mapnik/include/mapnik/octree.hpp

273 lines
8.4 KiB
C++

/*****************************************************************************
*
* This file is part of Mapnik (c++ mapping toolkit)
*
* Copyright (C) 2006 Artem Pavlenko
*
* This library 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 2.1 of the License, or (at your option) any later version.
*
* This library 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 this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
*****************************************************************************/
//$Id$
#ifndef _OCTREE_HPP_
#define _OCTREE_HPP_
// mapnik
#include <mapnik/global.hpp>
// boost
#include <boost/format.hpp>
#include <boost/utility.hpp>
// stl
#include <vector>
#include <iostream>
#include <deque>
namespace mapnik {
typedef boost::uint8_t byte ;
struct rgb
{
byte r;
byte g;
byte b;
rgb(byte r_, byte b_, byte g_)
: r(r_), g(g_), b(b_) {}
};
struct RGBPolicy
{
const static unsigned MAX_LEVELS = 6;
const static unsigned MIN_LEVELS = 3;
inline static unsigned index_from_level(unsigned level, rgb const& c)
{
unsigned shift = 7 - level;
return (((c.r >> shift) & 1) << 2)
| (((c.g >> shift) & 1) << 1)
| ((c.b >> shift) & 1);
}
};
template <typename T, typename InsertPolicy = RGBPolicy >
class octree : private boost::noncopyable
{
struct node
{
node ()
: reds(0),
greens(0),
blues(0),
count(0),
count2(0),
children_count(0),
index(0)
{
memset(&children_[0],0,sizeof(children_));
}
~node ()
{
for (unsigned i = 0;i < 8; ++i) {
if (children_[i] != 0) delete children_[i],children_[i]=0;
}
}
bool is_leaf() const { return count == 0; }
node * children_[8];
unsigned reds;
unsigned greens;
unsigned blues;
unsigned count;
unsigned count2;
byte children_count;
byte index;
};
struct node_cmp
{
bool operator() ( const node * lhs,const node* rhs) const
{
return lhs->count2 < rhs->count2;
}
};
std::deque<node*> reducible_[InsertPolicy::MAX_LEVELS];
unsigned max_colors_;
unsigned colors_;
unsigned leaf_level_;
bool has_alfa_;
public:
explicit octree(unsigned max_colors=256)
: max_colors_(max_colors),
colors_(0),
leaf_level_(InsertPolicy::MAX_LEVELS),
has_alfa_(false),
root_(new node())
{}
~octree() { delete root_;}
void hasAlfa(bool v)
{
has_alfa_=v;
}
bool hasAlfa()
{
return has_alfa_;
}
void insert(T const& data)
{
unsigned level = 0;
node * cur_node = root_;
while (true) {
cur_node->count2++;
if ( cur_node->count > 0 || level == leaf_level_)
{
cur_node->reds += data.r;
cur_node->greens += data.g;
cur_node->blues += data.b;
cur_node->count += 1;
if (cur_node->count == 1) ++colors_;
//if (colors_ >= max_colors_ - 1)
//reduce();
break;
}
unsigned idx = InsertPolicy::index_from_level(level,data);
if (cur_node->children_[idx] == 0) {
cur_node->children_count++;
cur_node->children_[idx] = new node();
if (level < leaf_level_-1)
{
reducible_[level+1].push_back(cur_node->children_[idx]);
}
}
cur_node = cur_node->children_[idx];
++level;
}
}
int quantize(rgb const& c) const
{
unsigned level = 0;
node * cur_node = root_;
while (cur_node)
{
if (cur_node->count != 0) return cur_node->index;
unsigned idx = InsertPolicy::index_from_level(level,c);
cur_node = cur_node->children_[idx];
++level;
}
return -1;
}
void create_palette(std::vector<rgb> & palette)
{
if (has_alfa_)
{
max_colors_--;
palette.push_back(rgb(0,0,0));
}
reduce();
palette.reserve(colors_);
create_palette(palette, root_);
}
void reduce()
{
// sort reducible
for (unsigned i=0;i<InsertPolicy::MAX_LEVELS;++i)
{
std::sort(reducible_[i].begin(), reducible_[i].end(),node_cmp());
}
while ( colors_ >= max_colors_ - 1)
{
while (leaf_level_ >0 && reducible_[leaf_level_-1].size() == 0)
{
--leaf_level_;
}
if (leaf_level_ < 1) continue;
if ( reducible_[leaf_level_-1].size() == 0) return;
// select best of all reducible:
unsigned red_idx = leaf_level_-1;
unsigned bestv = (*reducible_[red_idx].begin())->count2;
for(unsigned i=red_idx; i>=InsertPolicy::MIN_LEVELS; i--) if (!reducible_[i].empty()){
node *nd = *reducible_[i].begin();
unsigned gch = 0;
for(unsigned idx=0; idx<8; idx++){
if (nd->children_[idx])
gch += nd->children_[idx]->children_count;
}
if (gch==0 && nd->count2<bestv){
bestv = nd->count2;
red_idx = i;
}
}
typename std::deque<node*>::iterator pos = reducible_[red_idx].begin();
node * cur_node = *pos;
unsigned num_children = 0;
for (unsigned idx=0; idx < 8; ++idx)
{
if (cur_node->children_[idx] != 0)
{
cur_node->children_count--;
++num_children;
cur_node->reds += cur_node->children_[idx]->reds;
cur_node->greens += cur_node->children_[idx]->greens;
cur_node->blues += cur_node->children_[idx]->blues;
cur_node->count += cur_node->children_[idx]->count;
delete cur_node->children_[idx], cur_node->children_[idx]=0;
}
}
reducible_[red_idx].erase(pos);
if (num_children > 0 )
{
colors_ -= (num_children - 1);
}
}
}
void create_palette(std::vector<rgb> & palette, node * itr) const
{
if (itr->count != 0)
{
unsigned count = itr->count;
palette.push_back(rgb(byte(itr->reds/float(count)),
byte(itr->greens/float(count)),
byte(itr->blues/float(count))));
itr->index = palette.size() - 1;
}
for (unsigned i=0; i < 8 ;++i)
{
if (itr->children_[i] != 0)
create_palette(palette, itr->children_[i]);
}
}
private:
node * root_;
};
} // namespace mapnik
#endif /* _OCTREE_HPP_ */