fontconfig/src/fcweight.c

104 lines
2.8 KiB
C

/*
* fontconfig/src/fcweight.c
*
* Permission to use, copy, modify, distribute, and sell this software and its
* documentation for any purpose is hereby granted without fee, provided that
* the above copyright notice appear in all copies and that both that
* copyright notice and this permission notice appear in supporting
* documentation, and that the name of the author(s) not be used in
* advertising or publicity pertaining to distribution of the software without
* specific, written prior permission. The authors make no
* representations about the suitability of this software for any purpose. It
* is provided "as is" without express or implied warranty.
*
* THE AUTHOR(S) DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
* INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
* EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY SPECIAL, INDIRECT OR
* CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
* DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
* TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
* PERFORMANCE OF THIS SOFTWARE.
*/
#include "fcint.h"
static const struct {
int ot;
int fc;
} map[] = {
{ 0, FC_WEIGHT_THIN },
{ 100, FC_WEIGHT_THIN },
{ 200, FC_WEIGHT_EXTRALIGHT },
{ 300, FC_WEIGHT_LIGHT },
{ 350, FC_WEIGHT_DEMILIGHT },
{ 380, FC_WEIGHT_BOOK },
{ 400, FC_WEIGHT_REGULAR },
{ 500, FC_WEIGHT_MEDIUM },
{ 600, FC_WEIGHT_DEMIBOLD },
{ 700, FC_WEIGHT_BOLD },
{ 800, FC_WEIGHT_EXTRABOLD },
{ 900, FC_WEIGHT_BLACK },
{1000, FC_WEIGHT_EXTRABLACK },
};
static double lerp(double x, int x1, int x2, int y1, int y2)
{
int dx = x2 - x1;
int dy = y2 - y1;
assert (dx > 0 && dy >= 0 && x1 <= x && x <= x2);
return y1 + (x-x1) * dy / dx;
}
double
FcWeightFromOpenTypeDouble (double ot_weight)
{
int i;
if (ot_weight < 0)
return -1;
ot_weight = FC_MIN (ot_weight, map[(sizeof (map) / sizeof (map[0])) - 1].ot);
for (i = 1; ot_weight > map[i].ot; i++)
;
if (ot_weight == map[i].ot)
return map[i].fc;
/* Interpolate between two items. */
return lerp (ot_weight, map[i-1].ot, map[i].ot, map[i-1].fc, map[i].fc);
}
double
FcWeightToOpenTypeDouble (double fc_weight)
{
int i;
if (fc_weight < 0 || fc_weight > FC_WEIGHT_EXTRABLACK)
return -1;
for (i = 1; fc_weight > map[i].fc; i++)
;
if (fc_weight == map[i].fc)
return map[i].ot;
/* Interpolate between two items. */
return lerp (fc_weight, map[i-1].fc, map[i].fc, map[i-1].ot, map[i].ot);
}
int
FcWeightFromOpenType (int ot_weight)
{
return FcWeightFromOpenTypeDouble (ot_weight) + .5;
}
int
FcWeightToOpenType (int fc_weight)
{
return FcWeightToOpenTypeDouble (fc_weight) + .5;
}
#define __fcweight__
#include "fcaliastail.h"
#undef __fcweight__