/*

 * 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 + (dy*(x-x1) + dx/2) / 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__