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midi: yield more, fixes flickering backlight fade on some targets while playing midi. Some coding style clean up, it's a little better but still a mess

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git-svn-id: svn://svn.rockbox.org/rockbox/trunk@20562 a1c6a512-1295-4272-9138-f99709370657
This commit is contained in:
Nils Wallménius 2009-03-28 11:27:56 +00:00
parent 24ae50699d
commit 1adc869d9c
3 changed files with 321 additions and 353 deletions
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439
apps/plugins/midi/midiplay.c
View file

@ -29,24 +29,7 @@ PLUGIN_HEADER
PLUGIN_IRAM_DECLARE
/* variable button definitions */
#if CONFIG_KEYPAD == RECORDER_PAD
#define BTN_QUIT BUTTON_OFF
#define BTN_RIGHT BUTTON_RIGHT
#define BTN_UP BUTTON_UP
#define BTN_DOWN BUTTON_DOWN
#define BTN_LEFT BUTTON_LEFT
#define BTN_PLAY BUTTON_PLAY
#elif CONFIG_KEYPAD == ONDIO_PAD
#define BTN_QUIT BUTTON_OFF
#define BTN_RIGHT BUTTON_RIGHT
#define BTN_UP BUTTON_UP
#define BTN_DOWN BUTTON_DOWN
#define BTN_LEFT BUTTON_LEFT
#define BTN_PLAY (BUTTON_MENU | BUTTON_OFF)
#elif (CONFIG_KEYPAD == IRIVER_H100_PAD) || (CONFIG_KEYPAD == IRIVER_H300_PAD)
#if (CONFIG_KEYPAD == IRIVER_H100_PAD) || (CONFIG_KEYPAD == IRIVER_H300_PAD)
#define BTN_QUIT BUTTON_OFF
#define BTN_RIGHT BUTTON_RIGHT
#define BTN_UP BUTTON_UP
@ -209,27 +192,223 @@ PLUGIN_IRAM_DECLARE
struct MIDIfile * mf IBSS_ATTR;
int numberOfSamples IBSS_ATTR; /* the number of samples in the current tick */
int playingTime IBSS_ATTR; /* How many seconds into the file have we been playing? */
int samplesThisSecond IBSS_ATTR; /* How many samples produced during this second so far? */
int number_of_samples IBSS_ATTR; /* the number of samples in the current tick */
int playing_time IBSS_ATTR; /* How many seconds into the file have we been playing? */
int samples_this_second IBSS_ATTR; /* How many samples produced during this second so far? */
long bpm IBSS_ATTR;
int32_t gmbuf[BUF_SIZE*NBUF];
static unsigned int samples_in_buf;
int quit=0;
bool quit = false;
bool swap = false;
bool lastswap = true;
static int midimain(const void * filename);
static inline void synthbuf(void)
{
int32_t *outptr;
int i = BUF_SIZE;
#ifndef SYNC
if (lastswap == swap)
return;
lastswap = swap;
outptr = (swap ? gmbuf : gmbuf+BUF_SIZE);
#else
outptr = gmbuf;
#endif
/* synth samples for as many whole ticks as we can fit in the buffer */
for (; i >= number_of_samples; i -= number_of_samples)
{
synthSamples((int32_t*)outptr, number_of_samples);
outptr += number_of_samples;
#ifndef SYNC
/* synthbuf is called in interrupt context is SYNC is defined so it cannot yield
that bug causing the sim to crach when not using SYNC should really be fixed */
rb->yield();
#endif
if (tick() == 0)
quit = true;
}
/* how many samples did we write to the buffer? */
samples_in_buf = BUF_SIZE-i;
}
void get_more(unsigned char** start, size_t* size)
{
#ifndef SYNC
if(lastswap != swap)
{
printf("Buffer miss!"); /* Comment out the printf to make missses less noticable. */
}
#else
synthbuf(); /* For some reason midiplayer crashes when an update is forced */
#endif
*size = samples_in_buf*sizeof(int32_t);
#ifndef SYNC
*start = (unsigned char*)((swap ? gmbuf : gmbuf + BUF_SIZE));
swap = !swap;
#else
*start = (unsigned char*)(gmbuf);
#endif
}
static int midimain(const void * filename)
{
int a, notes_used, vol;
bool is_playing = true; /* false = paused */
printf("Loading file");
mf = loadFile(filename);
if (mf == NULL)
{
printf("Error loading file.");
return -1;
}
if (initSynth(mf, ROCKBOX_DIR "/patchset/patchset.cfg",
ROCKBOX_DIR "/patchset/drums.cfg") == -1)
return -1;
rb->pcm_play_stop();
#if INPUT_SRC_CAPS != 0
/* Select playback */
rb->audio_set_input_source(AUDIO_SRC_PLAYBACK, SRCF_PLAYBACK);
rb->audio_set_output_source(AUDIO_SRC_PLAYBACK);
#endif
rb->pcm_set_frequency(SAMPLE_RATE); /* 44100 22050 11025 */
/*
* tick() will do one MIDI clock tick. Then, there's a loop here that
* will generate the right number of samples per MIDI tick. The whole
* MIDI playback is timed in terms of this value.. there are no forced
* delays or anything. It just produces enough samples for each tick, and
* the playback of these samples is what makes the timings right.
*
* This seems to work quite well. On a laptop, anyway.
*/
printf("Okay, starting sequencing");
bpm = mf->div*1000000/tempo;
number_of_samples = SAMPLE_RATE/bpm;
/* Skip over any junk in the beginning of the file, so start playing */
/* after the first note event */
do
{
notes_used = 0;
for (a = 0; a < MAX_VOICES; a++)
if (voices[a].isUsed)
notes_used++;
tick();
} while (notes_used == 0);
playing_time = 0;
samples_this_second = 0;
synthbuf();
rb->pcm_play_data(&get_more, NULL, 0);
while (!quit)
{
#ifndef SYNC
synthbuf();
#endif
rb->yield();
/* Prevent idle poweroff */
rb->reset_poweroff_timer();
/* Code taken from Oscilloscope plugin */
switch (rb->button_get(false))
{
case BTN_UP:
case BTN_UP | BUTTON_REPEAT:
{
vol = rb->global_settings->volume;
if (vol < rb->sound_max(SOUND_VOLUME))
{
vol++;
rb->sound_set(SOUND_VOLUME, vol);
rb->global_settings->volume = vol;
}
break;
}
case BTN_DOWN:
case BTN_DOWN | BUTTON_REPEAT:
{
vol = rb->global_settings->volume;
if (vol > rb->sound_min(SOUND_VOLUME))
{
vol--;
rb->sound_set(SOUND_VOLUME, vol);
rb->global_settings->volume = vol;
}
break;
}
case BTN_LEFT:
{
/* Rewinding is tricky. Basically start the file over */
/* but run through the tracks without the synth running */
rb->pcm_play_stop();
seekBackward(5);
printf("Rewind to %d:%02d\n", playing_time/60, playing_time%60);
if (is_playing)
rb->pcm_play_data(&get_more, NULL, 0);
break;
}
case BTN_RIGHT:
{
rb->pcm_play_stop();
seekForward(5);
printf("Skip to %d:%02d\n", playing_time/60, playing_time%60);
if (is_playing)
rb->pcm_play_data(&get_more, NULL, 0);
break;
}
case BTN_PLAY:
{
if (is_playing)
{
printf("Paused at %d:%02d\n", playing_time/60, playing_time%60);
is_playing = false;
rb->pcm_play_stop();
} else
{
printf("Playing from %d:%02d\n", playing_time/60, playing_time%60);
is_playing = true;
rb->pcm_play_data(&get_more, NULL, 0);
}
break;
}
#ifdef BTN_RC_QUIT
case BTN_RC_QUIT:
#endif
case BTN_QUIT:
quit = true;
}
}
return 0;
}
enum plugin_status plugin_start(const void* parameter)
{
int retval = 0;
int retval;
PLUGIN_IRAM_INIT(rb)
if(parameter == NULL)
if (parameter == NULL)
{
rb->splash(HZ*2, " Play .MID file ");
return PLUGIN_OK;
@ -261,210 +440,8 @@ enum plugin_status plugin_start(const void* parameter)
#endif
rb->splash(HZ, "FINISHED PLAYING");
if(retval == -1)
if (retval == -1)
return PLUGIN_ERROR;
return PLUGIN_OK;
}
bool swap=0;
bool lastswap=1;
static inline void synthbuf(void)
{
int32_t *outptr;
int i=BUF_SIZE;
#ifndef SYNC
if(lastswap==swap) return;
lastswap=swap;
outptr=(swap ? gmbuf : gmbuf+BUF_SIZE);
#else
outptr=gmbuf;
#endif
/* synth samples for as many whole ticks as we can fit in the buffer */
for(; i >= numberOfSamples; i -= numberOfSamples)
{
synthSamples((int32_t*)outptr, numberOfSamples);
outptr += numberOfSamples;
if( tick() == 0 )
quit=1;
}
/* how many samples did we write to the buffer? */
samples_in_buf = BUF_SIZE-i;
}
void get_more(unsigned char** start, size_t* size)
{
#ifndef SYNC
if(lastswap!=swap)
{
printf("Buffer miss!"); // Comment out the printf to make missses less noticable.
}
#else
synthbuf(); // For some reason midiplayer crashes when an update is forced
#endif
*size = samples_in_buf*sizeof(int32_t);
#ifndef SYNC
*start = (unsigned char*)((swap ? gmbuf : gmbuf + BUF_SIZE));
swap=!swap;
#else
*start = (unsigned char*)(gmbuf);
#endif
}
static int midimain(const void * filename)
{
int notesUsed = 0;
int a=0;
printf("Loading file");
mf= loadFile(filename);
if(mf == NULL)
{
printf("Error loading file.");
return -1;
}
if (initSynth(mf, ROCKBOX_DIR "/patchset/patchset.cfg",
ROCKBOX_DIR "/patchset/drums.cfg") == -1)
return -1;
rb->pcm_play_stop();
#if INPUT_SRC_CAPS != 0
/* Select playback */
rb->audio_set_input_source(AUDIO_SRC_PLAYBACK, SRCF_PLAYBACK);
rb->audio_set_output_source(AUDIO_SRC_PLAYBACK);
#endif
rb->pcm_set_frequency(SAMPLE_RATE); // 44100 22050 11025
/*
* tick() will do one MIDI clock tick. Then, there's a loop here that
* will generate the right number of samples per MIDI tick. The whole
* MIDI playback is timed in terms of this value.. there are no forced
* delays or anything. It just produces enough samples for each tick, and
* the playback of these samples is what makes the timings right.
*
* This seems to work quite well. On a laptop, anyway.
*/
printf("Okay, starting sequencing");
bpm=mf->div*1000000/tempo;
numberOfSamples=SAMPLE_RATE/bpm;
/* Skip over any junk in the beginning of the file, so start playing */
/* after the first note event */
do
{
notesUsed = 0;
for(a=0; a<MAX_VOICES; a++)
if(voices[a].isUsed)
notesUsed++;
tick();
} while(notesUsed == 0);
playingTime = 0;
samplesThisSecond = 0;
synthbuf();
rb->pcm_play_data(&get_more, NULL, 0);
int isPlaying = 1; /* 0 = paused */
int vol=0;
while(!quit)
{
#ifndef SYNC
synthbuf();
#endif
rb->yield();
/* Prevent idle poweroff */
rb->reset_poweroff_timer();
/* Code taken from Oscilloscope plugin */
switch(rb->button_get(false))
{
case BTN_UP:
case BTN_UP | BUTTON_REPEAT:
vol = rb->global_settings->volume;
if (vol < rb->sound_max(SOUND_VOLUME))
{
vol++;
rb->sound_set(SOUND_VOLUME, vol);
rb->global_settings->volume = vol;
}
break;
case BTN_DOWN:
case BTN_DOWN | BUTTON_REPEAT:
vol = rb->global_settings->volume;
if (vol > rb->sound_min(SOUND_VOLUME))
{
vol--;
rb->sound_set(SOUND_VOLUME, vol);
rb->global_settings->volume = vol;
}
break;
case BTN_LEFT:
{
/* Rewinding is tricky. Basically start the file over */
/* but run through the tracks without the synth running */
rb->pcm_play_stop();
seekBackward(5);
printf("Rewind to %d:%02d\n", playingTime/60, playingTime%60);
if(isPlaying)
rb->pcm_play_data(&get_more, NULL, 0);
break;
}
case BTN_RIGHT:
{
rb->pcm_play_stop();
seekForward(5);
printf("Skip to %d:%02d\n", playingTime/60, playingTime%60);
if(isPlaying)
rb->pcm_play_data(&get_more, NULL, 0);
break;
}
case BTN_PLAY:
{
if(isPlaying == 1)
{
printf("Paused at %d:%02d\n", playingTime/60, playingTime%60);
isPlaying = 0;
rb->pcm_play_stop();
} else
{
printf("Playing from %d:%02d\n", playingTime/60, playingTime%60);
isPlaying = 1;
rb->pcm_play_data(&get_more, NULL, 0);
}
break;
}
#ifdef BTN_RC_QUIT
case BTN_RC_QUIT:
#endif
case BTN_QUIT:
quit=1;
}
}
return 0;
}

10
apps/plugins/midi/midiutil.h
View file

@ -32,8 +32,10 @@
#define SAMPLE_RATE SAMPR_44 /* 44100 */
#endif
#ifdef CPU_PP /* the pp based targets can't handle too many voices
mainly because they have to use 44100Hz sample rate */
/* Some of the pp based targets can't handle too many voices
mainly because they have to use 44100Hz sample rate, this could be
improved to increase MAX_VOICES for targets that can do 22kHz */
#ifdef CPU_PP
#define MAX_VOICES 16
#else
#define MAX_VOICES 24 /* Note: 24 midi channels is the minimum general midi spec implementation */
@ -166,6 +168,8 @@ extern struct GPatch * drumSet[128];
extern struct MIDIfile * mf;
extern int numberOfSamples;
extern int number_of_samples;
extern int playing_time IBSS_ATTR;
extern int samples_this_second IBSS_ATTR;
extern long bpm;

225
apps/plugins/midi/sequencer.c
View file

@ -23,10 +23,7 @@
#include "guspat.h"
#include "synth.h"
extern int playingTime IBSS_ATTR;
extern int samplesThisSecond IBSS_ATTR;
long tempo=375000;
long tempo = 375000;
/* From the old patch config.... each patch is scaled.
* Should be moved into patchset.cfg
@ -62,13 +59,13 @@ static inline void setVolScale(int a)
static inline void setVol(int ch, int vol)
{
int a=0;
chVol[ch]=vol;
int a;
chVol[ch] = vol;
/* If channel volume changes, we need to recalculate the volume scale */
/* factor for all voices active on this channel */
for(a=0; a<MAX_VOICES; a++)
if(voices[a].ch == ch)
for (a = 0; a < MAX_VOICES; a++)
if (voices[a].ch == ch)
setVolScale(a);
}
@ -77,8 +74,6 @@ static inline void setPatch(int ch, int pat)
chPat[ch]=pat;
}
/*
This is the new pitch bend table. There are 512 entries.
The middle entry is exactly 65536 - no bending.
@ -143,11 +138,12 @@ const uint32_t pitchTbl[] ICONST_ATTR={
static void findDelta(struct SynthObject * so, int ch, int note)
{
struct GWaveform * wf = patchSet[chPat[ch]]->waveforms[patchSet[chPat[ch]]->noteTable[note]];
so->wf=wf;
struct GWaveform * wf =
patchSet[chPat[ch]]->waveforms[patchSet[chPat[ch]]->noteTable[note]];
so->wf = wf;
/* Used to be unsigned int, but math had to be done in different order to avoid overflow */
unsigned long long delta= 0;
unsigned long long delta = 0;
/*
Old formula:
@ -169,10 +165,10 @@ static void findDelta(struct SynthObject * so, int ch, int note)
static inline void computeDeltas(int ch)
{
int a=0;
for(a = 0; a<MAX_VOICES; a++)
int a;
for (a = 0; a < MAX_VOICES; a++)
{
if(voices[a].isUsed && voices[a].ch == ch)
if (voices[a].isUsed && voices[a].ch == ch)
{
findDelta(&voices[a], ch, voices[a].note);
}
@ -212,16 +208,16 @@ inline void pressNote(int ch, int note, int vol)
if(ch == 14) return;
if(ch == 15) return;
*/
int a=0;
for(a=0; a<MAX_VOICES; a++)
int a;
for (a = 0; a < MAX_VOICES; a++)
{
if(voices[a].ch == ch && voices[a].note == note)
if (voices[a].ch == ch && voices[a].note == note)
break;
if(!voices[a].isUsed)
if (!voices[a].isUsed)
break;
}
if(a==MAX_VOICES)
if (a == MAX_VOICES)
{
// printf("\nVoice kill");
// printf("\nToo many voices playing at once. No more left");
@ -229,17 +225,17 @@ inline void pressNote(int ch, int note, int vol)
// for(a=0; a<48; a++)
// printf("\n#%d Ch=%d Note=%d curRate=%d curOffset=%d curPoint=%d targetOffset=%d", a, voices[a].ch, voices[a].note, voices[a].curRate, voices[a].curOffset, voices[a].curPoint, voices[a].targetOffset);
lastKill++;
if(lastKill == MAX_VOICES)
if (lastKill == MAX_VOICES)
lastKill = 0;
a = lastKill;
// return; /* None available */
}
voices[a].ch=ch;
voices[a].note=note;
voices[a].vol=vol;
voices[a].cp=0;
voices[a].state=STATE_ATTACK;
voices[a].decay=255;
voices[a].ch = ch;
voices[a].note = note;
voices[a].vol = vol;
voices[a].cp = 0;
voices[a].state = STATE_ATTACK;
voices[a].decay = 255;
setVolScale(a);
@ -251,28 +247,28 @@ inline void pressNote(int ch, int note, int vol)
* sr = WAVE sampling rate
*/
if(ch!=9)
if (ch != 9)
{
findDelta(&voices[a], ch, note);
/* Turn it on */
voices[a].isUsed=true;
voices[a].isUsed = true;
setPoint(&voices[a], 0);
} else
{
if(drumSet[note]!=NULL)
if (drumSet[note] != NULL)
{
if(note<35)
if (note < 35)
printf("NOTE LESS THAN 35, AND A DRUM PATCH EXISTS FOR THIS? WHAT THE HELL?");
struct GWaveform * wf = drumSet[note]->waveforms[0];
voices[a].wf=wf;
voices[a].wf = wf;
voices[a].delta = (((gustable[note]<<FRACTSIZE) / wf->rootFreq) * wf->sampRate / SAMPLE_RATE);
if(wf->mode & 28)
if (wf->mode & 28)
// printf("\nWoah, a drum patch has a loop. Stripping the loop...");
wf->mode = wf->mode & (255-28);
/* Turn it on */
voices[a].isUsed=true;
voices[a].isUsed = true;
setPoint(&voices[a], 0);
} else
@ -284,16 +280,15 @@ inline void pressNote(int ch, int note, int vol)
static void releaseNote(int ch, int note)
{
if(ch==9)
if (ch == 9)
return;
int a=0;
for(a=0; a<MAX_VOICES; a++)
int a;
for (a = 0; a < MAX_VOICES; a++)
{
if(voices[a].ch == ch && voices[a].note == note)
if (voices[a].ch == ch && voices[a].note == note)
{
if((voices[a].wf->mode & 28))
if (voices[a].wf->mode & 28)
{
setPoint(&voices[a], 3);
}
@ -306,10 +301,10 @@ static void sendEvent(struct Event * ev)
const unsigned char status_low = ev->status & 0x0F;
const unsigned char d1 = ev->d1;
const unsigned char d2 = ev->d2;
switch(ev->status & 0xF0)
switch (ev->status & 0xF0)
{
case MIDI_CONTROL:
switch(d1)
switch (d1)
{
case CTRL_VOLUME:
{
@ -318,7 +313,7 @@ static void sendEvent(struct Event * ev)
}
case CTRL_PANNING:
{
chPan[status_low]=d2;
chPan[status_low] = d2;
return;
}
case CTRL_DATAENT_MSB:
@ -365,7 +360,7 @@ static void sendEvent(struct Event * ev)
return;
case MIDI_NOTE_ON:
switch(d2)
switch (d2)
{
case 0: /* Release by vol=0 */
releaseNote(status_low, d1);
@ -381,139 +376,131 @@ static void sendEvent(struct Event * ev)
return;
case MIDI_PRGM:
if((status_low) != 9)
if (status_low != 9)
setPatch(status_low, d1);
}
}
void rewindFile(void)
{
int i=0;
for(i=0; i<mf->numTracks; i++)
int i;
for (i = 0; i < mf->numTracks; i++)
{
mf->tracks[i]->delta = 0;
mf->tracks[i]->pos = 0;
}
}
int tick(void) ICODE_ATTR;
void seekBackward(int nsec)
{
int notesUsed = 0, a=0;
int desiredTime = playingTime - nsec; /* Rewind 5 sec */
if(desiredTime < 0)
desiredTime = 0;
/* Set controllers to default values */
resetControllers();
/* Set the tempo to defalt */
bpm=mf->div*1000000/tempo;
numberOfSamples=SAMPLE_RATE/bpm;
/* Reset the tracks to start */
rewindFile();
/* Reset the time counter to 0 */
playingTime = 0;
samplesThisSecond = 0;
/* Quickly run through any initial things that occur before notes */
do
{
notesUsed = 0;
for(a=0; a<MAX_VOICES; a++)
if(voices[a].isUsed)
notesUsed++;
tick();
} while(notesUsed == 0);
/* Reset the time counter to 0 */
playingTime = 0;
samplesThisSecond = 0;
/* Tick until goal is reached */
while(playingTime < desiredTime)
tick();
}
void seekForward(int nsec)
{
int desiredTime = playingTime + nsec;
while(tick() && playingTime < desiredTime);
}
int tick(void)
{
if(mf==NULL)
if (mf == NULL)
return 0;
int a=0;
int tracksAdv=0;
for(a=0; a<mf->numTracks; a++)
int a, tracksAdv=0;
for (a = 0; a < mf->numTracks; a++)
{
struct Track * tr = mf->tracks[a];
if(tr == NULL)
if (tr == NULL)
printf("NULL TRACK: %d", a);
//BIG DEBUG STATEMENT
//printf("\nTrack %2d, Event = %4d of %4d, Delta = %5d, Next = %4d", a, tr->pos, tr->numEvents, tr->delta, getEvent(tr, tr->pos)->delta);
if(tr != NULL && (tr->pos < tr->numEvents))
if (tr != NULL && (tr->pos < tr->numEvents))
{
tr->delta++;
tracksAdv++;
while(getEvent(tr, tr->pos)->delta <= tr->delta)
while (getEvent(tr, tr->pos)->delta <= tr->delta)
{
struct Event * e = getEvent(tr, tr->pos);
if(e->status != 0xFF)
if (e->status != 0xFF)
{
sendEvent(e);
if(((e->status&0xF0) == MIDI_PRGM))
if ((e->status&0xF0) == MIDI_PRGM)
{
/* printf("\nPatch Event, patch[%d] ==> %d", e->status&0xF, e->d1); */
}
}
else
{
if(e->d1 == 0x51)
if (e->d1 == 0x51)
{
tempo = (((short)e->evData[0])<<16)|(((short)e->evData[1])<<8)|(e->evData[2]);
/* printf("\nMeta-Event: Tempo Set = %d", tempo); */
bpm=mf->div*1000000/tempo;
numberOfSamples=SAMPLE_RATE/bpm;
number_of_samples=SAMPLE_RATE/bpm;
}
}
tr->delta = 0;
tr->pos++;
if(tr->pos>=(tr->numEvents-1))
if (tr->pos >= (tr->numEvents-1))
break;
}
}
}
samplesThisSecond += numberOfSamples;
samples_this_second += number_of_samples;
while(samplesThisSecond >= SAMPLE_RATE)
while (samples_this_second >= SAMPLE_RATE)
{
samplesThisSecond -= SAMPLE_RATE;
playingTime++;
// printf("Time: %d sec\n", playingTime);
samples_this_second -= SAMPLE_RATE;
playing_time++;
}
if(tracksAdv != 0)
if (tracksAdv != 0)
return 1;
else
return 0;
}
void seekBackward(int nsec)
{
int notes_used, a;
int desired_time = playing_time - nsec; /* Rewind 5 sec */
if (desired_time < 0)
desired_time = 0;
/* Set controllers to default values */
resetControllers();
/* Set the tempo to defalt */
bpm = mf->div*1000000/tempo;
number_of_samples = SAMPLE_RATE/bpm;
/* Reset the tracks to start */
rewindFile();
/* Reset the time counter to 0 */
playing_time = 0;
samples_this_second = 0;
/* Quickly run through any initial things that occur before notes */
do
{
notes_used = 0;
for (a = 0; a < MAX_VOICES; a++)
if (voices[a].isUsed)
notes_used++;
tick();
} while (notes_used == 0);
/* Reset the time counter to 0 */
playing_time = 0;
samples_this_second = 0;
/* Tick until goal is reached */
while (playing_time < desired_time)
tick();
}
void seekForward(int nsec)
{
int desired_time = playing_time + nsec;
while (tick() && playing_time < desired_time);
}