/* 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 2006 Øyvind Kolås <pippin@gimp.org>

 */

#include "config.h"

#include <glib/gi18n-lib.h>

#ifdef GEGL_CHANT_PROPERTIES

gegl_chant_color  (color,    _("Color"),      "rgba(0.0,0.0,0.0,0.0)",

                             _("Color of paint to use for stroking."))

gegl_chant_double (width,    _("Width"),  0.0, 200.0, 2.0,

                             _("The width of the brush used to stroke the path."))

gegl_chant_double (opacity,  _("Opacity"),  -2.0, 2.0, 1.0,

                             _("Opacity of stroke, note, does not behave like SVG since at the moment stroking is done using an airbrush tool."))

gegl_chant_string (transform,_("Transform"), "",

                             _("svg style description of transform."))

gegl_chant_path   (d,        _("Vector"),

                             _("A GeglVector representing the path of the stroke"))

#else

#define GEGL_CHANT_TYPE_FILTER

#define GEGL_CHANT_C_FILE "vector-stroke.c"

#include "gegl-plugin.h"

/* the path api isn't public yet */

#include "property-types/gegl-path.h"

static void path_changed (GeglPath *path,

                          const GeglRectangle *roi,

                          gpointer userdata);

#include "gegl-chant.h"

#include <cairo.h>

static void path_changed (GeglPath *path,

                          const GeglRectangle *roi,

                          gpointer userdata)

{

  GeglRectangle rect = *roi;

  GeglChantO    *o   = GEGL_CHANT_PROPERTIES (userdata);

  /* invalidate the incoming rectangle */

  rect.x -= o->width/2;

  rect.y -= o->width/2;

  rect.width += o->width;

  rect.height += o->width;

  gegl_operation_invalidate (userdata, &rect, FALSE);

};

static void

prepare (GeglOperation *operation)

{

  GeglChantO *o = GEGL_CHANT_PROPERTIES (operation);

  gegl_operation_set_format (operation, "output", babl_format ("RaGaBaA float"));

  if (o->transform && o->transform[0] != '\0')

    {

      GeglMatrix3 matrix;

      gegl_matrix3_parse_string (&matrix, o->transform);

      gegl_path_set_matrix (o->d, &matrix);

    }

}

static GeglRectangle

get_bounding_box (GeglOperation *operation)

{

  GeglChantO    *o       = GEGL_CHANT_PROPERTIES (operation);

  GeglRectangle  defined = { 0, 0, 512, 512 };

  GeglRectangle *in_rect;

  gdouble        x0, x1, y0, y1;

  in_rect =  gegl_operation_source_get_bounding_box (operation, "input");

  gegl_path_get_bounds (o->d, &x0, &x1, &y0, &y1;;

  defined.x      = x0 - o->width/2;

  defined.y      = y0 - o->width/2;

  defined.width  = x1 - x0 + o->width;

  defined.height = y1 - y0 + o->width;

  if (in_rect)

    {

      gegl_rectangle_bounding_box (&defined, &defined, in_rect);

    }

  return defined;

}

#if 0

static gboolean gegl_path_is_closed (GeglPath *path)

{

  const GeglPathItem *knot;

  if (!path)

    return FALSE;

  knot = gegl_path_get_node (path, -1);

  if (!knot)

    return FALSE;

  if (knot->type == 'z')

    {

      return TRUE;

    }

  return FALSE;

}

#endif

#if 0

static GeglRectangle

get_cached_region (GeglOperation *operation)

{

  return get_bounding_box (operation);

}

#endif

static void gegl_path_cairo_play (GeglPath *path,

                                    cairo_t *cr);

static gboolean

process (GeglOperation       *operation,

         GeglBuffer          *input,

         GeglBuffer          *output,

         const GeglRectangle *result,

         gint                 level)

{

  GeglChantO *o = GEGL_CHANT_PROPERTIES (operation);

  gboolean need_stroke = FALSE;

  gdouble r,g,b,a;

  if (input)

    {

      gegl_buffer_copy (input, result, output, result);

    }

  else

    {

      gegl_buffer_clear (output, result);

    }

  if (o->width > 0.1 && o->opacity > 0.0001)

    {

      gegl_color_get_rgba (o->color, &r,&g,&b,&a);

      a *= o->opacity;

      if (a>0.001)

          need_stroke=TRUE;

    }

  if (need_stroke)

    {

      GStaticMutex mutex = G_STATIC_MUTEX_INIT;

      cairo_t *cr;

      cairo_surface_t *surface;

      guchar *data;

      g_static_mutex_lock (&mutex);

      data = (void*)gegl_buffer_linear_open (output, result, NULL, babl_format ("B'aG'aR'aA u8"));

      surface = cairo_image_surface_create_for_data (data,

                                                     CAIRO_FORMAT_ARGB32,

                                                     result->width,

                                                     result->height,

                                                     result->width * 4);

      cr = cairo_create (surface);

      cairo_translate (cr, -result->x, -result->y);

      cairo_set_line_width  (cr, o->width);

      cairo_set_line_cap    (cr, CAIRO_LINE_CAP_ROUND);

      cairo_set_line_join   (cr, CAIRO_LINE_JOIN_ROUND);

      gegl_path_cairo_play (o->d, cr);

      cairo_set_source_rgba (cr, r,g,b,a);

      cairo_stroke (cr);

      cairo_destroy (cr);

      gegl_buffer_linear_close (output, data);

      g_static_mutex_unlock (&mutex);

    }

  return  TRUE;

}

static void foreach_cairo (const GeglPathItem *knot,

                           gpointer              cr)

{

  switch (knot->type)

    {

      case 'M':

        cairo_move_to (cr, knot->point[0].x, knot->point[0].y);

        break;

      case 'L':

        cairo_line_to (cr, knot->point[0].x, knot->point[0].y);

        break;

      case 'C':

        cairo_curve_to (cr, knot->point[0].x, knot->point[0].y,

                            knot->point[1].x, knot->point[1].y,

                            knot->point[2].x, knot->point[2].y);

        break;

      case 'z':

        cairo_close_path (cr);

        break;

      default:

        g_print ("%s uh?:%c\n", G_STRLOC, knot->type);

    }

}

static void gegl_path_cairo_play (GeglPath *path,

                                    cairo_t *cr)

{

  gegl_path_foreach_flat (path, foreach_cairo, cr);

}

static GeglNode *detect (GeglOperation *operation,

                         gint           x,

                         gint           y)

{

  GeglChantO *o = GEGL_CHANT_PROPERTIES (operation);

  cairo_t *cr;

  cairo_surface_t *surface;

  gchar *data = "     ";

  gboolean result = FALSE;

  surface = cairo_image_surface_create_for_data ((guchar*)data,

                                                 CAIRO_FORMAT_ARGB32,

                                                 1,1,4);

  cr = cairo_create (surface);

  gegl_path_cairo_play (o->d, cr);

  cairo_set_line_width (cr, o->width);

  if (o->width > 0.1 && o->opacity > 0.0001)

    result = cairo_in_stroke (cr, x, y);

  cairo_destroy (cr);

  if (result)

    return operation->node;

  return NULL;

}

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_bounding_box = get_bounding_box;

  operation_class->prepare = prepare;

  operation_class->detect = detect;

  /*operation_class->no_cache = TRUE;*/

  gegl_operation_class_set_keys (operation_class,

    "name"        , "gegl:vector-stroke",

    "categories"  , "render",

    "description" , _("Renders a vector stroke"),

    NULL);

}

#endif