/* 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  (fill, _("Fill Color"),  "rgba(0.0,0.0,0.0,0.6)",
                         _("Color of paint to use for filling, use 0 opacity to disable filling"))
gegl_chant_color  (stroke,    _("Stroke Color"),      "rgba(0.0,0.0,0.0,0.0)",
                             _("Color of paint to use for stroking"))

gegl_chant_double (stroke_width,_("Stroke width"),  0.0, 200.0, 2.0,
                             _("The width of the brush used to stroke the path"))

gegl_chant_double (stroke_opacity,  _("Stroke 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_double (stroke_hardness, _("Hardness"),   0.0, 1.0, 0.6,
                             _("Hardness of the brush, 0.0 for a soft brush, 1.0 for a hard brush"))

gegl_chant_string (fill_rule,_("Fill rule"), "nonzero",
                             _("How to determine what to fill (nonzero|evenodd"))

gegl_chant_string (transform,_("Transform"), "",
                             _("SVG style description of transform"))

gegl_chant_double (fill_opacity, _("Fill opacity"),  -2.0, 2.0, 1.0,
                             _("The fill opacity to use"))

gegl_chant_path   (d,        _("Vector"),
                             _("A GeglVector representing the path of the stroke"))

#else

#define GEGL_CHANT_TYPE_FILTER
#define GEGL_CHANT_C_FILE "path.c"

#include "gegl-plugin.h"
#include "gegl-path.h"
static void path_changed (GeglPath *path,
                          const GeglRectangle *roi,
                          gpointer userdata);

#include "gegl-chant.h"
#include "gegl-buffer-private.h"
#include <cairo.h>
#include <math.h>

typedef struct StampStatic {
  gboolean    valid;
  const Babl *format;
  gfloat     *buf;
  gdouble     radius;
}StampStatic;

static void gegl_path_stroke  (GeglBuffer *buffer,
                               const GeglRectangle *clip_rect,
                               GeglPath *vector,
                               GeglColor  *color,
                               gdouble     linewidth,
                               gdouble     hardness,
                               gdouble     opacity);

static void gegl_path_stamp   (GeglBuffer *buffer,
                               const GeglRectangle *clip_rect,
                               gdouble     x,
                               gdouble     y,
                               gdouble     radius,
                               gdouble     hardness,
                               GeglColor  *color,
                               gdouble     opacity);

static void
gegl_path_stroke (GeglBuffer *buffer,
                  const GeglRectangle *clip_rect,
                  GeglPath *vector,
                  GeglColor  *color,
                  gdouble     linewidth,
                  gdouble     hardness,
                  gdouble     opacity)
{
  gfloat traveled_length = 0;
  gfloat need_to_travel = 0;
  gfloat x = 0,y = 0;
  GeglPathList *iter;
  gdouble       xmin, xmax, ymin, ymax;
  GeglRectangle extent;

  if (!vector)
    return;

  if (!clip_rect)
    {
      g_print ("using buffer extent\n");
      clip_rect = gegl_buffer_get_extent (buffer);
    }

  iter = gegl_path_get_flat_path (vector);
  gegl_path_get_bounds (vector, &xmin, &xmax, &ymin, &ymax);
  extent.x = floor (xmin);
  extent.y = floor (ymin);
  extent.width = ceil (xmax) - extent.x;
  extent.height = ceil (ymax) - extent.y;

  if (!gegl_rectangle_intersect (&extent, &extent, clip_rect))
   {
     return;
   }
  if (gegl_buffer_is_shared (buffer))
    while (!gegl_buffer_try_lock (buffer));

  /*gegl_buffer_clear (buffer, &extent);*/

  while (iter)
    {
      /*fprintf (stderr, "%c, %i %i\n", iter->d.type, iter->d.point[0].x, iter->d.point[0].y);*/
      switch (iter->d.type)
        {
          case 'M':
            x = iter->d.point[0].x;
            y = iter->d.point[0].y;
            need_to_travel = 0;
            traveled_length = 0;
            break;
          case 'L':
            {
              GeglPathPoint a,b;

              gfloat spacing;
              gfloat local_pos;
              gfloat distance;
              gfloat offset;
              gfloat leftover;
              gfloat radius = linewidth / 2.0;


              a.x = x;
              a.y = y;

              b.x = iter->d.point[0].x;
              b.y = iter->d.point[0].y;

              spacing = 0.2 * radius;

              distance = gegl_path_point_dist (&a, &b);

              leftover = need_to_travel - traveled_length;
              offset = spacing - leftover;

              local_pos = offset;

              if (distance > 0)
                for (;
                     local_pos <= distance;
                     local_pos += spacing)
                  {
                    GeglPathPoint spot;
                    gfloat ratio = local_pos / distance;
                    gfloat radius = linewidth/2;

                    gegl_path_point_lerp (&spot, &a, &b, ratio);

                    gegl_path_stamp (buffer, clip_rect,
                      spot.x, spot.y, radius, hardness, color, opacity);

                    traveled_length += spacing;
                  }

              need_to_travel += distance;

              x = b.x;
              y = b.y;
            }

            break;
          case 'u':
            g_error ("stroking uninitialized path\n");
            break;
          case 's':
            break;
          default:
            g_error ("can't stroke for instruction: %i\n", iter->d.type);
            break;
        }
      iter=iter->next;
    }

  if (gegl_buffer_is_shared (buffer))
    gegl_buffer_unlock (buffer);
}

static void
gegl_path_stamp (GeglBuffer *buffer,
                 const GeglRectangle *clip_rect,
                 gdouble     x,
                 gdouble     y,
                 gdouble     radius,
                 gdouble     hardness,
                 GeglColor  *color,
                 gdouble     opacity)
{
  gfloat col[4];
  StampStatic s = {FALSE,}; /* there should be a cache of stamps,
                               note that stamps are accessed in multiple threads
                             */

  GeglRectangle temp;
  GeglRectangle roi;

  roi.x = floor(x-radius);
  roi.y = floor(y-radius);
  roi.width = ceil (x+radius) - floor (x-radius);
  roi.height = ceil (y+radius) - floor (y-radius);

  gegl_color_get_pixel (color, babl_format ("RGBA float"), col);

  /* bail out if we wouldn't leave a mark on the buffer */
  if (!gegl_rectangle_intersect (&temp, &roi, clip_rect))
    {
      return;
    }

  if (s.format == NULL)
    s.format = babl_format ("RaGaBaA float");

  if (s.buf == NULL ||
      s.radius != radius)
    {
      if (s.buf != NULL)
        g_free (s.buf);
      /* allocate a little bit more, just in case due to rounding errors and
       * such */
      s.buf = g_malloc (4*4* (roi.width + 2 ) * (roi.height + 2));
      s.radius = radius;
      s.valid = TRUE;
    }
  g_assert (s.buf);

  gegl_buffer_get_unlocked (buffer, 1.0, &roi, s.format, s.buf, 0);

  {
    gint u, v;
    gint i=0;

    gfloat radius_squared = radius * radius;
    gfloat inner_radius_squared = (radius * hardness)*(radius * hardness);
    gfloat soft_range = radius_squared - inner_radius_squared;

    for (v= roi.y; v < roi.y + roi.height ; v++)
    {
      gfloat vy2 = (v-y)*(v-y);
      for (u= roi.x; u < roi.x + roi.width; u++)
        {
          gfloat o = (u-x) * (u-x) + vy2;

          if (o < inner_radius_squared)
             o = col[3];
          else if (o < radius_squared)
            {
              o = (1.0 - (o-inner_radius_squared) / (soft_range)) * col[3];
            }
          else
            {
              o=0.0;
            }
         if (o!=0.0)
           {
             gint c;
             o = o*opacity;
             for (c=0;c<4;c++)
               s.buf[i*4+c] = (s.buf[i*4+c] * (1.0-o) + col[c] * o);
           }
         i++;
        }
    }
  }
  gegl_buffer_set_unlocked (buffer, &roi, s.format, s.buf, 0);
  g_free (s.buf);
}

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->stroke_width/2;
  rect.y -= o->stroke_width/2;
  rect.width += o->stroke_width;
  rect.height += o->stroke_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->stroke_width/2;
  defined.y      = y0 - o->stroke_width/2;
  defined.width  = x1 - x0 + o->stroke_width;
  defined.height = y1 - y0 + o->stroke_width;

  if (in_rect)
    {
      gegl_rectangle_bounding_box (&defined, &defined, in_rect);
    }

  return defined;
}

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);

  if (input)
    {
      gegl_buffer_copy (input, result, output, result);
    }
  else
    {
      gegl_buffer_clear (output, result);
    }



  if (o->fill_opacity > 0.0001 && o->fill)
    {
      gdouble r,g,b,a;
      gegl_color_get_rgba (o->fill, &r,&g,&b,&a);
      a *= o->fill_opacity;
      if (a>0.001)
        {
          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);

          if (g_str_equal (o->fill_rule, "evenodd"))
            {
              cairo_set_fill_rule (cr, CAIRO_FILL_RULE_EVEN_ODD);
            }

          gegl_path_cairo_play (o->d, cr);
          cairo_set_source_rgba (cr, r,g,b,a);
          cairo_fill (cr);

          g_static_mutex_unlock (&mutex);
          gegl_buffer_linear_close (output, data);
        }
    }

  g_object_set_data (G_OBJECT (operation), "path-radius", GINT_TO_POINTER((gint)(o->stroke_width+1)/2));

  if (o->stroke_width > 0.1 && o->stroke_opacity > 0.0001)
    {
      gegl_path_stroke (output, result,
                                o->d,
                                o->stroke,
                                o->stroke_width,
                                o->stroke_hardness,
                                o->stroke_opacity);
    }

  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->stroke_width);


  if (o->stroke_width > 0.1 && o->stroke_opacity > 0.0001)
    result = cairo_in_stroke (cr, x, y);

  if (!result)
    {
      if (o->d)
        {
          gdouble r,g,b,a;
          gegl_color_get_rgba (o->fill, &r,&g,&b,&a);
          if (a * o->fill_opacity>0.8)
            result = cairo_in_fill (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:path",
    "categories"  , "render",
    "description" , _("Renders a brush stroke"),
    NULL);
}


#endif