642 lines
13 KiB
C
642 lines
13 KiB
C
/*
|
|
======================================================================
|
|
envelope.c
|
|
|
|
Envelope functions for an LWO2 reader.
|
|
|
|
Ernie Wright 16 Nov 00
|
|
====================================================================== */
|
|
|
|
#include "picointernal.h"
|
|
#include "lwo2.h"
|
|
|
|
/*
|
|
======================================================================
|
|
lwFreeEnvelope()
|
|
|
|
Free the memory used by an lwEnvelope.
|
|
====================================================================== */
|
|
|
|
void lwFreeEnvelope( lwEnvelope *env ){
|
|
if ( env ) {
|
|
if ( env->name ) {
|
|
_pico_free( env->name );
|
|
}
|
|
lwListFree( env->key, _pico_free );
|
|
lwListFree(env->cfilter, (void (*)(void *)) lwFreePlugin);
|
|
_pico_free( env );
|
|
}
|
|
}
|
|
|
|
|
|
static int compare_keys( lwKey *k1, lwKey *k2 ){
|
|
return k1->time > k2->time ? 1 : k1->time < k2->time ? -1 : 0;
|
|
}
|
|
|
|
|
|
/*
|
|
======================================================================
|
|
lwGetEnvelope()
|
|
|
|
Read an ENVL chunk from an LWO2 file.
|
|
====================================================================== */
|
|
|
|
lwEnvelope *lwGetEnvelope( picoMemStream_t *fp, int cksize ){
|
|
lwEnvelope *env;
|
|
lwKey *key = NULL;
|
|
lwPlugin *plug;
|
|
unsigned int id;
|
|
unsigned short sz;
|
|
float f[ 4 ];
|
|
int i, nparams, pos, rlen;
|
|
|
|
|
|
/* allocate the Envelope structure */
|
|
|
|
env = _pico_calloc( 1, sizeof( lwEnvelope ) );
|
|
if ( !env ) {
|
|
goto Fail;
|
|
}
|
|
|
|
/* remember where we started */
|
|
|
|
set_flen( 0 );
|
|
pos = _pico_memstream_tell( fp );
|
|
|
|
/* index */
|
|
|
|
env->index = getVX( fp );
|
|
|
|
/* first subchunk header */
|
|
|
|
id = getU4( fp );
|
|
sz = getU2( fp );
|
|
if ( 0 > get_flen() ) {
|
|
goto Fail;
|
|
}
|
|
|
|
/* process subchunks as they're encountered */
|
|
|
|
while ( 1 ) {
|
|
sz += sz & 1;
|
|
set_flen( 0 );
|
|
|
|
switch ( id ) {
|
|
case ID_TYPE:
|
|
env->type = getU2( fp );
|
|
break;
|
|
|
|
case ID_NAME:
|
|
env->name = getS0( fp );
|
|
break;
|
|
|
|
case ID_PRE:
|
|
env->behavior[ 0 ] = getU2( fp );
|
|
break;
|
|
|
|
case ID_POST:
|
|
env->behavior[ 1 ] = getU2( fp );
|
|
break;
|
|
|
|
case ID_KEY:
|
|
key = _pico_calloc( 1, sizeof( lwKey ) );
|
|
if ( !key ) {
|
|
goto Fail;
|
|
}
|
|
key->time = getF4( fp );
|
|
key->value = getF4( fp );
|
|
lwListInsert((void **) &env->key, key, (int (*)(void *, void *)) compare_keys);
|
|
env->nkeys++;
|
|
break;
|
|
|
|
case ID_SPAN:
|
|
if ( !key ) {
|
|
goto Fail;
|
|
}
|
|
key->shape = getU4( fp );
|
|
|
|
nparams = ( sz - 4 ) / 4;
|
|
if ( nparams > 4 ) {
|
|
nparams = 4;
|
|
}
|
|
for ( i = 0; i < nparams; i++ )
|
|
f[ i ] = getF4( fp );
|
|
|
|
switch ( key->shape ) {
|
|
case ID_TCB:
|
|
key->tension = f[ 0 ];
|
|
key->continuity = f[ 1 ];
|
|
key->bias = f[ 2 ];
|
|
break;
|
|
|
|
case ID_BEZI:
|
|
case ID_HERM:
|
|
case ID_BEZ2:
|
|
for ( i = 0; i < nparams; i++ )
|
|
key->param[ i ] = f[ i ];
|
|
break;
|
|
}
|
|
break;
|
|
|
|
case ID_CHAN:
|
|
plug = _pico_calloc( 1, sizeof( lwPlugin ) );
|
|
if ( !plug ) {
|
|
goto Fail;
|
|
}
|
|
|
|
plug->name = getS0( fp );
|
|
plug->flags = getU2( fp );
|
|
plug->data = getbytes( fp, sz - get_flen() );
|
|
|
|
lwListAdd( (void *) &env->cfilter, plug );
|
|
env->ncfilters++;
|
|
break;
|
|
|
|
default:
|
|
break;
|
|
}
|
|
|
|
/* error while reading current subchunk? */
|
|
|
|
rlen = get_flen();
|
|
if ( rlen < 0 || rlen > sz ) {
|
|
goto Fail;
|
|
}
|
|
|
|
/* skip unread parts of the current subchunk */
|
|
|
|
if ( rlen < sz ) {
|
|
_pico_memstream_seek( fp, sz - rlen, PICO_SEEK_CUR );
|
|
}
|
|
|
|
/* end of the ENVL chunk? */
|
|
|
|
rlen = _pico_memstream_tell( fp ) - pos;
|
|
if ( cksize < rlen ) {
|
|
goto Fail;
|
|
}
|
|
if ( cksize == rlen ) {
|
|
break;
|
|
}
|
|
|
|
/* get the next subchunk header */
|
|
|
|
set_flen( 0 );
|
|
id = getU4( fp );
|
|
sz = getU2( fp );
|
|
if ( 6 != get_flen() ) {
|
|
goto Fail;
|
|
}
|
|
}
|
|
|
|
return env;
|
|
|
|
Fail:
|
|
lwFreeEnvelope( env );
|
|
return NULL;
|
|
}
|
|
|
|
|
|
/*
|
|
======================================================================
|
|
lwFindEnvelope()
|
|
|
|
Returns an lwEnvelope pointer, given an envelope index.
|
|
====================================================================== */
|
|
|
|
lwEnvelope *lwFindEnvelope( lwEnvelope *list, int index ){
|
|
lwEnvelope *env;
|
|
|
|
env = list;
|
|
while ( env ) {
|
|
if ( env->index == index ) {
|
|
break;
|
|
}
|
|
env = env->next;
|
|
}
|
|
return env;
|
|
}
|
|
|
|
|
|
/*
|
|
======================================================================
|
|
range()
|
|
|
|
Given the value v of a periodic function, returns the equivalent value
|
|
v2 in the principal interval [lo, hi]. If i isn't NULL, it receives
|
|
the number of wavelengths between v and v2.
|
|
|
|
v2 = v - i * (hi - lo)
|
|
|
|
For example, range( 3 pi, 0, 2 pi, i ) returns pi, with i = 1.
|
|
====================================================================== */
|
|
|
|
static float range( float v, float lo, float hi, int *i ){
|
|
float v2, r = hi - lo;
|
|
|
|
if ( r == 0.0 ) {
|
|
if ( i ) {
|
|
*i = 0;
|
|
}
|
|
return lo;
|
|
}
|
|
|
|
v2 = lo + v - r * ( float ) floor( ( double ) v / r );
|
|
if ( i ) {
|
|
*i = -( int )( ( v2 - v ) / r + ( v2 > v ? 0.5 : -0.5 ) );
|
|
}
|
|
|
|
return v2;
|
|
}
|
|
|
|
|
|
/*
|
|
======================================================================
|
|
hermite()
|
|
|
|
Calculate the Hermite coefficients.
|
|
====================================================================== */
|
|
|
|
static void hermite( float t, float *h1, float *h2, float *h3, float *h4 ){
|
|
float t2, t3;
|
|
|
|
t2 = t * t;
|
|
t3 = t * t2;
|
|
|
|
*h2 = 3.0f * t2 - t3 - t3;
|
|
*h1 = 1.0f - *h2;
|
|
*h4 = t3 - t2;
|
|
*h3 = *h4 - t2 + t;
|
|
}
|
|
|
|
|
|
/*
|
|
======================================================================
|
|
bezier()
|
|
|
|
Interpolate the value of a 1D Bezier curve.
|
|
====================================================================== */
|
|
|
|
static float bezier( float x0, float x1, float x2, float x3, float t ){
|
|
float a, b, c, t2, t3;
|
|
|
|
t2 = t * t;
|
|
t3 = t2 * t;
|
|
|
|
c = 3.0f * ( x1 - x0 );
|
|
b = 3.0f * ( x2 - x1 ) - c;
|
|
a = x3 - x0 - c - b;
|
|
|
|
return a * t3 + b * t2 + c * t + x0;
|
|
}
|
|
|
|
|
|
/*
|
|
======================================================================
|
|
bez2_time()
|
|
|
|
Find the t for which bezier() returns the input time. The handle
|
|
endpoints of a BEZ2 curve represent the control points, and these have
|
|
(time, value) coordinates, so time is used as both a coordinate and a
|
|
parameter for this curve type.
|
|
====================================================================== */
|
|
|
|
static float bez2_time( float x0, float x1, float x2, float x3, float time,
|
|
float *t0, float *t1 ){
|
|
float v, t;
|
|
|
|
t = *t0 + ( *t1 - *t0 ) * 0.5f;
|
|
v = bezier( x0, x1, x2, x3, t );
|
|
if ( fabs( time - v ) > .0001f ) {
|
|
if ( v > time ) {
|
|
*t1 = t;
|
|
}
|
|
else{
|
|
*t0 = t;
|
|
}
|
|
return bez2_time( x0, x1, x2, x3, time, t0, t1 );
|
|
}
|
|
else{
|
|
return t;
|
|
}
|
|
}
|
|
|
|
|
|
/*
|
|
======================================================================
|
|
bez2()
|
|
|
|
Interpolate the value of a BEZ2 curve.
|
|
====================================================================== */
|
|
|
|
static float bez2( lwKey *key0, lwKey *key1, float time ){
|
|
float x, y, t, t0 = 0.0f, t1 = 1.0f;
|
|
|
|
if ( key0->shape == ID_BEZ2 ) {
|
|
x = key0->time + key0->param[ 2 ];
|
|
}
|
|
else{
|
|
x = key0->time + ( key1->time - key0->time ) / 3.0f;
|
|
}
|
|
|
|
t = bez2_time( key0->time, x, key1->time + key1->param[ 0 ], key1->time,
|
|
time, &t0, &t1 );
|
|
|
|
if ( key0->shape == ID_BEZ2 ) {
|
|
y = key0->value + key0->param[ 3 ];
|
|
}
|
|
else{
|
|
y = key0->value + key0->param[ 1 ] / 3.0f;
|
|
}
|
|
|
|
return bezier( key0->value, y, key1->param[ 1 ] + key1->value, key1->value, t );
|
|
}
|
|
|
|
|
|
/*
|
|
======================================================================
|
|
outgoing()
|
|
|
|
Return the outgoing tangent to the curve at key0. The value returned
|
|
for the BEZ2 case is used when extrapolating a linear pre behavior and
|
|
when interpolating a non-BEZ2 span.
|
|
====================================================================== */
|
|
|
|
static float outgoing( lwKey *key0, lwKey *key1 ){
|
|
float a, b, d, t, out;
|
|
|
|
switch ( key0->shape )
|
|
{
|
|
case ID_TCB:
|
|
a = ( 1.0f - key0->tension )
|
|
* ( 1.0f + key0->continuity )
|
|
* ( 1.0f + key0->bias );
|
|
b = ( 1.0f - key0->tension )
|
|
* ( 1.0f - key0->continuity )
|
|
* ( 1.0f - key0->bias );
|
|
d = key1->value - key0->value;
|
|
|
|
if ( key0->prev ) {
|
|
t = ( key1->time - key0->time ) / ( key1->time - key0->prev->time );
|
|
out = t * ( a * ( key0->value - key0->prev->value ) + b * d );
|
|
}
|
|
else{
|
|
out = b * d;
|
|
}
|
|
break;
|
|
|
|
case ID_LINE:
|
|
d = key1->value - key0->value;
|
|
if ( key0->prev ) {
|
|
t = ( key1->time - key0->time ) / ( key1->time - key0->prev->time );
|
|
out = t * ( key0->value - key0->prev->value + d );
|
|
}
|
|
else{
|
|
out = d;
|
|
}
|
|
break;
|
|
|
|
case ID_BEZI:
|
|
case ID_HERM:
|
|
out = key0->param[ 1 ];
|
|
if ( key0->prev ) {
|
|
out *= ( key1->time - key0->time ) / ( key1->time - key0->prev->time );
|
|
}
|
|
break;
|
|
|
|
case ID_BEZ2:
|
|
out = key0->param[ 3 ] * ( key1->time - key0->time );
|
|
if ( fabs( key0->param[ 2 ] ) > 1e-5f ) {
|
|
out /= key0->param[ 2 ];
|
|
}
|
|
else{
|
|
out *= 1e5f;
|
|
}
|
|
break;
|
|
|
|
case ID_STEP:
|
|
default:
|
|
out = 0.0f;
|
|
break;
|
|
}
|
|
|
|
return out;
|
|
}
|
|
|
|
|
|
/*
|
|
======================================================================
|
|
incoming()
|
|
|
|
Return the incoming tangent to the curve at key1. The value returned
|
|
for the BEZ2 case is used when extrapolating a linear post behavior.
|
|
====================================================================== */
|
|
|
|
static float incoming( lwKey *key0, lwKey *key1 ){
|
|
float a, b, d, t, in;
|
|
|
|
switch ( key1->shape )
|
|
{
|
|
case ID_LINE:
|
|
d = key1->value - key0->value;
|
|
if ( key1->next ) {
|
|
t = ( key1->time - key0->time ) / ( key1->next->time - key0->time );
|
|
in = t * ( key1->next->value - key1->value + d );
|
|
}
|
|
else{
|
|
in = d;
|
|
}
|
|
break;
|
|
|
|
case ID_TCB:
|
|
a = ( 1.0f - key1->tension )
|
|
* ( 1.0f - key1->continuity )
|
|
* ( 1.0f + key1->bias );
|
|
b = ( 1.0f - key1->tension )
|
|
* ( 1.0f + key1->continuity )
|
|
* ( 1.0f - key1->bias );
|
|
d = key1->value - key0->value;
|
|
|
|
if ( key1->next ) {
|
|
t = ( key1->time - key0->time ) / ( key1->next->time - key0->time );
|
|
in = t * ( b * ( key1->next->value - key1->value ) + a * d );
|
|
}
|
|
else{
|
|
in = a * d;
|
|
}
|
|
break;
|
|
|
|
case ID_BEZI:
|
|
case ID_HERM:
|
|
in = key1->param[ 0 ];
|
|
if ( key1->next ) {
|
|
in *= ( key1->time - key0->time ) / ( key1->next->time - key0->time );
|
|
}
|
|
break;
|
|
return in;
|
|
|
|
case ID_BEZ2:
|
|
in = key1->param[ 1 ] * ( key1->time - key0->time );
|
|
if ( fabs( key1->param[ 0 ] ) > 1e-5f ) {
|
|
in /= key1->param[ 0 ];
|
|
}
|
|
else{
|
|
in *= 1e5f;
|
|
}
|
|
break;
|
|
|
|
case ID_STEP:
|
|
default:
|
|
in = 0.0f;
|
|
break;
|
|
}
|
|
|
|
return in;
|
|
}
|
|
|
|
|
|
/*
|
|
======================================================================
|
|
evalEnvelope()
|
|
|
|
Given a list of keys and a time, returns the interpolated value of the
|
|
envelope at that time.
|
|
====================================================================== */
|
|
|
|
float evalEnvelope( lwEnvelope *env, float time ){
|
|
lwKey *key0, *key1, *skey, *ekey;
|
|
float t, h1, h2, h3, h4, in, out, offset = 0.0f;
|
|
int noff;
|
|
|
|
|
|
/* if there's no key, the value is 0 */
|
|
|
|
if ( env->nkeys == 0 ) {
|
|
return 0.0f;
|
|
}
|
|
|
|
/* if there's only one key, the value is constant */
|
|
|
|
if ( env->nkeys == 1 ) {
|
|
return env->key->value;
|
|
}
|
|
|
|
/* find the first and last keys */
|
|
|
|
skey = ekey = env->key;
|
|
while ( ekey->next ) ekey = ekey->next;
|
|
|
|
/* use pre-behavior if time is before first key time */
|
|
|
|
if ( time < skey->time ) {
|
|
switch ( env->behavior[ 0 ] )
|
|
{
|
|
case BEH_RESET:
|
|
return 0.0f;
|
|
|
|
case BEH_CONSTANT:
|
|
return skey->value;
|
|
|
|
case BEH_REPEAT:
|
|
time = range( time, skey->time, ekey->time, NULL );
|
|
break;
|
|
|
|
case BEH_OSCILLATE:
|
|
time = range( time, skey->time, ekey->time, &noff );
|
|
if ( noff % 2 ) {
|
|
time = ekey->time - skey->time - time;
|
|
}
|
|
break;
|
|
|
|
case BEH_OFFSET:
|
|
time = range( time, skey->time, ekey->time, &noff );
|
|
offset = noff * ( ekey->value - skey->value );
|
|
break;
|
|
|
|
case BEH_LINEAR:
|
|
out = outgoing( skey, skey->next )
|
|
/ ( skey->next->time - skey->time );
|
|
return out * ( time - skey->time ) + skey->value;
|
|
}
|
|
}
|
|
|
|
/* use post-behavior if time is after last key time */
|
|
|
|
else if ( time > ekey->time ) {
|
|
switch ( env->behavior[ 1 ] )
|
|
{
|
|
case BEH_RESET:
|
|
return 0.0f;
|
|
|
|
case BEH_CONSTANT:
|
|
return ekey->value;
|
|
|
|
case BEH_REPEAT:
|
|
time = range( time, skey->time, ekey->time, NULL );
|
|
break;
|
|
|
|
case BEH_OSCILLATE:
|
|
time = range( time, skey->time, ekey->time, &noff );
|
|
if ( noff % 2 ) {
|
|
time = ekey->time - skey->time - time;
|
|
}
|
|
break;
|
|
|
|
case BEH_OFFSET:
|
|
time = range( time, skey->time, ekey->time, &noff );
|
|
offset = noff * ( ekey->value - skey->value );
|
|
break;
|
|
|
|
case BEH_LINEAR:
|
|
in = incoming( ekey->prev, ekey )
|
|
/ ( ekey->time - ekey->prev->time );
|
|
return in * ( time - ekey->time ) + ekey->value;
|
|
}
|
|
}
|
|
|
|
/* get the endpoints of the interval being evaluated */
|
|
|
|
key0 = env->key;
|
|
while ( time > key0->next->time )
|
|
key0 = key0->next;
|
|
key1 = key0->next;
|
|
|
|
/* check for singularities first */
|
|
|
|
if ( time == key0->time ) {
|
|
return key0->value + offset;
|
|
}
|
|
else if ( time == key1->time ) {
|
|
return key1->value + offset;
|
|
}
|
|
|
|
/* get interval length, time in [0, 1] */
|
|
|
|
t = ( time - key0->time ) / ( key1->time - key0->time );
|
|
|
|
/* interpolate */
|
|
|
|
switch ( key1->shape )
|
|
{
|
|
case ID_TCB:
|
|
case ID_BEZI:
|
|
case ID_HERM:
|
|
out = outgoing( key0, key1 );
|
|
in = incoming( key0, key1 );
|
|
hermite( t, &h1, &h2, &h3, &h4 );
|
|
return h1 * key0->value + h2 * key1->value + h3 * out + h4 * in + offset;
|
|
|
|
case ID_BEZ2:
|
|
return bez2( key0, key1, time ) + offset;
|
|
|
|
case ID_LINE:
|
|
return key0->value + t * ( key1->value - key0->value ) + offset;
|
|
|
|
case ID_STEP:
|
|
return key0->value + offset;
|
|
|
|
default:
|
|
return offset;
|
|
}
|
|
}
|