/* ASE - Allegro Sprite Editor
 * Copyright (C) 2001-2005, 2007  David A. Capello
 *
 * 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 "config.h"

#ifndef USE_PRECOMPILED_HEADER

#include <allegro/color.h>

#include "console/console.h"
#include "modules/sprites.h"
#include "raster/image.h"
#include "raster/sprite.h"
#include "raster/stock.h"
#include "util/quantize.h"

#endif

void sprite_quantize(struct Sprite *sprite)
{
  PALETTE palette;

  sprite_quantize_ex(sprite, palette);

  /* just one palette */
  sprite_reset_palettes(sprite);
  sprite_set_palette(sprite, palette, 0);
}

void sprite_quantize_ex(Sprite *sprite, RGB *palette)
{
  Stock *stock;
  Image *flat_image;
  int c;

  stock = sprite_get_images(sprite, TARGET_ALL, FALSE, NULL, NULL);
  if (stock) {
    /* add a flat image with the current sprite's frame rendered */
    flat_image = image_new (sprite->imgtype, sprite->w, sprite->h);
    image_clear (flat_image, 0);
    sprite_render (sprite, flat_image, 0, 0);
    stock_add_image (stock, flat_image);

    /* generate the optimized palette */
    {
      int *ibmp;

      for (c=0; c<256; c++)
	palette[c].r = palette[c].g = palette[c].b = 255;

      ibmp = jmalloc (sizeof (int) * stock->nimage);
      for (c=0; c<stock->nimage; c++)
	ibmp[c] = 128;

      quantize_bitmaps1 (stock, palette, ibmp, TRUE);

      jfree (ibmp);
    }

    stock_free (stock);
    image_free (flat_image);
  }
}

/* quantize.c
 * Copyright (C) 2000-2002 by Ben "entheh" Davis
 *
 * Nobody can use these routines without the explicit
 * permission of Ben Davis: entheh@users.sourceforge.net
 *
 * Adapted to ASE by David A. Capello.
 *
 * See "LEGAL.txt" for details.
/ */

/* HACK ALERT: We use 'filler' to represent whether a colour in the palette
 * is reserved. This is only tested when the .r element can no longer
 * indicate whether an entry is reserved, i.e. when converting bitmaps.
 * NOTE: When converting bitmaps, they will not use reserved colours.
 */

#define TREE_DEPTH 2
/* TREE_DEPTH should be  a power of 2.  The lower it is,  the deeper the tree
 * will go.  This will not usually affect  the accuracy of colours generated,
 * but with images with  very subtle changes of colour,  the variation can be
 * lost with higher values of TREE_DEPTH.
 *
 * As these trees go deeper they use an extortionate amount of memory.  If it
 * runs out, you have no choice but to increase the value of TREE_DEPTH.
 */

/* quantize_bitmaps:
 * generates an  optimised palette  for the  list of
 * bitmaps specified. All bitmaps must be true-colour.  The number of bitmaps
 * must be passed in n_bmp, and bmp must point to an array of pointers to
 * BITMAP  structures.  bmp_i  should  point  to  an array  parallel  to bmp,
 * containing importance values for the bitmaps.  pal must point to a PALETTE
 * structure which will be filled with the optimised palette.
 *
 * pal will be scanned for predefined colours. Any entry where the .r element
 * is 255 will be considered a free entry. All others are taken as predefined
 * colours.  Predefined colours  will not  be changed,  and the  rest  of the
 * palette will be unaffected by them. There may be copies of these colours.
 *
 * If in the bitmaps this routine finds any occurrence of the colour to which
 * palette entry 0 is set,  it will be treated as  a transparency colour.  It
 * will not be considered when generating the palette.
 *
 * Under some  circumstances  there will  be palette  entries  left over.  If
 * fill_other != 0, they will be filled with black.  If fill_other == 0, they
 * will be left containing whatever values they contained before.
 *
 * This function  does not  convert the  bitmaps to  256-colour  format.  The
 * conversion must be done afterwards by the main program.
 */

typedef struct PALETTE_NODE
{
 unsigned int rl,gl,bl,rh,gh,bh;
 unsigned int n1,n2,Sr,Sg,Sb,E;
 struct PALETTE_NODE *parent;
 struct PALETTE_NODE *subnode[2][2][2];
} PALETTE_NODE;

static PALETTE_NODE *rgb_node[64][64][64];

static PALETTE_NODE *create_node(unsigned int rl,
                                 unsigned int gl,
                                 unsigned int bl,
                                 unsigned int rh,
                                 unsigned int gh,
                                 unsigned int bh,PALETTE_NODE *parent) {
 PALETTE_NODE *node;
 unsigned int rm,gm,bm;
 node=jmalloc(sizeof(PALETTE_NODE));
 if (!node)
  return NULL;
 node->rl=rl;
 node->gl=gl;
 node->bl=bl;
 node->rh=rh;
 node->gh=gh;
 node->bh=bh;
 node->E=node->Sb=node->Sg=node->Sr=node->n2=node->n1=0;
 node->parent=parent;
 if (rh-rl>TREE_DEPTH) {
  rm=(rl+rh)>>1;
  gm=(gl+gh)>>1;
  bm=(bl+bh)>>1;
  node->subnode[0][0][0]=create_node(rl,gl,bl,rm,gm,bm,node);
  node->subnode[0][0][1]=create_node(rm,gl,bl,rh,gm,bm,node);
  node->subnode[0][1][0]=create_node(rl,gm,bl,rm,gh,bm,node);
  node->subnode[0][1][1]=create_node(rm,gm,bl,rh,gh,bm,node);
  node->subnode[1][0][0]=create_node(rl,gl,bm,rm,gm,bh,node);
  node->subnode[1][0][1]=create_node(rm,gl,bm,rh,gm,bh,node);
  node->subnode[1][1][0]=create_node(rl,gm,bm,rm,gh,bh,node);
  node->subnode[1][1][1]=create_node(rm,gm,bm,rh,gh,bh,node);
 } else {
  for (bm=bl;bm<bh;bm++) {
   for (gm=gl;gm<gh;gm++) {
    for (rm=rl;rm<rh;rm++) {
     rgb_node[bm][gm][rm]=node;
    }
   }
  }
  node->subnode[1][1][1]=
  node->subnode[1][1][0]=
  node->subnode[1][0][1]=
  node->subnode[1][0][0]=
  node->subnode[0][1][1]=
  node->subnode[0][1][0]=
  node->subnode[0][0][1]=
  node->subnode[0][0][0]=0;
 }
 return node;
}

static PALETTE_NODE *collapse_empty(PALETTE_NODE *node,unsigned int *n_colours) {
 unsigned int b,g,r;
 for (b=0;b<2;b++) {
  for (g=0;g<2;g++) {
   for (r=0;r<2;r++) {
    if (node->subnode[b][g][r])
     node->subnode[b][g][r]=collapse_empty(node->subnode[b][g][r],n_colours);
   }
  }
 }
 if (node->n1==0) {
  jfree(node);
  node=0;
 } else if (node->n2) (*n_colours)++;
 return node;
}

static PALETTE_NODE *collapse_nodes(PALETTE_NODE *node,unsigned int *n_colours,
                                    unsigned int n_entries,unsigned int Ep) {
 unsigned int b,g,r;
 if (node->E<=Ep) {
  for (b=0;b<2;b++) {
   for (g=0;g<2;g++) {
    for (r=0;r<2;r++) {
     if (node->subnode[b][g][r]) {
      node->subnode[b][g][r]=collapse_nodes(node->subnode[b][g][r],
					    n_colours,n_entries,0);
      if (*n_colours<=n_entries) return node;
     }
    }
   }
  }
  if (node->parent->n2) (*n_colours)--;
  node->parent->n2+=node->n2;
  node->parent->Sr+=node->Sr;
  node->parent->Sg+=node->Sg;
  node->parent->Sb+=node->Sb;
  jfree(node);
  node=0;
 } else {
  for (b=0;b<2;b++) {
   for (g=0;g<2;g++) {
    for (r=0;r<2;r++) {
     if (node->subnode[b][g][r]) {
      node->subnode[b][g][r]=collapse_nodes(node->subnode[b][g][r],
					    n_colours,n_entries,Ep);
      if (*n_colours<=n_entries) return node;
     }
    }
   }
  }
 }
 return node;
}

static unsigned int distance_squared(int r,int g,int b) {
 return r*r+g*g+b*b;
}

static void minimum_Ep(PALETTE_NODE *node,unsigned int *Ep) {
 unsigned int r,g,b;
 if (node->E<*Ep) *Ep=node->E;
 for (b=0;b<2;b++) {
  for (g=0;g<2;g++) {
   for (r=0;r<2;r++) {
    if (node->subnode[b][g][r]) minimum_Ep(node->subnode[b][g][r],Ep);
   }
  }
 }
}

static void fill_palette(PALETTE_NODE *node,unsigned int *c,RGB *pal,int depth) {
 unsigned int r,g,b;
 if (node->n2) {
  for (;pal[*c].r!=255;(*c)++);
  pal[*c].r=node->Sr/node->n2;
  pal[*c].g=node->Sg/node->n2;
  pal[*c].b=node->Sb/node->n2;
  (*c)++;
 }
 for (b=0;b<2;b++) {
  for (g=0;g<2;g++) {
   for (r=0;r<2;r++) {
    if (node->subnode[b][g][r])
     fill_palette(node->subnode[b][g][r],c,pal,depth+1);
   }
  }
 }
}

static void destroy_tree(PALETTE_NODE *tree) {
 unsigned int r,g,b;
 for (b=0;b<2;b++) {
  for (g=0;g<2;g++) {
   for (r=0;r<2;r++) {
    if (tree->subnode[b][g][r]) destroy_tree(tree->subnode[b][g][r]);
   }
  }
 }
 jfree(tree);
}

int quantize_bitmaps1 (Stock *stock, RGB *pal, int *bmp_i, int fill_other)
{
 int c_bmp,x,y,c,r,g,b,n_colours=0,n_entries=0,Ep;
 PALETTE_NODE *tree,*node;

 /* only support RGB bitmaps */
 if ((stock->nimage < 1) || (stock->imgtype != IMAGE_RGB))
   return 0;

/*Create the tree structure*/
 tree=create_node(0,0,0,64,64,64,0);
/*Scan the bitmaps*/
 add_progress(stock->nimage+1);
 for (c_bmp=0;c_bmp<stock->nimage;c_bmp++) {
  if (stock->image[c_bmp]) {
   add_progress(stock->image[c_bmp]->h);
   for (y=0;y<stock->image[c_bmp]->h;y++) {
    for (x=0;x<stock->image[c_bmp]->w;x++) {
     c=stock->image[c_bmp]->method->getpixel(stock->image[c_bmp],x,y);
     r=_rgba_getr(c)>>2;
     g=_rgba_getg(c)>>2;
     b=_rgba_getb(c)>>2;
     node=rgb_node[b][g][r];
     node->n2+=bmp_i[c_bmp];
     node->Sr+=r*bmp_i[c_bmp];
     node->Sg+=g*bmp_i[c_bmp];
     node->Sb+=b*bmp_i[c_bmp];
     do {
      node->n1+=bmp_i[c_bmp];
      node->E+=distance_squared((r<<1)-node->rl-node->rh,
				(g<<1)-node->gl-node->gh,
				(b<<1)-node->bl-node->bh)*bmp_i[c_bmp];
      node=node->parent;
     } while (node);
    }
    do_progress(y);
   }
   del_progress();
  }
  do_progress(c_bmp);
 }
/*Collapse empty nodes in the tree, and count leaves*/
 tree=collapse_empty(tree,&n_colours);
/*Count free palette entries*/
 for (c=0;c<256;c++) {
  if (pal[c].r==255) n_entries++;
 }
/*Collapse nodes until there are few enough to fit in the palette*/
 if (n_colours > n_entries) {
  int n_colours1 = n_colours;
  add_progress(n_colours1 - n_entries);
  while (n_colours>n_entries) {
   Ep=0xFFFFFFFFul;
   minimum_Ep(tree,&Ep);
   tree=collapse_nodes(tree,&n_colours,n_entries,Ep);

   if (n_colours > n_entries)
    do_progress(n_colours1 - n_colours);
  }
  del_progress();
 }
 del_progress();
/*Fill palette*/
 c=0;
 fill_palette(tree,&c,pal,1);
 if (fill_other) {
  for (;c<256;c++) {
   if (pal[c].r==255)
     pal[c].b=pal[c].g=pal[c].r=0;
  }
 }
/*Free memory used by tree*/
 destroy_tree(tree);
 return n_colours;
}