+++ /dev/null
-/*
-======================================================================
-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 *) 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, (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;
- }
-}
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