Boost
C++ Libraries
...one of the most highly
regarded and expertly designed C++ library projects in the
world.
— Herb Sutter and Andrei
Alexandrescu, C++
Coding Standards
Boost
C++ Libraries
...one of the most highly
regarded and expertly designed C++ library projects in the
world.
— Herb Sutter and Andrei
Alexandrescu, C++
Coding Standards
Helper class to create SVG maps.
template<typename Point, bool SameScale, typename SvgCoordinateType> class svg_mapper : noncopyable { // ... };
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Parameter |
Default |
Description |
|---|---|---|
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typename Point |
Point type, for input geometries. |
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bool SameScale |
true |
Boolean flag indicating if horizontal and vertical scale should be the same. The default value is true |
|
typename SvgCoordinateType |
double |
Coordinate type of SVG points. SVG is capable to use floating point coordinates. Therefore the default value is double |
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Function |
Description |
Parameters |
|---|---|---|
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svg_mapper(std::ostream & stream, SvgCoordinateType width, SvgCoordinateType height, std::string const & width_height = "width=\"100%\" height=\"100%\"")
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Constructor, initializing the SVG map. Opens and initializes the SVG. Should be called explicitly. |
std::ostream &: stream: Output stream, should be a stream already open SvgCoordinateType: width: Width of the SVG map (in SVG pixels) SvgCoordinateType: height: Height of the SVG map (in SVG pixels) std::string const &: width_height: Optional information to increase width and/or height |
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~svg_mapper()
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Destructor, called automatically. Closes the SVG by streaming </svg> |
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Function |
Description |
Parameters |
Returns |
|---|---|---|---|
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template<typename Geometry> void add(Geometry const & geometry)
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Adds a geometry to the transformation matrix. After doing this, the specified geometry can be mapped fully into the SVG map. |
Geometry const &: geometry: A model of the specified concept |
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template<typename Geometry> void map(Geometry const & geometry, std::string const & style, double size = -1.0)
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Maps a geometry into the SVG map using the specified style. |
Geometry const &: geometry: A model of the specified concept std::string const &: style: String containing verbatim SVG style information double: size: Optional size (used for SVG points) in SVG pixels. For linestrings, specify linewidth in the SVG style information |
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template<typename TextPoint> void text(TextPoint const & point, std::string const & s, std::string const & style, double offset_x = 0.0, double offset_y = 0.0, double lineheight = 10.0)
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Adds a text to the SVG map. |
TextPoint const &: point: Location of the text (in map units) std::string const &: s: The text itself std::string const &: style: String containing verbatim SVG style information, of the text double: offset_x: Offset in SVG pixels, defaults to 0 double: offset_y: Offset in SVG pixels, defaults to 0 double: lineheight: Line height in SVG pixels, in case the text contains |
Either
#include <boost/geometry.hpp>
Or
#include <boost/geometry/io/svg/svg_mapper.hpp>
Shows the usage of svg_mapper
#include <iostream> #include <fstream> #include <boost/geometry.hpp> #include <boost/geometry/geometries/point_xy.hpp> #include <boost/geometry/geometries/polygon.hpp> int main() { // Specify the basic type typedef boost::geometry::model::d2::point_xy<double> point_type; // Declare some geometries and set their values point_type a; boost::geometry::assign_values(a, 3, 6); boost::geometry::model::polygon<point_type> b; boost::geometry::read_wkt("POLYGON((0 0,0 7,4 2,2 0,0 0))", b); boost::geometry::model::linestring<point_type> c; c.push_back(point_type(3, 4)); c.push_back(point_type(4, 5)); // Declare a stream and an SVG mapper std::ofstream svg("my_map.svg"); boost::geometry::svg_mapper<point_type> mapper(svg, 400, 400); // Add geometries such that all these geometries fit on the map mapper.add(a); mapper.add(b); mapper.add(c); // Draw the geometries on the SVG map, using a specific SVG style mapper.map(a, "fill-opacity:0.5;fill:rgb(153,204,0);stroke:rgb(153,204,0);stroke-width:2", 5); mapper.map(b, "fill-opacity:0.3;fill:rgb(51,51,153);stroke:rgb(51,51,153);stroke-width:2"); mapper.map(c, "opacity:0.4;fill:none;stroke:rgb(212,0,0);stroke-width:5"); // Destructor of map will be called - adding </svg> // Destructor of stream will be called, closing the file return 0; }
Output:
