/* The GIMP -- an image manipulation program
 * Copyright (C) 1995 Spencer Kimball and Peter Mattis
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 */
#include <stdlib.h>
#include <stdio.h>
#include "gdk/gdkkeysyms.h"
#include "appenv.h"
#include "drawable.h"
#include "errors.h"
#include "convolve.h"
#include "gdisplay.h"
#include "paint_funcs.h"
#include "paint_core.h"
#include "paint_options.h"
#include "selection.h"
#include "tool_options_ui.h"
#include "tools.h"
#include "gimage.h"

#include "libgimp/gimpintl.h"

#define FIELD_COLS    4
#define MIN_BLUR      64         /*  (8/9 original pixel)   */
#define MAX_BLUR      0.25       /*  (1/33 original pixel)  */
#define MIN_SHARPEN   -512
#define MAX_SHARPEN   -64

/*  the convolve structures  */

typedef struct _ConvolveOptions ConvolveOptions;
struct _ConvolveOptions
{
  PaintOptions  paint_options;

  ConvolveType  type;
  ConvolveType  type_d;
  GtkWidget    *type_w[2];

  double        pressure;
  double        pressure_d;
  GtkObject    *pressure_w;
};


/*  the convolve tool options  */
static ConvolveOptions * convolve_options = NULL;

/*  local variables  */
static int          matrix [25];
static int          matrix_size;
static int          matrix_divisor;

static float        custom_matrix [25] =
{
  0, 0, 0, 0, 0,
  0, 0, 0, 0, 0,
  0, 0, 1, 0, 0,
  0, 0, 0, 0, 0,
  0, 0, 0, 0, 0,
};

static float        blur_matrix [25] =
{
  0, 0, 0, 0, 0,
  0, 1, 1, 1, 0,
  0, 1, MIN_BLUR, 1, 0,
  0, 1, 1, 1, 0,
  0, 0 ,0, 0, 0,
};

static float        sharpen_matrix [25] =
{
  0, 0, 0, 0, 0,
  0, 1, 1, 1, 0,
  0, 1, MIN_SHARPEN, 1, 0,
  0, 1, 1, 1, 0,
  0, 0, 0, 0, 0,
};


/*  forward function declarations  */
static void         calculate_matrix     (ConvolveType, double, double);
static void         integer_matrix       (float *, int *, int);
static void         copy_matrix          (float *, float *, int);
static int          sum_matrix           (int *, int);

static void         convolve_motion      (PaintCore *, GimpDrawable *);


/* functions  */


static void
convolve_options_reset (void)
{
  ConvolveOptions *options = convolve_options;

  paint_options_reset ((PaintOptions *) options);

  gtk_adjustment_set_value (GTK_ADJUSTMENT (options->pressure_w),
			    options->pressure_d);
  gtk_toggle_button_set_active (GTK_TOGGLE_BUTTON (options->type_w[options->type_d]), TRUE);
}

static ConvolveOptions *
convolve_options_new (void)
{
  ConvolveOptions *options;

  GtkWidget *vbox;
  GtkWidget *hbox;
  GtkWidget *label;
  GtkWidget *scale;
  GtkWidget *frame;
  gchar* type_label[2] = { N_("Blur"), N_("Sharpen") };
  gint   type_value[2] = { BLUR_CONVOLVE, SHARPEN_CONVOLVE };

  /*  the new convolve tool options structure  */
  options = (ConvolveOptions *) g_malloc (sizeof (ConvolveOptions));
  paint_options_init ((PaintOptions *) options,
		      CONVOLVE,
		      convolve_options_reset);
  options->type     = options->type_d     = BLUR_CONVOLVE;
  options->pressure = options->pressure_d = 50.0;

  /*  the main vbox  */
  vbox = ((ToolOptions *) options)->main_vbox;

  /*  the pressure scale  */
  hbox = gtk_hbox_new (FALSE, 4);
  gtk_box_pack_start (GTK_BOX (vbox), hbox, FALSE, FALSE, 0);

  label = gtk_label_new (_("Pressure:"));
  gtk_misc_set_alignment (GTK_MISC (label), 1.0, 1.0);
  gtk_box_pack_start (GTK_BOX (hbox), label, FALSE, FALSE, 0);
  gtk_widget_show (label);

  options->pressure_w =
    gtk_adjustment_new (options->pressure_d, 0.0, 100.0, 1.0, 1.0, 0.0);
  scale = gtk_hscale_new (GTK_ADJUSTMENT (options->pressure_w));
  gtk_box_pack_start (GTK_BOX (hbox), scale, TRUE, TRUE, 0);
  gtk_scale_set_value_pos (GTK_SCALE (scale), GTK_POS_TOP);
  gtk_range_set_update_policy (GTK_RANGE (scale), GTK_UPDATE_DELAYED);
  gtk_signal_connect (GTK_OBJECT (options->pressure_w), "value_changed",
		      (GtkSignalFunc) tool_options_double_adjustment_update,
		      &options->pressure);
  gtk_widget_show (scale);
  gtk_widget_show (hbox);

  frame = tool_options_radio_buttons_new (N_("Convolve Type"), 
					  &options->type,
					   options->type_w,
					   type_label,
					   type_value,
					   2);
  gtk_toggle_button_set_active (GTK_TOGGLE_BUTTON (options->type_w[options->type_d]), TRUE);
  gtk_box_pack_start (GTK_BOX (vbox), frame, FALSE, FALSE, 0);
  gtk_widget_show (frame);

  return options;
}

void *
convolve_paint_func (PaintCore    *paint_core,
		     GimpDrawable *drawable,
		     int           state)
{
  switch (state)
    {
    case MOTION_PAINT:
      convolve_motion (paint_core, drawable);
      break;
    }

  return NULL;
}

static void
convolve_modifier_key_func (Tool        *tool,
			    GdkEventKey *kevent,
			    gpointer     gdisp_ptr)
{
  switch (kevent->keyval)
    {
    case GDK_Alt_L: case GDK_Alt_R:
      break;
    case GDK_Shift_L: case GDK_Shift_R:
      break;
    case GDK_Control_L: case GDK_Control_R:
      switch (convolve_options->type)
	{
	case BLUR_CONVOLVE:
	  gtk_toggle_button_set_active (GTK_TOGGLE_BUTTON (convolve_options->type_w[SHARPEN_CONVOLVE]), TRUE);
	  break;
	case SHARPEN_CONVOLVE:
	  gtk_toggle_button_set_active (GTK_TOGGLE_BUTTON (convolve_options->type_w[BLUR_CONVOLVE]), TRUE);
	  break;
	default:
	  break;
	}
      break; 
    }
}

Tool *
tools_new_convolve ()
{
  Tool * tool;
  PaintCore * private;

  /*  The tool options  */
  if (! convolve_options)
    {
      convolve_options = convolve_options_new ();
      tools_register (CONVOLVE, (ToolOptions *) convolve_options);

      /*  press all default buttons  */
      convolve_options_reset ();
    }

  tool = paint_core_new (CONVOLVE);
  tool->modifier_key_func = convolve_modifier_key_func;

  private = (PaintCore *) tool->private;
  private->paint_func = convolve_paint_func;

  return tool;
}

void
tools_free_convolve (Tool *tool)
{
  paint_core_free (tool);
}

static void
convolve_motion (PaintCore *paint_core,
		 GimpDrawable *drawable)
{
  GImage *gimage;
  TempBuf * area;
  unsigned char *temp_data;
  PixelRegion srcPR, destPR, tempPR;

  if (! (gimage = drawable_gimage (drawable)))
    return;

  /*  If the image type is indexed, don't convolve  */
  if ((drawable_type (drawable) == INDEXED_GIMAGE) ||
      (drawable_type (drawable) == INDEXEDA_GIMAGE))
    return;

  /*  Get a region which can be used to paint to  */
  if (! (area = paint_core_get_paint_area (paint_core, drawable)))
    return;

  /*  configure the pixel regions correctly  */
  pixel_region_init (&srcPR, drawable_data (drawable), area->x, area->y, area->width, area->height, FALSE);

  destPR.bytes = area->bytes;
  destPR.x = 0; destPR.y = 0;
  destPR.w = area->width;
  destPR.h = area->height;
  destPR.rowstride = area->width * destPR.bytes;
  destPR.data = temp_buf_data (area);

  calculate_matrix (convolve_options->type, convolve_options->pressure,
		    paint_core->curpressure);

  /*  convolve the source image with the convolve mask  */
  if (srcPR.w >= matrix_size && srcPR.h >= matrix_size)
    {
      /*  if the source has no alpha, then add alpha pixels  */
      if (!drawable_has_alpha (drawable))
	{
	  /* note: this architecture needlessly convolves the totally-
	     opaque alpha channel. A faster approach would be to keep
	     tempPR the same number of bytes as srcPR, and extend the
	     paint_core_replace_canvas API to handle non-alpha images. */

	  tempPR.bytes = srcPR.bytes + 1;
	  tempPR.x = 0; tempPR.y = 0;
	  tempPR.w = area->width;
	  tempPR.h = area->height;
	  tempPR.rowstride = tempPR.bytes * tempPR.w;
	  temp_data = g_malloc (tempPR.h * tempPR.rowstride);
	  tempPR.data = temp_data;

	  add_alpha_region (&srcPR, &tempPR);
	}
      else
	{
	  tempPR.bytes = srcPR.bytes;
	  tempPR.x = 0; tempPR.y = 0;
	  tempPR.w = area->width;
	  tempPR.h = area->height;
	  tempPR.rowstride = tempPR.bytes * tempPR.w;
	  temp_data = g_malloc (tempPR.h * tempPR.rowstride);
	  tempPR.data = temp_data;

	  copy_region (&srcPR, &tempPR);

	  tempPR.x = 0; tempPR.y = 0;
	  tempPR.w = area->width;
	  tempPR.h = area->height;
	  tempPR.data = temp_data;

	  multiply_alpha_region (&tempPR);
	}

      tempPR.x = 0; tempPR.y = 0;
      tempPR.w = area->width;
      tempPR.h = area->height;
      tempPR.data = temp_data;

      /*  Convolve the region  */
      convolve_region (&tempPR, &destPR, matrix, matrix_size,
		       matrix_divisor, NORMAL);

      if (drawable_has_alpha (drawable))
	  separate_alpha_region (&destPR);

      /*  Free the allocated temp space  */
      g_free (temp_data);
    }
  else
    {
      /*  if the source has no alpha, then add alpha pixels, otherwise copy  */
      if (!drawable_has_alpha (drawable))
	add_alpha_region (&srcPR, &destPR);
      else
	copy_region (&srcPR, &destPR);
    }

  /*  paste the newly painted canvas to the gimage which is being worked on  */
  paint_core_replace_canvas (paint_core, drawable, OPAQUE_OPACITY,
			   (int) (PAINT_OPTIONS_GET_OPACITY (convolve_options) * 255),
			   SOFT, INCREMENTAL);
}

static void
calculate_matrix (ConvolveType type,
		  double       pressure,
		  double       curpressure)
{
  float percent;

  /*  find percent of tool pressure  */
  percent = (pressure / 100.0) * curpressure;

  /*  get the appropriate convolution matrix and size and divisor  */
  switch (type)
    {
    case BLUR_CONVOLVE:
      matrix_size = 5;
      blur_matrix [12] = MIN_BLUR + percent * (MAX_BLUR - MIN_BLUR);
      copy_matrix (blur_matrix, custom_matrix, matrix_size);
      break;

    case SHARPEN_CONVOLVE:
      matrix_size = 5;
      sharpen_matrix [12] = MIN_SHARPEN + percent * (MAX_SHARPEN - MIN_SHARPEN);
      copy_matrix (sharpen_matrix, custom_matrix, matrix_size);
      break;

    case CUSTOM_CONVOLVE:
      matrix_size = 5;
      break;
    }

  integer_matrix (custom_matrix, matrix, matrix_size);
  matrix_divisor = sum_matrix (matrix, matrix_size);

  if (!matrix_divisor)
    matrix_divisor = 1;
}

static void
integer_matrix (float *source,
		int   *dest,
		int    size)
{
  int i;

#define PRECISION  10000

  for (i = 0; i < size*size; i++)
    *dest++ = (int) (*source ++ * PRECISION);
}

static void
copy_matrix (float *src,
	     float *dest,
	     int    size)
{
  int i;

  for (i = 0; i < size*size; i++)
    *dest++ = *src++;
}

static int
sum_matrix (int *matrix,
	    int  size)
{
  int sum = 0;

  size *= size;

  while (size --)
    sum += *matrix++;

  return sum;
}


static void *
convolve_non_gui_paint_func (PaintCore *paint_core,
			     GimpDrawable *drawable,
			     int        state)
{
  convolve_motion (paint_core, drawable);

  return NULL;
}

gboolean
convolve_non_gui (GimpDrawable *drawable,
    		  double        pressure,
		  int           num_strokes,
		  double       *stroke_array)
{
  int i;

  if (paint_core_init (&non_gui_paint_core, drawable,
		       stroke_array[0], stroke_array[1]))
    {
      /* Set the paint core's paint func */
      non_gui_paint_core.paint_func = convolve_non_gui_paint_func;

      non_gui_paint_core.startx = non_gui_paint_core.lastx = stroke_array[0];
      non_gui_paint_core.starty = non_gui_paint_core.lasty = stroke_array[1];

      if (num_strokes == 1)
	convolve_non_gui_paint_func (&non_gui_paint_core, drawable, 0);

      for (i = 1; i < num_strokes; i++)
	{
	  non_gui_paint_core.curx = stroke_array[i * 2 + 0];
	  non_gui_paint_core.cury = stroke_array[i * 2 + 1];

	  paint_core_interpolate (&non_gui_paint_core, drawable);

	  non_gui_paint_core.lastx = non_gui_paint_core.curx;
	  non_gui_paint_core.lasty = non_gui_paint_core.cury;
	}

      /* Finish the painting */
      paint_core_finish (&non_gui_paint_core, drawable, -1);

      /* Cleanup */
      paint_core_cleanup ();
      return TRUE;
    }
  else
    return FALSE;
}