/* This file is part of Evoral.
- * Copyright (C) 2008 Dave Robillard <http://drobilla.net>
+ * Copyright (C) 2008 David Robillard <http://drobilla.net>
* Copyright (C) 2000-2008 Paul Davis
- *
+ *
* Evoral is free software; you can redistribute it and/or modify it under the
* terms of the GNU General Public License as published by the Free Software
* Foundation; either version 2 of the License, or (at your option) any later
* version.
- *
+ *
* Evoral is distributed in the hope that it will be useful, but WITHOUT ANY
* WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
* FOR A PARTICULAR PURPOSE. See the GNU General Public License for details.
- *
+ *
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
if (!_dirty) {
return;
}
-
+
if ((npoints = _list.events().size()) > 2) {
-
+
/* Compute coefficients needed to efficiently compute a constrained spline
curve. See "Constrained Cubic Spline Interpolation" by CJC Kruger
(www.korf.co.uk/spline.pdf) for more details.
double fplast = 0;
for (i = 0, xx = _list.events().begin(); xx != _list.events().end(); ++xx, ++i) {
-
+
double xdelta; /* gcc is wrong about possible uninitialized use */
double xdelta2; /* ditto */
double ydelta; /* ditto */
}
/* compute (constrained) first derivatives */
-
+
if (i == 0) {
/* first segment */
-
+
fplast = ((3 * (y[1] - y[0]) / (2 * (x[1] - x[0]))) - (fpone * 0.5));
/* we don't store coefficients for i = 0 */
/* last segment */
fpi = ((3 * ydelta) / (2 * xdelta)) - (fplast * 0.5);
-
+
} else {
/* all other segments */
} else {
fpi = 2 / (slope_before + slope_after);
}
-
+
}
/* compute second derivative for either side of control point `i' */
-
+
fppL = (((-2 * (fpi + (2 * fplast))) / (xdelta))) +
((6 * ydelta) / xdelta2);
-
+
fppR = (2 * ((2 * fpi) + fplast) / xdelta) -
((6 * ydelta) / xdelta2);
-
+
/* compute polynomial coefficients */
double b, c, d;
- d = (fppR - fppL) / (6 * xdelta);
+ d = (fppR - fppL) / (6 * xdelta);
c = ((x[i] * fppL) - (x[i-1] * fppR))/(2 * xdelta);
-
+
double xim12, xim13;
double xi2, xi3;
-
+
xim12 = x[i-1] * x[i-1]; /* "x[i-1] squared" */
xim13 = xim12 * x[i-1]; /* "x[i-1] cubed" */
xi2 = x[i] * x[i]; /* "x[i] squared" */
xi3 = xi2 * x[i]; /* "x[i] cubed" */
-
+
b = (ydelta - (c * (xi2 - xim12)) - (d * (xi3 - xim13))) / xdelta;
/* store */
fplast = fpi;
}
-
+
}
_dirty = false;
if (x0 < min_x) {
- /* fill some beginning section of the array with the
- initial (used to be default) value
+ /* fill some beginning section of the array with the
+ initial (used to be default) value
*/
double frac = (min_x - x0) / (x1 - x0);
int32_t subveclen = (int32_t) floor (veclen * frac);
-
+
subveclen = min (subveclen, veclen);
for (i = 0; i < subveclen; ++i) {
int32_t subveclen = (int32_t) floor (original_veclen * frac);
float val;
-
+
subveclen = min (subveclen, veclen);
val = _list.events().back()->value;
return;
}
- if (npoints == 1 ) {
-
- for (i = 0; i < veclen; ++i) {
- vec[i] = _list.events().front()->value;
- }
- return;
- }
-
-
- if (npoints == 2) {
-
- /* linear interpolation between 2 points */
-
- /* XXX I'm not sure that this is the right thing to
- do here. but its not a common case for the envisaged
- uses.
- */
-
- if (veclen > 1) {
- dx = (hx - lx) / (veclen - 1) ;
- } else {
- dx = 0; // not used
- }
-
- double slope = (_list.events().back()->value - _list.events().front()->value)/
+ if (npoints == 1) {
+
+ for (i = 0; i < veclen; ++i) {
+ vec[i] = _list.events().front()->value;
+ }
+ return;
+ }
+
+
+ if (npoints == 2) {
+
+ /* linear interpolation between 2 points */
+
+ /* XXX I'm not sure that this is the right thing to
+ do here. but its not a common case for the envisaged
+ uses.
+ */
+
+ if (veclen > 1) {
+ dx = (hx - lx) / (veclen - 1) ;
+ } else {
+ dx = 0; // not used
+ }
+
+ double slope = (_list.events().back()->value - _list.events().front()->value)/
(_list.events().back()->when - _list.events().front()->when);
- double yfrac = dx*slope;
-
- vec[0] = _list.events().front()->value + slope * (lx - _list.events().front()->when);
-
- for (i = 1; i < veclen; ++i) {
- vec[i] = vec[i-1] + yfrac;
- }
-
- return;
- }
-
+ double yfrac = dx*slope;
+
+ vec[0] = _list.events().front()->value + slope * (lx - _list.events().front()->when);
+
+ for (i = 1; i < veclen; ++i) {
+ vec[i] = vec[i-1] + yfrac;
+ }
+
+ return;
+ }
+
if (_dirty) {
solve ();
}
rx = lx;
if (veclen > 1) {
+ dx = (hx - lx) / (veclen - 1);
+ } else {
+ dx = 0;
+ }
- dx = (hx - lx) / (veclen-1);
-
- for (i = 0; i < veclen; ++i, rx += dx) {
- vec[i] = multipoint_eval (rx);
- }
+ for (i = 0; i < veclen; ++i, rx += dx) {
+ vec[i] = multipoint_eval (rx);
}
}
double
Curve::multipoint_eval (double x)
-{
+{
pair<ControlList::EventList::const_iterator,ControlList::EventList::const_iterator> range;
ControlList::LookupCache& lookup_cache = _list.lookup_cache();
if ((lookup_cache.left < 0) ||
- ((lookup_cache.left > x) ||
- (lookup_cache.range.first == _list.events().end()) ||
+ ((lookup_cache.left > x) ||
+ (lookup_cache.range.first == _list.events().end()) ||
((*lookup_cache.range.second)->when < x))) {
-
+
ControlEvent cp (x, 0.0);
lookup_cache.range = equal_range (_list.events().begin(), _list.events().end(), &cp, ControlList::time_comparator);
range = lookup_cache.range;
- /* EITHER
-
+ /* EITHER
+
a) x is an existing control point, so first == existing point, second == next point
OR
b) x is between control points, so range is empty (first == second, points to where
to insert x)
-
+
*/
if (range.first == range.second) {
/* x does not exist within the list as a control point */
-
+
lookup_cache.left = x;
if (range.first == _list.events().begin()) {
// return default_value;
_list.events().front()->value;
}
-
+
if (range.second == _list.events().end()) {
/* we're after the last point */
return _list.events().back()->value;
ControlEvent* ev = *range.second;
return ev->coeff[0] + (ev->coeff[1] * x) + (ev->coeff[2] * x2) + (ev->coeff[3] * x2 * x);
- }
+ }
/* x is a control point in the data */
/* invalidate the cached range because its not usable */
extern "C" {
-void
+void
curve_get_vector_from_c (void *arg, double x0, double x1, float* vec, int32_t vecsize)
{
static_cast<Evoral::Curve*>(arg)->get_vector (x0, x1, vec, vecsize);
projects / ardour.git / blobdiff