/* This file is an image processing operation for GEGL

 *

 * GEGL 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.

 *

 * GEGL 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 GEGL; if not, see <http://www.gnu.org/licenses/>.

 *

 * Copyright 2007 Øyvind Kolås <pippin@gimp.org>

 */

#include "config.h"

#include <glib/gi18n-lib.h>

#ifdef GEGL_CHANT_PROPERTIES

gegl_chant_int (x0, _("X0"), 0, 1000, 0, _("Start x coordinate"))

gegl_chant_int (x1, _("X1"), 0, 1000, 200, _("End x coordinate"))

gegl_chant_int (y0, _("Y0"), 0, 1000, 0, _("Start y coordinate"))

gegl_chant_int (y1, _("Y1"), 0, 1000, 200, _("End y coordinate"))

gegl_chant_int (width,  _("Width"),  10, 10000, 1024, _("Width of plot"))

gegl_chant_int (height, _("Height"), 10, 10000, 256,  _("Height of plot"))

gegl_chant_double (min, _("Min"), -500.0, 500,  0.0, _("Value at bottom"))

gegl_chant_double (max, _("Max"), -500.0, 500,  8.0, _("Value at top"))

#else

#define GEGL_CHANT_TYPE_FILTER

#define GEGL_CHANT_C_FILE       "line-profile.c"

#include "gegl-chant.h"

#include <cairo.h>

static gfloat

buffer_sample (GeglBuffer *buffer,

               gint        x,

               gint        y,

               gint        component)

{

  gfloat rgba[4];

  GeglRectangle roi = {x,y,1,1};

  gegl_buffer_get (buffer, &roi, 1.0, babl_format ("RGBA float"), &rgba[0], GEGL_AUTO_ROWSTRIDE, GEGL_ABYSS_NONE);

  return rgba[component];

}

static gboolean

process (GeglOperation       *operation,

         GeglBuffer          *input,

         GeglBuffer          *output,

         const GeglRectangle *result,

         gint                 level)

{

  GeglChantO *o = GEGL_CHANT_PROPERTIES (operation);

  gint        width = MAX(MAX (o->width, o->x0), o->x1);

  gint        height = MAX(MAX (o->height, o->y0), o->y1);

  {

    GeglRectangle extent = {0,0,width,height};

    output = gegl_buffer_new (&extent, babl_format ("B'aG'aR'aA u8"));

  }

  {

    guchar  *buf = g_new0 (guchar, width * height * 4);

    cairo_t *cr;

    cairo_surface_t *surface = cairo_image_surface_create_for_data (buf, CAIRO_FORMAT_ARGB32, width, height, width * 4);

    cr = cairo_create (surface);

  /*  cairo_set_source_rgba (cr, 0.0, 0.0, 0.0, 1.0);

    cairo_rectangle (cr, 0,0, o->width, o->height);

    cairo_fill (cr);*/

#define val2y(val) (o->height - (val - o->min) * o->height / (o->max-o->min))

    cairo_set_source_rgba (cr, .0, .0, .8, 0.5);

    cairo_move_to (cr, 0, val2y(0.0));

    cairo_line_to (cr, o->width, val2y(0.0));

    cairo_set_source_rgba (cr, .8, .8, .0, 0.5);

    cairo_move_to (cr, 0, val2y(1.0));

    cairo_line_to (cr, o->width, val2y(1.0));

    cairo_stroke (cr);

    cairo_set_line_join (cr, CAIRO_LINE_JOIN_ROUND);

    {

      gint x;

      cairo_set_source_rgba (cr, 1.0, 0.0, 0.0, 1.0);

      for (x=0;x<o->width;x++)

        {

          gfloat t = (1.0*x)/o->width;

          gint sx = ((1.0-t) * o->x0) + (t * o->x1);

          gint sy = ((1.0-t) * o->y0) + (t * o->y1);

          cairo_line_to (cr, x, val2y(buffer_sample(input,sx,sy,0)));

        }

      cairo_stroke (cr);

    }

    {

      gint x;

      cairo_set_source_rgba (cr, 0.0, 1.0, 0.0, 1.0);

      for (x=0;x<o->width;x++)

        {

          gfloat t = (1.0*x)/o->width;

          gint sx = ((1.0-t) * o->x0) + (t * o->x1);

          gint sy = ((1.0-t) * o->y0) + (t * o->y1);

          cairo_line_to (cr, x, val2y(buffer_sample(input,sx,sy,1)));

        }

      cairo_stroke (cr);

    }

    {

      gint x;

      cairo_set_source_rgba (cr, 0.0, 0.0, 1.0, 1.0);

      for (x=0;x<o->width;x++)

        {

          gfloat t = (1.0*x)/o->width;

          gint sx = ((1.0-t) * o->x0) + (t * o->x1);

          gint sy = ((1.0-t) * o->y0) + (t * o->y1);

          cairo_line_to (cr, x, val2y(buffer_sample(input,sx,sy,2)));

        }

      cairo_stroke (cr);

    }

   cairo_set_source_rgba (cr, 1.0, 0.0, 0.0, 0.4);

   cairo_move_to (cr, o->x0, o->y0);

   cairo_line_to (cr, o->x1, o->y1);

   cairo_stroke (cr);

    gegl_buffer_set (output, NULL, 0, babl_format ("B'aG'aR'aA u8"), buf, GEGL_AUTO_ROWSTRIDE);

  }

  return TRUE;

}

static GeglRectangle

get_required_for_output (GeglOperation        *self,

                         const gchar         *input_pad,

                         const GeglRectangle *roi)

{

  return *gegl_operation_source_get_bounding_box (self, "input");

}

static GeglRectangle

get_bounding_box (GeglOperation *operation)

{

  GeglChantO   *o = GEGL_CHANT_PROPERTIES (operation);

  GeglRectangle defined = {0,0,o->width,o->height};

  defined.width  = MAX (MAX (o->width,  o->x0), o->x1);

  defined.height = MAX (MAX (o->height, o->y0), o->y1);

  return defined;

}

static void

gegl_chant_class_init (GeglChantClass *klass)

{

  GeglOperationClass       *operation_class;

  GeglOperationFilterClass *filter_class;

  operation_class = GEGL_OPERATION_CLASS (klass);

  filter_class    = GEGL_OPERATION_FILTER_CLASS (klass);

  filter_class->process = process;

  operation_class->get_required_for_output = get_required_for_output;

  operation_class->get_bounding_box = get_bounding_box;

  gegl_operation_class_set_keys (operation_class,

    "name"        , "gegl:line-profile",

    "categories"  , "debug",

    "description" ,

          _("Renders luminance profiles for red green and blue components along"

            " the specified line in the input buffer, plotted in a buffer of the"

            " specified size."),

          NULL);

}

#endif