aare/python/src/np_helper.hpp
Erik Fröjdh abb1d20ca3 WIP
2024-10-28 12:25:47 +01:00

115 lines
4.0 KiB
C++

#pragma once
#include <iostream>
#include <pybind11/numpy.h>
#include <pybind11/pybind11.h>
#include <pybind11/stl.h>
#include "aare/Frame.hpp"
#include "aare/NDArray.hpp"
namespace py = pybind11;
// Pass image data back to python as a numpy array
// template <typename T, ssize_t Ndim>
// py::array return_image_data(pl::ImageData<T, Ndim> *image) {
// py::capsule free_when_done(image, [](void *f) {
// pl::ImageData<T, Ndim> *foo =
// reinterpret_cast<pl::ImageData<T, Ndim> *>(f);
// delete foo;
// });
// return py::array_t<T>(
// image->shape(), // shape
// image->byte_strides(), // C-style contiguous strides for double
// image->data(), // the data pointer
// free_when_done); // numpy array references this parent
// }
// template <typename T> py::array return_vector(std::vector<T> *vec) {
// py::capsule free_when_done(vec, [](void *f) {
// std::vector<T> *foo = reinterpret_cast<std::vector<T> *>(f);
// delete foo;
// });
// return py::array_t<T>({vec->size()}, // shape
// {sizeof(T)}, // C-style contiguous strides for double
// vec->data(), // the data pointer
// free_when_done); // numpy array references this parent
// }
// template <typename Reader> py::array do_read(Reader &r, size_t n_frames) {
// py::array image;
// if (n_frames == 0)
// n_frames = r.total_frames();
// std::array<ssize_t, 3> shape{static_cast<ssize_t>(n_frames), r.rows(),
// r.cols()};
// const uint8_t item_size = r.bytes_per_pixel();
// if (item_size == 1) {
// image = py::array_t<uint8_t, py::array::c_style | py::array::forcecast>(
// shape);
// } else if (item_size == 2) {
// image =
// py::array_t<uint16_t, py::array::c_style | py::array::forcecast>(
// shape);
// } else if (item_size == 4) {
// image =
// py::array_t<uint32_t, py::array::c_style | py::array::forcecast>(
// shape);
// }
// r.read_into(reinterpret_cast<std::byte *>(image.mutable_data()), n_frames);
// return image;
// }
py::array return_frame(pl::Frame *ptr) {
py::capsule free_when_done(ptr, [](void *f) {
pl::Frame *foo = reinterpret_cast<pl::Frame *>(f);
delete foo;
});
const uint8_t item_size = ptr->bytes_per_pixel();
std::vector<ssize_t> shape;
for (auto val : ptr->shape())
if (val > 1)
shape.push_back(val);
std::vector<ssize_t> strides;
if (shape.size() == 1)
strides.push_back(item_size);
else if (shape.size() == 2) {
strides.push_back(item_size * shape[1]);
strides.push_back(item_size);
}
if (item_size == 1)
return py::array_t<uint8_t>(
shape, strides,
reinterpret_cast<uint8_t *>(ptr->data()), free_when_done);
else if (item_size == 2)
return py::array_t<uint16_t>(shape, strides,
reinterpret_cast<uint16_t *>(ptr->data()),
free_when_done);
else if (item_size == 4)
return py::array_t<uint32_t>(shape, strides,
reinterpret_cast<uint32_t *>(ptr->data()),
free_when_done);
return {};
}
// todo rewrite generic
template <class T, int Flags> auto get_shape_3d(py::array_t<T, Flags> arr) {
return pl::Shape<3>{arr.shape(0), arr.shape(1), arr.shape(2)};
}
template <class T, int Flags> auto make_span_3d(py::array_t<T, Flags> arr) {
return pl::DataSpan<T, 3>(arr.mutable_data(), get_shape_3d<T, Flags>(arr));
}
template <class T, int Flags> auto get_shape_2d(py::array_t<T, Flags> arr) {
return pl::Shape<2>{arr.shape(0), arr.shape(1)};
}
template <class T, int Flags> auto make_span_2d(py::array_t<T, Flags> arr) {
return pl::DataSpan<T, 2>(arr.mutable_data(), get_shape_2d<T, Flags>(arr));
}