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Optimize synth code by pre-computing the volume scaling for each note.

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Scaling is now calculated once per MIDI event at the most, instead of
once per sample. Increase voice ramping speed, increase number of
active voices a little.


git-svn-id: svn://svn.rockbox.org/rockbox/trunk@9870 a1c6a512-1295-4272-9138-f99709370657
This commit is contained in:
Stepan Moskovchenko 2006-05-03 19:32:22 +00:00
parent 7f1d214801
commit 28b5afd05a
4 changed files with 35 additions and 27 deletions
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47
apps/plugins/midi/sequencer.c
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@ -16,6 +16,7 @@
*
****************************************************************************/
void setVolScale(int a);
extern struct plugin_api * rb;
@ -24,8 +25,14 @@ long tempo=375000;
inline void setVol(int ch, int vol)
{
// printf("\nvolume[%d] %d ==> %d", ch, chVol[ch], vol);
int a=0;
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)
setVolScale(a);
}
inline void setPan(int ch, int pan)
@ -111,25 +118,13 @@ long pitchTbl[] ICONST_ATTR={
72901,72934,72967,72999,73032,73065,73098,73131,73164,73197,73230,73264,
73297,73330,73363,73396,73429,73462,73495,73528
};
/*
void findDelta(struct SynthObject * so, int ch, int note)
{
struct GWaveform * wf = patchSet[chPat[ch]]->waveforms[patchSet[chPat[ch]]->noteTable[note]];
so->wf=wf; // \|/ was 10
so->delta = (((gustable[note]<<10) / (wf->rootFreq)) * wf->sampRate / (SAMPLE_RATE));
so->delta = (so->delta * pitchTbl[chPW[ch]])>> 16;
}
*/
void findDelta(struct SynthObject * so, int ch, int note)
{
struct GWaveform * wf = patchSet[chPat[ch]]->waveforms[patchSet[chPat[ch]]->noteTable[note]];
so->wf=wf; // \|/ was 10
unsigned long delta= 0 ;
so->wf=wf;
unsigned long delta= 0; /* More percision- extra bit - not so off-key as before */
delta = (((gustable[note]<<FRACTSIZE) / (wf->rootFreq)) * wf->sampRate / (SAMPLE_RATE));
delta = (delta * pitchTbl[chPW[ch]])>> 16;
@ -139,7 +134,6 @@ void findDelta(struct SynthObject * so, int ch, int note)
inline void setPW(int ch, int msb, int lsb)
{
// printf("\npitchw[%d] %d ==> %d", ch, chPW[ch], msb);
chPW[ch] = msb<<2|lsb>>5;
int a=0;
@ -152,16 +146,26 @@ inline void setPW(int ch, int msb, int lsb)
}
}
/* Sets the volume scaling by channel volume and note volume */
/* This way we can do the multiplication/indexing once per */
/* MIDI event at the most, instead of once per sample. */
void setVolScale(int a)
{
struct SynthObject * so = &voices[a];
so->volscale = ((signed short int)so->vol*(signed short int)chVol[so->ch]);
}
void pressNote(int ch, int note, int vol)
{
static int lastKill = 0;
//Silences all channels but one, for easy debugging, for me.
/* Silences all channels but one, for easy debugging, for me. */
/*
if(ch == 0) return;
if(ch == 1) return;
if(ch == 2) return;
if(ch == 3) return;
// if(ch == 4) return;
if(ch == 4) return;
if(ch == 5) return;
if(ch == 6) return;
if(ch == 7) return;
@ -203,6 +207,7 @@ void pressNote(int ch, int note, int vol)
voices[a].state=STATE_ATTACK;
voices[a].decay=255;
setVolScale(a);
voices[a].loopState=STATE_NONLOOPING;
voices[a].loopDir = LOOPDIR_FORWARD;
@ -304,9 +309,7 @@ void sendEvent(struct Event * ev)
if((ev->status & 0xF0) == MIDI_PRGM)
{
if((ev->status & 0x0F) == 9)
printf("\nNOT PATCHING: Someone tried patching Channel 9 onto something?");
else
if((ev->status & 0x0F) != 9)
setPatch(ev->status & 0x0F, ev->d1);
}
}
@ -351,7 +354,7 @@ int tick(void)
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);
/* printf("\nMeta-Event: Tempo Set = %d", tempo); */
bpm=mf->div*1000000/tempo;
numberOfSamples=SAMPLE_RATE/bpm;