libvips/libsrc/mosaicing/templates.h

136 lines
3.5 KiB
C++

/* various interpolation templates
*/
/*
This file is part of VIPS.
VIPS is free software; you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program 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 Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
/*
These files are distributed with VIPS - http://www.vips.ecs.soton.ac.uk
*/
/* "fast" floor() ... on my laptop, anyway.
*/
#define FLOOR( V ) ((V) >= 0 ? (int)(V) : (int)((V) - 1))
#ifndef restrict
#ifdef __restrict
#define restrict __restrict
#else
#ifdef __restrict__
#define restrict __restrict__
#else
#define restrict
#endif
#endif
#endif
/* Fixed-point integer bicubic, used for 8 and 16-bit types.
*/
template <typename T> static int inline
bicubic_int(
const T uno_one, const T uno_two, const T uno_thr, const T uno_fou,
const T dos_one, const T dos_two, const T dos_thr, const T dos_fou,
const T tre_one, const T tre_two, const T tre_thr, const T tre_fou,
const T qua_one, const T qua_two, const T qua_thr, const T qua_fou,
const int *cx, const int *cy )
{
const int r0 =
(cx[0] * uno_one +
cx[1] * uno_two +
cx[2] * uno_thr +
cx[3] * uno_fou) >> VIPS_INTERPOLATE_SHIFT;
const int r1 =
(cx[0] * dos_one +
cx[1] * dos_two +
cx[2] * dos_thr +
cx[3] * dos_fou) >> VIPS_INTERPOLATE_SHIFT;
const int r2 =
(cx[0] * tre_one +
cx[1] * tre_two +
cx[2] * tre_thr +
cx[3] * tre_fou) >> VIPS_INTERPOLATE_SHIFT;
const int r3 =
(cx[0] * qua_one +
cx[1] * qua_two +
cx[2] * qua_thr +
cx[3] * qua_fou) >> VIPS_INTERPOLATE_SHIFT;
return( (cy[0] * r0 +
cy[1] * r1 +
cy[2] * r2 +
cy[3] * r3) >> VIPS_INTERPOLATE_SHIFT );
}
/* Floating-point bicubic, used for int/float/double types.
*/
template <typename T> static T inline
bicubic_float(
const T uno_one, const T uno_two, const T uno_thr, const T uno_fou,
const T dos_one, const T dos_two, const T dos_thr, const T dos_fou,
const T tre_one, const T tre_two, const T tre_thr, const T tre_fou,
const T qua_one, const T qua_two, const T qua_thr, const T qua_fou,
const double *cx, const double *cy )
{
return(
cy[0] * (cx[0] * uno_one +
cx[1] * uno_two +
cx[2] * uno_thr +
cx[3] * uno_fou) +
cy[1] * (cx[0] * dos_one +
cx[1] * dos_two +
cx[2] * dos_thr +
cx[3] * dos_fou) +
cy[2] * (cx[0] * tre_one +
cx[1] * tre_two +
cx[2] * tre_thr +
cx[3] * tre_fou) +
cy[3] * (cx[0] * qua_one +
cx[1] * qua_two +
cx[2] * qua_thr +
cx[3] * qua_fou) );
}
/* Given an offset in [0,1] (we can have x == 1 when building tables),
* calculate c0, c1, c2, c3, the catmull-rom coefficients. This is called
* from the interpolator, as well as from the table builder.
*/
static void inline
calculate_coefficients_catmull( const double x, double c[4] )
{
const double dx = 1.f - x;
const double x2 = dx * x;
const double mx2 = -.5f * x2;
g_assert( x >= 0 && x <= 1 );
c[0] = mx2 * dx;
c[1] = x2 * (-1.5f * x + 1.f) + dx;
c[2] = 1.f - (mx2 + c[1]);
c[3] = mx2 * x;
}