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--- youtube:python-mixing-005 [2024/02/28 18:26] – 削除 - 外部編集 (不明な日付) 127.0.0.1
+++ youtube:python-mixing-005 [2024/02/28 18:26] (現在) – ↷ toybox:python-mixing-005 から youtube:python-mixing-005 へページを移動しました。 freemikan
@@ 行 1: / 行 1: @@
+====== Boost.Pythonを使ってみる ======
+作成日: 2023-08-08 (火)
+[[https://youtu.be/_X_A6lev4fQ|第5回 Boost.Pythonを使ってみる]]
+プロジェクトレイアウト
+  .
+  └── extending-demos/
+      ├── Jamroot
+      ├── simple/
+      │   ├── Jamfile
+      │   ├── simple.cpp
+      │   └── test_simple.py
+      ├── point/
+      │   ├── Jamfile
+      │   ├── point.cpp
+      │   └── test_point.py
+      ├── pypoint/
+      │   ├── Jamfile
+      │   ├── pypoint.cpp
+      │   └── test_pypoint.py
+      └── fakegfx/
+          ├── Jamfile
+          ├── fakegfx.h
+          ├── fakegfx.cpp
+          └── test_fakegfx.py
+===== Jamroot =====
+<file jam>
+import python ;
+lib boost_python3 ;
+project
+  : requirements
+    <library>boost_python3
+;
+build-project simple ;
+build-project point ;
+build-project pypoint ;
+build-project fakegfx ;
+</file>
+===== プロジェクト simple =====
+==== simple.cpp ====
+<file cpp>
+#include <boost/python.hpp>
+#include <boost/algorithm/string.hpp>
+#include <iostream>
+namespace {
+void println(std::string const &s) {
+    std::cout << s << '\n';
+}
+std::string to_upper(std::string const &s) {
+    return boost::to_upper_copy<std::string>(s);
+}
+} // ns anon
+BOOST_PYTHON_MODULE(simple) {
+    namespace python = boost::python;
+    python::def("println", println);
+    python::def("to_upper", to_upper);
+}
+</file>
+==== test_simple.py ====
+<file python>
+import simple
+simple.println("Hello, Boost.Python!")
+u = simple.to_upper("Hello, Boost.Python!")
+simple.println(u)
+</file>
+==== Jamfile ====
+<file jam>
+project simple
+  : requirements
+    <location>.
+  ;
+python-extension simple : simple.cpp ;
+</file>
+===== プロジェクト point =====
+==== point.cpp ====
+<file cpp>
+#include <boost/python.hpp>
+namespace {
+    struct Point {
+        double x = 0.0;
+        double y = 0.0;
+        Point() = default;
+        Point(double x, double y) : x{x}, y{y} {}
+    };
+    void translate(Point &pt, double tx, double ty) {
+        pt.x += tx;
+        pt.y += ty;
+    }
+}
+BOOST_PYTHON_MODULE(point) {
+    using namespace boost::python;
+    class_<Point>("Point")
+        .def(init<double, double>())
+        .def("translate", translate)
+        .def_readwrite("x", &Point::x)
+        .def_readwrite("y", &Point::y);
+    def("translate", translate);
+}
+</file>
+==== test_point.py ====
+<file python>
+import point
+pt = point.Point()
+print(f"{pt.x},{pt.y}")
+pt.translate(100, -200)
+print(f"{pt.x},{pt.y}")
+</file>
+==== Jamfile ====
+<file jam>
+project point
+  : requirements
+    <location>.
+    ;
+python-extension point : point.cpp ;
+</file>
+===== プロジェクト pypoint =====
+==== pypoint.cpp ====
+<file cpp>
+#include <boost/python.hpp>
+namespace {
+    void translate(boost::python::object pt, double tx, double ty) {
+        pt.attr("x") += tx;
+        pt.attr("y") += ty;
+    }
+} // ns anon
+BOOST_PYTHON_MODULE(pypoint) {
+    boost::python::def("translate", translate);
+}
+</file>
+==== test_pypoint.py ====
+<file python>
+import pypoint
+class Point:
+    def __init__(self, x, y):
+        self.x = x
+        self.y = y
+pt = Point(1, 2)
+pypoint.translate(pt, 100, -200)
+print(f"{pt.x},{pt.y}")
+</file>
+==== Jamfile ====
+<file jam>
+project pypoint
+  : requirements
+    <location>.
+    ;
+python-extension pypoint : pypoint.cpp ;
+</file>
+===== プロジェクト fakegfx =====
+==== fakegfx.h ====
+<file cpp>
+#ifndef FAKEGFX_H
+#define FAKEGFX_H
+#include <iostream>
+struct Point {
+    Point() = default;
+    Point(double x, double y) : x{x}, y{y} {}
+    double x, y;
+};
+inline void translate(Point &pt, double tx, double ty) {
+    pt.x += tx;
+    pt.y += ty;
+}
+class Shape {
+public:
+    virtual ~Shape() = default;
+    virtual void draw() const = 0;
+};
+class RectangleShape : public Shape {
+public:
+    RectangleShape(Point const &position)
+        : position_{position} {}
+    void draw() const override {
+        std::cout << "▬" << std::endl;
+    }
+private:
+    Point position_;
+};
+inline void draw_shape(Shape const &shape) {
+    shape.draw();
+}
+inline void draw_rectangle_shape(RectangleShape const &shape) {
+    shape.draw();
+}
+#endif
+</file>
+==== fakegfx.cpp ====
+<file cpp>
+#include "fakegfx.h"
+#include <boost/python.hpp>
+#include <boost/current_function.hpp>
+#include <iostream>
+namespace {
+class ShapeWrap : public Shape, public boost::python::wrapper<Shape> {
+public:
+    void draw() const override {
+        this->get_override("draw")();
+    }
+};
+class RectangleShapeWrap
+        : public RectangleShape
+        , public boost::python::wrapper<RectangleShape> {
+public:
+    RectangleShapeWrap(Point const &position) : RectangleShape{position} {}
+    void draw() const override {
+        if (boost::python::override draw = this->get_override("draw")) {
+            draw();
+        } else {
+            RectangleShape::draw();
+        }
+    }
+    void default_draw() const {
+        std::cout << BOOST_CURRENT_FUNCTION << std::endl;
+        RectangleShape::draw();
+    }
+};
+} // ns anon
+BOOST_PYTHON_MODULE(fakegfx) {
+    using namespace boost::python;
+    class_<Point>("Point")
+        .def(init<double, double>())
+        .def("translate", &translate)
+        .def_readwrite("x", &Point::x)
+        .def_readwrite("y", &Point::y);
+    class_<ShapeWrap, boost::noncopyable>("Shape")
+        .def("draw", pure_virtual(&Shape::draw));
+    class_<RectangleShapeWrap, bases<Shape>, boost::noncopyable>("RectangleShape", init<Point const&>())
+        .def("draw", &RectangleShape::draw /*1*/, &RectangleShapeWrap::default_draw /*2*/);
+        // drawの呼び出しを、関数2に転送する
+        // 関数2のシグネチャが関数1と一致することを保証させる
+        // 関数1の指定はそのためだけに必要となる
+    def("draw_shape", draw_shape);
+    def("draw_rectangle_shape", draw_rectangle_shape);
+}
+</file>
+==== test_fakegfx.py ====
+<file python>
+import fakegfx
+# some points
+pt = fakegfx.Point(1, 2)
+print(f"{pt.x}, {pt.y}")
+pt.translate(-100, 200)
+print(f"{pt.x}, {pt.y}")
+pt2 = fakegfx.Point()
+print(f"{pt2.x}, {pt2.y}")
+# circle shape
+# derived from C++ shape class
+# Shape <- CircleShape
+class CircleShape(fakegfx.Shape):
+    def draw(self):
+        #super().draw() # cause pure virtual function call
+        print("○")
+circle = CircleShape()
+# rectangle shape
+# defined in C++ code
+rectangle = fakegfx.RectangleShape(pt)
+# square shape
+# derived from C++ rectangle shape class
+# Shape <- RectangleShape <- SquareSahpe
+class SquareShape(fakegfx.RectangleShape):
+    def __init__(self):
+        super().__init__(pt)
+    def draw(self):
+        fakegfx.RectangleShape.draw(self) # test non-cyclic
+        print("▧")
+square = SquareShape()
+print("#circle#")
+fakegfx.draw_shape(circle)
+print("#rectangle#")
+fakegfx.draw_shape(rectangle)
+print("#square#")
+fakegfx.draw_shape(square)
+print("-circle-")
+circle.draw()
+print("-rectangle-")
+rectangle.draw()
+print("-square-")
+square.draw()
+</file>
+==== Jamfile ====
+<file jam>
+project extending
+  : requirements
+    <location>.
+    ;
+python-extension fakegfx : fakegfx.cpp ;
+</file>