mirror of
https://github.com/libretro/scummvm.git
synced 2024-12-11 19:54:03 +00:00
401 lines
16 KiB
C++
401 lines
16 KiB
C++
/* ScummVM - Graphic Adventure Engine
|
|
*
|
|
* ScummVM is the legal property of its developers, whose names
|
|
* are too numerous to list here. Please refer to the COPYRIGHT
|
|
* file distributed with this source distribution.
|
|
*
|
|
* 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.
|
|
*
|
|
*/
|
|
|
|
/// \brief Declarations related to the MidiParser class
|
|
|
|
#ifndef SOUND_MIDIPARSER_H
|
|
#define SOUND_MIDIPARSER_H
|
|
|
|
#include "common/scummsys.h"
|
|
#include "common/endian.h"
|
|
|
|
class MidiDriver_BASE;
|
|
|
|
|
|
|
|
//////////////////////////////////////////////////
|
|
//
|
|
// Support entities
|
|
//
|
|
//////////////////////////////////////////////////
|
|
|
|
/**
|
|
* Maintains time and position state within a MIDI stream.
|
|
* A single Tracker struct is used by MidiParser to keep track
|
|
* of its current position in the MIDI stream. The Tracker
|
|
* struct, however, allows alternative locations to be cached.
|
|
* See MidiParser::jumpToTick() for an example of tracking
|
|
* multiple locations within a MIDI stream. NOTE: It is
|
|
* important to also maintain pre-parsed EventInfo data for
|
|
* each Tracker location.
|
|
*/
|
|
struct Tracker {
|
|
byte * _play_pos; ///< A pointer to the next event to be parsed
|
|
uint32 _play_time; ///< Current time in microseconds; may be in between event times
|
|
uint32 _play_tick; ///< Current MIDI tick; may be in between event ticks
|
|
uint32 _last_event_time; ///< The time, in microseconds, of the last event that was parsed
|
|
uint32 _last_event_tick; ///< The tick at which the last parsed event occurs
|
|
byte _running_status; ///< Cached MIDI command, for MIDI streams that rely on implied event codes
|
|
|
|
Tracker() { clear(); }
|
|
|
|
/// Copy constructor for each duplication of Tracker information.
|
|
Tracker(const Tracker ©) :
|
|
_play_pos(copy._play_pos),
|
|
_play_time(copy._play_time),
|
|
_play_tick(copy._play_tick),
|
|
_last_event_time(copy._last_event_time),
|
|
_last_event_tick(copy._last_event_tick),
|
|
_running_status(copy._running_status)
|
|
{ }
|
|
|
|
/// Clears all data; used by the constructor for initialization.
|
|
void clear() {
|
|
_play_pos = 0;
|
|
_play_time = 0;
|
|
_play_tick = 0;
|
|
_last_event_time = 0;
|
|
_last_event_tick = 0;
|
|
_running_status = 0;
|
|
}
|
|
};
|
|
|
|
/**
|
|
* Provides comprehensive information on the next event in the MIDI stream.
|
|
* An EventInfo struct is instantiated by format-specific implementations
|
|
* of MidiParser::parseNextEvent() each time another event is needed.
|
|
*/
|
|
struct EventInfo {
|
|
byte * start; ///< Position in the MIDI stream where the event starts.
|
|
///< For delta-based MIDI streams (e.g. SMF and XMIDI), this points to the delta.
|
|
uint32 delta; ///< The number of ticks after the previous event that this event should occur.
|
|
byte event; ///< Upper 4 bits are the command code, lower 4 bits are the MIDI channel.
|
|
///< For META, event == 0xFF. For SysEx, event == 0xF0.
|
|
union {
|
|
struct {
|
|
byte param1; ///< The first parameter in a simple MIDI message.
|
|
byte param2; ///< The second parameter in a simple MIDI message.
|
|
} basic;
|
|
struct {
|
|
byte type; ///< For META events, this indicates the META type.
|
|
byte * data; ///< For META and SysEx events, this points to the start of the data.
|
|
} ext;
|
|
};
|
|
uint32 length; ///< For META and SysEx blocks, this indicates the length of the data.
|
|
///< For Note On events, a non-zero value indicates that no Note Off event
|
|
///< will occur, and the MidiParser will have to generate one itself.
|
|
///< For all other events, this value should always be zero.
|
|
|
|
byte channel() { return event & 0x0F; } ///< Separates the MIDI channel from the event.
|
|
byte command() { return event >> 4; } ///< Separates the command code from the event.
|
|
};
|
|
|
|
/**
|
|
* Provides expiration tracking for hanging notes.
|
|
* Hanging notes are used when a MIDI format does not include explicit Note Off
|
|
* events, or when "Smart Jump" is enabled so that active notes are intelligently
|
|
* expired when a jump occurs. The NoteTimer struct keeps track of how much
|
|
* longer a note should remain active before being turned off.
|
|
*/
|
|
struct NoteTimer {
|
|
byte channel; ///< The MIDI channel on which the note was played
|
|
byte note; ///< The note number for the active note
|
|
uint32 time_left; ///< The time, in microseconds, remaining before the note should be turned off
|
|
NoteTimer() : channel(0), note(0), time_left(0) {}
|
|
};
|
|
|
|
|
|
|
|
|
|
//////////////////////////////////////////////////
|
|
//
|
|
// MidiParser declaration
|
|
//
|
|
//////////////////////////////////////////////////
|
|
|
|
/**
|
|
* A framework and common functionality for parsing event-based music streams.
|
|
* The MidiParser provides a framework in which to load,
|
|
* parse and traverse event-based music data. Note the
|
|
* avoidance of the phrase "MIDI data." Despite its name,
|
|
* MidiParser derivatives can be used to manage a wide
|
|
* variety of event-based music formats. It is, however,
|
|
* based on the premise that the format in question can
|
|
* be played in the form of specification MIDI events.
|
|
*
|
|
* In order to use MidiParser to parse your music format,
|
|
* follow these steps:
|
|
*
|
|
* <b>STEP 1: Write a MidiParser derivative.</b>
|
|
* The MidiParser base class provides functionality
|
|
* considered common to the task of parsing event-based
|
|
* music. In order to parse a particular format, create
|
|
* a derived class that implements, at minimum, the
|
|
* following format-specific methods:
|
|
* - loadMusic
|
|
* - parseNextEvent
|
|
*
|
|
* In addition to the above functions, the derived class
|
|
* may also override the default MidiParser behavior for
|
|
* the following methods:
|
|
* - resetTracking
|
|
* - allNotesOff
|
|
* - unloadMusic
|
|
* - property
|
|
* - getTick
|
|
*
|
|
* Please see the documentation for these individual
|
|
* functions for more information on their use.
|
|
*
|
|
* The naming convention for classes derived from
|
|
* MidiParser is MidiParser_XXX, where "XXX" is some
|
|
* short designator for the format the class will
|
|
* support. For instance, the MidiParser derivative
|
|
* for parsing the Standard MIDI File format is
|
|
* MidiParser_SMF.
|
|
*
|
|
* <b>STEP 2: Create an object of your derived class.</b>
|
|
* Each MidiParser object can parse at most one (1) song
|
|
* at a time. However, a MidiParser object can be reused
|
|
* to play another song once it is no longer needed to
|
|
* play whatever it was playing. In other words, MidiParser
|
|
* objects do not have to be destroyed and recreated from
|
|
* one song to the next.
|
|
*
|
|
* <b>STEP 3: Specify a MidiDriver to send events to.</b>
|
|
* MidiParser works by sending MIDI and meta events to a
|
|
* MidiDriver. In the simplest configuration, you can plug
|
|
* a single MidiParser directly into the output MidiDriver
|
|
* being used. However, you can only plug in one at a time;
|
|
* otherwise channel conflicts will occur. Furthermore,
|
|
* meta events that may be needed to interactively control
|
|
* music flow cannot be handled because they are being
|
|
* sent directly to the output device.
|
|
*
|
|
* If you need more control over the MidiParser while it's
|
|
* playing, you can create your own "pseudo-MidiDriver" and
|
|
* place it in between your MidiParser and the output
|
|
* MidiDriver. The MidiParser will send events to your
|
|
* pseudo-MidiDriver, which in turn must send them to the
|
|
* output MidiDriver (or do whatever special handling is
|
|
* required).
|
|
*
|
|
* To specify the MidiDriver to send music output to,
|
|
* use the MidiParser::setMidiDriver method.
|
|
*
|
|
* <b>STEP 4: Specify the onTimer call rate.</b>
|
|
* MidiParser bases the timing of its parsing on an external
|
|
* clock. Every time MidiParser::onTimer is called, a bit
|
|
* more music is parsed. You must specify how many
|
|
* microseconds will occur between each call to onTimer,
|
|
* in order to ensure an accurate music tempo.
|
|
*
|
|
* To set the onTimer call rate, in microseconds,
|
|
* use the MidiParser::setTimerRate method. The onTimer
|
|
* call rate will typically match the timer rate for
|
|
* the output MidiDriver used. This rate can be obtained
|
|
* by calling MidiDriver::getBaseTempo.
|
|
*
|
|
* <b>STEP 5: Load the music.</b>
|
|
* MidiParser requires that the music data already be loaded
|
|
* into memory. The client code is responsible for memory
|
|
* management on this block of memory. That means that the
|
|
* client code must ensure that the data remain in memory
|
|
* while the MidiParser is using it, and properly freed
|
|
* after it is no longer needed. Some MidiParser variants may
|
|
* require internal buffers as well; memory management for those
|
|
* buffers is the responsibility of the MidiParser object.
|
|
*
|
|
* To load the music into the MidiParser, use the
|
|
* MidiParser::loadMusic method, specifying a memory pointer
|
|
* to the music data and the size of the data. (NOTE: Some
|
|
* MidiParser variants don't require a size, and 0 is fine.
|
|
* However, when writing client code to use MidiParser, it is
|
|
* best to assume that a valid size will be required.
|
|
*
|
|
* Convention requires that each implementation of
|
|
* MidiParser::loadMusic automatically set up default tempo
|
|
* and current track. This effectively means that the
|
|
* MidiParser will start playing as soon as timer events
|
|
* start coming in.
|
|
*
|
|
* <b>STEP 6: Activate a timer source for the MidiParser.</b>
|
|
* The easiest timer source to use is the timer of the
|
|
* output MidiDriver. You can attach the MidiDriver's
|
|
* timer output directly to a MidiParser by calling
|
|
* MidiDriver::setTimerCallback. In this case, the timer_proc
|
|
* will be the static method MidiParser::timerCallback,
|
|
* and timer_param will be a pointer to your MidiParser object.
|
|
*
|
|
* This configuration only allows one MidiParser to be driven
|
|
* by the MidiDriver at a time. To drive more MidiDrivers, you
|
|
* will need to create a "pseudo-MidiDriver" as described earlier,
|
|
* In such a configuration, the pseudo-MidiDriver should be set
|
|
* as the timer recipient in MidiDriver::setTimerCallback, and
|
|
* could then call MidiParser::onTimer for each MidiParser object.
|
|
*
|
|
* <b>STEP 7: Music shall begin to play!</b>
|
|
* Congratulations! At this point everything should be hooked up
|
|
* and the MidiParser should generate music. Note that there is
|
|
* no way to "stop" the MidiParser. You can "pause" the MidiParser
|
|
* simply by not sending timer events to it, or you can call
|
|
* MidiParser::unloadMusic to permanently stop the music. (This
|
|
* method resets everything and detaches the MidiParser from the
|
|
* memory block containing the music data.)
|
|
*/
|
|
class MidiParser {
|
|
protected:
|
|
uint16 _active_notes[128]; ///< Each uint16 is a bit mask for channels that have that note on.
|
|
NoteTimer _hanging_notes[32]; ///< Maintains expiration info for up to 32 notes.
|
|
///< Used for "Smart Jump" and MIDI formats that do not include explicit Note Off events.
|
|
byte _hanging_notes_count; ///< Count of hanging notes, used to optimize expiration.
|
|
|
|
MidiDriver_BASE *_driver; ///< The device to which all events will be transmitted.
|
|
uint32 _timer_rate; ///< The time in microseconds between onTimer() calls. Obtained from the MidiDriver.
|
|
uint32 _ppqn; ///< Pulses Per Quarter Note. (We refer to "pulses" as "ticks".)
|
|
uint32 _tempo; ///< Microseconds per quarter note.
|
|
uint32 _psec_per_tick; ///< Microseconds per tick (_tempo / _ppqn).
|
|
bool _autoLoop; ///< For lightweight clients that don't provide their own flow control.
|
|
bool _smartJump; ///< Support smart expiration of hanging notes when jumping
|
|
bool _centerPitchWheelOnUnload; ///< Center the pitch wheels when unloading a song
|
|
bool _sendSustainOffOnNotesOff; ///< Send a sustain off on a notes off event, stopping hanging notes
|
|
byte *_tracks[120]; ///< Multi-track MIDI formats are supported, up to 120 tracks.
|
|
byte _num_tracks; ///< Count of total tracks for multi-track MIDI formats. 1 for single-track formats.
|
|
byte _active_track; ///< Keeps track of the currently active track, in multi-track formats.
|
|
|
|
Tracker _position; ///< The current time/position in the active track.
|
|
EventInfo _next_event; ///< The next event to transmit. Events are preparsed
|
|
///< so each event is parsed only once; this permits
|
|
///< simulated events in certain formats.
|
|
bool _abort_parse; ///< If a jump or other operation interrupts parsing, flag to abort.
|
|
|
|
protected:
|
|
static uint32 readVLQ(byte * &data);
|
|
virtual void resetTracking();
|
|
virtual void allNotesOff();
|
|
virtual void parseNextEvent(EventInfo &info) = 0;
|
|
|
|
void activeNote(byte channel, byte note, bool active);
|
|
void hangingNote(byte channel, byte note, uint32 ticks_left, bool recycle = true);
|
|
void hangAllActiveNotes();
|
|
|
|
virtual void sendToDriver(uint32 b);
|
|
void sendToDriver(byte status, byte firstOp, byte secondOp) {
|
|
sendToDriver(status | ((uint32)firstOp << 8) | ((uint32)secondOp << 16));
|
|
}
|
|
|
|
/**
|
|
* Platform independent BE uint32 read-and-advance.
|
|
* This helper function reads Big Endian 32-bit numbers
|
|
* from a memory pointer, at the same time advancing
|
|
* the pointer.
|
|
*/
|
|
uint32 read4high(byte * &data) {
|
|
uint32 val = READ_BE_UINT32(data);
|
|
data += 4;
|
|
return val;
|
|
}
|
|
|
|
/**
|
|
* Platform independent LE uint16 read-and-advance.
|
|
* This helper function reads Little Endian 16-bit numbers
|
|
* from a memory pointer, at the same time advancing
|
|
* the pointer.
|
|
*/
|
|
uint16 read2low(byte * &data) {
|
|
uint16 val = READ_LE_UINT16(data);
|
|
data += 2;
|
|
return val;
|
|
}
|
|
|
|
public:
|
|
/**
|
|
* Configuration options for MidiParser
|
|
* The following options can be set to modify MidiParser's
|
|
* behavior.
|
|
*/
|
|
enum {
|
|
/**
|
|
* Events containing a pitch bend command should be treated as
|
|
* single-byte padding before the real event. This allows the
|
|
* MidiParser to work with some malformed SMF files from Simon 1/2.
|
|
*/
|
|
mpMalformedPitchBends = 1,
|
|
|
|
/**
|
|
* Sets auto-looping, which can be used by lightweight clients
|
|
* that don't provide their own flow control.
|
|
*/
|
|
mpAutoLoop = 2,
|
|
|
|
/**
|
|
* Sets smart jumping, which intelligently expires notes that are
|
|
* active when a jump is made, rather than just cutting them off.
|
|
*/
|
|
mpSmartJump = 3,
|
|
|
|
/**
|
|
* Center the pitch wheels when unloading music in preparation
|
|
* for the next piece of music.
|
|
*/
|
|
mpCenterPitchWheelOnUnload = 4,
|
|
|
|
/**
|
|
* Sends a sustain off event when a notes off event is triggered.
|
|
* Stops hanging notes.
|
|
*/
|
|
mpSendSustainOffOnNotesOff = 5
|
|
};
|
|
|
|
public:
|
|
typedef void (*XMidiCallbackProc)(byte eventData, void *refCon);
|
|
|
|
MidiParser();
|
|
virtual ~MidiParser() { allNotesOff(); }
|
|
|
|
virtual bool loadMusic(byte *data, uint32 size) = 0;
|
|
virtual void unloadMusic();
|
|
virtual void property(int prop, int value);
|
|
|
|
void setMidiDriver(MidiDriver_BASE *driver) { _driver = driver; }
|
|
void setTimerRate(uint32 rate) { _timer_rate = rate; }
|
|
void setTempo(uint32 tempo);
|
|
void onTimer();
|
|
|
|
bool isPlaying() const { return (_position._play_pos != 0); }
|
|
void stopPlaying();
|
|
|
|
bool setTrack(int track);
|
|
bool jumpToTick(uint32 tick, bool fireEvents = false, bool stopNotes = true, bool dontSendNoteOn = false);
|
|
|
|
uint32 getPPQN() { return _ppqn; }
|
|
virtual uint32 getTick() { return _position._play_tick; }
|
|
|
|
static void defaultXMidiCallback(byte eventData, void *refCon);
|
|
|
|
static MidiParser *createParser_SMF();
|
|
static MidiParser *createParser_XMIDI(XMidiCallbackProc proc = defaultXMidiCallback, void *refCon = 0);
|
|
static void timerCallback(void *data) { ((MidiParser *) data)->onTimer(); }
|
|
};
|
|
|
|
#endif
|