/* babl - dynamically extendable universal pixel conversion library.
 * Copyright (C) 2005, Øyvind Kolås.
 *
 * This library 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 3 of the License, or (at your option) any later version.
 *
 * This library 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 library; if not, see
 * <http://www.gnu.org/licenses/>.
 */

#include "config.h"
#include <string.h>
#include <stdint.h>
#include <assert.h>
#include <math.h>

#include "babl-internal.h"
#include "babl-base.h"


static inline void
convert_double_u15_scaled (BablConversion *conversion,
                           double          min_val,
                           double          max_val,
                           uint16_t        min,
                           uint16_t        max,
                           char           *src,
                           char           *dst,
                           int             src_pitch,
                           int             dst_pitch,
                           long            n)
{
  while (n--)
    {
      double   dval = *(double *) src;
      uint16_t u15val;

      if (dval < min_val)
        u15val = min;
      else if (dval > max_val)
        u15val = max;
      else
        u15val = rint ((dval - min_val) / (max_val - min_val) * (max - min) + min);

      *(uint16_t *) dst = u15val;
      dst              += dst_pitch;
      src              += src_pitch;
    }
}

static inline void
convert_u15_double_scaled (BablConversion *conversion,
                           double          min_val,
                           double          max_val,
                           uint16_t min,
                           uint16_t max,
                           char    *src,
                           char    *dst,
                           int      src_pitch,
                           int      dst_pitch,
                           long     n)
{
  while (n--)
    {
      int    u15val = *(uint16_t *) src;
      double dval;

      if (u15val < min)
        dval = min_val;
      else if (u15val > max)
        dval = max_val;
      else
        dval = (u15val - min) / (double) (max - min) * (max_val - min_val) + min_val;

      (*(double *) dst) = dval;
      dst              += dst_pitch;
      src              += src_pitch;
    }
}

#define MAKE_CONVERSIONS(name, min_val, max_val, min, max)      \
  static void \
  convert_ ## name ## _double (BablConversion *conversion, \
                               void *src, \
                               void *dst, \
                               int src_pitch, \
                               int dst_pitch, \
                               long n)                               \
  { \
    convert_u15_double_scaled (conversion, min_val, max_val, min, max, \
                               src, dst, src_pitch, dst_pitch, n); \
  }                                                               \
  static void \
  convert_double_ ## name (BablConversion *conversion, void *src, \
                           void *dst, \
                           int src_pitch, \
                           int dst_pitch, \
                           long n)                                 \
  { \
    convert_double_u15_scaled (conversion, min_val, max_val, min, max, \
                               src, dst, src_pitch, dst_pitch, n); \
  }

MAKE_CONVERSIONS (u15, 0.0, 1.0, 0, (1<<15))

void
babl_base_type_u15 (void)
{
  babl_hmpf_on_name_lookups--;
  babl_type_new (
    "u15",
    "bits", 16,
    NULL);

  babl_conversion_new (
    babl_type ("u15"),
    babl_type_from_id (BABL_DOUBLE),
    "plane", convert_u15_double,
    NULL
  );

  babl_conversion_new (
    babl_type_from_id (BABL_DOUBLE),
    babl_type ("u15"),
    "plane", convert_double_u15,
    NULL
  );
  babl_hmpf_on_name_lookups++;
}
