
chn->Flags |= 1; // Update when channel on
// TODO: verify - i think this actually stores the freq to mul by,
// which is 32-bit --GM
chn->_44 = (60+(chn->J00&0x0F))*4;
chn->_42 = (60+(chn->J00>>4))*4;
}
}
void InitCommandK(it_engine *ite, it_host *chn)
{
if(chn->CVal != 0)
chn->DKL = chn->CVal;
InitNoCommand(ite, chn);
if((chn->Flags & 4) != 0)
{
InitVibrato(ite, chn);
it_slave *slave = &ite->slave[chn->SCOffst];
InitCommandD7(ite, chn, slave);
chn->Flags |= 2; // Always update.
}
}
void InitCommandL(it_engine *ite, it_host *chn)
{
if(chn->CVal != 0)
chn->DKL = chn->CVal;
if((chn->Flags & 4) != 0)
{
InitCommandG11(ite, chn);
it_slave *slave = &ite->slave[chn->SCOffst];
InitCommandD7(ite, chn, slave);
chn->Flags |= 2; // Always update.
}
}
void InitCommandM2(it_engine *ite, it_host *chn, uint8_t al)
{
if((chn->Flags & 4) != 0)
{
it_slave *slave = &ite->slave[chn->SCOffst];
slave->CVl = al;
slave->Flags |= 16; // recalc volume
}
chn->CV = al;
}
void InitCommandM(it_engine *ite, it_host *chn)
{
InitNoCommand(ite, chn);
if(chn->CVal > 0x40) return;
InitCommandM2(ite, chn, chn->CVal);
}
void InitCommandN(it_engine *ite, it_host *chn)
{
if(chn->CVal != 0)
chn->N00 = chn->CVal;
InitNoCommand(ite, chn);
if((chn->N00 & 0x0F) == 0)
{
chn->_40 = (chn->_40 & 0xFF00) | ((((int16_t)chn->N00)>>4) & 0xFF);
chn->Flags |= 2; // Always update effect
} else if((chn->N00 & 0xF0) == 0) {
chn->_40 = (chn->_40 & 0xFF00) | ((-(int16_t)chn->N00) & 0xFF);
chn->Flags |= 2;
} else if((chn->N00 & 0x0F) == 0x0F) {
uint8_t al = (chn->N00>>4) + chn->CV;
if(al > 64) al = 64;
InitCommandM2(ite, chn, al);
return;
} else if((chn->N00 & 0xF0) == 0xF0) {
//
uint8_t al = (chn->N00>>4) - chn->CV;
if((chn->N00>>4) < chn->CV) al = 0;
InitCommandM2(ite, chn, al);
return;
}
}
void InitCommandO(it_engine *ite, it_host *chn)
{
if(chn->CVal != 0)
chn->O00 = chn->CVal;
InitNoCommand(ite, chn);
if((chn->Msk & 0x33) == 0) return;
if(chn->Nt2 >= 120) return;
if((chn->Flags & 4) == 0) return;
uint32_t eax;
it_slave *slave = &ite->slave[chn->SCOffst];
eax = ((uint32_t)chn->O00) + (((uint32_t)chn->OxH)<<8);
eax <<= 8;
if(eax >= slave->Loop_End)
{
if((ite->hdr.Flags & 16) == 0) return;
eax = slave->Loop_End-1;
}
slave->OldSampleOffset = slave->Sample_Offset = eax;
slave->SmpErr = 0;
}
void InitCommandP(it_engine *ite, it_host *chn)
{
if(chn->CVal != 0)
chn->P00 = chn->CVal;
InitNoCommand(ite, chn);
uint8_t dl = chn->CP;
if((chn->Flags & 4) != 0)
{
it_slave *slave = &ite->slave[chn->SCOffst];
dl = slave->PS; // Pan set
}
if(dl == 100) // Surround??
return;
uint8_t al = chn->P00;
if((al & 0x0F) == 0)
{
chn->_40 = (chn->_40 & 0xFF00) + ((-(int16_t)(al >> 4)) & 0x00FF);
chn->Flags |= 2; // Always update effect
} else if((al & 0xF0) == 0) {
chn->_40 = (chn->_40 & 0xFF00) + (((int16_t)al) & 0x00FF);
chn->Flags |= 2;
} else if((al & 0x0F) == 0x0F) {
uint8_t xal = dl - (al>>4);
if(dl < (al>>4)) xal = 0;
InitCommandX2(ite, chn, xal);
} else if((al & 0xF0) == 0xF0) {
al = al + dl;
if(al > 64) al = 64;
InitCommandX2(ite, chn, al);
}
}
void InitCommandQ(it_engine *ite, it_host *chn)
{
InitNoCommand(ite, chn);
if(chn->CVal != 0)
chn->Q00 = chn->CVal;
if((chn->Flags & 4) != 0)
{
chn->Flags |= 1;
if((chn->Msk & 0x11) != 0)
{
chn->RTC = chn->CVal & 0x0F; // retrig countdown
} else {
CommandQ(ite, chn);
}
}
}
void InitCommandR(it_engine *ite, it_host *chn)
{
uint8_t ah = chn->CVal & 0x0F; // AH = depth
uint8_t al = chn->CVal & 0xF0; // AL = speed.
if(ah != 0 || al != 0)
{
al >>= 2;
if(al != 0) chn->TSp = al;
ah <<= 1;
if(ah != 0) chn->TDp = ah;
}
InitNoCommand(ite, chn);
if((chn->Flags & 4) != 0)
{
chn->Flags |= 1; // Update mode.
InitTremelo(ite, chn);
}
}
void InitCommandS(it_engine *ite, it_host *chn)
{
uint8_t al = chn->CVal;
it_slave *slave;
uint16_t cx;
if(al != 0)
chn->S00 = al;
al = chn->S00;
uint8_t ah = al;
ah &= 0xF0;
al &= 0x0F;
chn->_40 = (ah<<8) | al; // Misc effects data.
switch(ah>>4)
{
case 0x0: // 0
case 0x1: // 1
case 0x2: // 2
break;
case 0x3: // 3 - set vibrato waveform
if(al <= 3) chn->VWF = al;
break;
case 0x4: // 4 - set tremelo waveform
if(al <= 3) chn->TWF = al;
break;
case 0x5: // 5 - set panbrello waveform
if(al <= 3)
{
chn->PWF = al;
chn->PPo = 0;
}
break;
case 0x6: // 6 - extra delay of x frames
ite->CurrentTick += al;
ite->ProcessTick += al;
break;
case 0x7: // 7 - instrument functions
switch(al)
{
case 0x0: // Past note cut
InitNoCommand(ite, chn);
al = chn->HCN | 0x80;
for(slave = &ite->slave[0], cx = ite->NumChannels; cx != 0; cx--, slave++)
{
if(al != slave->HCN) continue;
if((ite->d.DriverFlags & 2) != 0)
slave->Flags |= 0x200;
else
slave->Flags = 0x200;
}
return;
case 0x1: // Past note off
case 0x2: // Past note fade
InitNoCommand(ite, chn);
ah = (al == 0x1 ? 4 : 8);
for(slave = &ite->slave[0], cx = ite->NumChannels; cx != 0; cx--, slave++)
{
if(al == slave->HCN)
{
slave->Flags |= ah;
GetLoopInformation(ite, slave);
}
}
return;
case 0x3: // Set NNA to cut
case 0x4: // Set NNA to continue
case 0x5: // Set NNA to off
case 0x6: // Set NNA to fade
InitNoCommand(ite, chn);
if((chn->Flags & 4) != 0)
{
it_slave *slave = &ite->slave[chn->SCOffst];
slave->NNA = al-3;
}
return;
// the comments are backwards here so I've fixed them --GM
case 0x7: // Set volume envelope off
InitNoCommand(ite, chn);
if((chn->Flags & 4) != 0)
{
it_slave *slave = &ite->slave[chn->SCOffst];
slave->Flags &= ~0x1000;
}
return;
case 0x8: // Set volume envelope on
InitNoCommand(ite, chn);
if((chn->Flags & 4) != 0)
{
it_slave *slave = &ite->slave[chn->SCOffst];
slave->Flags |= 0x1000;
}
return;
case 0x9: // Set panning envelope off
InitNoCommand(ite, chn);
if((chn->Flags & 4) != 0)
{
it_slave *slave = &ite->slave[chn->SCOffst];
slave->Flags &= ~0x2000;
}
break;
case 0xA: // Set panning envelope on
InitNoCommand(ite, chn);
if((chn->Flags & 4) != 0)
{
it_slave *slave = &ite->slave[chn->SCOffst];
slave->Flags |= 0x2000;
}
break;
case 0xB: // Set pitch envelope off
InitNoCommand(ite, chn);
if((chn->Flags & 4) != 0)
{
it_slave *slave = &ite->slave[chn->SCOffst];
slave->Flags |= ~0x4000;
}
break;
case 0xC: // Set pitch envelope on
InitNoCommand(ite, chn);
if((chn->Flags & 4) != 0)
{
it_slave *slave = &ite->slave[chn->SCOffst];
slave->Flags |= 0x4000;
}
break;
case 0xD:
case 0xE:
case 0xF:
break;
} break;
case 0x8: // 8 - set pan
ah = al;
ah <<= 4;
al |= ah;
ah = 0;
if(((al+2)&0xFF) < al) ah++;
al += 2;
al >>= 2;
al |= (ah << 6);
// TODO: verify
InitNoCommand(ite, chn);
InitCommandX2(ite, chn, al);
return;
case 0x9: // 9 - set surround
if(al == 1)
{
al = 100;
InitNoCommand(ite, chn);
InitCommandX2(ite, chn, al);
return;
}
break;
case 0xA: // A - Set high order offset
chn->OxH = al;
break;
case 0xB: // B - loop control
InitNoCommand(ite, chn);
if(al == 0)
{
chn->PLR = ite->CurrentRow;
} else if(chn->PLC == 0) {
chn->PLC = al;
ite->ProcessRow = ((uint16_t)chn->PLR)-1;
ite->PatternLooping = 1;
} else if((--chn->PLC) != 0) {
ite->ProcessRow = ((uint16_t)chn->PLR)-1;
ite->PatternLooping = 1;
} else {
chn->PLR = 1+ite->CurrentRow;
}
return;
case 0xC: // C - note cut
chn->Flags |= 1;
break;
case 0xD: // D - note delay
chn->Flags |= 2;
return;
case 0xE: // E - pattern delay
if(ite->RowDelayOn == 0)
{
ite->RowDelay = al+1;
ite->RowDelayOn = 1;
}
break;
case 0xF: // F - MIDI Macro select
chn->SFx = al;
break;
}
InitNoCommand(ite, chn);
}
void InitCommandT(it_engine *ite, it_host *chn)
{
if(chn->CVal != 0)
chn->T00 = chn->CVal;
if(chn->T00 >= 0x20)
{
ite->Tempo = chn->T00;
Music_InitTempo(ite);
InitNoCommand(ite, chn);
} else {
InitNoCommand(ite, chn);
chn->Flags |= 2; // Update mode
}
}
void InitCommandU(it_engine *ite, it_host *chn)
{
if((chn->Msk & 0x11) != 0)
{
chn->VPo = 0;
chn->LVi = 0;
}
uint8_t ah = chn->CVal & 0x0F; // AH = depth
uint8_t al = chn->CVal & 0xF0; // AL = speed.
if(al != 0)
{
al >>= 2;
chn->VSp = al;
}
if(ah != 0)
{
if((ite->hdr.Flags & 16) != 0)
ah *= 2;
chn->VDp = ah;
}
InitNoCommand(ite, chn);
if((chn->Flags & 4) != 0)
{
chn->Flags |= 1; // Update mode.
InitVibrato(ite, chn);
}
}
void InitCommandV(it_engine *ite, it_host *chn)
{
if(chn->CVal <= 0x80)
{
ite->GlobalVolume = chn->CVal;
RecalculateAllVolumes(ite);
}
InitNoCommand(ite, chn);
}
void InitCommandW(it_engine *ite, it_host *chn)
{
// Global volume slides!
InitNoCommand(ite, chn);
if(chn->CVal != 0)
chn->W00 = chn->CVal;
if(chn->W00 == 0)
{
return;
} else if((chn->W00 & 0xF0) == 0) {
chn->_40 = (chn->_40 & 0xFF00) | (0xFF & (int16_t)(-chn->W00));
chn->Flags |= 2;
} else if((chn->W00 & 0x0F) == 0) {
chn->_40 = (chn->_40 & 0xFF00) | (0xFF & (int16_t)(chn->W00>>4));
chn->Flags |= 2;
} else if((chn->W00 & 0xF0) == 0xF0) {
if(ite->GlobalVolume >= (chn->W00 & 0x0F))
ite->GlobalVolume -= (chn->W00 & 0x0F);
else
ite->GlobalVolume = 0;
RecalculateAllVolumes(ite);
} else if((chn->W00 & 0x0F) == 0x0F) {
ite->GlobalVolume += (chn->W00>>4);
if((ite->GlobalVolume & 0x80) != 0)
ite->GlobalVolume = 128;
RecalculateAllVolumes(ite);
}
}
void InitCommandX(it_engine *ite, it_host *chn)
{
InitNoCommand(ite, chn);
uint16_t ax = chn->CVal;
ax += 2;
ax >>= 2;
InitCommandX2(ite, chn, (uint8_t)ax);
}
void InitCommandX2(it_engine *ite, it_host *chn, uint8_t al)
{
if((chn->Flags & 4) != 0)
{
it_slave *slave = &ite->slave[chn->SCOffst];
slave->PS = slave->Pan = al;
slave->Flags |= 64+2; // Recalculate pan
}
chn->CP = al;
}
void InitCommandY(it_engine *ite, it_host *chn)
{
uint8_t ah = chn->CVal & 0x0F; // AH = depth
uint8_t al = chn->CVal & 0xF0;
if(ah != 0 || al != 0)
{
al >>= 4;
if(al != 0)
chn->PSp = al;
ah <<= 1;
if(ah != 0)
chn->PDp = ah;
}
InitNoCommand(ite, chn);
if((chn->Flags & 4) != 0)
{
chn->Flags |= 1; // Update mode.
CommandY(ite, chn);
}
}
void InitCommandZ(it_engine *ite, it_host *chn)
{
// Macros start at 120h, 320h
InitNoCommand(ite, chn);
uint16_t bx = chn->CVal;
it_slave *slave = &ite->slave[chn->SCOffst];
if((bx & 0x80) == 0)
{
bx = chn->SFx & 0x0F; // 0->7Fh - BX = SFx number
bx <<= 5;
bx += 0x120;
MIDITranslate(ite, chn, slave, bx);
} else {
// Macros!
bx &= 0x7F;
bx <<= 5; // BX = (xx-80x)*20h
bx += 0x320;
MIDITranslate(ite, chn, slave, bx);
}
}
void NoCommand(it_engine *ite, it_host *chn)
{
// DS:DI points to CIT Area
USED(ite, chn);
}
void CommandD(it_engine *ite, it_host *chn)
{
it_slave *slave = &ite->slave[chn->SCOffst];
uint8_t al = chn->VCh + slave->VS; // Volset.
if((al & 0x80) == 0)
{
if(al > 64)
{
chn->Flags &= ~1;
al = 64;
}
} else {
chn->Flags &= ~1;
al = 0;
}
CommandD2(ite, chn, slave, al);
}
void CommandD2(it_engine *ite, it_host *chn, it_slave *slave, uint8_t al)
{
USED(ite);
slave->Vol = al;
slave->VS = al;
chn->VSe = al;
slave->Flags |= 16; // Recalc vol
}
void CommandE(it_engine *ite, it_host *chn)
{
CommandEChain(ite, chn, chn->_40);
}
void CommandEChain(it_engine *ite, it_host *chn, int16_t bx)
{
it_slave *slave = &ite->slave[chn->SCOffst];
PitchSlideDown(ite, chn, slave, bx);
slave->Frequency_Set = slave->Frequency;
}
void CommandF(it_engine *ite, it_host *chn)
{
CommandFChain(ite, chn, chn->_40);
}
void CommandFChain(it_engine *ite, it_host *chn, int16_t bx)
{
it_slave *slave = &ite->slave[chn->SCOffst];
PitchSlideUp(ite, chn, slave, bx);
slave->Frequency_Set = slave->Frequency;
}
void CommandG(it_engine *ite, it_host *chn)
{
if((chn->Flags & 16) == 0)
return;
int16_t bx = chn->_40;
it_slave *slave = &ite->slave[chn->SCOffst];
if((chn->_42 & 0xFF) != 1)
{
// Slide down
PitchSlideDown(ite, chn, slave, bx);
// Check that frequency is above porta
// to frequency.
uint32_t eax = slave->Frequency;
if(eax <= chn->Porta_Frequency)
{
eax = chn->Porta_Frequency;
chn->Flags &= ~(3 | 16); // Turn off calling
slave->Frequency = eax;
}
slave->Frequency_Set = eax;
} else {
// Slide up!
PitchSlideUp(ite, chn, slave, bx);
// Check that
// 1) Channel is on
// 2) Frequency (set) is below porta to
// frequency
uint32_t eax = slave->Frequency;
if((slave->Flags & 0x200) == 0 && eax < chn->Porta_Frequency)
{
slave->Frequency_Set = eax;
return;
}
slave->Flags &= ~0x200;
chn->Flags |= 4; // Turn on.
eax = chn->Porta_Frequency;
chn->Flags &= ~(3 | 16); // Turn off calling
slave->Frequency = eax;
slave->Frequency_Set = eax;
}
}
void InitVibrato(it_engine *ite, it_host *chn)
{
if((ite->hdr.Flags & 0x10) == 0)
{
CommandH(ite, chn);
} else {
it_slave *slave = &ite->slave[chn->SCOffst];
slave->Flags |= 32; // Freq change...
CommandH5(ite, chn, slave, chn->LVi);
}
}
void CommandH(it_engine *ite, it_host *chn)
{
it_slave *slave = &ite->slave[chn->SCOffst];
slave->Flags |= 32; // Freq change...
// Add speed. / Save value
chn->VPo += chn->VSp;
// Mov BH, [DI+38h] // AL = waveform
// gg wp --GM
int8_t al = 0;
if(chn->VWF != 3)
{
// probably not wise to try to emulate out-of-range vibrato types.
// well, at least for now. we can research these later. --GM
switch(chn->VWF)
{
case 0:
al = FineSineData[chn->VPo];
break;
case 1:
al = FineRampDownData[chn->VPo];
break;
case 2:
al = FineSquareWave[chn->VPo];
break;
default:
sysfatal("out of range vibrato types not emulated!");
}
} else {
al = (Random(ite)&127)-64; // Random.
}
chn->LVi = al; // Save last vibrato.
CommandH5(ite, chn, slave, al);
}
void CommandH5(it_engine *ite, it_host *chn, it_slave *slave, int8_t al)
{
int16_t ax = ((int16_t)al) * (int16_t)(int8_t)(chn->VDp);
ax <<= 2;
ax += 0x80;
ax >>= 8; // actual code then simply uses AH --GM
if((ite->hdr.Flags & 16) != 0)
{
// don't ask me why sackit does weird things here,
// i could have sworn Jeff had done a one's complement
// but that seems to not be the case (in IT 2.14 at least) --GM
ax = -ax;
}
//MovZX BX, AH
// AH = EEx/FEx command value
if(ax < 0)
PitchSlideDown(ite, chn, slave, -ax);
else
PitchSlideUp(ite, chn, slave, ax);
}
void CommandI(it_engine *ite, it_host *chn)
{
it_slave *slave = &ite->slave[chn->SCOffst];
slave->Flags |= 16; // recalc volume;
chn->TCD--;
if((chn->TCD & 0x80) != 0 || chn->TCD == 0)
{
chn->Too ^= 1;
chn->TCD = (uint8_t)(chn->Too != 0 ? (chn->_40>>8) : (chn->_40&0xFF));
}
if(chn->Too != 1)
slave->Vol = 0;
}
void CommandJ(it_engine *ite, it_host *chn)
{
it_slave *slave = &ite->slave[chn->SCOffst];
int16_t bx = chn->_40;
slave->Flags |= 32;
bx += 2;
if(bx >= 6)
{
chn->_40 = 0;
return;
}
chn->_40 = bx;
uint64_t rad = (uint64_t)slave->Frequency;
rad *= (uint64_t)PitchTable[(bx == 2 ? chn->_42 : chn->_44)/4];
//printf("honk %lX\n", rad);
// FIXME work out how this damn thing works
rad >>= (uint64_t)16;
/*
if((rad & (uint64_t)0xFFFF000000000000LLU) != 0)
rad &= ~(uint64_t)0xFFFFFFFFLLU;
else
rad >>= (uint64_t)rad;
*/
slave->Frequency = (uint32_t)rad;
}
void CommandK(it_engine *ite, it_host *chn)
{
CommandH(ite, chn);
CommandD(ite, chn);
}
void CommandL(it_engine *ite, it_host *chn)
{
if((chn->Flags & 16) != 0)
{
CommandG(ite, chn);
chn->Flags |= 1;
}
CommandD(ite, chn);
}
void CommandN(it_engine *ite, it_host *chn)
{
uint8_t al = chn->CV + chn->_40;
if((al & 0x80) == 0)
al = 0;
else if(al > 64)
al = 64;
InitCommandM2(ite, chn, al);
}
void CommandP(it_engine *ite, it_host *chn)
{
int8_t al = chn->CP;
if((chn->Flags & 4) != 0)
{
it_slave *slave = &ite->slave[chn->SCOffst];
al = slave->PS;
}
al += (int8_t)(chn->_40 & 0xFF);
if(al < 0)
al = 0;
else if(al > 64)
al = 64;
InitCommandX2(ite, chn, al);
}
void CommandQ(it_engine *ite, it_host *chn)
{
chn->RTC--;
if(chn->RTC != 0 && chn->RTC != 0xFF)
return;
// OK... reset counter.
chn->RTC = chn->Q00 & 0x0F; // retrig count done.
//And BX, 0F00Fh
it_slave *slave = &ite->slave[chn->SCOffst];
if((ite->d.DriverFlags & 2) != 0) // Hiqual?
{
if((ite->hdr.Flags & 4) == 0) // Instrument mode?
{
// Sample mode
memcpy(slave+64, slave, sizeof(it_slave));
(slave+64)->Flags |= 0x200; // Cut
(slave+64)->HCN |= 0x80; // Disowned
} else {
// Instrument mode
it_slave *dest = &ite->slave[0];
uint16_t cx = ite->NumChannels;
for(; cx != 0; cx--, dest++)
{
if((dest->Flags & 1) == 0)
{
memcpy(dest, slave, sizeof(it_slave));
dest->Flags |= 0x200; // Cut
dest->HCN |= 0x80; // Disowned
slave = dest;
// TODO: verify C behaviour
chn->SCOffst = (dest - &ite->slave[0]);
break;
}
}
}
}
slave->OldSampleOffset = 0;
slave->SmpErr = 0;
slave->Sample_Offset = 0;
slave->Flags |= 0x540;
uint8_t al = slave->VS;
int check = 0;
switch(chn->Q00>>4)
{
case 0x0:
return;
case 0x1:
al--;
check = -1;
break;
case 0x2:
al -= 2;
check = -1;
break;
case 0x3:
al -= 4;
check = -1;
break;
case 0x4:
al -= 8;
check = -1;
break;
case 0x5:
al -= 16;
check = -1;
break;
case 0x6:
al <<= 1;
al /= 3;
break;
case 0x7:
al >>= 1;
break;
case 0x8:
return;
case 0x9:
al++;
check = 1;
break;
case 0xA:
al += 2;
check = 1;
break;
case 0xB:
al += 4;
check = 1;
break;
case 0xC:
al += 8;
check = 1;
break;
case 0xD:
al += 16;
check = 1;
break;
case 0xE:
al = (al + al + al) >> 1;
check = 1;
break;
case 0xF:
al <<= 1;
check = 1;
break;
}
if(check < 0 && (al & 0x80) != 0)
al = 0;
else if(check > 0 && al > 64)
al = 64;
slave->VS = slave->Vol = al;
chn->VSe = al;
slave->Flags |= 16; // recalc volume flag
if(chn->Smp == 101) // MIDI sample
MIDITranslate(ite, chn, slave, MIDICOMMAND_STOPNOTE);
}
void InitTremelo(it_engine *ite, it_host *chn)
{
if((ite->hdr.Flags & 0x10) == 0)
{
CommandR(ite, chn);
} else {
it_slave *slave = &ite->slave[chn->SCOffst];
slave->Flags |= 64; // Volume change...
CommandR2(ite, chn, slave, chn->LTr);
}
}
void CommandR(it_engine *ite, it_host *chn)
{
it_slave *slave = &ite->slave[chn->SCOffst];
slave->Flags |= 64; // Volume change
// TODO: verify
// Add speed. / Save value
chn->TPo += chn->TSp;
int8_t al = 0;
if(chn->TWF != 3)
{
// probably not wise to try to emulate out-of-range vibrato types.
// well, at least for now. we can research these later. --GM
switch(chn->TWF)
{
case 0:
al = FineSineData[chn->TPo];
break;
case 1:
al = FineRampDownData[chn->TPo];
break;
case 2:
al = FineSquareWave[chn->TPo];
break;
default:
sysfatal("out of range vibrato types not emulated!");
}
} else {
al = (Random(ite)&127)-64; // Random.
}
CommandR2(ite, chn, slave, al);
}
void CommandR2(it_engine *ite, it_host *chn, it_slave *slave, int8_t al)
{
USED(ite);
int16_t ax;
ax = al;
ax *= (int16_t)(int8_t)(chn->TDp);
ax <<= 2;
ax += 0x80;
ax >>= 8;
al = slave->Vol + ax;
if((al & 0x80) != 0)
al = 0;
if(al > 64)
al = 64;
slave->Vol = al;
}
void CommandS(it_engine *ite, it_host *chn)
{
// Have to handle SDx, SCx
// AH = command, AL = value.
uint8_t ah = (chn->_40>>8);
uint8_t al = (chn->_40&0xFF);
USED(al);
if(ah == 0xD0)
{
// this is just an 8-bit dec in a 16-bit value --GM
if(chn->_40 == 0) chn->_40 |= 0xFF;
else chn->_40--;
if((chn->_40 & 0x80) == 0 && (chn->_40 & 0xFF) != 0)
return;
chn->Flags &= ~3;
InitNoCommand(ite, chn);
chn->Flags |= 64;
// Check whether chn is on
if((ite->hdr.Chnl_Vol[chn->HCN] & 0x80) == 0) return;
if((chn->Flags & 32) != 0) return;
if((chn->Flags & 4) == 0) return; // Channel was off.
it_slave *slave = &ite->slave[chn->SCOffst];
slave->Flags |= 0x800;
} else if(ah == 0xC0) {
if((chn->Flags & 4) == 0) return;
// this is just an 8-bit dec in a 16-bit value --GM
if(chn->_40 == 0) chn->_40 |= 0xFF;
else chn->_40--;
if((chn->_40 & 0x80) == 0 && (chn->_40 & 0xFF) != 0)
return;
it_slave *slave = &ite->slave[chn->SCOffst]; // Note cut.
chn->Flags &= ~4;
if(slave->Smp != 100 && (ite->d.DriverFlags & 2) == 0)
slave->Flags = 0x200;
else
slave->Flags |= 0x200;
}
}
void CommandT(it_engine *ite, it_host *chn)
{
// TODO: verify - flow somewhat different from original source --GM
if((chn->T00 & 0xF0) != 0)
{
// Slide up
ite->Tempo += chn->T00;
ite->Tempo -= 0x10;
} else {
// Slide down
ite->Tempo -= 0x10;
if(ite->Tempo < 0x20)
ite->Tempo = 0x20;
}
ite->d.DriverSetTempo(ite, ite->Tempo);
}
void CommandW(it_engine *ite, it_host *chn)
{
// Global volume slide!
int16_t ax = (int16_t)(int8_t)(chn->_40 & 0xFF);
ax += ite->GlobalVolume;
if((ax & 0x8000) != 0)
ax = 0;
if((ax & 0xFF) > 128)
ax = 128;
ite->GlobalVolume = ax;
RecalculateAllVolumes(ite);
}
void CommandY(it_engine *ite, it_host *chn)
{
// TODO!
USED(ite, chn);
}
#if 0
void CommandY(it_engine *ite, it_host *chn)
{
Test Byte Ptr [DI], 4
JZ CommandY5
it_slave *slave = &ite->slave[chn->SCOffst];
Mov BH, [DI+28h] // AL = waveform
Cmp BH, 3
JAE CommandY1
Mov BL, [DI+29h] // Pos
Add BL, [DI+2Bh] // Add speed.
Mov [DI+29h], BL // Save value
Mov AL, [FineSineData+BX] // AL = -64 -> 64
Jmp CommandY2
CommandY1: // Random panning make
// speed the delay time.
Dec Byte Ptr [DI+29h]
JZ CommandY6
JS CommandY6
Mov AL, [DI+2Ch]
Jmp CommandY2
CommandY6:
Mov BL, [DI+2Bh]
Mov [DI+29h], BL // reset countdown.
Call Random
And AL, 127
Sub AL, 64
Mov [DI+2Ch], AL
CommandY2:
IMul Byte Ptr [DI+2Ah]
SAL AX, 2
Add AX, 80h
MovZX BX, AH
// AH = panning change
Mov AL, [SI+2Bh] // AL = panning
Cmp AL, 100 // Surround?
JE CommandY5
Add AL, AH
JNS CommandY3
Xor AL, AL
CommandY3:
Cmp AL, 64
JBE CommandY4
Mov AL, 64
CommandY4:
Or Byte Ptr [SI], 2 // Panning change
Mov [SI+2Ah], AL
CommandY5:
Ret
}
#endif