diff --git a/docs/quick-start/bind.md b/docs/quick-start/bind.md index b146a056..e1ddb346 100644 --- a/docs/quick-start/bind.md +++ b/docs/quick-start/bind.md @@ -103,9 +103,4 @@ For example, `vm->bind__add__` is preferred over `vm->bind_method<1>(type, "__ad ### Bind a property -You can use `vm->property(...)` to create a `property` object and assign it to an type object. - -### Further reading - -See [linalg.h](https://github.com/blueloveTH/pocketpy/blob/main/src/linalg.h) for a complete example that uses all the binding functions -for `vec2`, `vec3` and `mat3x3` types. \ No newline at end of file +You can use `vm->property(...)` to create a `property` object and assign it to an type object. \ No newline at end of file diff --git a/docs/quick-start/example.md b/docs/quick-start/example.md new file mode 100644 index 00000000..3e117c7f --- /dev/null +++ b/docs/quick-start/example.md @@ -0,0 +1,93 @@ +--- +icon: dot +label: 'Complete example' +order: 0 +--- + +In this example, we will create a `linalg` module +and implement a `vec2` type with some methods. +And make them available in python just like this. + +```python +from linalg import vec2 + +# construct a vec2 +a = vec2(1.0, 2.0) +b = vec2(0.0, -1.0) + +# add two vec2 +print(a + b) # vec2(1.0, 1.0) + +# set x component +a.x = 8.0 +print(a) # vec2(8.0, 2.0) + +# use dot method +print(a.dot(b)) # -2.0 +``` + +### Implement `Vec2` struct in cpp + +```cpp +struct Vec2{ + float x, y; + Vec2() : x(0.0f), y(0.0f) {} + Vec2(float x, float y) : x(x), y(y) {} + Vec2(const Vec2& v) : x(v.x), y(v.y) {} + Vec2 operator+(const Vec2& v) const { return Vec2(x + v.x, y + v.y); } + float dot(const Vec2& v) const { return x * v.x + y * v.y; } +}; +``` + +### Create `PyVec2` wrapper + +```cpp +struct PyVec2: Vec2 { + PY_CLASS(PyVec2, linalg, vec2) + + PyVec2() : Vec2() {} + PyVec2(const Vec2& v) : Vec2(v) {} + PyVec2(const PyVec2& v) : Vec2(v) {} + + static void _register(VM* vm, PyObject* mod, PyObject* type){ + vm->bind_constructor<3>(type, [](VM* vm, ArgsView args){ + float x = CAST_F(args[1]); + float y = CAST_F(args[2]); + return VAR(Vec2(x, y)); + }); + + vm->bind__repr__(OBJ_GET(Type, type), [](VM* vm, PyObject* obj){ + PyVec2& self = _CAST(PyVec2&, obj); + std::stringstream ss; + ss << "vec2(" << self.x << ", " << self.y << ")"; + return VAR(ss.str()); + }); + + vm->bind__add__(OBJ_GET(Type, type), [](VM* vm, PyObject* obj, PyObject* other){ + PyVec2& self = _CAST(PyVec2&, obj); + PyVec2& other_ = CAST(PyVec2&, other); + return VAR_T(PyVec2, self + other_); + }); + + vm->bind_method<1>(type, "dot", [](VM* vm, ArgsView args){ + PyVec2& self = _CAST(PyVec2&, args[0]); + PyVec2& other = CAST(PyVec2&, args[1]); + return VAR(self.dot(other)); + }); + } +}; +``` + +### Create `linalg` module + +```cpp +void add_module_linalg(VM* vm){ + PyObject* linalg = vm->new_module("linalg"); + // register PyVec2 + PyVec2::register_class(vm, linalg); +} +``` + +### Further reading + +See [linalg.h](https://github.com/blueloveTH/pocketpy/blob/main/src/linalg.h) for the complete implementation. \ No newline at end of file