/*********************************************************/
/* Image manipulation routines. Calls mapobject_shade.c  */
/* functions to compute the shading of the image at each */
/* pixel. These routines are used by the functions in    */
/* mapobject_preview.c and mapobject_apply.c             */
/*********************************************************/

#include "config.h"

#include <string.h>

#include <sys/types.h>

#include <gtk/gtk.h>

#include <libgimp/gimp.h>

#include "mapobject_main.h"
#include "mapobject_preview.h"
#include "mapobject_shade.h"
#include "mapobject_ui.h"
#include "mapobject_image.h"

GimpDrawable *input_drawable, *output_drawable;
GimpPixelRgn source_region,dest_region;

GimpDrawable *box_drawables[6];
GimpPixelRgn box_regions[6];

GimpDrawable *cylinder_drawables[2];
GimpPixelRgn cylinder_regions[2];

guchar   *preview_rgb_data = NULL;

glong   maxcounter,old_depth,max_depth;
gint    imgtype,width,height,in_channels,out_channels;
GimpRGB  background;
gdouble oldtreshold;

gint border_x1, border_y1, border_x2, border_y2;

/******************/
/* Implementation */
/******************/

GimpRGB
peek (gint x,
      gint y)
{
  static guchar data[4];

  GimpRGB color;

  gimp_pixel_rgn_get_pixel (&source_region, data, x, y);

  color.r = (gdouble) (data[0]) / 255.0;
  color.g = (gdouble) (data[1]) / 255.0;
  color.b = (gdouble) (data[2]) / 255.0;

  if (input_drawable->bpp == 4)
    {
      if (in_channels == 4)
        color.a = (gdouble) (data[3]) / 255.0;
      else
        color.a = 1.0;
    }
  else
    {
      color.a = 1.0;
    }

  return color;
}

static GimpRGB
peek_box_image (gint image,
		gint x,
		gint y)
{
  static guchar data[4];

  GimpRGB color;

  gimp_pixel_rgn_get_pixel (&box_regions[image], data, x, y);

  color.r = (gdouble) (data[0]) / 255.0;
  color.g = (gdouble) (data[1]) / 255.0;
  color.b = (gdouble) (data[2]) / 255.0;

  if (box_drawables[image]->bpp == 4)
    {
      if (gimp_drawable_has_alpha (box_drawables[image]->drawable_id))
        color.a = (gdouble) (data[3]) / 255.0;
      else
        color.a = 1.0;
    }
  else
    {
      color.a = 1.0;
    }

  return color;
}

static GimpRGB
peek_cylinder_image (gint image,
		     gint x,
		     gint y)
{
  static guchar data[4];

  GimpRGB color;

  gimp_pixel_rgn_get_pixel (&cylinder_regions[image],data, x, y);

  color.r = (gdouble) (data[0]) / 255.0;
  color.g = (gdouble) (data[1]) / 255.0;
  color.b = (gdouble) (data[2]) / 255.0;

  if (cylinder_drawables[image]->bpp == 4)
    {
      if (gimp_drawable_has_alpha (cylinder_drawables[image]->drawable_id))
        color.a = (gdouble) (data[3]) / 255.0;
      else
        color.a = 1.0;
    }
  else
    {
      color.a = 1.0;
    }

  return color;
}

void
poke (gint      x,
      gint      y,
      GimpRGB  *color,
      gpointer  data)
{
  static guchar col[4];

  gimp_rgba_get_uchar (color, &col[0], &col[1], &col[2], &col[3]);

  gimp_pixel_rgn_set_pixel (&dest_region, col, x, y);
}

gint
checkbounds (gint x,
	     gint y)
{
  if (x < border_x1 || y < border_y1 || x >= border_x2 || y >= border_y2)
    return FALSE;
  else
    return TRUE;
}

static gint
checkbounds_box_image (gint image,
		       gint x,
		       gint y)
{
  gint w, h;

  w = box_drawables[image]->width;
  h = box_drawables[image]->height;

  if (x < 0 || y < 0 || x >= w || y >= h)
    return FALSE ;
  else
    return TRUE ;
}

static gint
checkbounds_cylinder_image (gint image,
			    gint x,
			    gint y)
{
  gint w, h;

  w = cylinder_drawables[image]->width;
  h = cylinder_drawables[image]->height;

  if (x < 0 || y < 0 || x >= w || y >= h)
    return FALSE;
  else
    return TRUE;
}

GimpVector3
int_to_pos (gint x,
	    gint y)
{
  GimpVector3 pos;

  pos.x = (gdouble) x / (gdouble) width;
  pos.y = (gdouble) y / (gdouble) height;
  pos.z = 0.0;

  return pos;
}

void
pos_to_int (gdouble  x,
	    gdouble  y,
	    gint    *scr_x,
	    gint    *scr_y)
{
  *scr_x = (gint) ((x * (gdouble) width));
  *scr_y = (gint) ((y * (gdouble) height));
}

/**********************************************/
/* Compute the image color at pos (u,v) using */
/* Quartics bilinear interpolation stuff.     */
/**********************************************/

GimpRGB
get_image_color (gdouble  u,
		 gdouble  v,
		 gint    *inside)
{
  gint    x1, y1, x2, y2;
  GimpRGB p[4];

  pos_to_int (u, v, &x1, &y1);

  if (mapvals.tiled == TRUE)
    {
      *inside = TRUE;

      if (x1 < 0) x1 = (width-1) - (-x1 % width);
      else        x1 = x1 % width;
  
      if (y1 < 0) y1 = (height-1) - (-y1 % height);
      else        y1 = y1 % height;

      x2 = (x1 + 1) % width;
      y2 = (y1 + 1) % height;

      p[0] = peek (x1, y1);
      p[1] = peek (x2, y1);
      p[2] = peek (x1, y2);
      p[3] = peek (x2, y2);

      return gimp_bilinear_rgba (u * width, v * height, p);
    }

  if (checkbounds (x1, y1) == FALSE)
    {
      *inside =FALSE;

      return background;
    }

  x2 = (x1 + 1);
  y2 = (y1 + 1);

  if (checkbounds (x2, y2) == FALSE)
   {
     *inside = TRUE;

     return peek (x1, y1);
   }

  *inside=TRUE;

  p[0] = peek (x1, y1);
  p[1] = peek (x2, y1);
  p[2] = peek (x1, y2);
  p[3] = peek (x2, y2);

  return gimp_bilinear_rgba (u * width, v * height, p);
}

GimpRGB
get_box_image_color (gint    image,
		     gdouble u,
		     gdouble v)
{
  gint    w, h;
  gint    x1, y1, x2, y2;
  GimpRGB p[4];
 
  w = box_drawables[image]->width;
  h = box_drawables[image]->height;

  x1 = (gint) ((u * (gdouble) w));
  y1 = (gint) ((v * (gdouble) h));

  if (checkbounds_box_image (image, x1, y1) == FALSE)
    return background;

  x2 = (x1 + 1);
  y2 = (y1 + 1);

  if (checkbounds_box_image (image, x2, y2) == FALSE)
    return peek_box_image (image, x1,y1);

  p[0] = peek_box_image (image, x1, y1);
  p[1] = peek_box_image (image, x2, y1);
  p[2] = peek_box_image (image, x1, y2);
  p[3] = peek_box_image (image, x2, y2);

  return gimp_bilinear_rgba (u * w, v * h, p);
}

GimpRGB
get_cylinder_image_color (gint    image,
			  gdouble u,
			  gdouble v)
{
  gint    w, h;
  gint    x1, y1, x2, y2;
  GimpRGB p[4];
 
  w = cylinder_drawables[image]->width;
  h = cylinder_drawables[image]->height;

  x1 = (gint) ((u * (gdouble) w));
  y1 = (gint) ((v * (gdouble) h));

  if (checkbounds_cylinder_image (image, x1, y1) == FALSE)
    return background;

  x2 = (x1 + 1);
  y2 = (y1 + 1);

  if (checkbounds_cylinder_image (image, x2, y2) == FALSE)
    return peek_cylinder_image (image, x1,y1);

  p[0] = peek_cylinder_image (image, x1, y1);
  p[1] = peek_cylinder_image (image, x2, y1);
  p[2] = peek_cylinder_image (image, x1, y2);
  p[3] = peek_cylinder_image (image, x2, y2);

  return gimp_bilinear_rgba (u * w, v * h, p);
}

/****************************************/
/* Allocate memory for temporary images */
/****************************************/

gint
image_setup (GimpDrawable *drawable,
	     gint       interactive)
{
  /* Set the tile cache size */
  /* ======================= */

  gimp_tile_cache_ntiles ((drawable->width + gimp_tile_width() - 1) /
			  gimp_tile_width ());

  /* Get some useful info on the input drawable */
  /* ========================================== */

  input_drawable  = drawable;
  output_drawable = drawable;

  gimp_drawable_mask_bounds (drawable->drawable_id,
			     &border_x1, &border_y1, &border_x2, &border_y2);

  width  = input_drawable->width;
  height = input_drawable->height;

  gimp_pixel_rgn_init (&source_region, input_drawable,
		       0, 0, width, height, FALSE, FALSE);

  maxcounter = (glong) width * (glong) height;

  if (mapvals.transparent_background == TRUE)
    {
      gimp_rgba_set (&background, 0.0, 0.0, 0.0, 0.0);
    }
  else
    {
      gimp_context_get_background (&background);
      gimp_rgb_set_alpha (&background, 1.0);
    }

  /* Assume at least RGB */
  /* =================== */

  in_channels = 3;
  if (gimp_drawable_has_alpha (input_drawable->drawable_id) == TRUE)
    in_channels++;

  if (interactive == TRUE)
    {
      preview_rgb_data = g_new0 (guchar, PREVIEW_HEIGHT * PREVIEW_WIDTH * 3);
    }

  return TRUE;
}
