rocket/sync/track.c
Erik Faye-Lund 739fc21cfd player: return interpolated value as double
The heavy lifting was already done in double precision, so just
return the full value to the user without truncating to float.
2012-10-19 17:10:57 +02:00

129 lines
2.9 KiB
C

/* Copyright (C) 2010 Erik Faye-Lund and Egbert Teeselink
* For conditions of distribution and use, see copyright notice in COPYING
*/
#include <stdlib.h>
#include <assert.h>
#include <math.h>
#ifndef M_PI
#define M_PI 3.141926
#endif
#include "sync.h"
#include "track.h"
#include "base.h"
static double key_linear(const struct track_key k[2], double row)
{
double t = (row - k[0].row) / (k[1].row - k[0].row);
return k[0].value + (k[1].value - k[0].value) * t;
}
static double key_smooth(const struct track_key k[2], double row)
{
double t = (row - k[0].row) / (k[1].row - k[0].row);
t = t * t * (3 - 2 * t);
return k[0].value + (k[1].value - k[0].value) * t;
}
static double key_ramp(const struct track_key k[2], double row)
{
double t = (row - k[0].row) / (k[1].row - k[0].row);
t = pow(t, 2.0);
return k[0].value + (k[1].value - k[0].value) * t;
}
double sync_get_val(const struct sync_track *t, double row)
{
int idx, irow;
/* If we have no keys at all, return a constant 0 */
if (!t->num_keys)
return 0.0f;
irow = (int)floor(row);
idx = key_idx_floor(t, irow);
/* at the edges, return the first/last value */
if (idx < 0)
return t->keys[0].value;
if (idx > (int)t->num_keys - 2)
return t->keys[t->num_keys - 1].value;
/* interpolate according to key-type */
switch (t->keys[idx].type) {
case KEY_STEP:
return t->keys[idx].value;
case KEY_LINEAR:
return key_linear(t->keys + idx, row);
case KEY_SMOOTH:
return key_smooth(t->keys + idx, row);
case KEY_RAMP:
return key_ramp(t->keys + idx, row);
default:
assert(0);
return 0.0f;
}
}
int sync_find_key(const struct sync_track *t, int row)
{
int lo = 0, hi = t->num_keys;
/* binary search, t->keys is sorted by row */
while (lo < hi) {
int mi = (lo + hi) / 2;
assert(mi != hi);
if (t->keys[mi].row < row)
lo = mi + 1;
else if (t->keys[mi].row > row)
hi = mi;
else
return mi; /* exact hit */
}
assert(lo == hi);
/* return first key after row, negated and biased (to allow -0) */
return -lo - 1;
}
#ifndef SYNC_PLAYER
int sync_set_key(struct sync_track *t, const struct track_key *k)
{
int idx = sync_find_key(t, k->row);
if (idx < 0) {
/* no exact hit, we need to allocate a new key */
void *tmp;
idx = -idx - 1;
tmp = realloc(t->keys, sizeof(struct track_key) *
(t->num_keys + 1));
if (!tmp)
return -1;
t->num_keys++;
t->keys = tmp;
memmove(t->keys + idx + 1, t->keys + idx,
sizeof(struct track_key) * (t->num_keys - idx - 1));
}
t->keys[idx] = *k;
return 0;
}
int sync_del_key(struct sync_track *t, int pos)
{
void *tmp;
int idx = sync_find_key(t, pos);
assert(idx >= 0);
memmove(t->keys + idx, t->keys + idx + 1,
sizeof(struct track_key) * (t->num_keys - idx - 1));
assert(t->keys);
tmp = realloc(t->keys, sizeof(struct track_key) *
(t->num_keys - 1));
if (t->num_keys != 1 && !tmp)
return -1;
t->num_keys--;
t->keys = tmp;
return 0;
}
#endif