/* Fold up x into bands.

 *

 * 5/6/15

 *  - from copy.c

 * 10/6/15

 *  - add @factor option

 */

/*

  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., 51 Franklin Street, Fifth Floor, Boston, MA

  02110-1301  USA

 */

/*

  These files are distributed with VIPS - http://www.vips.ecs.soton.ac.uk

 */

/*

#define VIPS_DEBUG

 */

#ifdef HAVE_CONFIG_H

#include <config.h>

#endif /*HAVE_CONFIG_H*/

#include <glib/gi18n-lib.h>

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include <math.h>

#include <vips/vips.h>

#include <vips/internal.h>

#include <vips/debug.h>

#include "pconversion.h"

typedef struct _VipsBandunfold {

  VipsConversion parent_instance;

  /* The input image.

   */

  VipsImage *in;

  int factor;

} VipsBandunfold;

typedef VipsConversionClass VipsBandunfoldClass;

G_DEFINE_TYPE(VipsBandunfold, vips_bandunfold, VIPS_TYPE_CONVERSION);

static int

vips_bandunfold_gen(VipsRegion *out_region,

  void *seq, void *a, void *b, gboolean *stop)

{

  VipsBandunfold *bandunfold = (VipsBandunfold *) b;

  VipsRegion *ir = (VipsRegion *) seq;

  VipsImage *in = ir->im;

  VipsImage *out = out_region->im;

  VipsRect *r = &out_region->valid;

  int esize = VIPS_IMAGE_SIZEOF_ELEMENT(in);

  int psize = VIPS_IMAGE_SIZEOF_PEL(out);

  VipsRect need;

  int y;

  need.left = r->left / bandunfold->factor;

  need.top = r->top;

  need.width = 1 + VIPS_RECT_RIGHT(r) / bandunfold->factor - need.left;

  need.height = r->height;

  if (vips_region_prepare(ir, &need))

    return -1;

  for (y = 0; y < r->height; y++) {

    VipsPel *p = VIPS_REGION_ADDR(ir,

             r->left / bandunfold->factor, r->top + y) +

      (r->left % bandunfold->factor) * esize;

    VipsPel *q = VIPS_REGION_ADDR(out_region, r->left, r->top + y);

    /* We can't use vips_region_region() since we change pixel

     * coordinates.

     */

    memcpy(q, p, (size_t) r->width * psize);

  }

  return 0;

}

static int

vips_bandunfold_build(VipsObject *object)

{

  VipsObjectClass *class = VIPS_OBJECT_GET_CLASS(object);

  VipsConversion *conversion = VIPS_CONVERSION(object);

  VipsBandunfold *bandunfold = (VipsBandunfold *) object;

  VipsImage **t = (VipsImage **) vips_object_local_array(object, 1);

  VipsImage *in;

  if (VIPS_OBJECT_CLASS(vips_bandunfold_parent_class)->build(object))

    return -1;

  in = bandunfold->in;

  if (vips_image_decode(in, &t[0]))

    return -1;

  in = t[0];

  if (bandunfold->factor == 0)

    bandunfold->factor = in->Bands; // FIXME: Invalidates operation cache

  if (in->Bands % bandunfold->factor != 0) {

    vips_error(class->nickname,

      "%s", _("@factor must be a factor of image bands"));

    return -1;

  }

  if (vips_image_pipelinev(conversion->out,

      VIPS_DEMAND_STYLE_THINSTRIP, in, NULL))

    return -1;

  conversion->out->Xsize *= bandunfold->factor;

  conversion->out->Bands /= bandunfold->factor;

  if (vips_image_generate(conversion->out,

      vips_start_one, vips_bandunfold_gen, vips_stop_one,

      in, bandunfold))

    return -1;

  return 0;

}

static void

vips_bandunfold_class_init(VipsBandunfoldClass *class)

{

  GObjectClass *gobject_class = G_OBJECT_CLASS(class);

  VipsObjectClass *vobject_class = VIPS_OBJECT_CLASS(class);

  VipsOperationClass *operation_class = VIPS_OPERATION_CLASS(class);

  VIPS_DEBUG_MSG("vips_bandunfold_class_init\n");

  gobject_class->set_property = vips_object_set_property;

  gobject_class->get_property = vips_object_get_property;

  vobject_class->nickname = "bandunfold";

  vobject_class->description = _("unfold image bands into x axis");

  vobject_class->build = vips_bandunfold_build;

  operation_class->flags = VIPS_OPERATION_SEQUENTIAL;

  VIPS_ARG_IMAGE(class, "in", 1,

    _("Input"),

    _("Input image"),

    VIPS_ARGUMENT_REQUIRED_INPUT,

    G_STRUCT_OFFSET(VipsBandunfold, in));

  VIPS_ARG_INT(class, "factor", 11,

    _("Factor"),

    _("Unfold by this factor"),

    VIPS_ARGUMENT_OPTIONAL_INPUT,

    G_STRUCT_OFFSET(VipsBandunfold, factor),

    0, 10000000, 0);

}

static void

vips_bandunfold_init(VipsBandunfold *bandunfold)

{

  /* 0 means unfold by width, see above.

   */

  bandunfold->factor = 0;

}

/**

 * vips_bandunfold: (method)

 * @in: input image

 * @out: (out): output image

 * @...: `NULL`-terminated list of optional named arguments

 *

 * Unfold image bands into x axis.

 * Use @factor to set how much to unfold by: @factor 3, for example, will make

 * the output image three times wider than the input, and with one third

 * as many bands. By default, all bands are unfolded.

 *

 * ::: tip "Optional arguments"

 *     * @factor: `gint`, unfold by this factor

 *

 * ::: seealso

 *     [ctor@Image.csvload], [method@Image.bandfold].

 *

 * Returns: 0 on success, -1 on error.

 */

int

vips_bandunfold(VipsImage *in, VipsImage **out, ...)

{

  va_list ap;

  int result;

  va_start(ap, out);

  result = vips_call_split("bandunfold", ap, in, out);

  va_end(ap);

  return result;

}