mapnik/include/mapnik/placement_finder.hpp
Artem Pavlenko 85ecc33d7f + applied patch from Jochen Topf :
* text_convert="none|toupper|tolower"
 Convert all text to upper/lower case before rendering. "none" doesn't do
 anything with the text and is the default. Works for labels along lines
 or at points.

* line_spacing="<number>"
 Add this many pixels space between two lines in text labels that have
 been broken into several lines. Default is 0. Doesn't do anything for
 labels along lines.

* character_spacing="<number>"
 Add this many pixels space between two characters in a text. Default is 0.
 Currently only works for text labels on point geometries. This should
 also be implemented for labels along lines, but I'll leave that for
 another day.

* wrap_character="<character>"
 Instead of breaking text into lines on spaces, use this character. This
 is useful, when you want to make sure that labels are broken at the right
 spot. Note that you'll probably want to make wrap_width small so that
 your lines are actually broken, otherwise you'll see the wrap_character
 in the output. Default is ' ' (space). Doesn't do anything for labels
 along lines.
2009-07-20 15:30:19 +00:00

140 lines
5.4 KiB
C++

/*****************************************************************************
*
* This file is part of Mapnik (c++ mapping toolkit)
*
* Copyright (C) 2006 Artem Pavlenko
* Copyright (C) 2006 10East Corp.
*
* 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 __PLACEMENT_FINDER__
#define __PLACEMENT_FINDER__
#include <mapnik/ctrans.hpp>
#include <mapnik/label_collision_detector.hpp>
#include <mapnik/text_symbolizer.hpp>
#include <mapnik/shield_symbolizer.hpp>
#include <mapnik/geometry.hpp>
#include <mapnik/text_path.hpp>
#include <queue>
namespace mapnik
{
typedef text_path placement_element;
struct placement : boost::noncopyable
{
placement(string_info & info_, shield_symbolizer const& sym, bool has_dimensions_= false);
placement(string_info & info_, text_symbolizer const& sym);
~placement();
string_info & info;
position displacement_;
label_placement_e label_placement;
std::queue< Envelope<double> > envelopes;
//output
boost::ptr_vector<placement_element> placements;
int wrap_width;
unsigned char wrap_char;
int text_ratio;
int label_spacing; // distance between repeated labels on a single geometry
unsigned label_position_tolerance; //distance the label can be moved on the line to fit, if 0 the default is used
bool force_odd_labels; //Always try render an odd amount of labels
double max_char_angle_delta;
double minimum_distance;
bool avoid_edges;
bool has_dimensions;
bool allow_overlap;
std::pair<double, double> dimensions;
};
template <typename DetectorT>
class placement_finder : boost::noncopyable
{
public:
placement_finder(DetectorT & detector);
//Try place a single label at the given point
void find_point_placement(placement & p, double pos_x, double pos_y, vertical_alignment_e = MIDDLE, unsigned line_spacing=0, unsigned character_spacing=0);
//Iterate over the given path, placing point labels with respect to label_spacing
template <typename T>
void find_point_placements(placement & p, T & path);
//Iterate over the given path, placing line-following labels with respect to label_spacing
template <typename T>
void find_line_placements(placement & p, T & path);
void update_detector(placement & p);
void clear();
private:
///Helpers for find_line_placement
///Returns a possible placement on the given line, does not test for collisions
//index: index of the node the current line ends on
//distance: distance along the given index that the placement should start at, this includes the offset,
// as such it may be > or < the length of the current line, so this must be checked for
//orientation: if set to != 0 the placement will be attempted with the given orientation
// otherwise it will autodetect the orientation.
// If >= 50% of the characters end up upside down, it will be retried the other way.
// RETURN: 1/-1 depending which way up the string ends up being.
std::auto_ptr<placement_element> get_placement_offset(placement & p,
const std::vector<vertex2d> & path_positions,
const std::vector<double> & path_distances,
int & orientation, unsigned index, double distance);
///Tests wether the given placement_element be placed without a collision
// Returns true if it can
// NOTE: This edits p.envelopes so it can be used afterwards (you must clear it otherwise)
bool test_placement(placement & p, const std::auto_ptr<placement_element> & current_placement, const int & orientation);
///Does a line-circle intersect calculation
// NOTE: Follow the strict pre conditions
// Pre Conditions: x1,y1 is within radius distance of cx,cy. x2,y2 is outside radius distance of cx,cy
// This means there is exactly one intersect point
// Result is returned in ix, iy
void find_line_circle_intersection(
const double &cx, const double &cy, const double &radius,
const double &x1, const double &y1, const double &x2, const double &y2,
double &ix, double &iy);
///General Internals
DetectorT & detector_;
Envelope<double> const& dimensions_;
};
}
#endif