void
gimp_channel_select_scan_convert (GimpChannel     *channel,
                                  const gchar     *undo_desc,
                                  GimpScanConvert *scan_convert,
                                  gint             offset_x,
                                  gint             offset_y,
                                  GimpChannelOps   op,
                                  gboolean         antialias,
                                  gboolean         feather,
                                  gdouble          feather_radius_x,
                                  gdouble          feather_radius_y,
                                  gboolean         push_undo)
{
  GimpItem    *item;
  GimpChannel *add_on;

  g_return_if_fail (GIMP_IS_CHANNEL (channel));
  g_return_if_fail (gimp_item_is_attached (GIMP_ITEM (channel)));
  g_return_if_fail (undo_desc != NULL);
  g_return_if_fail (scan_convert != NULL);

  if (push_undo)
    gimp_channel_push_undo (channel, undo_desc);

  /*  if applicable, replace the current selection  */
  if (op == GIMP_CHANNEL_OP_REPLACE)
    gimp_channel_clear (channel, NULL, FALSE);

  item = GIMP_ITEM (channel);

  add_on = gimp_channel_new_mask (gimp_item_get_image (item),
                                  gimp_item_width (item),
                                  gimp_item_height (item));
  gimp_scan_convert_render (scan_convert,
                            gimp_drawable_get_tiles (GIMP_DRAWABLE (add_on)),
                            offset_x, offset_y, antialias);

  if (feather)
    gimp_channel_feather (add_on,
                          feather_radius_x,
                          feather_radius_y,
                          FALSE /* no undo */);

  gimp_channel_combine_mask (channel, add_on, op, 0, 0);
  g_object_unref (add_on);
}
void
gimp_channel_select_scan_convert (GimpChannel     *channel,
                                  const gchar     *undo_desc,
                                  GimpScanConvert *scan_convert,
                                  gint             offset_x,
                                  gint             offset_y,
                                  GimpChannelOps   op,
                                  gboolean         antialias,
                                  gboolean         feather,
                                  gdouble          feather_radius_x,
                                  gdouble          feather_radius_y,
                                  gboolean         push_undo)
{
  GimpItem   *item;
  GeglBuffer *add_on;

  g_return_if_fail (GIMP_IS_CHANNEL (channel));
  g_return_if_fail (gimp_item_is_attached (GIMP_ITEM (channel)));
  g_return_if_fail (undo_desc != NULL);
  g_return_if_fail (scan_convert != NULL);

  if (push_undo)
    gimp_channel_push_undo (channel, undo_desc);

  /*  if applicable, replace the current selection  */
  if (op == GIMP_CHANNEL_OP_REPLACE)
    gimp_channel_clear (channel, NULL, FALSE);

  item = GIMP_ITEM (channel);

  add_on = gegl_buffer_new (GEGL_RECTANGLE (0, 0,
                                            gimp_item_get_width  (item),
                                            gimp_item_get_height (item)),
                            babl_format ("Y float"));

  gimp_scan_convert_render (scan_convert, add_on,
                            offset_x, offset_y, antialias);

  if (feather)
    gimp_gegl_apply_feather (add_on, NULL, NULL, add_on, NULL,
                             feather_radius_x,
                             feather_radius_y);

  gimp_channel_combine_buffer (channel, add_on, op, 0, 0);
  g_object_unref (add_on);
}
static void
gimp_drawable_stroke_scan_convert (GimpDrawable      *drawable,
                                   GimpStrokeOptions *options,
                                   GimpScanConvert   *scan_convert)
{
  GimpContext *context = GIMP_CONTEXT (options);
  GimpImage   *image;
  gdouble      width;
  TileManager *base;
  TileManager *mask;
  gint         x, y, w, h;
  gint         bytes;
  gint         off_x, off_y;
  guchar       bg[1] = { 0, };
  PixelRegion  maskPR, basePR;

  image = gimp_item_get_image (GIMP_ITEM (drawable));

  /*  must call gimp_channel_is_empty() instead of relying on
   *  gimp_drawable_mask_intersect() because the selection pretends to
   *  be empty while it is being stroked, to prevent masking itself.
   */
  if (gimp_channel_is_empty (gimp_image_get_mask (image)))
    {
      x = 0;
      y = 0;
      w = gimp_item_width (GIMP_ITEM (drawable));
      h = gimp_item_height (GIMP_ITEM (drawable));
    }
  else if (! gimp_drawable_mask_intersect (drawable, &x, &y, &w, &h))
    {
      return;
    }

  gimp_item_offsets (GIMP_ITEM (drawable), &off_x, &off_y);

  width = options->width;

  if (options->unit != GIMP_UNIT_PIXEL)
    {
      gimp_scan_convert_set_pixel_ratio (scan_convert,
                                         image->yresolution /
                                         image->xresolution);

      width *= (image->yresolution /
                _gimp_unit_get_factor (image->gimp, options->unit));
    }

  gimp_scan_convert_stroke (scan_convert, width,
                            options->join_style,
                            options->cap_style,
                            options->miter_limit,
                            options->dash_offset,
                            options->dash_info);

  /* fill a 1-bpp Tilemanager with black, this will describe the shape
   * of the stroke.
   */
  mask = tile_manager_new (w, h, 1);
  pixel_region_init (&maskPR, mask, 0, 0, w, h, TRUE);
  color_region (&maskPR, bg);

  /* render the stroke into it */
  gimp_scan_convert_render (scan_convert, mask,
                            x + off_x, y + off_y,
                            options->antialias);

  bytes = gimp_drawable_bytes_with_alpha (drawable);

  base = tile_manager_new (w, h, bytes);
  pixel_region_init (&basePR, base, 0, 0, w, h, TRUE);
  pixel_region_init (&maskPR, mask, 0, 0, w, h, FALSE);

  switch (options->style)
    {
    case GIMP_STROKE_STYLE_SOLID:
      {
        guchar tmp_col[MAX_CHANNELS] = { 0, };
        guchar col[MAX_CHANNELS]     = { 0, };

        gimp_rgb_get_uchar (&context->foreground,
                            &tmp_col[RED_PIX],
                            &tmp_col[GREEN_PIX],
                            &tmp_col[BLUE_PIX]);

        gimp_image_transform_color (image, gimp_drawable_type (drawable), col,
                                    GIMP_RGB, tmp_col);
        col[bytes - 1] = OPAQUE_OPACITY;

        color_region_mask (&basePR, &maskPR, col);
      }
      break;

    case GIMP_STROKE_STYLE_PATTERN:
      {
        GimpPattern *pattern;
        TempBuf     *pat_buf;
        gboolean     new_buf;

        pattern = gimp_context_get_pattern (context);
        pat_buf = gimp_image_transform_temp_buf (image,
                                                 gimp_drawable_type (drawable),
                                                 pattern->mask, &new_buf);

        pattern_region (&basePR, &maskPR, pat_buf, x, y);

        if (new_buf)
          temp_buf_free (pat_buf);
      }
      break;
    }

  /* Apply to drawable */
  pixel_region_init (&basePR, base, 0, 0, w, h, FALSE);
  gimp_drawable_apply_region (drawable, &basePR,
                              TRUE, _("Render Stroke"),
                              gimp_context_get_opacity (context),
                              gimp_context_get_paint_mode (context),
                              NULL, x, y);

  tile_manager_unref (mask);
  tile_manager_unref (base);

  gimp_drawable_update (drawable, x, y, w, h);
}