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C++使用svg++开源库处理svg矢量图文件--遍历所有元素
svg++是一个基于boost的开源的头文件库，可以用来处理svg文件
下载svg++:https://github.com/svgpp/svgpp
解压后待使用。同时把third_party文件夹下的几个文件夹也拷贝到\svgpp-master\include 下方便使用。
编译好boost库，我编译的是静态lib库，不需要动态库dll文件，待用。
新建win32项目，设置头文件目录：
E:\Projects\boost_1_68_0\boost_1_68_0 boost库的头文件位置
svgpp-master\svgpp-master\include svg++库的头文件位置
设置库文件目录：
E:\Projects\boost_1_68_0\boost_1_68_0\stage\lib boost库编译出的lib文件的路径
编写示例代码：
#include "svgpp/document_traversal.hpp"
#include "rapidxml_ns/rapidxml_ns.hpp"
#include "svgpp/policy/xml/rapidxml_ns.hpp"
#include "svgpp/svgpp.hpp"
#include "rapidxml_ns/rapidxml_ns_utils.hpp"
using namespace svgpp;
typedef rapidxml_ns::xml_node<> const * xml_element_t;
//输出遍历到每种元素时的打印信息
void printMessage(std::string msg)
{
std::cout << msg.c_str() << std::endl;
}
//此类实现遍历到每种元素时打印相关信息，此处限于篇幅，只实现遍历path元素时打印信息
class Context
{
public:
void path_move_to(double x, double y, tag::coordinate::absolute) {
printMessage("path_move_to");
};
void path_line_to(double x, double y, tag::coordinate::absolute) {
printMessage("path_line_to");
};
void path_line_to_ortho(double coord, bool horizontal, tag::coordinate::absolute)
{
printMessage("path_line_to_ortho");
}
void path_cubic_bezier_to(
double x1, double y1,
double x2, double y2,
double x, double y,
tag::coordinate::absolute) {
printMessage("path_cubic_bezier_to");
};
void path_quadratic_bezier_to(
double x1, double y1,
double x, double y,
tag::coordinate::absolute) {
printMessage("path_quadratic_bezier_to");
};
void path_quadratic_bezier_to(
double x, double y,
tag::coordinate::absolute) {
printMessage("path_quadratic_bezier_to 2");
};
void path_elliptical_arc_to(
double rx, double ry, double x_axis_rotation,
bool large_arc_flag, bool sweep_flag,
double x, double y,
tag::coordinate::absolute) {
printMessage("path_elliptical_arc_to");
};
void path_close_subpath() {
printMessage("path_close_subpath");
};
void path_exit() {
printMessage("path_exit");
};
void on_enter_element(tag::element::any) {
printMessage("on_enter_element");
};
void on_exit_element() {
printMessage("on_exit_element");
};
void transform_matrix(const boost::array<double, 6> & matrix) {
printMessage("transform_matrix");
}
};
//为了需要遍历的各种元素
typedef
boost::mpl::set<
// SVG Structural Elements
tag::element::svg,
tag::element::g,
// SVG Shape Elements
tag::element::circle,
tag::element::ellipse,
tag::element::line,
tag::element::path,
tag::element::polygon,
tag::element::polyline,
tag::element::rect
>::type processed_elements_t;
//shapes_attributes_by_element for 遍历元素的各种属性
//transform for 遍历元素的变换矩阵
typedef
boost::mpl::insert<
traits::shapes_attributes_by_element,
tag::attribute::transform
>::type processed_attributes_t;
void loadSvg(xml_element_t xml_root_element)
{
Context context;
document_traversal<
processed_elements<processed_elements_t>,
processed_attributes<processed_attributes_t>
>::load_document(xml_root_element, context);
}
void test1()
{
try
{
}
catch (std::exception const & e)
{
std::cerr << "Error: " << e.what() << "\n";
return;
}
}
int main()
{
test1();
}
svg文件的内容如下：
<?xml version="1.0" encoding="UTF-8"?>
<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" width="1322pt" height="1653pt" viewBox="0 0 1322 1653" version="1.1">
<g id="surface0">
<path style=" stroke:none;fill-rule:evenodd;fill:rgb(100%,0%,0%);fill-opacity:1;" d="M 60.136719 1577.839844 L 1262.730469 1577.839844 L 1262.730469 74.773438 L 60.136719 74.773438 L 60.136719 1577.839844 Z M 60.136719 1577.839844 "/>
<path style=" stroke:none;fill-rule:evenodd;fill:rgb(100%,100%,100%);fill-opacity:1;" d="M 931.25 1549.910156 C 931.25 1546.789063 926.570313 1546.789063 926.570313 1549.910156 C 926.570313 1553.03125 931.25 1553.03125 931.25 1549.910156 "/>
<path style="fill:none;stroke-width:0.008;stroke-linecap:round;stroke-linejoin:miter;stroke:rgb(100%,100%,100%);stroke-opacity:1;stroke-miterlimit:10;" d="M -1446456719.25 -366325561.25 L -1446456719.25 -366325561.25 " transform="matrix(0.00000000000119844,0,0,-0.00000000000119844,533.03689,1460.48003)"/>
<rect x=".01" y=".01" width="4.98" height="2.98" fill="none" stroke="blue" stroke-width=".03"/>
</g>
</svg>
//以下是程序的输出结果
on_enter_element
on_enter_element
path_move_to
path_line_to
path_line_to
path_line_to
path_line_to
path_close_subpath
path_move_to
path_exit
on_exit_element
on_enter_element
path_move_to
path_cubic_bezier_to
path_cubic_bezier_to
path_exit
on_exit_element
on_enter_element
path_move_to
path_line_to
path_exit
on_exit_element
on_enter_element
path_move_to
path_line_to
path_line_to
path_line_to
path_close_subpath
path_exit
on_exit_element
on_exit_element
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发表于 2019-3-5 10:19:54
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