zmusic/source/midisources/midisource_hmi.cpp
Christoph Oelckers a4eae42ec5 - initial commit
2020-01-02 17:52:30 +01:00

996 lines
25 KiB
C++

/*
** music_hmi_midiout.cpp
** Code to let ZDoom play HMI MIDI music through the MIDI streaming API.
**
**---------------------------------------------------------------------------
** Copyright 2010 Randy Heit
** 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 BY THE AUTHOR ``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.
**---------------------------------------------------------------------------
**
*/
// HEADER FILES ------------------------------------------------------------
#include <algorithm>
#include <assert.h>
#include "midisource.h"
#include "zmusic/zmusic_internal.h"
#include "zmusic/m_swap.h"
// MACROS ------------------------------------------------------------------
#define HMP_NEW_DATE "013195"
#define HMI_SONG_MAGIC "HMI-MIDISONG061595"
#define TRACK_MAGIC "HMI-MIDITRACK"
// Used by SendCommand to check for unexpected end-of-track conditions.
#define CHECK_FINISHED \
if (track->TrackP >= track->MaxTrackP) \
{ \
track->Finished = true; \
return events; \
}
// In song header
#define HMI_DIVISION_OFFSET 0xD4
#define HMI_TRACK_COUNT_OFFSET 0xE4
#define HMI_TRACK_DIR_PTR_OFFSET 0xE8
#define HMP_DIVISION_OFFSET 0x38
#define HMP_TRACK_COUNT_OFFSET 0x30
#define HMP_DESIGNATIONS_OFFSET 0x94
#define HMP_TRACK_OFFSET_0 0x308 // original HMP
#define HMP_TRACK_OFFSET_1 0x388 // newer HMP
// In track header
#define HMITRACK_DATA_PTR_OFFSET 0x57
#define HMITRACK_DESIGNATION_OFFSET 0x99
#define HMPTRACK_LEN_OFFSET 4
#define HMPTRACK_DESIGNATION_OFFSET 8
#define HMPTRACK_MIDI_DATA_OFFSET 12
#define NUM_HMP_DESIGNATIONS 5
#define NUM_HMI_DESIGNATIONS 8
// MIDI device types for designation
#define HMI_DEV_GM 0xA000 // Generic General MIDI (not a real device)
#define HMI_DEV_MPU401 0xA001 // MPU-401, Roland Sound Canvas, Ensoniq SoundScape, Rolad RAP-10
#define HMI_DEV_OPL2 0xA002 // SoundBlaster (Pro), ESS AudioDrive
#define HMI_DEV_MT32 0xA004 // MT-32
#define HMI_DEV_SBAWE32 0xA008 // SoundBlaster AWE32
#define HMI_DEV_OPL3 0xA009 // SoundBlaster 16, Microsoft Sound System, Pro Audio Spectrum 16
#define HMI_DEV_GUS 0xA00A // Gravis UltraSound, Gravis UltraSound Max/Ace
// TYPES -------------------------------------------------------------------
struct HMISong::TrackInfo
{
const uint8_t *TrackBegin;
size_t TrackP;
size_t MaxTrackP;
uint32_t Delay;
uint32_t PlayedTime;
uint16_t Designation[NUM_HMI_DESIGNATIONS];
bool Enabled;
bool Finished;
uint8_t RunningStatus;
uint32_t ReadVarLenHMI();
uint32_t ReadVarLenHMP();
};
// EXTERNAL FUNCTION PROTOTYPES --------------------------------------------
// PUBLIC FUNCTION PROTOTYPES ----------------------------------------------
// PRIVATE FUNCTION PROTOTYPES ---------------------------------------------
// EXTERNAL DATA DECLARATIONS ----------------------------------------------
// PRIVATE DATA DEFINITIONS ------------------------------------------------
// PUBLIC DATA DEFINITIONS -------------------------------------------------
// CODE --------------------------------------------------------------------
//==========================================================================
//
// HMISong Constructor
//
// Buffers the file and does some validation of the HMI header.
//
//==========================================================================
HMISong::HMISong (const uint8_t *data, size_t len)
{
if (len < 0x100)
{ // Way too small to be HMI.
return;
}
MusHeader.resize(len);
memcpy(MusHeader.data(), data, len);
NumTracks = 0;
// Do some validation of the MIDI file
if (memcmp(&MusHeader[0], HMI_SONG_MAGIC, sizeof(HMI_SONG_MAGIC)) == 0)
{
SetupForHMI((int)len);
}
else if (memcmp(&MusHeader[0], "HMIMIDIP", 8) == 0)
{
SetupForHMP((int)len);
}
}
//==========================================================================
//
// HMISong :: SetupForHMI
//
//==========================================================================
void HMISong::SetupForHMI(int len)
{
int i, p;
auto MusPtr = &MusHeader[0];
ReadVarLen = ReadVarLenHMI;
NumTracks = GetShort(MusPtr + HMI_TRACK_COUNT_OFFSET);
if (NumTracks <= 0)
{
return;
}
// The division is the number of pulses per quarter note (PPQN).
// HMI files have two values here, a full value and a quarter value. Some games,
// notably Quarantines, have identical values for some reason, so it's safer to
// use the quarter value and multiply it by four than to trust the full value.
Division = GetShort(MusPtr + HMI_DIVISION_OFFSET) << 2;
Tempo = InitialTempo = 4000000;
Tracks.resize(NumTracks + 1);
int track_dir = GetInt(MusPtr + HMI_TRACK_DIR_PTR_OFFSET);
// Gather information about each track
for (i = 0, p = 0; i < NumTracks; ++i)
{
int start = GetInt(MusPtr + track_dir + i*4);
int tracklen, datastart;
if (start > len - HMITRACK_DESIGNATION_OFFSET - 4)
{ // Track is incomplete.
continue;
}
// BTW, HMI does not actually check the track header.
if (memcmp(MusPtr + start, TRACK_MAGIC, 13) != 0)
{
continue;
}
// The track ends where the next one begins. If this is the
// last track, then it ends at the end of the file.
if (i == NumTracks - 1)
{
tracklen = len - start;
}
else
{
tracklen = GetInt(MusPtr + track_dir + i*4 + 4) - start;
}
// Clamp incomplete tracks to the end of the file.
tracklen = std::min(tracklen, len - start);
if (tracklen <= 0)
{
continue;
}
// Offset to actual MIDI events.
datastart = GetInt(MusPtr + start + HMITRACK_DATA_PTR_OFFSET);
tracklen -= datastart;
if (tracklen <= 0)
{
continue;
}
// Store track information
Tracks[p].TrackBegin = MusPtr + start + datastart;
Tracks[p].TrackP = 0;
Tracks[p].MaxTrackP = tracklen;
// Retrieve track designations. We can't check them yet, since we have not yet
// connected to the MIDI device.
for (int ii = 0; ii < NUM_HMI_DESIGNATIONS; ++ii)
{
Tracks[p].Designation[ii] = GetShort(MusPtr + start + HMITRACK_DESIGNATION_OFFSET + ii*2);
}
p++;
}
// In case there were fewer actual chunks in the file than the
// header specified, update NumTracks with the current value of p.
NumTracks = p;
}
//==========================================================================
//
// HMISong :: SetupForHMP
//
//==========================================================================
void HMISong::SetupForHMP(int len)
{
int track_data;
int i, p;
auto MusPtr = &MusHeader[0];
ReadVarLen = ReadVarLenHMP;
if (MusPtr[8] == 0)
{
track_data = HMP_TRACK_OFFSET_0;
}
else if (memcmp(MusPtr + 8, HMP_NEW_DATE, sizeof(HMP_NEW_DATE)) == 0)
{
track_data = HMP_TRACK_OFFSET_1;
}
else
{ // unknown HMIMIDIP version
return;
}
NumTracks = GetInt(MusPtr + HMP_TRACK_COUNT_OFFSET);
if (NumTracks <= 0)
{
return;
}
// The division is the number of pulses per quarter note (PPQN).
Division = GetInt(MusPtr + HMP_DIVISION_OFFSET);
Tempo = InitialTempo = 1000000;
Tracks.resize(NumTracks + 1);
// Gather information about each track
for (i = 0, p = 0; i < NumTracks; ++i)
{
int start = track_data;
int tracklen;
if (start > len - HMPTRACK_MIDI_DATA_OFFSET)
{ // Track is incomplete.
break;
}
tracklen = GetInt(MusPtr + start + HMPTRACK_LEN_OFFSET);
track_data += tracklen;
// Clamp incomplete tracks to the end of the file.
tracklen = std::min(tracklen, len - start);
if (tracklen <= 0)
{
continue;
}
// Subtract track header size.
tracklen -= HMPTRACK_MIDI_DATA_OFFSET;
if (tracklen <= 0)
{
continue;
}
// Store track information
Tracks[p].TrackBegin = MusPtr + start + HMPTRACK_MIDI_DATA_OFFSET;
Tracks[p].TrackP = 0;
Tracks[p].MaxTrackP = tracklen;
// Retrieve track designations. We can't check them yet, since we have not yet
// connected to the MIDI device.
#if 0
// This is completely a guess based on knowledge of how designations work with
// HMI files. Some songs contain nothing but zeroes for this data, so I'd rather
// not go around using it without confirmation.
Printf("Track %d: %d %08x %d: \034I", i, GetInt(MusPtr + start),
GetInt(MusPtr + start + 4), GetInt(MusPtr + start + 8));
int designations = HMP_DESIGNATIONS_OFFSET +
GetInt(MusPtr + start + HMPTRACK_DESIGNATION_OFFSET) * 4 * NUM_HMP_DESIGNATIONS;
for (int ii = 0; ii < NUM_HMP_DESIGNATIONS; ++ii)
{
Printf(" %04x", GetInt(MusPtr + designations + ii*4));
}
Printf("\n");
#endif
Tracks[p].Designation[0] = HMI_DEV_GM;
Tracks[p].Designation[1] = HMI_DEV_GUS;
Tracks[p].Designation[2] = HMI_DEV_OPL2;
Tracks[p].Designation[3] = 0;
p++;
}
// In case there were fewer actual chunks in the file than the
// header specified, update NumTracks with the current value of p.
NumTracks = p;
}
//==========================================================================
//
// HMISong :: CheckCaps
//
// Check track designations and disable tracks that have not been
// designated for the device we will be playing on.
//
//==========================================================================
void HMISong::CheckCaps(int tech)
{
// What's the equivalent HMI device for our technology?
if (tech == MIDIDEV_FMSYNTH)
{
tech = HMI_DEV_OPL3;
}
else if (tech == MIDIDEV_MIDIPORT)
{
tech = HMI_DEV_MPU401;
}
else
{ // Good enough? Or should we just say we're GM.
tech = HMI_DEV_SBAWE32;
}
for (int i = 0; i < NumTracks; ++i)
{
Tracks[i].Enabled = false;
// Track designations are stored in a 0-terminated array.
for (unsigned int j = 0; j < NUM_HMI_DESIGNATIONS && Tracks[i].Designation[j] != 0; ++j)
{
if (Tracks[i].Designation[j] == tech)
{
Tracks[i].Enabled = true;
}
// If a track is designated for device 0xA000, it will be played by a MIDI
// driver for device types 0xA000, 0xA001, and 0xA008. Why this does not
// include the GUS, I do not know.
else if (Tracks[i].Designation[j] == HMI_DEV_GM)
{
Tracks[i].Enabled = (tech == HMI_DEV_MPU401 || tech == HMI_DEV_SBAWE32);
}
// If a track is designated for device 0xA002, it will be played by a MIDI
// driver for device types 0xA002 or 0xA009.
else if (Tracks[i].Designation[j] == HMI_DEV_OPL2)
{
Tracks[i].Enabled = (tech == HMI_DEV_OPL3);
}
// Any other designation must match the specific MIDI driver device number.
// (Which we handled first above.)
if (Tracks[i].Enabled)
{ // This track's been enabled, so we can stop checking other designations.
break;
}
}
}
}
//==========================================================================
//
// HMISong :: DoInitialSetup
//
// Sets the starting channel volumes.
//
//==========================================================================
void HMISong :: DoInitialSetup()
{
for (int i = 0; i < 16; ++i)
{
ChannelVolumes[i] = 100;
}
}
//==========================================================================
//
// HMISong :: DoRestart
//
// Rewinds every track.
//
//==========================================================================
void HMISong :: DoRestart()
{
int i;
// Set initial state.
FakeTrack = &Tracks[NumTracks];
NoteOffs.clear();
for (i = 0; i <= NumTracks; ++i)
{
Tracks[i].TrackP = 0;
Tracks[i].Finished = false;
Tracks[i].RunningStatus = 0;
Tracks[i].PlayedTime = 0;
}
ProcessInitialMetaEvents ();
for (i = 0; i < NumTracks; ++i)
{
Tracks[i].Delay = ReadVarLen(&Tracks[i]);
}
Tracks[i].Delay = 0; // for the FakeTrack
Tracks[i].Enabled = true;
TrackDue = Tracks.data();
TrackDue = FindNextDue();
}
//==========================================================================
//
// HMISong :: CheckDone
//
//==========================================================================
bool HMISong::CheckDone()
{
return TrackDue == nullptr;
}
//==========================================================================
//
// HMISong :: MakeEvents
//
// Copies MIDI events from the file and puts them into a MIDI stream
// buffer. Returns the new position in the buffer.
//
//==========================================================================
uint32_t *HMISong::MakeEvents(uint32_t *events, uint32_t *max_event_p, uint32_t max_time)
{
uint32_t *start_events;
uint32_t tot_time = 0;
uint32_t time = 0;
uint32_t delay;
start_events = events;
while (TrackDue && events < max_event_p && tot_time <= max_time)
{
// It's possible that this tick may be nothing but meta-events and
// not generate any real events. Repeat this until we actually
// get some output so we don't send an empty buffer to the MIDI
// device.
do
{
delay = TrackDue->Delay;
time += delay;
// Advance time for all tracks by the amount needed for the one up next.
tot_time += delay * Tempo / Division;
AdvanceTracks(delay);
// Play all events for this tick.
do
{
bool sysex_noroom = false;
uint32_t *new_events = SendCommand(events, TrackDue, time, max_event_p - events, sysex_noroom);
if (sysex_noroom)
{
return events;
}
TrackDue = FindNextDue();
if (new_events != events)
{
time = 0;
}
events = new_events;
}
while (TrackDue && TrackDue->Delay == 0 && events < max_event_p);
}
while (start_events == events && TrackDue);
time = 0;
}
return events;
}
//==========================================================================
//
// HMISong :: AdvanceTracks
//
// Advances time for all tracks by the specified amount.
//
//==========================================================================
void HMISong::AdvanceTracks(uint32_t time)
{
for (int i = 0; i <= NumTracks; ++i)
{
if (Tracks[i].Enabled && !Tracks[i].Finished)
{
Tracks[i].Delay -= time;
Tracks[i].PlayedTime += time;
}
}
NoteOffs.AdvanceTime(time);
}
//==========================================================================
//
// HMISong :: SendCommand
//
// Places a single MIDIEVENT in the event buffer.
//
//==========================================================================
uint32_t *HMISong::SendCommand (uint32_t *events, TrackInfo *track, uint32_t delay, ptrdiff_t room, bool &sysex_noroom)
{
uint32_t len;
uint8_t event, data1 = 0, data2 = 0;
// If the next event comes from the fake track, pop an entry off the note-off queue.
if (track == FakeTrack)
{
AutoNoteOff off;
NoteOffs.Pop(off);
events[0] = delay;
events[1] = 0;
events[2] = MIDI_NOTEON | off.Channel | (off.Key << 8);
return events + 3;
}
sysex_noroom = false;
size_t start_p = track->TrackP;
CHECK_FINISHED
event = track->TrackBegin[track->TrackP++];
CHECK_FINISHED
// The actual event type will be filled in below. If it's not a NOP,
// the events pointer will be advanced once the actual event is written.
// Otherwise, we do it at the end of the function.
events[0] = delay;
events[1] = 0;
events[2] = MEVENT_NOP << 24;
if (event != MIDI_SYSEX && event != MIDI_META && event != MIDI_SYSEXEND && event != 0xFe)
{
// Normal short message
if ((event & 0xF0) == 0xF0)
{
if (MIDI_CommonLengths[event & 15] > 0)
{
data1 = track->TrackBegin[track->TrackP++];
if (MIDI_CommonLengths[event & 15] > 1)
{
data2 = track->TrackBegin[track->TrackP++];
}
}
}
else if ((event & 0x80) == 0)
{
data1 = event;
event = track->RunningStatus;
}
else
{
track->RunningStatus = event;
data1 = track->TrackBegin[track->TrackP++];
}
CHECK_FINISHED
if (MIDI_EventLengths[(event&0x70)>>4] == 2)
{
data2 = track->TrackBegin[track->TrackP++];
}
// Monitor channel volume controller changes.
if ((event & 0x70) == (MIDI_CTRLCHANGE & 0x70) && data1 == 7)
{
data2 = VolumeControllerChange(event & 15, data2);
}
if (event != MIDI_META)
{
events[2] = event | (data1<<8) | (data2<<16);
}
if (ReadVarLen == ReadVarLenHMI && (event & 0x70) == (MIDI_NOTEON & 0x70))
{ // HMI note on events include the time until an implied note off event.
NoteOffs.AddNoteOff(track->ReadVarLenHMI(), event & 0x0F, data1);
}
}
else
{
// SysEx events could potentially not have enough room in the buffer...
if (event == MIDI_SYSEX || event == MIDI_SYSEXEND)
{
len = ReadVarLen(track);
if (len >= (MAX_MIDI_EVENTS-1)*3*4 || skipSysex)
{ // This message will never fit. Throw it away.
track->TrackP += len;
}
else if (len + 12 >= (size_t)room * 4)
{ // Not enough room left in this buffer. Backup and wait for the next one.
track->TrackP = start_p;
sysex_noroom = true;
return events;
}
else
{
uint8_t *msg = (uint8_t *)&events[3];
if (event == MIDI_SYSEX)
{ // Need to add the SysEx marker to the message.
events[2] = (MEVENT_LONGMSG << 24) | (len + 1);
*msg++ = MIDI_SYSEX;
}
else
{
events[2] = (MEVENT_LONGMSG << 24) | len;
}
memcpy(msg, &track->TrackBegin[track->TrackP], len);
msg += len;
// Must pad with 0
while ((size_t)msg & 3)
{
*msg++ = 0;
}
track->TrackP += len;
}
}
else if (event == MIDI_META)
{
// It's a meta-event
event = track->TrackBegin[track->TrackP++];
CHECK_FINISHED
len = ReadVarLen(track);
CHECK_FINISHED
if (track->TrackP + len <= track->MaxTrackP)
{
switch (event)
{
case MIDI_META_EOT:
track->Finished = true;
break;
case MIDI_META_TEMPO:
Tempo =
(track->TrackBegin[track->TrackP+0]<<16) |
(track->TrackBegin[track->TrackP+1]<<8) |
(track->TrackBegin[track->TrackP+2]);
events[0] = delay;
events[1] = 0;
events[2] = (MEVENT_TEMPO << 24) | Tempo;
break;
}
track->TrackP += len;
if (track->TrackP == track->MaxTrackP)
{
track->Finished = true;
}
}
else
{
track->Finished = true;
}
}
else if (event == 0xFE)
{ // Skip unknown HMI events.
event = track->TrackBegin[track->TrackP++];
CHECK_FINISHED
if (event == 0x13 || event == 0x15)
{
track->TrackP += 6;
}
else if (event == 0x12 || event == 0x14)
{
track->TrackP += 2;
}
else if (event == 0x10)
{
track->TrackP += 2;
CHECK_FINISHED
track->TrackP += track->TrackBegin[track->TrackP] + 5;
CHECK_FINISHED
}
else
{ // No idea.
track->Finished = true;
}
}
}
if (!track->Finished)
{
track->Delay = ReadVarLen(track);
}
// Advance events pointer unless this is a non-delaying NOP.
if (events[0] != 0 || MEVENT_EVENTTYPE(events[2]) != MEVENT_NOP)
{
if (MEVENT_EVENTTYPE(events[2]) == MEVENT_LONGMSG)
{
events += 3 + ((MEVENT_EVENTPARM(events[2]) + 3) >> 2);
}
else
{
events += 3;
}
}
return events;
}
//==========================================================================
//
// HMISong :: ProcessInitialMetaEvents
//
// Handle all the meta events at the start of each track.
//
//==========================================================================
void HMISong::ProcessInitialMetaEvents ()
{
TrackInfo *track;
int i;
uint8_t event;
uint32_t len;
for (i = 0; i < NumTracks; ++i)
{
track = &Tracks[i];
while (!track->Finished &&
track->TrackP < track->MaxTrackP - 4 &&
track->TrackBegin[track->TrackP] == 0 &&
track->TrackBegin[track->TrackP+1] == 0xFF)
{
event = track->TrackBegin[track->TrackP+2];
track->TrackP += 3;
len = ReadVarLen(track);
if (track->TrackP + len <= track->MaxTrackP)
{
switch (event)
{
case MIDI_META_EOT:
track->Finished = true;
break;
case MIDI_META_TEMPO:
SetTempo(
(track->TrackBegin[track->TrackP+0]<<16) |
(track->TrackBegin[track->TrackP+1]<<8) |
(track->TrackBegin[track->TrackP+2])
);
break;
}
}
track->TrackP += len;
}
if (track->TrackP >= track->MaxTrackP - 4)
{
track->Finished = true;
}
}
}
//==========================================================================
//
// HMISong :: ReadVarLenHMI static
//
//==========================================================================
uint32_t HMISong::ReadVarLenHMI(TrackInfo *track)
{
return track->ReadVarLenHMI();
}
//==========================================================================
//
// HMISong :: ReadVarLenHMP static
//
//==========================================================================
uint32_t HMISong::ReadVarLenHMP(TrackInfo *track)
{
return track->ReadVarLenHMP();
}
//==========================================================================
//
// HMISong :: TrackInfo :: ReadVarLenHMI
//
// Reads a variable-length SMF number.
//
//==========================================================================
uint32_t HMISong::TrackInfo::ReadVarLenHMI()
{
uint32_t time = 0, t = 0x80;
while ((t & 0x80) && TrackP < MaxTrackP)
{
t = TrackBegin[TrackP++];
time = (time << 7) | (t & 127);
}
return time;
}
//==========================================================================
//
// HMISong :: TrackInfo :: ReadVarLenHMP
//
// Reads a variable-length HMP number. This is similar to the standard SMF
// variable length number, except it's stored little-endian, and the high
// bit set means the number is done.
//
//==========================================================================
uint32_t HMISong::TrackInfo::ReadVarLenHMP()
{
uint32_t time = 0;
uint8_t t = 0;
int off = 0;
while (!(t & 0x80) && TrackP < MaxTrackP)
{
t = TrackBegin[TrackP++];
time |= (t & 127) << off;
off += 7;
}
return time;
}
//==========================================================================
//
// NoteOffQueue :: AddNoteOff
//
//==========================================================================
void NoteOffQueue::AddNoteOff(uint32_t delay, uint8_t channel, uint8_t key)
{
uint32_t i = (uint32_t)size();
resize(i + 1);
while (i > 0 && (*this)[Parent(i)].Delay > delay)
{
(*this)[i] = (*this)[Parent(i)];
i = Parent(i);
}
(*this)[i].Delay = delay;
(*this)[i].Channel = channel;
(*this)[i].Key = key;
}
//==========================================================================
//
// NoteOffQueue :: Pop
//
//==========================================================================
bool NoteOffQueue::Pop(AutoNoteOff &item)
{
if (size() > 0)
{
item = front();
front() = back();
pop_back();
Heapify();
return true;
}
return false;
}
//==========================================================================
//
// NoteOffQueue :: AdvanceTime
//
//==========================================================================
void NoteOffQueue::AdvanceTime(uint32_t time)
{
// Because the time is decreasing by the same amount for every entry,
// the heap property is maintained.
for (auto &item : *this)
{
assert(item.Delay >= time);
item.Delay -= time;
}
}
//==========================================================================
//
// NoteOffQueue :: Heapify
//
//==========================================================================
void NoteOffQueue::Heapify()
{
unsigned int i = 0;
for (;;)
{
unsigned int l = Left(i);
unsigned int r = Right(i);
unsigned int smallest = i;
if (l < (unsigned)size() && (*this)[l].Delay < (*this)[i].Delay)
{
smallest = l;
}
if (r < (unsigned)size() && (*this)[r].Delay < (*this)[smallest].Delay)
{
smallest = r;
}
if (smallest == i)
{
break;
}
std::swap((*this)[i], (*this)[smallest]);
i = smallest;
}
}
//==========================================================================
//
// HMISong :: FindNextDue
//
// Scans every track for the next event to play. Returns nullptr if all events
// have been consumed.
//
//==========================================================================
HMISong::TrackInfo *HMISong::FindNextDue ()
{
TrackInfo *track;
uint32_t best;
int i;
// Give precedence to whichever track last had events taken from it.
if (TrackDue != FakeTrack && !TrackDue->Finished && TrackDue->Delay == 0)
{
return TrackDue;
}
if (TrackDue == FakeTrack && NoteOffs.size() != 0 && NoteOffs[0].Delay == 0)
{
FakeTrack->Delay = 0;
return FakeTrack;
}
// Check regular tracks.
track = nullptr;
best = 0xFFFFFFFF;
for (i = 0; i < NumTracks; ++i)
{
if (Tracks[i].Enabled && !Tracks[i].Finished && Tracks[i].Delay < best)
{
best = Tracks[i].Delay;
track = &Tracks[i];
}
}
// Check automatic note-offs.
if (NoteOffs.size() != 0 && NoteOffs[0].Delay <= best)
{
FakeTrack->Delay = NoteOffs[0].Delay;
return FakeTrack;
}
return track;
}